The Southern Highland Fold and Thrust Belt(SHFTB),the boundary of the Australian plate and the New Guinea Highland block,significantly contributes to the convergent deformation along the plate bound-ary.However,due to...The Southern Highland Fold and Thrust Belt(SHFTB),the boundary of the Australian plate and the New Guinea Highland block,significantly contributes to the convergent deformation along the plate bound-ary.However,due to the lack of observation data,the detailed slip pattern of the SHFTB and the orogenic mechanism beneath the New Guinea Highlands remains controversial.On 25 February 2018,the M_(w)7.5 Papua New Guinea(PNG)earthquake struck the southeastern segment of the SHFTB.The detailed rupture characteristics of this event is significant for further clarifying the inter-seismic slip pattern along the SHFTB.Here,the coseismic deformation field of this earthquake was obtained using high-resolution ALOS-2 satellite images.We find that the 2018 M_(w)7.5 PNG earthquake ruptured a large-scaled fault(SHFTB)extending to the lower crust(deeper than 20 km)beneath the New Guinea Highlands,with a dip angle of 24°.The slips on the fault plane are equivalent to moment magnitudes of M_(w)7.51.Three major asperities with thrust-dominated slip of up to 3.94 m are detected on the fault plane.This finding implies that the slip pattern on the eastern segment of the SHFTB is dominated by thrust,rather than with significant sinistral movement,as previously reported.The tectonic deformation across the New Guinea Highlands is possibly concentrated on the large-scale fault SHFTB and primarily controls the intra-continental orogeny in the central Papua New Guinea.展开更多
Climate change is impacting on climate dependent activities such as Avocado farming in Tanzania. The extent of the impact of climate change in agriculture depends on the level of vulnerability or exposure of farmers t...Climate change is impacting on climate dependent activities such as Avocado farming in Tanzania. The extent of the impact of climate change in agriculture depends on the level of vulnerability or exposure of farmers to these impacts. This study addresses gender vulnerabilities to Avocado smallholder farmers to climate change in the Southern Highlands regions of Tanzania where the temperature and rainfall stresses are relevant using the Livelihood Vulnerability Index (LVI) and tested for significant difference in their vulnerability levels by applying independent two sample student’s t-test based on gender by using a sample of 104 Avocado smallholder farming. The results in this study revealed that both male and female avocado farmers were vulnerable to the effects of climate change and variability, but the vulnerabilities varied with gender. Female small holder farmers were more vulnerable to socio-demographic profile, livelihood strategies, social network, water and food major components of the LVI, whereas were more vulnerable to social network and health. The vulnerability indices revealed that female small holder farmers were more sensitive to the impact of climate change and variability. It was also found that female small holder farmers have the least adaptive capacities. In all, female small holder farmers are more vulnerable to climate change and variability than male. There is a need for better gender-sensitive approaches to adaptation planning and implementation to ensure that both men and women have equal opportunities to benefit from adaptation options in agriculture.展开更多
This paper studies the effect of basalt and tephra dusts,as alternatives to chemical fertilizers,on soil fertility and Radish(Raphanus sativus)production.The experiment was conducted in the field and in the labo...This paper studies the effect of basalt and tephra dusts,as alternatives to chemical fertilizers,on soil fertility and Radish(Raphanus sativus)production.The experiment was conducted in the field and in the laboratory in the years 2017 and 2018 on two separate plots so as to annul residual effects of fertilizers).The experimental design in the field was a randomized complete block design(56 m^(2)),including five treatments and three replications:control(T_(0)),basalt dust(T_(1)),tephra dust(T_(2)),effective micro-organism(EM)fertilizer(T_(3))and NPK 20-10-10(T_(4)).The main results show the following decreasing trend based on yield:T_(1)>T_(3)>T_(0)>T_(4)>T_(2).The best yields appear in T_(1) and T_(3) probably because they supplied the highest levels of soil nutrients to match the needs of the crops.Although T_(2) plants performed poorly,soil properties like pH.H_(2)O(6.14 to 6.49),sum of exchangeable bases,base saturation,available phosphorus and cation balance were improved after tephra treatment.T_(2) plants might have performed poorly due to intrinsic properties of the tephra dust like low availability of trace elements compared to T_(1) and T_(3).T_(4) plants show the highest number of leaves,leaf area index and plant height.The Fe,Mn,Cu and Zn levels in bulbs and leaves will not pose danger of toxicity to human upon consumption and could serve as nutrient supplement for children and expectant mothers.The most profitable treatment is T_(1) permitting to recommend the popularization of basalt dust for radish cultivation as an alternative to chemical fertilizers.展开更多
Kigezi highlands currently experiences changes in precipitation and temperature which modify the evaporation and soil moisture storage leading to alterations in runoff and other components of hydrological systems. Ext...Kigezi highlands currently experiences changes in precipitation and temperature which modify the evaporation and soil moisture storage leading to alterations in runoff and other components of hydrological systems. Extreme events, like floods and droughts, are more intense and frequent. Furthermore heavy unpredictable rainfall has become frequent in the area, causing soil erosion and floods that destroy crops. Soil erosion is particularly a pressing challenge due to steep-sided hills leading to deterioration of soil nutrients including soil fertility. The unpredictable rains and droughts are attributed to climate change and variability. Consequently, climate change and variability have caused a significant impact on soil nutrients which have affected the agricultural productivity in the area. This paper presents findings of empirical study which explored the climate variability and soil nutrient status along altitudinal gradient. The paper particularly addresses key questions of: land management practices in the study area, nutrient availability and their effects on productivity of selected crops along altitudinal gradient in changing climate and variability. Independent variables such as topographic sequence along altitudinal gradient were evaluated against dependent variables such as yield harvests of selected grown crops and soil nutrients. Samples for crop yields were collected along transect of 0.5 kilometer using a quadrant of 4 × 4 m<sup>2</sup> along attitudinal gradient. Soil samples were taken from selected plots at 0-20cm soil depth for nutrient analysis. Analysis of physical and chemical soil parameters was carried out on soil samples and these include: soil pH, soil organic content, total nitrogen, available soil phosphorous and exchangeable bases (Ca, Mg, K and Na). The study showed that middle parts of the transects had the highest concentration of most soil nutrients, probably because the middle parts could have been a deposition centre for some organic matter from the upper parts of the hills, and lower lying areas were being affected by floods that affects the decomposition of organic matter which is the main source of nutrients. Similarly, the middle parts of the study were the most fertile due to the high concentration of soil nutrient compositions. This indicates that crop yields were significantly affected by availability of soil nutrients along same gradient, attributable to the severity in soil erosion, nutrients leaching and farming practices.展开更多
Extensional and compressional structures are globally abundant on Mars. Distribution of these structures and their ages constrain the crustal stress state and tectonic evolution of the planet. Here in this paper, we r...Extensional and compressional structures are globally abundant on Mars. Distribution of these structures and their ages constrain the crustal stress state and tectonic evolution of the planet. Here in this paper, we report on our investigation over the distribution of the tectonic structures and timings of the associated stress fields from the Noachis-Sabaea region. Thereafter, we hypothesize possible origins in relation to the internal/external processes through detailed morphostructural mapping. In doing so, we have extracted the absolute model ages of these linear tectonic structures using crater size-frequency distribution measurements, buffered crater counting in particular. The estimated ages indicate that the tectonic structures are younger than the mega impacts events(especially Hellas) and instead they reveal two dominant phases of interior dynamics prevailing on the southern highlands, firstly the extensional phase terminating around3.8 Ga forming grabens and then compressional phase around 3.5-3.6 Ga producing wrinkle ridges and lobate scarps. These derived absolute model ages of the grabens exhibit the age ca. 100 Ma younger than the previously documented end of the global extensional phase. The following compressional activity corresponds to the peak of global contraction period in Early Hesperian. Therefore, we conclude that the planet wide heat loss mechanism, involving crustal stretching coupled with gravitationally driven relaxation(i.e.,lithospheric mobility) resulted in the extensional structures around Late Noachian(around 3.8 Ga). Lately cooling related global contraction generated compressional stress ensuing shortening of the upper crust of the southern highlands at the Early Hesperian period(around 3.5-3.6 Ga).展开更多
Based on the fifth-generation reanalysis dataset from the European Centre for Medium-Range Weather Forecasts for 1979–2019,we investigated the effects of the circumglobal teleconnection(CGT)on the interdecadal variat...Based on the fifth-generation reanalysis dataset from the European Centre for Medium-Range Weather Forecasts for 1979–2019,we investigated the effects of the circumglobal teleconnection(CGT)on the interdecadal variation of the March atmospheric heat source(AHS)over the Southeast Asian low-latitude highlands(SEALLH).The dominant mode of the March AHS over the SEALLH features a monopole structure with an 8–11-year period.Decadal variations in the AHS make an important contribution to the 11-year low-pass filtered component of the AHS index,whichexplains 54.3%of the total variance.The CGT shows a clear interdecadal variation,which explains 59.3%of the total variance.The March AHS over the SEALLH is significantly related to the CGT on interdecadal timescales.When the CGT is optimally excited by a significant cyclonic vorticity source near northern Africa(i.e.,in its positive phase),the SEALLH is dominated by anomalous southerly winds and ascending motions on the east of the anomalous cyclone.The enhanced advection and upward transfer result in a high-enthalpy air mass that converges into and condenses over the SEALLH,leading to a largerthan-average March AHS over this region.The key physical processes revealed by this diagnostic analysis are supported by numerical experiments.展开更多
Wild vegetables contribute immensely to the culinary basket and livelihoods of rural communities in sub-Saharan Africa, especially among the people of Lebialem highlands of south western Cameroon where at least 26 suc...Wild vegetables contribute immensely to the culinary basket and livelihoods of rural communities in sub-Saharan Africa, especially among the people of Lebialem highlands of south western Cameroon where at least 26 such species are consumed as vegetables. To promote the consumption of these vegetables, the nutritional quality of five preferred species in this area, Amaranthus dubius Mart. Ex Thell., Gnetum africanum Welw., Lomariopsis guineensis (Unerw.) Alston, Pennisetum purpureum Schumach and Vernonia amygdalina Del., was assessed using standard methods. L. guineensis had the highest carbohydrate, protein, calorific value and ash content, and the lowest fat content of 4.05%, very rich in K, Ca and Mg and the amino acids leucine, arginine, lysine, phenylalanine and histidine. The amino acid content was generally higher than 25 mg/100g. Steroids, flavanoids and tannins occurred in moderate to high levels in all five species. Alkaloids and saponins occurred at very low levels, while triterpenes only occurred at very low levels in P. purpureum. The quality of Lomariopsis guineensis, a fern recently reported for the first time as edible is very promising. Pennisetum purpureum, popular as a forage plant, has now been shown to be valuable in the human diet. The study has established the safe and rich nutritional value of these vegetables and that their consumption could combat malnutrition and prevent some of the common nutritionally-related ailments.展开更多
To estimate the genetic relationship of Vietnamese pigs in Central Highlands, we compared cytochrome b sequences of Vietnamese wild boars and Vietnamese domestic pigs with other Asian and European wild boars. The resu...To estimate the genetic relationship of Vietnamese pigs in Central Highlands, we compared cytochrome b sequences of Vietnamese wild boars and Vietnamese domestic pigs with other Asian and European wild boars. The results showed that there were two wild boar populations locating in Vietnam Central Highlands including wild boars of group I and wild boars of group II. The Vietnamese wild boars of group II and domestic pigs were genetically close to Asian A1 and Asian A2 wild boar groups, whereas the Vietnamese wild boars of group I were genetically distinct from Asian A1, Asian A2 wild boar groups. The phylogenetic tree demonstrated that the Vietnamese wild boars of group I were clustered in one clade which was distinct from Asian wild boars and Europe wild boars. In addition, the Vietnamese wild boars of group I were estimated to have diverged from European wild boars at 421500 YBP, indicating that Vietnamese wild boar of group I could be isolated from other Asian wild boars. The single nucleotide polymorphism analysis showed that three Asian haplotypes were contributed in Vietnamese wild boars including A3 (TATG) haplotype in Vietnamese wild boar of group I and A1 (CATA) haplotype and A2 (CATG) haplotype in Vietnamese wild boars of group II. The A1 haplotype and A2 haplotype were also distributed in Vietnamese domestic pigs. Thus, there is a high possibility that Vietnam Central Highlands is a principal source for research on genetic diversity in Asian wild boar and domestic pig populations.展开更多
Some geological studies were performed in the Rafflesia Trail, near Kampung Jedip, in Lojing Highlands, Kelantan. This area is famous for its Rafflesia and has become one of the tourism attractions in Kelantan. Howeve...Some geological studies were performed in the Rafflesia Trail, near Kampung Jedip, in Lojing Highlands, Kelantan. This area is famous for its Rafflesia and has become one of the tourism attractions in Kelantan. However, the recent development of agricultural activities has significant effects on the area. The objective of these studies is to give substantial geological information including geomorphology, lithology, structural features, geohazard potentials, and water quality analysis in the study area. Desk study was conducted by reviewing some literatures related to the topic and the study area. Field work was organized during a scientific expedition in January 2014, to collect data, samples, and photographs. Geomorphologically, the study area is a mountainous area which mostly consists of mountain ridges and mountain valleys. Some fluvial features occur in the study area, such as waterfalls, cascades, rapids, runs, pools, potholes, lateral bars, and point bars. This area is composed of granitic rocks, mostly granite porphyry, and covered by superficial deposits of Quaternary age. The geological structure that is commonly found in the study area is joints, where they divide the rock body into large, roughly angular blocks, which is called as brecciation. The potential geohazard in the study area is landslides, where some of them are composed of soil only and others are mixtures of rock and soil. The water quality analysis has managed to identify that the stream water in this area generally has the quality of Class III (according to INWQS for Malaysia). These studies recommend that this area should be supported as a sustainable tourism site in Lojing Highlands.展开更多
The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing seve...The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing severe water shortage that leads to poor agricultural productivity and imparts serious negative impact on human lives. It is essential to develop water resources in a sustainable way to ensure food security and economic development. The water scarcity is due to the lack of resource management and due to the changes in environmental factors. In Ethiopia ground water is a major source of drinking water to vast rural population. The country’s perennial water budget depends on the ground and spring water system. The ever increasing population, mismanagement and global climatic changes are having an adverse impact on these resources. To harvest the available resources in a sustainable way will help to meet the needs of present era without compromising the future generation. The present study is an approach to compare and utilize the traditional water harvesting practices of Himalaya in Ethiopian highlands. A detailed study of the water sources and mechanism of ground water, geology and social management system of their water resources were studied booth side. Further application of the indigenous technical knowledge for sustainable of the ground water is proposed based on Himalayan practices. The Ethiopian “Minches” could be preserved and better utilized by adopting the merits of time tested indigenous management system of “Naule” of Himalaya.展开更多
Moringa oleifera is a multipurpose tree used to remedy problems related to food insecurity and soil fertility degradation. Proper husbandry of this crop is contingent on the use of seedlings of good quality. This stud...Moringa oleifera is a multipurpose tree used to remedy problems related to food insecurity and soil fertility degradation. Proper husbandry of this crop is contingent on the use of seedlings of good quality. This study aimed at assessing the germination and early seedling growth with different soaking durations and substrates composition. The seeds were obtained from the Far North region of Cameroon. A randomized complete block design with three replications was used. Two factors were tested;soaking duration with 4 treatment levels of 0 day, 4 days, 8 days and 12 days and substrates with 8 treatment levels: 100% soil, 75% soil + 25% poultry manure (PM), 50% soil + 50% PM, 25% soil + 75% PM, 100% sand, 75% sand + 25% PM, 50% sand + 50% PM and 25% sand + 75% PM. Germinated seeds and growth parameters were collected after every 5 days. The results showed that soaking duration and substrate composition influence germination and initial development of M. oleifera (p ≤ 0.05). At 25 days after soaking (DAS), soaking durations of 0 day (68.7%) and 8 days (53.1%) showed the highest germination percentages while seeds soaked for 12 days occupied the least position with 37.5%. At the same time, 75% soil + 25% PM (68.7%), 100% sand (64.5%) and 100% soil (60.5%) with the unsoaked seeds showed the highest germination percentages. The least germination percentages were represented by 50% sand + 50% PM and 25% sand + 75% PM with 35.5% and 27%, respectively. Unsoaked seeds with the substrates of 50% soil + 50% PM are the best practice for M. oleifera seedling production in the nursery.展开更多
Dealing with water resources issues requires understanding of the community perception. It is important to create a communicative partnership between community and government towards sustainable water resources manage...Dealing with water resources issues requires understanding of the community perception. It is important to create a communicative partnership between community and government towards sustainable water resources management. Opinion survey is an essential step to gather the point of view from local community. However, it always generates a large and complex dataset that are difficult to be interpreted by decision maker. In order to overcome this difficulty, statistical methods are applied to develop an interpretability model for decision maker. This study demonstrated the application of Descriptive Analysis and Principle Factor Analysis （PFA） to reduce the complexity of opinion survey dataset by revealing underlying information. A total of 106 respondents were interviewed; consisting of 68 male and 38 female respondents respectively. This study first applied descriptive analysis to identify the basic score for each variable, and these variables are soil erosion （68.9%）, degradation of water quality （65.1%）, degradation of freshwater ecosystem （61.0%）, water shortage （50%）, agricultural solid waste problem （46.2%）, water borne diseases （23.6%）, illegal land clearing （21.7%）, legal land clearing （15.1%）, uncontrolled river water abstraction in upstream （54.7%））, poor solid waste management （34.0%）, low awareness of local community （61.3%）, haphazard planning and development （74.5%） and administration mistake （37.0%）. Based on the PFA result, a total of four rotated factors were extracted, representing different aspects of water related issues in Cameron Highlands. Factor 1, 2, 3 and 4 were summarised to four topics namely： （1） water environment degradation caused by illegal solid waste disposal and low awareness of community, （2） agricultural development leading to negative impacts on water resources such as water shortage and ecosystem deterioration, （3） land clearing activity leading to serious land erosion （4） human health problem due to e-coli bacterial pollution and administration mistake on land development in Cameron Highlands.展开更多
There is limited information on the pedological requirements of <i><span>Triumfetta cordifolia</span></i>. A starting point <span style="font-family:;" "="">for&l...There is limited information on the pedological requirements of <i><span>Triumfetta cordifolia</span></i>. A starting point <span style="font-family:;" "="">for</span><span style="font-family:;" "=""> establishing such information requires knowledge on the growing environment of the species. The aim of this study was to <span>assess the physicochemical properties and mycorrhizal status in the rhizosphere of <i><span>Triumeffa cordifolia</span></i></span>. Soil and root samples from the rhizosphere </span>of <i><span>T. cordifolia</span></i> were collected from three localities (Santchou, Bandjoun<span style="font-family:;" "="">,</span><span style="font-family:;" "=""> and Balatchi) in the West Region of Cameroon. The results show that the soils are dominated by a loamy texture and have a mean porosity > 50%. Mean bulk density ranges from 0.91 ± 0.02 to 1.26 ± 0.04 g</span><span style="font-family:;" "=""><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span><span style="font-family:;" "="">cm<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>3</sup>. The sum of exchangeable cations ranges from medium (6.45 ± 1.02) to high (11.21 ± 1.35) and are evident of the satisfactory soil organic matter (OM) content in the various localities (5.90% ± 0.42% to 10.65% ± 0.73%). Total nitrogen (TN) content of the soils ranged from low (0.10%) to very high (0.41%). Biological activity is low due to very poor OM quality (mean C/N > 20). The average available phosphorus status ranged from medium (18.32 ± 3.91 ppm) to very high (69.39 ± 26.09 ppm). The Cationic Exchange Capacity (CEC) was moderate (19.28 - 29.28 cmol</span><span style="font-family:;" "=""><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span><span style="font-family:;" "="">kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>) and was mainly contributed by soil organic matter. Base saturation ranged from low (28.0%) to medium (48.83%). Assessment of endomycorrhizal colonization showed that the intensity (I), frequency (Fr) and specific density of spores (Ds) were not significantly different among sites. A high level of available P in the Santchou soils appears to be the major cause for </span><span style="font-family:;" "="">the </span><span style="font-family:;" "="">lowest values of Fr, I</span><span style="font-family:;" "="">,</span><span style="font-family:;" "=""> and Ds observed. These results reaffirm the link between soil physicochemical properties and endomycorrhizal infection in <i><span>T. cordifolia</span></i></span>. Site characteristics and soil OM quality are factors to be considered in promoting the establishment of mycorrhizal symbiosis for profitable and sustainable cultivation of <i><span>T. cordifolia</span></i>.展开更多
The valorisation of plant genetic resources following the Access and Benefit Sharing (ABS) process of the Nagoya Protocol requires the mastery of traditional knowledge associated with their uses by local populations. ...The valorisation of plant genetic resources following the Access and Benefit Sharing (ABS) process of the Nagoya Protocol requires the mastery of traditional knowledge associated with their uses by local populations. The objectives of this study were to survey the aromatic or cosmetics plants species used by the populations and to collect information on the knowledge associated with their uses in the Western highlands of Cameroon. Ethnobotanical surveys were carried out in 12 localities, where 251 individuals, including 206 men and 45 women, whose ages ranged from 25 to 81 years were interviewed. Information on each of the plant species mentioned and their different uses were recorded. A total of 103 species in 81 genera and 46 families were cited for aromatic or cosmetic uses, of which the most represented were the Lamiaceae (18 species), Asteraceae, and Zingiberaceae (7 species each). The identified plants were grouped into four categories of use: medicinal (56.31%), cosmetic (10.68%), food (6.80%), and cultural (1.94%). Most of the species surveyed were herbaceous (66%) with leaves being the most used part. The diversity index values of the respondents showed 10 species that were very well known and used by the populations: Eryngium foetidum, Chenopodium ambrosioides, Ocimum gratissimum, Piper umbellatum, Cinnamomum zeylanicum, Aframomum melegueta, Citrus limon, Costus afer, Cyperus rotundus, and Mondia whitei. These species were mainly used for: cough, spiritual protection, sexual weakness, cysts, diabetes, prostate, rheumatism, filaria, insomnia, female sterility, jaundice, scabies, haemorrhoids, high blood pressure and asthma. The results obtained constitute a valuable source of information that can contribute to the establishment of value chains allowing the effective valorisation of species following the ABS process.展开更多
Climate change and food security are among the pressing challenges facing humanity in the 21</span><sup><span style="font-family:Verdana;">st</span></sup><span style="fo...Climate change and food security are among the pressing challenges facing humanity in the 21</span><sup><span style="font-family:Verdana;">st</span></sup><span style="font-family:Verdana;"> century. Soil organic carbon (SOC) stocks, total nitrogen (TN), texture, and bulk density (BD) are important soil properties, which control climate change. Three land use systems (smallholder </span></span><span style="font-family:Verdana;">farmlands</span><span style="font-family:Verdana;">, grazing land</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;">, and forest lands) that coexist in the </span><span style="font-family:Verdana;">Bamenda Highlands (BH) influence ecosystem</span><span style="font-family:Verdana;"> services and induce soil degradation with the loss of SOC. The objective of this study was to evaluate the variation of SOC and some soil physicochemical properties as affected by the three land use systems (LUS). A total of 21 composite soil samples collected from 7 microclimatic zones of BH following “S” shape plots to the depth of 0 - 30 cm, were analysed for moisture content (MC), SOC, TN, BD, available phosphorus (Av.P), pH and texture. The results revealed that grazing land had the lowest mean sand content (40.79 ± 4.07). Mean MC, TN</span><span style="font-family:Verdana;"> and</span><span style="font-family:Verdana;"> SOC (%) content were significantly higher </span><span style="font-family:""><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05) </span></span><span style="font-family:Verdana;">in forest land than those </span><span style="font-family:Verdana;">in</span><span style="font-family:Verdana;"> the grazing land </span><span style="font-family:Verdana;">and smallholder farmlands</span><span style="font-family:Verdana;">. Conversely, BD and Av.P were significantly higher</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05)</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">in smallholder farmlands than grazing and forest lands probably due to different</span><span style="font-family:Verdana;"> litter accumulation and agricultural practices. </span><span style="font-family:""><span style="font-family:Verdana;">Moisture content and TN revealed positive significant correlations (</span><i><span style="font-family:Verdana;">p</span></i></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) with SOC, while BD and Av.P revealed negative significant correlations (</span><i><span style="font-family:Verdana;">p</span></i></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.05)</span><span style="font-family:Verdana;">. Mean SOC density in </span><span style="font-family:Verdana;">smallholder farmlands (132.91 ± 9.48 tC/ha)</span><span style="font-family:Verdana;"> was </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">lowest among the three land use types. Losses in CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> equivalence, as a result of land use change </span></span><span style="font-family:Verdana;">from forest lands to smallholder farmlands</span><span style="font-family:Verdana;"> w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> 137.33 t/ha while that from </span><span style="font-family:Verdana;">grazing lands to smallholder farmlands were</span><span style="font-family:Verdana;"> 109.13 t/ha. </span><span style="font-family:""><span style="font-family:Verdana;">Total organic carbon (TOC) stocks differed significantly (</span><i><span style="font-family:Verdana;">p</span></i></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.05) from smallholder farmlands (10.73 Mt) to forest lands (91.13 Mt)</span><span style="font-family:Verdana;">. A sustainable farming</span><span style="font-family:""><span style="font-family:Verdana;"> technique that enhances SOC sequestration and minimizes soil CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> emissions is therefore recommended to replace tillage ridges formation commonly practiced by smallholder farmers.展开更多
In Cameroon in general and in the Highlands of Cameroon in particular, there is no fracture map since its realization is not easy. The region’s harsh accessibility and climatic conditions make it difficult to carry o...In Cameroon in general and in the Highlands of Cameroon in particular, there is no fracture map since its realization is not easy. The region’s harsh accessibility and climatic conditions make it difficult to carry out geological prospecting field missions that require large investments. This study proposes a semi-automatic lineament mapping approach to facilitate the elaboration of the fracture map in the West Cameroon Highlands. It uses neural networks in tandem with PCI Geomatica’s LINE algorithm to extract lineaments semi-automatically from an ALOS PALSAR 2 radar image. The cellular neural network algorithm of Lepage et al (2000) is implemented to enhance the pre-processed radar image. Then, the LINE module of Geomatica is applied </span><span style="font-family:Verdana;">to</span><span style="font-family:Verdana;"> the enhanced image for the automatic extraction of lineaments. Finally, a control and a validation of the expert by spatial analysis allows elaborat</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> the fracture map. The results obtained show that neural networks enhance and facilitate the identification of lineaments on the image. The resulting map contains more than 1800 fractures with major directions N20<span style="white-space:nowrap;">°</span> - 30<span style="white-space:nowrap;">°</span>, NS, N10<span style="white-space:nowrap;">°</span> - 20<span style="white-space:nowrap;">°</span>, N50<span style="white-space:nowrap;">°</span> - 60<span style="white-space:nowrap;">°</span>, N70<span style="white-space:nowrap;">°</span> - 80<span style="white-space:nowrap;">°</span>, N80<span style="white-space:nowrap;">°</span> - 90<span style="white-space:nowrap;">°</span>, N100<span style="white-space:nowrap;">°</span> - 110<span style="white-space:nowrap;">°</span>, N110<span style="white-space:nowrap;">°</span> - 120<span style="white-space:nowrap;">°</span> and N130<span style="white-space:nowrap;">°</span> - 140<span style="white-space:nowrap;">°</span> and N140<span style="white-space:nowrap;">°</span> - 150<span style="white-space:nowrap;">°</span>. It can be very useful for geological and hydrogeological studies, and especially to inform on the productivity of aquifers in this region of high agro-pastoral and mining interest for Cameroon and the Central African sub-region.展开更多
This study was conducted from June 2021 to January 2023 to assess the genetic diversity of giant African snails in the western highlands of Cameroon. A total of 652 snails were randomly collected from the wild in thre...This study was conducted from June 2021 to January 2023 to assess the genetic diversity of giant African snails in the western highlands of Cameroon. A total of 652 snails were randomly collected from the wild in three localities in the western highlands (Bafang, Bafoussam, and Santchou). The study revealed significant variations in morphobiometric characteristics both between species and localities. The predominant shell coloration was brownish with yellow zigzag stripes (65%), while the dominant coloration for shell openings was whitish (48%). Regarding foot coloration, both brown with spotted black and black with spotted brown colorations were dominant (29%). The highest recorded live weight of snails (39.33 ± 34) was found in the species Archachatina marginata. In terms of length measurements (in mm), the length of the right and left sides of the shell was higher in the A. fulica species (49.8 ± 19.7 mm and 40.07 ± 18 mm, respectively). Bafang exhibited the highest values for shell length (56 ± 11 mm) and shell width (46.52 ± 11.46 mm). A. fulica recorded the highest shell length (81.5 ± 27 mm), while A. marginata recorded the highest shell width (49.6 ± 12.1 mm), with the highest values observed in A. fulica from fulica having a slightly higher aperture width value (30 ± 10 mm) compared to A. marginata, while A. marginata had the highest value for aperture length measurement (54.5 ± 12 mm). A. fulica also exhibited the highest values for the length from apex to the first whorl and the length from left to right of the first whorl (43.2 ± 18 mm and 39 ± 19.8 mm, respectively). Strong and positive correlations were observed between the live weight of snails and body measurements regardless of species, except for the number of whorls, which showed very weak or negative correlations with other body measurements. The results of Hierarchical Cluster Analysis (HCA) revealed three distinct snail population types. These findings provide valuable insights into the phenotypic diversity of edible land snails in the western highlands of Cameroon and can be considered in improvement and conservation programs aimed at enhancing snail meat yield.展开更多
Mountainous ecosystem soils are subject to colonization nowadays for agri</span><span style="font-family:Verdana;">cultural purposes due to an increasing population in towns making the</span&g...Mountainous ecosystem soils are subject to colonization nowadays for agri</span><span style="font-family:Verdana;">cultural purposes due to an increasing population in towns making the</span><span style="font-family:Verdana;"> detailed </span><span style="font-family:Verdana;">characterization of such soils indispensable. This work aims to characterize</span><span style="font-family:Verdana;"> the steep slopes soils of the Dschang hills and to evaluate their fertility level for </span><span style="font-family:Verdana;">agricultural valorization. Thus, four soil profiles were dug at various topographic</span><span style="font-family:Verdana;"> positions (summit (SP), shoulder (MP), backslope (BP) and footslope (PP)) following a toposequence. Samples of disturbed and undisturbed soils were taken and analyzed in the laboratory according to standard methods. The Fertility</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Capability</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Classification (FCC) and simple limitation methods were used to identify major agricultural constraints. The main results show that </span><span style="font-family:Verdana;">profiles thickness is moderate, between 0 and 120 cm, with a high sand</span><span style="font-family:Verdana;"> content </span><span style="font-family:Verdana;">(at least 50%) over the entire toposequence, especially at the surface. The</span><span style="font-family:Verdana;"> study site has four types of soils, namely Eutric</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Cambisols (ochric) in SP and L</span><span style="font-family:Verdana;">eptic</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Eutric</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Cambisols (Humic) in MP, Eutric</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Cambisols (Humic) in BP</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and Stagnic</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Oxygleyic</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Dystric</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Gleysols</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">(Humic) in pp. The soils are very acidic at PP, moderately acidic at BP and SP and slightly acidic at MP. Organic matter is higher at the surface than at depth at the topographic segments of MP, BP and PP and low to SP. The C/N ratio is high (>17) in all profiles except P4 </span><span style="font-family:Verdana;">(<10). In addition, the cation exchange capacity (CEC), the sum of</span><span style="font-family:Verdana;"> exchangeable bases, total nitrogen and available phosphorus is low in all profiles. The Ca/</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Mg/K balance in all the profiles shows a cation imbalance and a relatively </span><span style="font-family:Verdana;">high concentration of exchangeable potassium compared to the ideal</span><span style="font-family:Verdana;"> situation (76% Ca, 18% Mg and 6% K). The major constraints to crop production are: aluminum toxicity (a) and nutrients leaching (e), textural discontinuity (LS), flooding (g), low nutrient reserve (k), sand (S), clay (C) and slope (t). Hence the fertility capacity classes of these soils are CCaegk (PP), SSek (BP), SSte (MP) and LSaek (SP). To improve the yield, it will require off-season crop cultivation, fertilization and liming, and earthworks.展开更多
A study was conducted in the Tsegede highlands of Tigray Region, northern Ethiopia to determine the changes in some physical and chemical attributes across three adjacent acidic soil sites with different elevation and...A study was conducted in the Tsegede highlands of Tigray Region, northern Ethiopia to determine the changes in some physical and chemical attributes across three adjacent acidic soil sites with different elevation and three land use types. Analytical results of the collected surface layer soil samples showed significant (P ≤ 0.05) correlation of soil bulk density, OM and total N with elevation. In the lower elevation site (Indaslasie), soil OM content declined by about 43 and 52% compared with that of the two higher elevation sites (Cheguarcudo and Indamariam), respectively. Soil pH, exchangeable acidity, exchangeable Al, OM, total N and available phosphorus also exhibited significant (P ≤ 0.05) disparity across the three land use types of the area. Soils of the forest land were less acidic by 0.43 and 0.68 pH units than the cultivated and grazing lands, respectively. The soil OM content of the cultivated land was significantly lower by about 25 and 35% than the grazing and forest land soils, respectively. Available soil P status was low and showed significant correlations with pH (r = 0.65), exchangeable acidity (r = –0.58) and Al (r = –0.53). In general, the study results revealed altitude did not impose any significant effect in aggravating soil acidity whereas land use type affected significantly not only soil acidity but also the important soil fertility related parameters such as OM, total N and available P contents. Therefore, it can be suggested that besides to the usual acid soil management and/or reclamation practices, introducing proper land use management systems are of paramount importance.展开更多
基金funded by the Natural Science Foundation of Hubei Province(2022CFB260,2021CFB508)the National Natural Science Foundation of China(No.42074007No.42130101).
文摘The Southern Highland Fold and Thrust Belt(SHFTB),the boundary of the Australian plate and the New Guinea Highland block,significantly contributes to the convergent deformation along the plate bound-ary.However,due to the lack of observation data,the detailed slip pattern of the SHFTB and the orogenic mechanism beneath the New Guinea Highlands remains controversial.On 25 February 2018,the M_(w)7.5 Papua New Guinea(PNG)earthquake struck the southeastern segment of the SHFTB.The detailed rupture characteristics of this event is significant for further clarifying the inter-seismic slip pattern along the SHFTB.Here,the coseismic deformation field of this earthquake was obtained using high-resolution ALOS-2 satellite images.We find that the 2018 M_(w)7.5 PNG earthquake ruptured a large-scaled fault(SHFTB)extending to the lower crust(deeper than 20 km)beneath the New Guinea Highlands,with a dip angle of 24°.The slips on the fault plane are equivalent to moment magnitudes of M_(w)7.51.Three major asperities with thrust-dominated slip of up to 3.94 m are detected on the fault plane.This finding implies that the slip pattern on the eastern segment of the SHFTB is dominated by thrust,rather than with significant sinistral movement,as previously reported.The tectonic deformation across the New Guinea Highlands is possibly concentrated on the large-scale fault SHFTB and primarily controls the intra-continental orogeny in the central Papua New Guinea.
文摘Climate change is impacting on climate dependent activities such as Avocado farming in Tanzania. The extent of the impact of climate change in agriculture depends on the level of vulnerability or exposure of farmers to these impacts. This study addresses gender vulnerabilities to Avocado smallholder farmers to climate change in the Southern Highlands regions of Tanzania where the temperature and rainfall stresses are relevant using the Livelihood Vulnerability Index (LVI) and tested for significant difference in their vulnerability levels by applying independent two sample student’s t-test based on gender by using a sample of 104 Avocado smallholder farming. The results in this study revealed that both male and female avocado farmers were vulnerable to the effects of climate change and variability, but the vulnerabilities varied with gender. Female small holder farmers were more vulnerable to socio-demographic profile, livelihood strategies, social network, water and food major components of the LVI, whereas were more vulnerable to social network and health. The vulnerability indices revealed that female small holder farmers were more sensitive to the impact of climate change and variability. It was also found that female small holder farmers have the least adaptive capacities. In all, female small holder farmers are more vulnerable to climate change and variability than male. There is a need for better gender-sensitive approaches to adaptation planning and implementation to ensure that both men and women have equal opportunities to benefit from adaptation options in agriculture.
文摘This paper studies the effect of basalt and tephra dusts,as alternatives to chemical fertilizers,on soil fertility and Radish(Raphanus sativus)production.The experiment was conducted in the field and in the laboratory in the years 2017 and 2018 on two separate plots so as to annul residual effects of fertilizers).The experimental design in the field was a randomized complete block design(56 m^(2)),including five treatments and three replications:control(T_(0)),basalt dust(T_(1)),tephra dust(T_(2)),effective micro-organism(EM)fertilizer(T_(3))and NPK 20-10-10(T_(4)).The main results show the following decreasing trend based on yield:T_(1)>T_(3)>T_(0)>T_(4)>T_(2).The best yields appear in T_(1) and T_(3) probably because they supplied the highest levels of soil nutrients to match the needs of the crops.Although T_(2) plants performed poorly,soil properties like pH.H_(2)O(6.14 to 6.49),sum of exchangeable bases,base saturation,available phosphorus and cation balance were improved after tephra treatment.T_(2) plants might have performed poorly due to intrinsic properties of the tephra dust like low availability of trace elements compared to T_(1) and T_(3).T_(4) plants show the highest number of leaves,leaf area index and plant height.The Fe,Mn,Cu and Zn levels in bulbs and leaves will not pose danger of toxicity to human upon consumption and could serve as nutrient supplement for children and expectant mothers.The most profitable treatment is T_(1) permitting to recommend the popularization of basalt dust for radish cultivation as an alternative to chemical fertilizers.
文摘Kigezi highlands currently experiences changes in precipitation and temperature which modify the evaporation and soil moisture storage leading to alterations in runoff and other components of hydrological systems. Extreme events, like floods and droughts, are more intense and frequent. Furthermore heavy unpredictable rainfall has become frequent in the area, causing soil erosion and floods that destroy crops. Soil erosion is particularly a pressing challenge due to steep-sided hills leading to deterioration of soil nutrients including soil fertility. The unpredictable rains and droughts are attributed to climate change and variability. Consequently, climate change and variability have caused a significant impact on soil nutrients which have affected the agricultural productivity in the area. This paper presents findings of empirical study which explored the climate variability and soil nutrient status along altitudinal gradient. The paper particularly addresses key questions of: land management practices in the study area, nutrient availability and their effects on productivity of selected crops along altitudinal gradient in changing climate and variability. Independent variables such as topographic sequence along altitudinal gradient were evaluated against dependent variables such as yield harvests of selected grown crops and soil nutrients. Samples for crop yields were collected along transect of 0.5 kilometer using a quadrant of 4 × 4 m<sup>2</sup> along attitudinal gradient. Soil samples were taken from selected plots at 0-20cm soil depth for nutrient analysis. Analysis of physical and chemical soil parameters was carried out on soil samples and these include: soil pH, soil organic content, total nitrogen, available soil phosphorous and exchangeable bases (Ca, Mg, K and Na). The study showed that middle parts of the transects had the highest concentration of most soil nutrients, probably because the middle parts could have been a deposition centre for some organic matter from the upper parts of the hills, and lower lying areas were being affected by floods that affects the decomposition of organic matter which is the main source of nutrients. Similarly, the middle parts of the study were the most fertile due to the high concentration of soil nutrient compositions. This indicates that crop yields were significantly affected by availability of soil nutrients along same gradient, attributable to the severity in soil erosion, nutrients leaching and farming practices.
基金supported by JSPS KAKENHI(Grant-in-Aid for Scientific Research on Innovative Areas) Grant No. 26106002 (Hadean Bio-Science)
文摘Extensional and compressional structures are globally abundant on Mars. Distribution of these structures and their ages constrain the crustal stress state and tectonic evolution of the planet. Here in this paper, we report on our investigation over the distribution of the tectonic structures and timings of the associated stress fields from the Noachis-Sabaea region. Thereafter, we hypothesize possible origins in relation to the internal/external processes through detailed morphostructural mapping. In doing so, we have extracted the absolute model ages of these linear tectonic structures using crater size-frequency distribution measurements, buffered crater counting in particular. The estimated ages indicate that the tectonic structures are younger than the mega impacts events(especially Hellas) and instead they reveal two dominant phases of interior dynamics prevailing on the southern highlands, firstly the extensional phase terminating around3.8 Ga forming grabens and then compressional phase around 3.5-3.6 Ga producing wrinkle ridges and lobate scarps. These derived absolute model ages of the grabens exhibit the age ca. 100 Ma younger than the previously documented end of the global extensional phase. The following compressional activity corresponds to the peak of global contraction period in Early Hesperian. Therefore, we conclude that the planet wide heat loss mechanism, involving crustal stretching coupled with gravitationally driven relaxation(i.e.,lithospheric mobility) resulted in the extensional structures around Late Noachian(around 3.8 Ga). Lately cooling related global contraction generated compressional stress ensuing shortening of the upper crust of the southern highlands at the Early Hesperian period(around 3.5-3.6 Ga).
基金This work was supported by the National Natural Science Foundation of China(Grant No.42030603)the Natural Science Foundation of Yunnan Province(2019FY003006)the Postgraduate Research and Innovation foundation of Yunnan University(2021Z017).
文摘Based on the fifth-generation reanalysis dataset from the European Centre for Medium-Range Weather Forecasts for 1979–2019,we investigated the effects of the circumglobal teleconnection(CGT)on the interdecadal variation of the March atmospheric heat source(AHS)over the Southeast Asian low-latitude highlands(SEALLH).The dominant mode of the March AHS over the SEALLH features a monopole structure with an 8–11-year period.Decadal variations in the AHS make an important contribution to the 11-year low-pass filtered component of the AHS index,whichexplains 54.3%of the total variance.The CGT shows a clear interdecadal variation,which explains 59.3%of the total variance.The March AHS over the SEALLH is significantly related to the CGT on interdecadal timescales.When the CGT is optimally excited by a significant cyclonic vorticity source near northern Africa(i.e.,in its positive phase),the SEALLH is dominated by anomalous southerly winds and ascending motions on the east of the anomalous cyclone.The enhanced advection and upward transfer result in a high-enthalpy air mass that converges into and condenses over the SEALLH,leading to a largerthan-average March AHS over this region.The key physical processes revealed by this diagnostic analysis are supported by numerical experiments.
文摘Wild vegetables contribute immensely to the culinary basket and livelihoods of rural communities in sub-Saharan Africa, especially among the people of Lebialem highlands of south western Cameroon where at least 26 such species are consumed as vegetables. To promote the consumption of these vegetables, the nutritional quality of five preferred species in this area, Amaranthus dubius Mart. Ex Thell., Gnetum africanum Welw., Lomariopsis guineensis (Unerw.) Alston, Pennisetum purpureum Schumach and Vernonia amygdalina Del., was assessed using standard methods. L. guineensis had the highest carbohydrate, protein, calorific value and ash content, and the lowest fat content of 4.05%, very rich in K, Ca and Mg and the amino acids leucine, arginine, lysine, phenylalanine and histidine. The amino acid content was generally higher than 25 mg/100g. Steroids, flavanoids and tannins occurred in moderate to high levels in all five species. Alkaloids and saponins occurred at very low levels, while triterpenes only occurred at very low levels in P. purpureum. The quality of Lomariopsis guineensis, a fern recently reported for the first time as edible is very promising. Pennisetum purpureum, popular as a forage plant, has now been shown to be valuable in the human diet. The study has established the safe and rich nutritional value of these vegetables and that their consumption could combat malnutrition and prevent some of the common nutritionally-related ailments.
文摘To estimate the genetic relationship of Vietnamese pigs in Central Highlands, we compared cytochrome b sequences of Vietnamese wild boars and Vietnamese domestic pigs with other Asian and European wild boars. The results showed that there were two wild boar populations locating in Vietnam Central Highlands including wild boars of group I and wild boars of group II. The Vietnamese wild boars of group II and domestic pigs were genetically close to Asian A1 and Asian A2 wild boar groups, whereas the Vietnamese wild boars of group I were genetically distinct from Asian A1, Asian A2 wild boar groups. The phylogenetic tree demonstrated that the Vietnamese wild boars of group I were clustered in one clade which was distinct from Asian wild boars and Europe wild boars. In addition, the Vietnamese wild boars of group I were estimated to have diverged from European wild boars at 421500 YBP, indicating that Vietnamese wild boar of group I could be isolated from other Asian wild boars. The single nucleotide polymorphism analysis showed that three Asian haplotypes were contributed in Vietnamese wild boars including A3 (TATG) haplotype in Vietnamese wild boar of group I and A1 (CATA) haplotype and A2 (CATG) haplotype in Vietnamese wild boars of group II. The A1 haplotype and A2 haplotype were also distributed in Vietnamese domestic pigs. Thus, there is a high possibility that Vietnam Central Highlands is a principal source for research on genetic diversity in Asian wild boar and domestic pig populations.
文摘Some geological studies were performed in the Rafflesia Trail, near Kampung Jedip, in Lojing Highlands, Kelantan. This area is famous for its Rafflesia and has become one of the tourism attractions in Kelantan. However, the recent development of agricultural activities has significant effects on the area. The objective of these studies is to give substantial geological information including geomorphology, lithology, structural features, geohazard potentials, and water quality analysis in the study area. Desk study was conducted by reviewing some literatures related to the topic and the study area. Field work was organized during a scientific expedition in January 2014, to collect data, samples, and photographs. Geomorphologically, the study area is a mountainous area which mostly consists of mountain ridges and mountain valleys. Some fluvial features occur in the study area, such as waterfalls, cascades, rapids, runs, pools, potholes, lateral bars, and point bars. This area is composed of granitic rocks, mostly granite porphyry, and covered by superficial deposits of Quaternary age. The geological structure that is commonly found in the study area is joints, where they divide the rock body into large, roughly angular blocks, which is called as brecciation. The potential geohazard in the study area is landslides, where some of them are composed of soil only and others are mixtures of rock and soil. The water quality analysis has managed to identify that the stream water in this area generally has the quality of Class III (according to INWQS for Malaysia). These studies recommend that this area should be supported as a sustainable tourism site in Lojing Highlands.
文摘The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing severe water shortage that leads to poor agricultural productivity and imparts serious negative impact on human lives. It is essential to develop water resources in a sustainable way to ensure food security and economic development. The water scarcity is due to the lack of resource management and due to the changes in environmental factors. In Ethiopia ground water is a major source of drinking water to vast rural population. The country’s perennial water budget depends on the ground and spring water system. The ever increasing population, mismanagement and global climatic changes are having an adverse impact on these resources. To harvest the available resources in a sustainable way will help to meet the needs of present era without compromising the future generation. The present study is an approach to compare and utilize the traditional water harvesting practices of Himalaya in Ethiopian highlands. A detailed study of the water sources and mechanism of ground water, geology and social management system of their water resources were studied booth side. Further application of the indigenous technical knowledge for sustainable of the ground water is proposed based on Himalayan practices. The Ethiopian “Minches” could be preserved and better utilized by adopting the merits of time tested indigenous management system of “Naule” of Himalaya.
文摘Moringa oleifera is a multipurpose tree used to remedy problems related to food insecurity and soil fertility degradation. Proper husbandry of this crop is contingent on the use of seedlings of good quality. This study aimed at assessing the germination and early seedling growth with different soaking durations and substrates composition. The seeds were obtained from the Far North region of Cameroon. A randomized complete block design with three replications was used. Two factors were tested;soaking duration with 4 treatment levels of 0 day, 4 days, 8 days and 12 days and substrates with 8 treatment levels: 100% soil, 75% soil + 25% poultry manure (PM), 50% soil + 50% PM, 25% soil + 75% PM, 100% sand, 75% sand + 25% PM, 50% sand + 50% PM and 25% sand + 75% PM. Germinated seeds and growth parameters were collected after every 5 days. The results showed that soaking duration and substrate composition influence germination and initial development of M. oleifera (p ≤ 0.05). At 25 days after soaking (DAS), soaking durations of 0 day (68.7%) and 8 days (53.1%) showed the highest germination percentages while seeds soaked for 12 days occupied the least position with 37.5%. At the same time, 75% soil + 25% PM (68.7%), 100% sand (64.5%) and 100% soil (60.5%) with the unsoaked seeds showed the highest germination percentages. The least germination percentages were represented by 50% sand + 50% PM and 25% sand + 75% PM with 35.5% and 27%, respectively. Unsoaked seeds with the substrates of 50% soil + 50% PM are the best practice for M. oleifera seedling production in the nursery.
文摘Dealing with water resources issues requires understanding of the community perception. It is important to create a communicative partnership between community and government towards sustainable water resources management. Opinion survey is an essential step to gather the point of view from local community. However, it always generates a large and complex dataset that are difficult to be interpreted by decision maker. In order to overcome this difficulty, statistical methods are applied to develop an interpretability model for decision maker. This study demonstrated the application of Descriptive Analysis and Principle Factor Analysis （PFA） to reduce the complexity of opinion survey dataset by revealing underlying information. A total of 106 respondents were interviewed; consisting of 68 male and 38 female respondents respectively. This study first applied descriptive analysis to identify the basic score for each variable, and these variables are soil erosion （68.9%）, degradation of water quality （65.1%）, degradation of freshwater ecosystem （61.0%）, water shortage （50%）, agricultural solid waste problem （46.2%）, water borne diseases （23.6%）, illegal land clearing （21.7%）, legal land clearing （15.1%）, uncontrolled river water abstraction in upstream （54.7%））, poor solid waste management （34.0%）, low awareness of local community （61.3%）, haphazard planning and development （74.5%） and administration mistake （37.0%）. Based on the PFA result, a total of four rotated factors were extracted, representing different aspects of water related issues in Cameron Highlands. Factor 1, 2, 3 and 4 were summarised to four topics namely： （1） water environment degradation caused by illegal solid waste disposal and low awareness of community, （2） agricultural development leading to negative impacts on water resources such as water shortage and ecosystem deterioration, （3） land clearing activity leading to serious land erosion （4） human health problem due to e-coli bacterial pollution and administration mistake on land development in Cameron Highlands.
文摘There is limited information on the pedological requirements of <i><span>Triumfetta cordifolia</span></i>. A starting point <span style="font-family:;" "="">for</span><span style="font-family:;" "=""> establishing such information requires knowledge on the growing environment of the species. The aim of this study was to <span>assess the physicochemical properties and mycorrhizal status in the rhizosphere of <i><span>Triumeffa cordifolia</span></i></span>. Soil and root samples from the rhizosphere </span>of <i><span>T. cordifolia</span></i> were collected from three localities (Santchou, Bandjoun<span style="font-family:;" "="">,</span><span style="font-family:;" "=""> and Balatchi) in the West Region of Cameroon. The results show that the soils are dominated by a loamy texture and have a mean porosity > 50%. Mean bulk density ranges from 0.91 ± 0.02 to 1.26 ± 0.04 g</span><span style="font-family:;" "=""><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span><span style="font-family:;" "="">cm<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>3</sup>. The sum of exchangeable cations ranges from medium (6.45 ± 1.02) to high (11.21 ± 1.35) and are evident of the satisfactory soil organic matter (OM) content in the various localities (5.90% ± 0.42% to 10.65% ± 0.73%). Total nitrogen (TN) content of the soils ranged from low (0.10%) to very high (0.41%). Biological activity is low due to very poor OM quality (mean C/N > 20). The average available phosphorus status ranged from medium (18.32 ± 3.91 ppm) to very high (69.39 ± 26.09 ppm). The Cationic Exchange Capacity (CEC) was moderate (19.28 - 29.28 cmol</span><span style="font-family:;" "=""><span style="white-space:nowrap;"><span style="white-space:nowrap;">⋅</span></span></span><span style="font-family:;" "="">kg<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>) and was mainly contributed by soil organic matter. Base saturation ranged from low (28.0%) to medium (48.83%). Assessment of endomycorrhizal colonization showed that the intensity (I), frequency (Fr) and specific density of spores (Ds) were not significantly different among sites. A high level of available P in the Santchou soils appears to be the major cause for </span><span style="font-family:;" "="">the </span><span style="font-family:;" "="">lowest values of Fr, I</span><span style="font-family:;" "="">,</span><span style="font-family:;" "=""> and Ds observed. These results reaffirm the link between soil physicochemical properties and endomycorrhizal infection in <i><span>T. cordifolia</span></i></span>. Site characteristics and soil OM quality are factors to be considered in promoting the establishment of mycorrhizal symbiosis for profitable and sustainable cultivation of <i><span>T. cordifolia</span></i>.
文摘The valorisation of plant genetic resources following the Access and Benefit Sharing (ABS) process of the Nagoya Protocol requires the mastery of traditional knowledge associated with their uses by local populations. The objectives of this study were to survey the aromatic or cosmetics plants species used by the populations and to collect information on the knowledge associated with their uses in the Western highlands of Cameroon. Ethnobotanical surveys were carried out in 12 localities, where 251 individuals, including 206 men and 45 women, whose ages ranged from 25 to 81 years were interviewed. Information on each of the plant species mentioned and their different uses were recorded. A total of 103 species in 81 genera and 46 families were cited for aromatic or cosmetic uses, of which the most represented were the Lamiaceae (18 species), Asteraceae, and Zingiberaceae (7 species each). The identified plants were grouped into four categories of use: medicinal (56.31%), cosmetic (10.68%), food (6.80%), and cultural (1.94%). Most of the species surveyed were herbaceous (66%) with leaves being the most used part. The diversity index values of the respondents showed 10 species that were very well known and used by the populations: Eryngium foetidum, Chenopodium ambrosioides, Ocimum gratissimum, Piper umbellatum, Cinnamomum zeylanicum, Aframomum melegueta, Citrus limon, Costus afer, Cyperus rotundus, and Mondia whitei. These species were mainly used for: cough, spiritual protection, sexual weakness, cysts, diabetes, prostate, rheumatism, filaria, insomnia, female sterility, jaundice, scabies, haemorrhoids, high blood pressure and asthma. The results obtained constitute a valuable source of information that can contribute to the establishment of value chains allowing the effective valorisation of species following the ABS process.
文摘Climate change and food security are among the pressing challenges facing humanity in the 21</span><sup><span style="font-family:Verdana;">st</span></sup><span style="font-family:Verdana;"> century. Soil organic carbon (SOC) stocks, total nitrogen (TN), texture, and bulk density (BD) are important soil properties, which control climate change. Three land use systems (smallholder </span></span><span style="font-family:Verdana;">farmlands</span><span style="font-family:Verdana;">, grazing land</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;">, and forest lands) that coexist in the </span><span style="font-family:Verdana;">Bamenda Highlands (BH) influence ecosystem</span><span style="font-family:Verdana;"> services and induce soil degradation with the loss of SOC. The objective of this study was to evaluate the variation of SOC and some soil physicochemical properties as affected by the three land use systems (LUS). A total of 21 composite soil samples collected from 7 microclimatic zones of BH following “S” shape plots to the depth of 0 - 30 cm, were analysed for moisture content (MC), SOC, TN, BD, available phosphorus (Av.P), pH and texture. The results revealed that grazing land had the lowest mean sand content (40.79 ± 4.07). Mean MC, TN</span><span style="font-family:Verdana;"> and</span><span style="font-family:Verdana;"> SOC (%) content were significantly higher </span><span style="font-family:""><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05) </span></span><span style="font-family:Verdana;">in forest land than those </span><span style="font-family:Verdana;">in</span><span style="font-family:Verdana;"> the grazing land </span><span style="font-family:Verdana;">and smallholder farmlands</span><span style="font-family:Verdana;">. Conversely, BD and Av.P were significantly higher</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">(</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05)</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">in smallholder farmlands than grazing and forest lands probably due to different</span><span style="font-family:Verdana;"> litter accumulation and agricultural practices. </span><span style="font-family:""><span style="font-family:Verdana;">Moisture content and TN revealed positive significant correlations (</span><i><span style="font-family:Verdana;">p</span></i></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) with SOC, while BD and Av.P revealed negative significant correlations (</span><i><span style="font-family:Verdana;">p</span></i></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.05)</span><span style="font-family:Verdana;">. Mean SOC density in </span><span style="font-family:Verdana;">smallholder farmlands (132.91 ± 9.48 tC/ha)</span><span style="font-family:Verdana;"> was </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">lowest among the three land use types. Losses in CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> equivalence, as a result of land use change </span></span><span style="font-family:Verdana;">from forest lands to smallholder farmlands</span><span style="font-family:Verdana;"> w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> 137.33 t/ha while that from </span><span style="font-family:Verdana;">grazing lands to smallholder farmlands were</span><span style="font-family:Verdana;"> 109.13 t/ha. </span><span style="font-family:""><span style="font-family:Verdana;">Total organic carbon (TOC) stocks differed significantly (</span><i><span style="font-family:Verdana;">p</span></i></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.05) from smallholder farmlands (10.73 Mt) to forest lands (91.13 Mt)</span><span style="font-family:Verdana;">. A sustainable farming</span><span style="font-family:""><span style="font-family:Verdana;"> technique that enhances SOC sequestration and minimizes soil CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> emissions is therefore recommended to replace tillage ridges formation commonly practiced by smallholder farmers.
文摘In Cameroon in general and in the Highlands of Cameroon in particular, there is no fracture map since its realization is not easy. The region’s harsh accessibility and climatic conditions make it difficult to carry out geological prospecting field missions that require large investments. This study proposes a semi-automatic lineament mapping approach to facilitate the elaboration of the fracture map in the West Cameroon Highlands. It uses neural networks in tandem with PCI Geomatica’s LINE algorithm to extract lineaments semi-automatically from an ALOS PALSAR 2 radar image. The cellular neural network algorithm of Lepage et al (2000) is implemented to enhance the pre-processed radar image. Then, the LINE module of Geomatica is applied </span><span style="font-family:Verdana;">to</span><span style="font-family:Verdana;"> the enhanced image for the automatic extraction of lineaments. Finally, a control and a validation of the expert by spatial analysis allows elaborat</span><span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> the fracture map. The results obtained show that neural networks enhance and facilitate the identification of lineaments on the image. The resulting map contains more than 1800 fractures with major directions N20<span style="white-space:nowrap;">°</span> - 30<span style="white-space:nowrap;">°</span>, NS, N10<span style="white-space:nowrap;">°</span> - 20<span style="white-space:nowrap;">°</span>, N50<span style="white-space:nowrap;">°</span> - 60<span style="white-space:nowrap;">°</span>, N70<span style="white-space:nowrap;">°</span> - 80<span style="white-space:nowrap;">°</span>, N80<span style="white-space:nowrap;">°</span> - 90<span style="white-space:nowrap;">°</span>, N100<span style="white-space:nowrap;">°</span> - 110<span style="white-space:nowrap;">°</span>, N110<span style="white-space:nowrap;">°</span> - 120<span style="white-space:nowrap;">°</span> and N130<span style="white-space:nowrap;">°</span> - 140<span style="white-space:nowrap;">°</span> and N140<span style="white-space:nowrap;">°</span> - 150<span style="white-space:nowrap;">°</span>. It can be very useful for geological and hydrogeological studies, and especially to inform on the productivity of aquifers in this region of high agro-pastoral and mining interest for Cameroon and the Central African sub-region.
文摘This study was conducted from June 2021 to January 2023 to assess the genetic diversity of giant African snails in the western highlands of Cameroon. A total of 652 snails were randomly collected from the wild in three localities in the western highlands (Bafang, Bafoussam, and Santchou). The study revealed significant variations in morphobiometric characteristics both between species and localities. The predominant shell coloration was brownish with yellow zigzag stripes (65%), while the dominant coloration for shell openings was whitish (48%). Regarding foot coloration, both brown with spotted black and black with spotted brown colorations were dominant (29%). The highest recorded live weight of snails (39.33 ± 34) was found in the species Archachatina marginata. In terms of length measurements (in mm), the length of the right and left sides of the shell was higher in the A. fulica species (49.8 ± 19.7 mm and 40.07 ± 18 mm, respectively). Bafang exhibited the highest values for shell length (56 ± 11 mm) and shell width (46.52 ± 11.46 mm). A. fulica recorded the highest shell length (81.5 ± 27 mm), while A. marginata recorded the highest shell width (49.6 ± 12.1 mm), with the highest values observed in A. fulica from fulica having a slightly higher aperture width value (30 ± 10 mm) compared to A. marginata, while A. marginata had the highest value for aperture length measurement (54.5 ± 12 mm). A. fulica also exhibited the highest values for the length from apex to the first whorl and the length from left to right of the first whorl (43.2 ± 18 mm and 39 ± 19.8 mm, respectively). Strong and positive correlations were observed between the live weight of snails and body measurements regardless of species, except for the number of whorls, which showed very weak or negative correlations with other body measurements. The results of Hierarchical Cluster Analysis (HCA) revealed three distinct snail population types. These findings provide valuable insights into the phenotypic diversity of edible land snails in the western highlands of Cameroon and can be considered in improvement and conservation programs aimed at enhancing snail meat yield.
文摘Mountainous ecosystem soils are subject to colonization nowadays for agri</span><span style="font-family:Verdana;">cultural purposes due to an increasing population in towns making the</span><span style="font-family:Verdana;"> detailed </span><span style="font-family:Verdana;">characterization of such soils indispensable. This work aims to characterize</span><span style="font-family:Verdana;"> the steep slopes soils of the Dschang hills and to evaluate their fertility level for </span><span style="font-family:Verdana;">agricultural valorization. Thus, four soil profiles were dug at various topographic</span><span style="font-family:Verdana;"> positions (summit (SP), shoulder (MP), backslope (BP) and footslope (PP)) following a toposequence. Samples of disturbed and undisturbed soils were taken and analyzed in the laboratory according to standard methods. The Fertility</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Capability</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Classification (FCC) and simple limitation methods were used to identify major agricultural constraints. The main results show that </span><span style="font-family:Verdana;">profiles thickness is moderate, between 0 and 120 cm, with a high sand</span><span style="font-family:Verdana;"> content </span><span style="font-family:Verdana;">(at least 50%) over the entire toposequence, especially at the surface. The</span><span style="font-family:Verdana;"> study site has four types of soils, namely Eutric</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Cambisols (ochric) in SP and L</span><span style="font-family:Verdana;">eptic</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Eutric</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Cambisols (Humic) in MP, Eutric</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Cambisols (Humic) in BP</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and Stagnic</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Oxygleyic</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Dystric</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Gleysols</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">(Humic) in pp. The soils are very acidic at PP, moderately acidic at BP and SP and slightly acidic at MP. Organic matter is higher at the surface than at depth at the topographic segments of MP, BP and PP and low to SP. The C/N ratio is high (>17) in all profiles except P4 </span><span style="font-family:Verdana;">(<10). In addition, the cation exchange capacity (CEC), the sum of</span><span style="font-family:Verdana;"> exchangeable bases, total nitrogen and available phosphorus is low in all profiles. The Ca/</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">Mg/K balance in all the profiles shows a cation imbalance and a relatively </span><span style="font-family:Verdana;">high concentration of exchangeable potassium compared to the ideal</span><span style="font-family:Verdana;"> situation (76% Ca, 18% Mg and 6% K). The major constraints to crop production are: aluminum toxicity (a) and nutrients leaching (e), textural discontinuity (LS), flooding (g), low nutrient reserve (k), sand (S), clay (C) and slope (t). Hence the fertility capacity classes of these soils are CCaegk (PP), SSek (BP), SSte (MP) and LSaek (SP). To improve the yield, it will require off-season crop cultivation, fertilization and liming, and earthworks.
文摘A study was conducted in the Tsegede highlands of Tigray Region, northern Ethiopia to determine the changes in some physical and chemical attributes across three adjacent acidic soil sites with different elevation and three land use types. Analytical results of the collected surface layer soil samples showed significant (P ≤ 0.05) correlation of soil bulk density, OM and total N with elevation. In the lower elevation site (Indaslasie), soil OM content declined by about 43 and 52% compared with that of the two higher elevation sites (Cheguarcudo and Indamariam), respectively. Soil pH, exchangeable acidity, exchangeable Al, OM, total N and available phosphorus also exhibited significant (P ≤ 0.05) disparity across the three land use types of the area. Soils of the forest land were less acidic by 0.43 and 0.68 pH units than the cultivated and grazing lands, respectively. The soil OM content of the cultivated land was significantly lower by about 25 and 35% than the grazing and forest land soils, respectively. Available soil P status was low and showed significant correlations with pH (r = 0.65), exchangeable acidity (r = –0.58) and Al (r = –0.53). In general, the study results revealed altitude did not impose any significant effect in aggravating soil acidity whereas land use type affected significantly not only soil acidity but also the important soil fertility related parameters such as OM, total N and available P contents. Therefore, it can be suggested that besides to the usual acid soil management and/or reclamation practices, introducing proper land use management systems are of paramount importance.
