Stocking and structural composition of a deciduous broad-leaved forest were determined to predict coarse woody debris quantity by quantifying the empirical relationships between these two attributes.The most ecologica...Stocking and structural composition of a deciduous broad-leaved forest were determined to predict coarse woody debris quantity by quantifying the empirical relationships between these two attributes.The most ecologically significant families by stem density were Salicaceae,Betulaceae,Fagaceae,and Aceraceae.P opulus davidiana was the most dominant species followed by B etula dahurica,Quercus mongolica,and Acer mono.The four species accounted for 69.5%of total stems.Numerous small-diameter species characterized the coarse woody debris showing a reversed J-shaped distribution.The coarse debris of P.davidiana,B.dahurica,and Q.mongolica mainly comprised the 10–20 cm size class,whereas A.mono debris was mainly in the 5–10 cm size class.The spatial patterns of different size classes of coarse woody debris were analyzed using the g-function to determine the size of the tree at its death.The results indicate that the spatial patterns at the 0–50 m scale shifted gradually from an aggregated to a random pattern.For some species,the larger coarse debris might change from an aggregated to a random distribution more easily.Given the importance of coarse woody debris in forest ecosystems,its composition and patterns can improve understanding of community structure and dynamics.The aggregation pattern might be due to density dependence and self-thinning effects,as well as by succession and mortality.The four dominant species across the different size classes showed distinct aggregated distribution features at different spatial scales.This suggests a correlation between the dominant species population,size class,and aggregated distribution of coarse woody debris.展开更多
The spatial-temporal variation of understory light availability has important influences on species diversity and community assembly.However,the distribution characteristics and influencing factors of understory light...The spatial-temporal variation of understory light availability has important influences on species diversity and community assembly.However,the distribution characteristics and influencing factors of understory light availability have not been fully elucidated,especially in temperate deciduous,broad-leaved forests.In this study,the understory light availability was monitored monthly(May–October)in a temperate deciduous,broad-leaved forest in Henan Province,China.Differences in the light availability among different months and habitat types were statistically analyzed using Kruskal–Wallis method,respectively.Partial least squares path modeling(PLS-PM)was used to explore the direct and/or indirect effects of stand structure,dominant species and topographic factors on the light environment.Results showed that there were differences in light environments among the four habitat types and during the studied six months.The PLS-PM results showed that the stand structure and the dominant species were negatively correlated with the light environment,and the path coefficient values were−0.089(P=0.042)and−0.130(P=0.004),respectively.Our result indicated that the understory light availability exhibit a distinct spatial and temporal heterogeneity in temperate deciduous,broad-leaved forest of north China.The characteristics of woody plant community,especially the abundance of one of the dominant plant species,were the important factors affecting the understory light availability.展开更多
Secondary forests, created after heavy logging,are an important part of China's forests. We investigated forest biomass and its accumulation rate in 38 plots in a tropical secondary forest on Hainan Island. These ...Secondary forests, created after heavy logging,are an important part of China's forests. We investigated forest biomass and its accumulation rate in 38 plots in a tropical secondary forest on Hainan Island. These secondary forests are moderate carbon sinks, averaging1.96–2.17 t C ha-1 a-1. Biomass increment is largely by medium-sized(10–35 m) trees. Tree mortality accounts for almost 30% of the biomass and plays a negligible role in biomass accumulation estimates. Mortality rate is highly dependent on tree size. For small trees and seedlings, it is related to competition due to elevated irradiance after logging. Regarding prospective biomass and rates of accumulation, recovery is not as rapid as in secondary forests of cleared land. Therefore, tropical forests are susceptible to logging operations and need careful forest management.展开更多
A study was carried out in the 50-ha Korup Forest Dynamic Plot in South West Cameroon, to evaluate the diversity of mycorrhizal associations as well as to determine the effect of habitat types on the type of mycorrhiz...A study was carried out in the 50-ha Korup Forest Dynamic Plot in South West Cameroon, to evaluate the diversity of mycorrhizal associations as well as to determine the effect of habitat types on the type of mycorrhizal association. A total of 781 individual trees belonging to 51 families, 165 genera and 252 tree species, were sampled from the four habitat types found in the plot: low drier, hill slope, ridge top and wetland complexes. In each habitat type, all stems ≤ 1 cm depth at breast height had already been tagged, measured, mapped and identified to the species level. Root samples were collected, cleared, stained and examined microscopically for mycorrhizal type. Of the total number of species sampled, 248 (98.41%) formed mycorrhizal associations with only 4 (1.59%) being non mycorrhizal. For mycorrhizal trees, 232 (93.55%) formed exclusively arbuscular mycorrhiza, 10 (4.03%) formed ectomycorrhiza, while 6 (2.42%) formed both ecto- and arbuscular mycorrhiza. The ridge top harbored the least number (152) of mycorrhizal trees while the low drier area harbored the most number (266) of mycorrhizal trees. Although habitat effect was not significant in influencing mycorrhizal colonization of tree species, some tree species did show aggregated patterns in particular habitats.展开更多
基金supported by The National Science Foundation of China(31770567,31570630)。
文摘Stocking and structural composition of a deciduous broad-leaved forest were determined to predict coarse woody debris quantity by quantifying the empirical relationships between these two attributes.The most ecologically significant families by stem density were Salicaceae,Betulaceae,Fagaceae,and Aceraceae.P opulus davidiana was the most dominant species followed by B etula dahurica,Quercus mongolica,and Acer mono.The four species accounted for 69.5%of total stems.Numerous small-diameter species characterized the coarse woody debris showing a reversed J-shaped distribution.The coarse debris of P.davidiana,B.dahurica,and Q.mongolica mainly comprised the 10–20 cm size class,whereas A.mono debris was mainly in the 5–10 cm size class.The spatial patterns of different size classes of coarse woody debris were analyzed using the g-function to determine the size of the tree at its death.The results indicate that the spatial patterns at the 0–50 m scale shifted gradually from an aggregated to a random pattern.For some species,the larger coarse debris might change from an aggregated to a random distribution more easily.Given the importance of coarse woody debris in forest ecosystems,its composition and patterns can improve understanding of community structure and dynamics.The aggregation pattern might be due to density dependence and self-thinning effects,as well as by succession and mortality.The four dominant species across the different size classes showed distinct aggregated distribution features at different spatial scales.This suggests a correlation between the dominant species population,size class,and aggregated distribution of coarse woody debris.
基金This work a contribution to Youth Foundation of Natural Science Foundation of Henan Province(212300410153)The Young Talents Promotion Project of Henan Province(2020HYTP037)+1 种基金Science and Technology Project of Henan Provincial Department of Natural Resources(No.2021-178-9)Basic scientific research expenses of Henan Province(2021JB02014).
文摘The spatial-temporal variation of understory light availability has important influences on species diversity and community assembly.However,the distribution characteristics and influencing factors of understory light availability have not been fully elucidated,especially in temperate deciduous,broad-leaved forests.In this study,the understory light availability was monitored monthly(May–October)in a temperate deciduous,broad-leaved forest in Henan Province,China.Differences in the light availability among different months and habitat types were statistically analyzed using Kruskal–Wallis method,respectively.Partial least squares path modeling(PLS-PM)was used to explore the direct and/or indirect effects of stand structure,dominant species and topographic factors on the light environment.Results showed that there were differences in light environments among the four habitat types and during the studied six months.The PLS-PM results showed that the stand structure and the dominant species were negatively correlated with the light environment,and the path coefficient values were−0.089(P=0.042)and−0.130(P=0.004),respectively.Our result indicated that the understory light availability exhibit a distinct spatial and temporal heterogeneity in temperate deciduous,broad-leaved forest of north China.The characteristics of woody plant community,especially the abundance of one of the dominant plant species,were the important factors affecting the understory light availability.
基金supported by The C-project Excellent Talent Project of Hainan Universitythe National Natural Science Foundation of China(Grant No.31200347)
文摘Secondary forests, created after heavy logging,are an important part of China's forests. We investigated forest biomass and its accumulation rate in 38 plots in a tropical secondary forest on Hainan Island. These secondary forests are moderate carbon sinks, averaging1.96–2.17 t C ha-1 a-1. Biomass increment is largely by medium-sized(10–35 m) trees. Tree mortality accounts for almost 30% of the biomass and plays a negligible role in biomass accumulation estimates. Mortality rate is highly dependent on tree size. For small trees and seedlings, it is related to competition due to elevated irradiance after logging. Regarding prospective biomass and rates of accumulation, recovery is not as rapid as in secondary forests of cleared land. Therefore, tropical forests are susceptible to logging operations and need careful forest management.
文摘A study was carried out in the 50-ha Korup Forest Dynamic Plot in South West Cameroon, to evaluate the diversity of mycorrhizal associations as well as to determine the effect of habitat types on the type of mycorrhizal association. A total of 781 individual trees belonging to 51 families, 165 genera and 252 tree species, were sampled from the four habitat types found in the plot: low drier, hill slope, ridge top and wetland complexes. In each habitat type, all stems ≤ 1 cm depth at breast height had already been tagged, measured, mapped and identified to the species level. Root samples were collected, cleared, stained and examined microscopically for mycorrhizal type. Of the total number of species sampled, 248 (98.41%) formed mycorrhizal associations with only 4 (1.59%) being non mycorrhizal. For mycorrhizal trees, 232 (93.55%) formed exclusively arbuscular mycorrhiza, 10 (4.03%) formed ectomycorrhiza, while 6 (2.42%) formed both ecto- and arbuscular mycorrhiza. The ridge top harbored the least number (152) of mycorrhizal trees while the low drier area harbored the most number (266) of mycorrhizal trees. Although habitat effect was not significant in influencing mycorrhizal colonization of tree species, some tree species did show aggregated patterns in particular habitats.
