Sacred forests play a valuable role in the conservation of local biodiversity and provide numerous ecosystem services in Cameroon. The aim of this study was to estimate floristic diversity, stand structures and carbon...Sacred forests play a valuable role in the conservation of local biodiversity and provide numerous ecosystem services in Cameroon. The aim of this study was to estimate floristic diversity, stand structures and carbon stocks in the sacred forests of Bandrefam and Batoufam (western Cameroon). The floristic inventory and the stand structures were carried out in 25 m × 25 m plots for individuals with diameters greater than 10 cm;5 m × 5 m for individuals with diameters less than 10 cm. Carbon stocks were estimated using the non-destructive method and allometric equations. The floristic inventory identified 65 species divided into 57 genera and 30 families in the Bandrefam sacred forest and 45 species divided into 42 genera and 27 families in the Batoufam sacred forest. In the Bandrefam, the most important families are Phyllanthaceae (53.98%), Moraceae (21.69%), Lamiaceae (20.15%). At Batoufam, the most important families are Phyllanthaceae (39.73%), Fabaceae (28.47%), Araliaceae (23.77%). Malacantha alnifolia (55.14%), Vitex grandifolia (18.43%), Bosqueia angolensis (15.06%) were the most important species in Bandrefam. Otherwise, Malacantha alnifolia (28%), Polyscias fulva (22.73%), Psychotria sp. (21.28%) were the most important in Batoufam. The Bandrefam sacred forest has the highest tree density (2669 stems/ha). Total carbon stock is 484.88 ± 2.28 tC/ha at Batoufam and 313.95 ± 0.93 tC/ha at Bandrefam. The economic value varies between 5858.04 ± 27.62 USD/ha in Batoufam sacred forest and 3788.51 ± 11.26 USD/ha in Bandrefam sacred forest. The number of individuals and small-diameter trees has little influence on the carbon stocks in the trees. Medium-diameter trees store the most carbon, and very large-diameter trees, which are very poorly represented, store less carbon. In another way, wood density and the basal areas influence the carbon storage of the trees.展开更多
The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rig...The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rigor in the management of these forests, which can result in the loss of species of high conservation value. The study was carried out in communal forests in the south-east zone of Cameroon. Its aim was to carry out a floristic inventory and then compare the list of species with the IUCN catalog. Twenty-four plots, each with a surface area of 0.2 ha, were set up in the Gari-Gombo communal forest. All timbers with a DBH ≥ 5 cm were systematically counted. A total of 176 species, belonging to 144 genera and 45 families, were surveyed. Fabaceae (42.08%), Malvaceae (39%), Euphorbiaceae (24.64%), Moraceae (20.92%), Apocynaceae (18.64%), Cecropiaceae (16.60%), Ulmaceae (14.76%), Meliaceae (14.61%), Violaceae (14.08%), Combretaceae (12.67%), Theobroma cacao (21.17%), Baphia leptobotrys (18.06%), Rinorea sp. (14.09%), Musanga cecropioides (12.18%), Terminalia superba (10.32%), Neosloetiopsis kamerunensis (10.14%), Celtis zenkeri (8.29%) and Alstonia boonei (7.77%) were the most important taxa. Nearly 90% of the species in this forest are Guinean species, with a dominance of Guinean-Congolese species (66%). Fourteen (14) threatened species have been identified in the FCGG. This study, which highlights the rich biodiversity of communal forests, is important for guiding biodiversity conservation policies in ecosystems used for production.展开更多
We evaluated the dynamics of land use in the Bouba Ndjidda National Park (BNNP) and adjacent areas, in northern Cameroon. Using a maximum likelihood supervised classification of satellite images from 1990 to 2016, cou...We evaluated the dynamics of land use in the Bouba Ndjidda National Park (BNNP) and adjacent areas, in northern Cameroon. Using a maximum likelihood supervised classification of satellite images from 1990 to 2016, coupled with field and a socio-economic survey, we performed a robust land-use classification. Between 1990 and 2016, the area included eight classes of land use, with the largest in 1990 being the woody savannah (42.9%) followed by the gallery forest (20.2%) and the clear forest (16.3%). Between 1990 and 1999, the gallery forest lost 64.8% of its area mostly to the benefit of woody savannahs. Between 1999 and 2016, the largest loss of area was that of the clear forest, which decreased generally by 43.2% in favor of woody savannah. Rates of increase of crop field areas were 59.6% and 78.8% respectively for the periods of 1990 to 1999 and 1999 to 2016 to the detriment of woody savannahs. We attribute the changes in land use observed mainly to the increasing human population and associated agriculture, overgrazing, fuelwood harvesting and bush fires. The exploitation of non-timber forest products and climatic factors may also have changed the vegetation cover. We recommend the implementation of farming techniques with low impact on the environment such as agroforestry.展开更多
Carbon is continuously being removed from the atmosphere by photosynthesis and stored in carbon pools(live,dead,and soil carbon)of forest ecosystems.However,carbon stock in dead wood and of trees with diameters at bre...Carbon is continuously being removed from the atmosphere by photosynthesis and stored in carbon pools(live,dead,and soil carbon)of forest ecosystems.However,carbon stock in dead wood and of trees with diameters at breast height(dbh)between 5 and 10 cm is often not considered in many studies carried out in the Congo Basin Forest.The relationship between tree diversity,life-forms and carbon stocks has received little attention.This study was carried out on the outskirts of Deng Deng National Park(DDNP)to determine tree diversity(dominant families,species richness and Shannon index),assess carbon stocks in the five carbon compartments(living tree,understory,fine roots,dead wood and litter)as well as to analyze the relationship between(1)carbon stocks and tree diversity;and,(2)between carbon stock and life-forms.The Shannon index of trees≥10 cm dbh ranged from 2.6 in riparian forest to 4.3 in secondary forest;and for the tree between 5 and 10 cm,it ranged to 1.56 in riparian forest to 3.68 in the secondary forest.The study site housed 16 species,7 genera and 3 families which are only found in trees of dbh between 5 and 10 cm.The average total carbon stock of the five compartments varied from 200.1 t ha-1 in forest residues to 439.1 t ha-1 in secondary forest.Dead wood carbon stock varied from 1.2 t ha-1 in riparian forests to 12.51t ha-1 in agroforests.The above ground carbon stocks for trees with diameter between 5 and 10 cm varied from 0.7 t ha-1 in young fallow fields to 5.02 t ha-1 in old secondary forests.This study reveals a low but positive correlation between species richness and total carbon stocks,as well as a significant positive relationship between life-forms and total carbon stocks.The findings highlight the need for more data concerning carbon content of dead wood,carbon of trees≥5 cm<10 cm dbh and the relationship between carbon stocks and tree diversity from other areas of the Congo Basin for a good understanding of the contribution of tropical forests to climate change mitigation.展开更多
Introduction:Cameroon’s tropical rainforests are nowadays strewn with rural forests maintained by local popula‑tions;however,these forests are not officially recognized in the non‑permanent forest domain.Rural forest...Introduction:Cameroon’s tropical rainforests are nowadays strewn with rural forests maintained by local popula‑tions;however,these forests are not officially recognized in the non‑permanent forest domain.Rural forests are non‑delimited riparian areas within the dense moist forest,reserved for rural housing,agricultural activities and agroforestry practices,freely exploited by the local communities for their livelihood without them having any rights to artisanal and commercial logging.This study aimed at contributing to the flora knowledge and the conservation state of woody plant species in rainforests.The study was carried out in two rural forests located in the Eastern and Southern agroforestry zones of Cameroon.Methods:The method adopted for floristic inventories combined a fixed area sampling unit and a variable area sampling unit.Woody individuals with diameter at breast height(dbh)<3.2 cm were counted and shrubs of 3.2≤dbh<10 cm were measured to analyse the understorey,while trees with dbh≥10 cm were measured and identified to characterize the canopy.Results:In the Essiengbot‑Mbankoho rural forest in Eastern Cameroon,468 species belonging to 61 families were recorded in the understory while 227 species belonging to 53 families were identified at the canopy level.A total of 40(7.68%)threatened species,18(3.45%)Near Threatened species and 408(78.31%)Least Concern species were recorded.In the Nbgwassa‑Opkweng rural forest in Southern Cameroon,534 species belonging to 64 families were identified in the understory while 225 species belonging to 43 families were recorded in the canopy.A total of 54(9.69%)threatened species,25(4.49%)Near Threatened species and 421(75.58%)Least Concern species were identified in this forest.Shannon’s diversity indices were above five in the understories and canopies of both forests.Shade‑bearer species were the most represented in the understories while the non‑pioneer light‑demanding and shade‑bearer species were the most abundant in the canopies.Conclusions:Despite the influence of slash‑and‑burn agriculture and subsistence farming practices,rural forests managed by local populations provide opportunities for preserving plant biodiversity.However,the presence of threatened species,pioneer species and non‑pioneer light‑demanding species in these forests is an indicator of mod‑erate and man‑induced disturbances that,in the absence of a forest management plan or sustainable management,may threaten this biodiversity.Legal management of rural forests could help in limiting the anthropogenic activities and pressures on community forests.展开更多
文摘Sacred forests play a valuable role in the conservation of local biodiversity and provide numerous ecosystem services in Cameroon. The aim of this study was to estimate floristic diversity, stand structures and carbon stocks in the sacred forests of Bandrefam and Batoufam (western Cameroon). The floristic inventory and the stand structures were carried out in 25 m × 25 m plots for individuals with diameters greater than 10 cm;5 m × 5 m for individuals with diameters less than 10 cm. Carbon stocks were estimated using the non-destructive method and allometric equations. The floristic inventory identified 65 species divided into 57 genera and 30 families in the Bandrefam sacred forest and 45 species divided into 42 genera and 27 families in the Batoufam sacred forest. In the Bandrefam, the most important families are Phyllanthaceae (53.98%), Moraceae (21.69%), Lamiaceae (20.15%). At Batoufam, the most important families are Phyllanthaceae (39.73%), Fabaceae (28.47%), Araliaceae (23.77%). Malacantha alnifolia (55.14%), Vitex grandifolia (18.43%), Bosqueia angolensis (15.06%) were the most important species in Bandrefam. Otherwise, Malacantha alnifolia (28%), Polyscias fulva (22.73%), Psychotria sp. (21.28%) were the most important in Batoufam. The Bandrefam sacred forest has the highest tree density (2669 stems/ha). Total carbon stock is 484.88 ± 2.28 tC/ha at Batoufam and 313.95 ± 0.93 tC/ha at Bandrefam. The economic value varies between 5858.04 ± 27.62 USD/ha in Batoufam sacred forest and 3788.51 ± 11.26 USD/ha in Bandrefam sacred forest. The number of individuals and small-diameter trees has little influence on the carbon stocks in the trees. Medium-diameter trees store the most carbon, and very large-diameter trees, which are very poorly represented, store less carbon. In another way, wood density and the basal areas influence the carbon storage of the trees.
文摘The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rigor in the management of these forests, which can result in the loss of species of high conservation value. The study was carried out in communal forests in the south-east zone of Cameroon. Its aim was to carry out a floristic inventory and then compare the list of species with the IUCN catalog. Twenty-four plots, each with a surface area of 0.2 ha, were set up in the Gari-Gombo communal forest. All timbers with a DBH ≥ 5 cm were systematically counted. A total of 176 species, belonging to 144 genera and 45 families, were surveyed. Fabaceae (42.08%), Malvaceae (39%), Euphorbiaceae (24.64%), Moraceae (20.92%), Apocynaceae (18.64%), Cecropiaceae (16.60%), Ulmaceae (14.76%), Meliaceae (14.61%), Violaceae (14.08%), Combretaceae (12.67%), Theobroma cacao (21.17%), Baphia leptobotrys (18.06%), Rinorea sp. (14.09%), Musanga cecropioides (12.18%), Terminalia superba (10.32%), Neosloetiopsis kamerunensis (10.14%), Celtis zenkeri (8.29%) and Alstonia boonei (7.77%) were the most important taxa. Nearly 90% of the species in this forest are Guinean species, with a dominance of Guinean-Congolese species (66%). Fourteen (14) threatened species have been identified in the FCGG. This study, which highlights the rich biodiversity of communal forests, is important for guiding biodiversity conservation policies in ecosystems used for production.
文摘We evaluated the dynamics of land use in the Bouba Ndjidda National Park (BNNP) and adjacent areas, in northern Cameroon. Using a maximum likelihood supervised classification of satellite images from 1990 to 2016, coupled with field and a socio-economic survey, we performed a robust land-use classification. Between 1990 and 2016, the area included eight classes of land use, with the largest in 1990 being the woody savannah (42.9%) followed by the gallery forest (20.2%) and the clear forest (16.3%). Between 1990 and 1999, the gallery forest lost 64.8% of its area mostly to the benefit of woody savannahs. Between 1999 and 2016, the largest loss of area was that of the clear forest, which decreased generally by 43.2% in favor of woody savannah. Rates of increase of crop field areas were 59.6% and 78.8% respectively for the periods of 1990 to 1999 and 1999 to 2016 to the detriment of woody savannahs. We attribute the changes in land use observed mainly to the increasing human population and associated agriculture, overgrazing, fuelwood harvesting and bush fires. The exploitation of non-timber forest products and climatic factors may also have changed the vegetation cover. We recommend the implementation of farming techniques with low impact on the environment such as agroforestry.
基金funded by a grant from the“Organisation pour la Conservation et le Developpement(OCD)”entitled“Forest Ecosystem Services”。
文摘Carbon is continuously being removed from the atmosphere by photosynthesis and stored in carbon pools(live,dead,and soil carbon)of forest ecosystems.However,carbon stock in dead wood and of trees with diameters at breast height(dbh)between 5 and 10 cm is often not considered in many studies carried out in the Congo Basin Forest.The relationship between tree diversity,life-forms and carbon stocks has received little attention.This study was carried out on the outskirts of Deng Deng National Park(DDNP)to determine tree diversity(dominant families,species richness and Shannon index),assess carbon stocks in the five carbon compartments(living tree,understory,fine roots,dead wood and litter)as well as to analyze the relationship between(1)carbon stocks and tree diversity;and,(2)between carbon stock and life-forms.The Shannon index of trees≥10 cm dbh ranged from 2.6 in riparian forest to 4.3 in secondary forest;and for the tree between 5 and 10 cm,it ranged to 1.56 in riparian forest to 3.68 in the secondary forest.The study site housed 16 species,7 genera and 3 families which are only found in trees of dbh between 5 and 10 cm.The average total carbon stock of the five compartments varied from 200.1 t ha-1 in forest residues to 439.1 t ha-1 in secondary forest.Dead wood carbon stock varied from 1.2 t ha-1 in riparian forests to 12.51t ha-1 in agroforests.The above ground carbon stocks for trees with diameter between 5 and 10 cm varied from 0.7 t ha-1 in young fallow fields to 5.02 t ha-1 in old secondary forests.This study reveals a low but positive correlation between species richness and total carbon stocks,as well as a significant positive relationship between life-forms and total carbon stocks.The findings highlight the need for more data concerning carbon content of dead wood,carbon of trees≥5 cm<10 cm dbh and the relationship between carbon stocks and tree diversity from other areas of the Congo Basin for a good understanding of the contribution of tropical forests to climate change mitigation.
基金The study was supported by CIRAD and the International Foundation for Science(IFS).
文摘Introduction:Cameroon’s tropical rainforests are nowadays strewn with rural forests maintained by local popula‑tions;however,these forests are not officially recognized in the non‑permanent forest domain.Rural forests are non‑delimited riparian areas within the dense moist forest,reserved for rural housing,agricultural activities and agroforestry practices,freely exploited by the local communities for their livelihood without them having any rights to artisanal and commercial logging.This study aimed at contributing to the flora knowledge and the conservation state of woody plant species in rainforests.The study was carried out in two rural forests located in the Eastern and Southern agroforestry zones of Cameroon.Methods:The method adopted for floristic inventories combined a fixed area sampling unit and a variable area sampling unit.Woody individuals with diameter at breast height(dbh)<3.2 cm were counted and shrubs of 3.2≤dbh<10 cm were measured to analyse the understorey,while trees with dbh≥10 cm were measured and identified to characterize the canopy.Results:In the Essiengbot‑Mbankoho rural forest in Eastern Cameroon,468 species belonging to 61 families were recorded in the understory while 227 species belonging to 53 families were identified at the canopy level.A total of 40(7.68%)threatened species,18(3.45%)Near Threatened species and 408(78.31%)Least Concern species were recorded.In the Nbgwassa‑Opkweng rural forest in Southern Cameroon,534 species belonging to 64 families were identified in the understory while 225 species belonging to 43 families were recorded in the canopy.A total of 54(9.69%)threatened species,25(4.49%)Near Threatened species and 421(75.58%)Least Concern species were identified in this forest.Shannon’s diversity indices were above five in the understories and canopies of both forests.Shade‑bearer species were the most represented in the understories while the non‑pioneer light‑demanding and shade‑bearer species were the most abundant in the canopies.Conclusions:Despite the influence of slash‑and‑burn agriculture and subsistence farming practices,rural forests managed by local populations provide opportunities for preserving plant biodiversity.However,the presence of threatened species,pioneer species and non‑pioneer light‑demanding species in these forests is an indicator of mod‑erate and man‑induced disturbances that,in the absence of a forest management plan or sustainable management,may threaten this biodiversity.Legal management of rural forests could help in limiting the anthropogenic activities and pressures on community forests.
