Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Differe...Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.展开更多
Callistemon viminalis(C.viminalis)is a plant that has been reported to have a various medicinal values such as antibacterial,antifungal,antioxidant activities and other pharmaceutical and insecticidal properties.This ...Callistemon viminalis(C.viminalis)is a plant that has been reported to have a various medicinal values such as antibacterial,antifungal,antioxidant activities and other pharmaceutical and insecticidal properties.This review covers the potentials,applications and properties of different extracts from different parts(branches,flowers,fruits,bark,leaves)of C.viminalis.Furthermore,the chemical structures of the bioactive compounds were reported for biological activities.All the results supported the traditional uses of C.viminalis in folk medicine.In addition,some researches supported the use of C.viminalis extracts for the preparation of metal oxide nanoparticles.展开更多
The large larch beetle,Ips cembrae,is a significant pest causing the death of larch.In 2020,the attack density of I.cembrae on larch trap trees and standing trees was evaluated using sample sections placed along the t...The large larch beetle,Ips cembrae,is a significant pest causing the death of larch.In 2020,the attack density of I.cembrae on larch trap trees and standing trees was evaluated using sample sections placed along the trunk.As a defensive measure against I.cembrae,trap trees were highly effective in both spring and summer.The attack density increased with increasing trap tree surface area/volume.Galleries were established evenly throughout the entire trunk including the thin upper portion.When the number of trap trees was low and their capacity full,a continual aggregation of adults occurred due to pheromone communication,leading to attacks on healthy standing trees in the immediate vicinity.It was found that I.cembrae attacked standing trees from the trunk base,with a continual colonization of the stem up to 70%of the tree height in a time-differentiated progression of development stages.The attack density of I.cembrae on standing trees was up to 40%lower than on the trap trees.展开更多
Ice storms can cause substantial damage to tree crowns and lead to growth reduction.However,in uneven-aged stands,the growth of an individual tree may also increase due to crown release caused by the damage or mortali...Ice storms can cause substantial damage to tree crowns and lead to growth reduction.However,in uneven-aged stands,the growth of an individual tree may also increase due to crown release caused by the damage or mortality of neighboring trees.Three years after the devastating ice storm in 2014 in mixed uneven-aged Dinaric forests(Croatia),we cored 156 European beech(Fagus sylvatica)and 85 silver fir(Abies alba)trees across 20 permanent sample plots to study the post-storm growth response as a function of tree,stand,site,spatial arrangement and local competition factors.The ice storm damaged over 84% of trees on the sampled plots.Among the cored trees,52.7% exhibited growth reduction,which on average amounted to3.1%relative to the pre-disturbance average.Trees with less than 40% crown damage maintained their pre-disturbance growth rates or experienced only minor growth suppression.While 60% of beech trees suffered a growth reduction at an average rate of 7.2%,the average radial increment of fir after the storm was 14.0% higher compared to the pre-storm rate.A linear mixedeffects model suggests that the growth response can largely be explained by the focal and neighboring tree species identity,tree competition pressure,focal and neighboring tree damage,crown size,slenderness index and stoniness.Growth release was positively associated with fir,inverse distance-weighted crown damage of the nearest neighbor,shorter crowns,slenderness,less stony sites and less damaged trees.The analysis suggests that at the same level of local competition load,trees with a broadleaved and damaged nearest neighbor are more likely to experience growth release than those with a coniferous or undamaged nearest neighbor.This implies that unevenaged stands with a substantial presence and mingling of both conifers and broadleaves are expected to be more resilient to ice storms and are less likely to suffer growth reduction.展开更多
The history of mankind contains so many illustrations of well-classified and violent struggles against various animals over crop production in agricultural fields, attacks on human life or competition in order to have...The history of mankind contains so many illustrations of well-classified and violent struggles against various animals over crop production in agricultural fields, attacks on human life or competition in order to have access to certain natural resources. The aim of this study is to characterise the human-wildlife conflicts that occur around the KBNP, especially with regard to primates. Surveys were carried out in 260 households selected using the snowball method. The results showed that human-wildlife conflicts around the KBNP are characterised by the destruction of crops in riparian fields by monkeys, chimpanzees and gorillas, the destruction of houses, physical attacks and zoonoses. Despite the conservation and protection measures for wildlife and local populations put in place by the Park’s managers, conflicts between local populations and the Park’s wild animals are still visible. These conflicts lead to the detention of wild animals by local people roaming in the villages and to poaching on the Park’s boundaries. The weakness of the community management policy on the part of the park managers and the resentment of the indigenous peoples towards the restriction of their access to natural resources are the major constraints on the sustainable management of conflicts between the local populations and the wild animals in the KBNP. The strategies for the sustainable resolution of human-wildlife conflicts around the KBNP must be geared towards and integrated into a community conservation approach.展开更多
基金funded by the Deanship of Scientific Research at King Saud University with the research group project No.RGP-VPP-010
文摘Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.
文摘Callistemon viminalis(C.viminalis)is a plant that has been reported to have a various medicinal values such as antibacterial,antifungal,antioxidant activities and other pharmaceutical and insecticidal properties.This review covers the potentials,applications and properties of different extracts from different parts(branches,flowers,fruits,bark,leaves)of C.viminalis.Furthermore,the chemical structures of the bioactive compounds were reported for biological activities.All the results supported the traditional uses of C.viminalis in folk medicine.In addition,some researches supported the use of C.viminalis extracts for the preparation of metal oxide nanoparticles.
基金supported by Ministry of Agriculture of the Czech Republic in grant[QK1920433].“Influence of protective measuresagainst the populations of bark beetles according to population density”。
文摘The large larch beetle,Ips cembrae,is a significant pest causing the death of larch.In 2020,the attack density of I.cembrae on larch trap trees and standing trees was evaluated using sample sections placed along the trunk.As a defensive measure against I.cembrae,trap trees were highly effective in both spring and summer.The attack density increased with increasing trap tree surface area/volume.Galleries were established evenly throughout the entire trunk including the thin upper portion.When the number of trap trees was low and their capacity full,a continual aggregation of adults occurred due to pheromone communication,leading to attacks on healthy standing trees in the immediate vicinity.It was found that I.cembrae attacked standing trees from the trunk base,with a continual colonization of the stem up to 70%of the tree height in a time-differentiated progression of development stages.The attack density of I.cembrae on standing trees was up to 40%lower than on the trap trees.
基金supported by the Croatian Science Foundation(project number IP-2018-01-8820)the Slovenian Research Agency core funding(grant number P4-0059).
文摘Ice storms can cause substantial damage to tree crowns and lead to growth reduction.However,in uneven-aged stands,the growth of an individual tree may also increase due to crown release caused by the damage or mortality of neighboring trees.Three years after the devastating ice storm in 2014 in mixed uneven-aged Dinaric forests(Croatia),we cored 156 European beech(Fagus sylvatica)and 85 silver fir(Abies alba)trees across 20 permanent sample plots to study the post-storm growth response as a function of tree,stand,site,spatial arrangement and local competition factors.The ice storm damaged over 84% of trees on the sampled plots.Among the cored trees,52.7% exhibited growth reduction,which on average amounted to3.1%relative to the pre-disturbance average.Trees with less than 40% crown damage maintained their pre-disturbance growth rates or experienced only minor growth suppression.While 60% of beech trees suffered a growth reduction at an average rate of 7.2%,the average radial increment of fir after the storm was 14.0% higher compared to the pre-storm rate.A linear mixedeffects model suggests that the growth response can largely be explained by the focal and neighboring tree species identity,tree competition pressure,focal and neighboring tree damage,crown size,slenderness index and stoniness.Growth release was positively associated with fir,inverse distance-weighted crown damage of the nearest neighbor,shorter crowns,slenderness,less stony sites and less damaged trees.The analysis suggests that at the same level of local competition load,trees with a broadleaved and damaged nearest neighbor are more likely to experience growth release than those with a coniferous or undamaged nearest neighbor.This implies that unevenaged stands with a substantial presence and mingling of both conifers and broadleaves are expected to be more resilient to ice storms and are less likely to suffer growth reduction.
文摘The history of mankind contains so many illustrations of well-classified and violent struggles against various animals over crop production in agricultural fields, attacks on human life or competition in order to have access to certain natural resources. The aim of this study is to characterise the human-wildlife conflicts that occur around the KBNP, especially with regard to primates. Surveys were carried out in 260 households selected using the snowball method. The results showed that human-wildlife conflicts around the KBNP are characterised by the destruction of crops in riparian fields by monkeys, chimpanzees and gorillas, the destruction of houses, physical attacks and zoonoses. Despite the conservation and protection measures for wildlife and local populations put in place by the Park’s managers, conflicts between local populations and the Park’s wild animals are still visible. These conflicts lead to the detention of wild animals by local people roaming in the villages and to poaching on the Park’s boundaries. The weakness of the community management policy on the part of the park managers and the resentment of the indigenous peoples towards the restriction of their access to natural resources are the major constraints on the sustainable management of conflicts between the local populations and the wild animals in the KBNP. The strategies for the sustainable resolution of human-wildlife conflicts around the KBNP must be geared towards and integrated into a community conservation approach.
