We studied the impacts of liana cutting as a forest management tool on liana diversity (species richness, Shannon diversity index) and community structure (diam- eter distribution, basal area, species dominance) i...We studied the impacts of liana cutting as a forest management tool on liana diversity (species richness, Shannon diversity index) and community structure (diam- eter distribution, basal area, species dominance) in the Asenanyo Forest Reserve, Ghana. Two types of silvicul- turally treated forests were studied: Logging treated (LT) and Tropical Shelterwood System (TSS) treated forests. An untreated primary forest was included as a control, result- ing in three forest management systems. Lianas with diameter 〉2 cm were identified in ten 40 × 40 m2 plots within each management system. Liana cutting signifi- cantly reduced liana species richness, Shannon diversity index, and basal area in the LT forest after two decades. However, liana species richness and basal area werecomparable in the TSS treated and untreated forests, indi- cating significant recovery in the former after over six decades. Sφrensen similarity index of liana species com- position between the untreated forest and each of the treated forests was moderate. Our findings suggest that liana cutting most likely influenced the dominance of some liana species. In view of the adverse impact of blanket liana cutting on liana diversity, selective liana cutting is rec- ommended as a means of controlling liana numbers while maintaining liana diversity.展开更多
Aims Liana research has increased in the past two decades,yet there is still inadequate comparison of liana communities at a cross-con-tinental scale.We compared liana assemblages in tropical forest ecosystems of Ghan...Aims Liana research has increased in the past two decades,yet there is still inadequate comparison of liana communities at a cross-con-tinental scale.We compared liana assemblages in tropical forest ecosystems of Ghana and Malaysia,thereby determining patterns and mechanisms that are common or unique to the regions.Methods Liana diversity,community structure and taxonomic composition were determined in 60 plots of 40×40 m2 in three forest types(primary,disturbed secondary,selectively logged)in each biogeo-graphic area.Two traits,climbing mechanisms and dispersal modes were determined for all species and individuals via direct field observation and with published literature.Data were analyzed at biogeographic(using combined forest data)and forest-type levels.Important Findings Both observed and rarefied-extrapolated species richness of lianas were significantly higher in Ghanaian forests compared to Malaysian forests.In most cases,species diversity indices(Shannon diversity index,Margalef,Fisher’s alpha)showed significantly higher liana diversity at Ghanaian forests at biogeographic and forest-type lev-els.Similarly,Ghanaian forests harbored significantly higher values of liana abundance and basal area than Malaysian forests at both biogeographic and forest-type levels.The taxonomic composition of lianas differed considerably between the two biogeographic areas at all levels,although similarity in composition increased at generic and family levels.Though above-ground biomass of lianas was simi-lar between the two biogeographic regions,variations occurred at forest-type level between the two regions.The two biogeographic areas showed some similarities in assemblages of liana climbing mechanisms.Although more species of lianas were adapted for animal dispersal than other dispersal modes in both countries,the majority of liana individuals in Ghana were wind dispersed whereas the majority of liana individuals in Malaysia were animal dispersed.We speculate that the differences in liana community assemblages between the two biogeographic areas are due to historical and evo-lutionary processes,as well as climatic variation between the two biogeographic regions.展开更多
Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the respon...Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the response of liana communities to disturbance,calling for more research in the area.The present study was carried out to investigate the response of liana diversity and structure to human disturbance within two major forests in the Penang National Park,Malaysia.The study also looked at the implication of the findings for conservation.Methods A total of 15 40×40-m^(2)(or 40-m×40-m)plots each were randomly located across a range of habitats in a primary forest and disturbed secondary forest.Trees with diameter at breast height≥10 cm were examined for lianas with diameter≥2 cm.Both lianas and trees were enumerated and compared between the two forests.Diversity and structural variables of lianas were compared between the two forests using the t-test analysis.Tree abundance was also compared between the two forests with t-test,while linear regression analysis was run to determine the effects of tree abundance on liana abundance.Important Findings A total of 46 liana species belonging to 27 genera and 15 families were identified in the study.Human disturbance significantly reduced liana species richness and species diversity in the secondary forest.Liana abundance remained the same in both forests whereas liana basal area was;7 times higher in the primary forest.Twiners and hook climbers were significantly more abundant in the primary and secondary forest,respectively.Large diameter lianas were more abundant in the primary forest compared with the secondary forest.The diameter distribution of most families in the primary forest followed the inverted J-shaped curve whereas only a few of the families in the secondary forest did so.Tree abundance was significantly higher in the primary forest.The abundance of lianas significantly depended on tree abundance in all the forests.The study has provided evidence of negative effects of human disturbance on liana diversity and structure that does not auger well for biodiversity in the forest.In view of the critical role of lianas in maintaining biodiversity in the forest ecosystem,lianas in the national park should be protected from further exploitation.展开更多
Aim lianas are abundant and diverse throughout the world and consti-tute an important structural and functional component of tropical forests.This study aims to investigate liana diversity,abundance and their function...Aim lianas are abundant and diverse throughout the world and consti-tute an important structural and functional component of tropical forests.This study aims to investigate liana diversity,abundance and their functional traits in Indian tropical dry evergreen forest(TDEF).Methods a total of ten 1-ha plots,one each in 10 Indian TDEF sites were demarcated.Each 1-ha plot was divided into one-hundred 10-×10-m quadrats to facilitate woody species inventory.all lianas≥1 cm diameter measured at 130 cm from the rooting point and all trees≥10-cm girth at breast height(gbh)were recorded from the study sites to analyze the patterns of liana diversity and abundance and also to compare the contribution of lianas to the total woody species richness,density and basal area.liana variables across the study sites were compared using one-way analysis of variance.The qualitative functional traits of inventoried lianas and trees were assessed on the field and referring to pertinent field manuals.Important Findingsa total of 9237 liana individuals(ranged from 408-1658 individu-als ha^(−1))representing 52 species,45 genera and 28 families were encountered from the 10 study sites.liana species richness ranged from 11-31 species ha^(−1) in 10 sites,which averaged 23.4(±5.7)species ha^(−1).The total basal area of lianas in the study sites was 7.3 m^(2)(0.20-1.76 m^(2) ha^(−1)).There was a significant variation in liana species richness,density and basal area across the studied sites.on the whole,lianas contributed 52%,49.3%and 4.1%to the total woody species(lianas and trees)richness,density and basal area,respectively.liana trait analysis revealed the majority(50%)of lianas belonged to brevi-deciduous type.stem twining was the chief climbing mechanism,exhibited by 21 species(52.6%of total abundance).more than half of the liana species(34 species;6925 individuals)had microphyllous leaves.Fleshy-fruited lianas mostly bearing berries and drupes constituted the major fruit type in the studied sites.Zoochory was the predominant dispersal mode observed in 63.4% of species.Considering the ecological and func-tional role of lianas in Indian TDEF,the need for conservation is emphasized.展开更多
Aims Lianas are expected to influence composition,structure and func-tioning of forest systems due to unequal distribution across the potential set of host plants.However,our understanding of mecha-nisms associated wi...Aims Lianas are expected to influence composition,structure and func-tioning of forest systems due to unequal distribution across the potential set of host plants.However,our understanding of mecha-nisms associated with preferences for specific hosts is still limited,and so is our ability to discern between endogenous and exogenous forces driving forest dynamics in the long run.In this paper,we eval-uated whether the dominant liana Hedera helix can indirectly con-tribute to the eventual dominance of the small multi-stemmed tree Corylus avellana in a remnant temperate forest in central Iberian Peninsula from comparatively reduced liana infestation on C.avel-lana relative to co-occurring woody species.Methods through principal component analysis and co-occurrence ana-lysis,we studied the distribution and spatial association between woody species and the liana H.helix.We analyzed the relationship between the number of species in a plot and the number of species infested by the liana to test the hypothesis that H.helix is a gen-eralist liana.through generalized linear mixed models,we tested the dynamic-multi-stemmed growth form of C.avellana as a plaus-ible life strategy to withstand,in the long run,the liana infestation.In particular,we tested(i)the relationship between stem size and the probability of H.helix infestation including all the tree species within plots and(ii)the relationship between stem size and mortal-ity as evidence of the stem turn over in the tree C.avellana.Important Findings Our results indicate that H.helix and C.avellana significantly co-occur in mature stands of this remnant temperate forest where pion-eer woody species are absent.Hedera helix severely infests all the woody species whenever stem size exceed≈25 cm perimeter and there is physical contact at the base of the stem.this implies that all the trees in the community are potential hosts for H.helix.Mixed models indicate that both,infestation by H.helix and stem mortality,are positively related to C.avellana stem perimeter.Reduced long-term infestation of the liana by means of a multi-stemmed growth form with high stem turnover in C.avellana might be an advantage with respect to unipodial tree species.thus,the liana-tree coexistence pattern may be interpreted as an indirect positive interaction that,contrary to previous findings,results here in species dominance instead of species coexistence.展开更多
Lianas are a principal physiognomic component of tropical and subtropical forests and are typically considered to be parasites of trees. In contrast, the substantial contribution of lianas to rainforest leaf litter pr...Lianas are a principal physiognomic component of tropical and subtropical forests and are typically considered to be parasites of trees. In contrast, the substantial contribution of lianas to rainforest leaf litter production (up to 40%) suggests that they play important roles in nutrient cycles and may benefit their host trees. Lianas contribute disproportionately to total forest litter production at least partially because lianas invest relatively little in support structures and proportionately much more to leaf production when compared with trees. In contrast to tree leaves, liana leaves are higher in nutrient concentrations, relatively short-lived, and decompose more rapidly. In addition, the special life form of lianas allows them to grow vertically and horizontally in the forest and relocate nutrients, mainly towards their host trees, through the production of leaf litter. Consequently, lianas may contribute substantially to the high rainforest productivity, and the roles they play in liana/tree associations and rainforest dynamics needs to be re-evaluated.展开更多
基金supported by TWAS-USM Postgraduate Fellowship and Research University Grant(RU)(1001/PBIOLOGI/815086)
文摘We studied the impacts of liana cutting as a forest management tool on liana diversity (species richness, Shannon diversity index) and community structure (diam- eter distribution, basal area, species dominance) in the Asenanyo Forest Reserve, Ghana. Two types of silvicul- turally treated forests were studied: Logging treated (LT) and Tropical Shelterwood System (TSS) treated forests. An untreated primary forest was included as a control, result- ing in three forest management systems. Lianas with diameter 〉2 cm were identified in ten 40 × 40 m2 plots within each management system. Liana cutting signifi- cantly reduced liana species richness, Shannon diversity index, and basal area in the LT forest after two decades. However, liana species richness and basal area werecomparable in the TSS treated and untreated forests, indi- cating significant recovery in the former after over six decades. Sφrensen similarity index of liana species com- position between the untreated forest and each of the treated forests was moderate. Our findings suggest that liana cutting most likely influenced the dominance of some liana species. In view of the adverse impact of blanket liana cutting on liana diversity, selective liana cutting is rec- ommended as a means of controlling liana numbers while maintaining liana diversity.
基金We gratefully acknowledge the support of TWAS-USM Postgraduate Fellowship and Research University Grant(RU)(1001/PBIOLOGI/815086).
文摘Aims Liana research has increased in the past two decades,yet there is still inadequate comparison of liana communities at a cross-con-tinental scale.We compared liana assemblages in tropical forest ecosystems of Ghana and Malaysia,thereby determining patterns and mechanisms that are common or unique to the regions.Methods Liana diversity,community structure and taxonomic composition were determined in 60 plots of 40×40 m2 in three forest types(primary,disturbed secondary,selectively logged)in each biogeo-graphic area.Two traits,climbing mechanisms and dispersal modes were determined for all species and individuals via direct field observation and with published literature.Data were analyzed at biogeographic(using combined forest data)and forest-type levels.Important Findings Both observed and rarefied-extrapolated species richness of lianas were significantly higher in Ghanaian forests compared to Malaysian forests.In most cases,species diversity indices(Shannon diversity index,Margalef,Fisher’s alpha)showed significantly higher liana diversity at Ghanaian forests at biogeographic and forest-type lev-els.Similarly,Ghanaian forests harbored significantly higher values of liana abundance and basal area than Malaysian forests at both biogeographic and forest-type levels.The taxonomic composition of lianas differed considerably between the two biogeographic areas at all levels,although similarity in composition increased at generic and family levels.Though above-ground biomass of lianas was simi-lar between the two biogeographic regions,variations occurred at forest-type level between the two regions.The two biogeographic areas showed some similarities in assemblages of liana climbing mechanisms.Although more species of lianas were adapted for animal dispersal than other dispersal modes in both countries,the majority of liana individuals in Ghana were wind dispersed whereas the majority of liana individuals in Malaysia were animal dispersed.We speculate that the differences in liana community assemblages between the two biogeographic areas are due to historical and evo-lutionary processes,as well as climatic variation between the two biogeographic regions.
基金TWAS-USM Postgraduate Fellowship and Research University Grant(RU)(1001/PBIOLOGI/815046).
文摘Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the response of liana communities to disturbance,calling for more research in the area.The present study was carried out to investigate the response of liana diversity and structure to human disturbance within two major forests in the Penang National Park,Malaysia.The study also looked at the implication of the findings for conservation.Methods A total of 15 40×40-m^(2)(or 40-m×40-m)plots each were randomly located across a range of habitats in a primary forest and disturbed secondary forest.Trees with diameter at breast height≥10 cm were examined for lianas with diameter≥2 cm.Both lianas and trees were enumerated and compared between the two forests.Diversity and structural variables of lianas were compared between the two forests using the t-test analysis.Tree abundance was also compared between the two forests with t-test,while linear regression analysis was run to determine the effects of tree abundance on liana abundance.Important Findings A total of 46 liana species belonging to 27 genera and 15 families were identified in the study.Human disturbance significantly reduced liana species richness and species diversity in the secondary forest.Liana abundance remained the same in both forests whereas liana basal area was;7 times higher in the primary forest.Twiners and hook climbers were significantly more abundant in the primary and secondary forest,respectively.Large diameter lianas were more abundant in the primary forest compared with the secondary forest.The diameter distribution of most families in the primary forest followed the inverted J-shaped curve whereas only a few of the families in the secondary forest did so.Tree abundance was significantly higher in the primary forest.The abundance of lianas significantly depended on tree abundance in all the forests.The study has provided evidence of negative effects of human disturbance on liana diversity and structure that does not auger well for biodiversity in the forest.In view of the critical role of lianas in maintaining biodiversity in the forest ecosystem,lianas in the national park should be protected from further exploitation.
基金Ministry of Environment and Forests,Government of India,New Delhi(22/16/2011-(SG)-RE).
文摘Aim lianas are abundant and diverse throughout the world and consti-tute an important structural and functional component of tropical forests.This study aims to investigate liana diversity,abundance and their functional traits in Indian tropical dry evergreen forest(TDEF).Methods a total of ten 1-ha plots,one each in 10 Indian TDEF sites were demarcated.Each 1-ha plot was divided into one-hundred 10-×10-m quadrats to facilitate woody species inventory.all lianas≥1 cm diameter measured at 130 cm from the rooting point and all trees≥10-cm girth at breast height(gbh)were recorded from the study sites to analyze the patterns of liana diversity and abundance and also to compare the contribution of lianas to the total woody species richness,density and basal area.liana variables across the study sites were compared using one-way analysis of variance.The qualitative functional traits of inventoried lianas and trees were assessed on the field and referring to pertinent field manuals.Important Findingsa total of 9237 liana individuals(ranged from 408-1658 individu-als ha^(−1))representing 52 species,45 genera and 28 families were encountered from the 10 study sites.liana species richness ranged from 11-31 species ha^(−1) in 10 sites,which averaged 23.4(±5.7)species ha^(−1).The total basal area of lianas in the study sites was 7.3 m^(2)(0.20-1.76 m^(2) ha^(−1)).There was a significant variation in liana species richness,density and basal area across the studied sites.on the whole,lianas contributed 52%,49.3%and 4.1%to the total woody species(lianas and trees)richness,density and basal area,respectively.liana trait analysis revealed the majority(50%)of lianas belonged to brevi-deciduous type.stem twining was the chief climbing mechanism,exhibited by 21 species(52.6%of total abundance).more than half of the liana species(34 species;6925 individuals)had microphyllous leaves.Fleshy-fruited lianas mostly bearing berries and drupes constituted the major fruit type in the studied sites.Zoochory was the predominant dispersal mode observed in 63.4% of species.Considering the ecological and func-tional role of lianas in Indian TDEF,the need for conservation is emphasized.
基金J.M.G.was granted with a Postdoctoral Fellowship at the University of Alcalá.E.G.thanks support of FONDECYT grant 1140070The last sampling period was funded by the FUNDIVER project(MINECO:CGL2015-69186-C2-2-R).
文摘Aims Lianas are expected to influence composition,structure and func-tioning of forest systems due to unequal distribution across the potential set of host plants.However,our understanding of mecha-nisms associated with preferences for specific hosts is still limited,and so is our ability to discern between endogenous and exogenous forces driving forest dynamics in the long run.In this paper,we eval-uated whether the dominant liana Hedera helix can indirectly con-tribute to the eventual dominance of the small multi-stemmed tree Corylus avellana in a remnant temperate forest in central Iberian Peninsula from comparatively reduced liana infestation on C.avel-lana relative to co-occurring woody species.Methods through principal component analysis and co-occurrence ana-lysis,we studied the distribution and spatial association between woody species and the liana H.helix.We analyzed the relationship between the number of species in a plot and the number of species infested by the liana to test the hypothesis that H.helix is a gen-eralist liana.through generalized linear mixed models,we tested the dynamic-multi-stemmed growth form of C.avellana as a plaus-ible life strategy to withstand,in the long run,the liana infestation.In particular,we tested(i)the relationship between stem size and the probability of H.helix infestation including all the tree species within plots and(ii)the relationship between stem size and mortal-ity as evidence of the stem turn over in the tree C.avellana.Important Findings Our results indicate that H.helix and C.avellana significantly co-occur in mature stands of this remnant temperate forest where pion-eer woody species are absent.Hedera helix severely infests all the woody species whenever stem size exceed≈25 cm perimeter and there is physical contact at the base of the stem.this implies that all the trees in the community are potential hosts for H.helix.Mixed models indicate that both,infestation by H.helix and stem mortality,are positively related to C.avellana stem perimeter.Reduced long-term infestation of the liana by means of a multi-stemmed growth form with high stem turnover in C.avellana might be an advantage with respect to unipodial tree species.thus,the liana-tree coexistence pattern may be interpreted as an indirect positive interaction that,contrary to previous findings,results here in species dominance instead of species coexistence.
基金supported by a National Science and Technology Pillar Program from the Ministry of Environmental Protection of China(2008BAC39B02)a grant from the QCAS Biotechnology Fund
文摘Lianas are a principal physiognomic component of tropical and subtropical forests and are typically considered to be parasites of trees. In contrast, the substantial contribution of lianas to rainforest leaf litter production (up to 40%) suggests that they play important roles in nutrient cycles and may benefit their host trees. Lianas contribute disproportionately to total forest litter production at least partially because lianas invest relatively little in support structures and proportionately much more to leaf production when compared with trees. In contrast to tree leaves, liana leaves are higher in nutrient concentrations, relatively short-lived, and decompose more rapidly. In addition, the special life form of lianas allows them to grow vertically and horizontally in the forest and relocate nutrients, mainly towards their host trees, through the production of leaf litter. Consequently, lianas may contribute substantially to the high rainforest productivity, and the roles they play in liana/tree associations and rainforest dynamics needs to be re-evaluated.