Altitudinal changes in species richness, species diversity, species evenness, life-form spectrum, and community structure of arrow bamboo (Fargesia spathacea) were studied within 11 plots from 1 500 m to 2 600 m asl o...Altitudinal changes in species richness, species diversity, species evenness, life-form spectrum, and community structure of arrow bamboo (Fargesia spathacea) were studied within 11 plots from 1 500 m to 2 600 m asl on Mount Shennongjia in Central China. From the lowest plot (1 680 m) to the highest one (2 570 m), vascular plants declined from 30 to 7 species, following a linear model ofY=55.99-1.83X (d.f.=9,F-value=48.64,r 2=0.84,P<0.001); species diversity, reduced from 3.13 to 1.78, following a linear model ofY=4.67–0.10X (d.f.=9,F-value=22.82,r 2=0.72,P=0.001); species evenness varied from 0.83 to 0.99, but presented little relationship to the altitude (r=0.112,P=0.742). In the life-form spectra, with the increase of altitude, the percentage of annual plants (r=0.60), underground bulb perennials (r=0.40), and big trees (r=0.35) tended to increase; shrubs (r=?0.52) and middle-sized trees (r=?0.45) tended to decline; perennial grasses (r=0.04) and semi-shrubs (r=0.03) were not strongly related to the altitudinal gradient. Arrow bamboo communities could be classified into five groups: bamboo under evergreen broad-leaved forest, under deciduous broad-leaved forest, under temperate coniferous forest, under cold-temperate coniferous and mixed forest, and pure bamboo community.展开更多
As one of the main food bamboo species of the giant panda(Ailuropoda melanoleuca),Fargesia denudata is widely distributed in the understory of spruce-fir forests in the mountainous area of southwestern China.However,t...As one of the main food bamboo species of the giant panda(Ailuropoda melanoleuca),Fargesia denudata is widely distributed in the understory of spruce-fir forests in the mountainous area of southwestern China.However,the driving factors of its biomass and distribution in the forests are still unclear.We conducted a systematic investigation of the tree and shrub layers(including bamboos)of 209 subplots(20 m×20 m)in a Forest Global Earth Observatory plot,the Wanglang Plot(25.2 ha),to explore the effects of abiotic(topographic and soil characteristics)and biotic(tree density,total basal area(TBA),shrub coverage,etc.)factors on the aboveground biomass of F.denudata(bamboo biomass hereafter).Bamboo biomass averaged 1.17 ton/ha,with a large variation from 0 to 4.88 ton/ha(95%confidence interval)among the 209 subplots.Bamboo biomass increased significantly with elevation,slope and mean diameter at breast height of trees,and decreased significantly with tree density,shrub coverage and soil pH.However,bamboo biomass was not significantly correlated with tree TBA,aspect,soil organic matter or total nitrogen content.The random forest model indicated that topographic factors and biotic factors had greater influences on the bamboo biomass than soil characteristics in general.Specifically,topographic factors mainly affected the bamboo biomass by changing tree density and soil characteristics.Our results can provide valuable guidance for the protection of giant pandas and the management of subalpine spruce-fir forests.展开更多
基金This study is a part of bamboo research project within ZEF (Center for Development Researches P.N. 52015) of Bonn University+1 种基金financed by GTZ Germany.
文摘Altitudinal changes in species richness, species diversity, species evenness, life-form spectrum, and community structure of arrow bamboo (Fargesia spathacea) were studied within 11 plots from 1 500 m to 2 600 m asl on Mount Shennongjia in Central China. From the lowest plot (1 680 m) to the highest one (2 570 m), vascular plants declined from 30 to 7 species, following a linear model ofY=55.99-1.83X (d.f.=9,F-value=48.64,r 2=0.84,P<0.001); species diversity, reduced from 3.13 to 1.78, following a linear model ofY=4.67–0.10X (d.f.=9,F-value=22.82,r 2=0.72,P=0.001); species evenness varied from 0.83 to 0.99, but presented little relationship to the altitude (r=0.112,P=0.742). In the life-form spectra, with the increase of altitude, the percentage of annual plants (r=0.60), underground bulb perennials (r=0.40), and big trees (r=0.35) tended to increase; shrubs (r=?0.52) and middle-sized trees (r=?0.45) tended to decline; perennial grasses (r=0.04) and semi-shrubs (r=0.03) were not strongly related to the altitudinal gradient. Arrow bamboo communities could be classified into five groups: bamboo under evergreen broad-leaved forest, under deciduous broad-leaved forest, under temperate coniferous forest, under cold-temperate coniferous and mixed forest, and pure bamboo community.
基金supported by the National Natural Science Foundation of China(31988102)the National Key Research and Development Program of China(2017YFC0503906).
文摘As one of the main food bamboo species of the giant panda(Ailuropoda melanoleuca),Fargesia denudata is widely distributed in the understory of spruce-fir forests in the mountainous area of southwestern China.However,the driving factors of its biomass and distribution in the forests are still unclear.We conducted a systematic investigation of the tree and shrub layers(including bamboos)of 209 subplots(20 m×20 m)in a Forest Global Earth Observatory plot,the Wanglang Plot(25.2 ha),to explore the effects of abiotic(topographic and soil characteristics)and biotic(tree density,total basal area(TBA),shrub coverage,etc.)factors on the aboveground biomass of F.denudata(bamboo biomass hereafter).Bamboo biomass averaged 1.17 ton/ha,with a large variation from 0 to 4.88 ton/ha(95%confidence interval)among the 209 subplots.Bamboo biomass increased significantly with elevation,slope and mean diameter at breast height of trees,and decreased significantly with tree density,shrub coverage and soil pH.However,bamboo biomass was not significantly correlated with tree TBA,aspect,soil organic matter or total nitrogen content.The random forest model indicated that topographic factors and biotic factors had greater influences on the bamboo biomass than soil characteristics in general.Specifically,topographic factors mainly affected the bamboo biomass by changing tree density and soil characteristics.Our results can provide valuable guidance for the protection of giant pandas and the management of subalpine spruce-fir forests.
