Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South Amer...Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South America) and Macedonia, Southern Europe), within which the life-form spectra are distributed. Genetic optimization methods are used to expand the primary nodal number to the complete number of life-form categories. The distribution of the elements exhibits a stochastic, binomial distribution and the utopia line and curve are summarized which enhance accuracy of the climatic data and of the consequent numbers of plant species occurrences. Expansion of the distribution of each life-form category is approximated within the Z utopia hyperplane with use of the functional approximation algorithm. This process gives additional structure and informative value to the Z plane, enhancing our ability to make informed policy decisions concerning species and ecosystem conservation.展开更多
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
The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland everg...The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland evergreen rainforest' formation and exhibit striking similarities and conspicuous differences with the equatorial rainforests in Asia-Pacific as well as tropical seasonal rainforests in southwestern China near the Tropic of Cancer. We found these common attributes of the rainforests in Meghalaya: familial composition with predominance of Euphorbiaceae, Lauraceae, Meliaceae, Moraceae, Myrsiticaceae,Myrtaceae and Rubiaceae; deciduousness in evergreen physiognomy; dominance of mega-and mesophanerophytic life-forms; abundance of species with low frequency of occurrence(rare and aggregated species); low proportional abundance of the abundant species; and truncated lognormal abundance distribution. The levels of stand density and stand basal area were comparable with seasonal rainforests in southwestern China, but were lower than equatorial rainforests. Tropical Asian species predominated flora, commanding 95% of the abundance. The differences include overall low stature(height) of the forest, inconspicuous stratification in canopy, fewer species and individuals of liana, thicker understory,higher proportion of rare species, absence of locally endemic species and relatively greater dominance of Fagaceae and Theaceae. The richness of species per hectare(S) was considerably lower at higher latitudes in Meghalaya than in equatorial rainforests, but was comparable with seasonal rainforests. Shannon's diversity index(H’=4.40 nats for ≥10 cm gbh and 4.25 nats for ≥30 cm gbh) was lower on higher latitudes in Meghalaya in comparison to species-rich equatorial rainforests, but it was the highest among all lowland rainforests near the Tropic of Cancer.展开更多
Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external wall.The relationship between their valve morphology and habitat means that diatoms can be used as bioindicat...Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external wall.The relationship between their valve morphology and habitat means that diatoms can be used as bioindicators to characterize the aquatic environment.To estimate the differential distribution and diversity of diatom assemblages along the coastal line,we collected phytoplankton samples from 114 coastal sites of waters of R.O.Korea.We applied the unweighted pair-group technique using the arithmetic averages clustering method to cluster the sampling sites,apart from those where the biota consisted of other groups,such as dinoflagellates,into four regions:the Yellow Sea,South Sea,southern East Sea,and northern East Sea.Indicator species analysis in each region led to the selection of tychoplanktonic,chain-forming,attached species to substrates and psychrophilic indicator diatoms,respectively,each of which represented a planktonic lifestyle associated with one of the four regions.This study shows the diatom assemblages to serve as bioindicators of Korean coastal water in winter,and the subsequent seasonal survey will provide a starting point for the improved understanding of Korean diatom-based ecoregions,in both time and space.展开更多
Aims We aimed to quantify the variation of leafδ^(13)C along an arid and semi-arid grassland transect in northern China.We also evaluated the effects of environmental factors(i.e.precipitation,temperature and altitud...Aims We aimed to quantify the variation of leafδ^(13)C along an arid and semi-arid grassland transect in northern China.We also evaluated the effects of environmental factors(i.e.precipitation,temperature and altitude)on the spatial variation of leafδ^(13)C in northern grasslands and Tibetan Plateau,China.Method We sampled leaves of plant species belonging to three herb genera(Stipa spp.,Leymus spp.and Cleistogenes spp.)and three shrub genera(Caragana spp.,Reaumuria spp.and Nitraria spp.)for carbon isotope analysis from 50 locations along a 3200-km arid and semiarid grassland transect in northern China.Leafδ^(13)C data in Tibetan Plateau and northern grasslands in China were also compiled from studies in literature.Important Findings Along the transect,leafδ^(13)C for C_(3)plants ranged from−28.0‰to−23.3‰,and from−16.3‰to−13.8‰for C_(4)plant Cleistogenes spp..The change in leafδ^(13)C ranged from−0.26‰to−3.51‰with every 100 mm increase of annual precipitation,and leafδ^(13)C of shrubs(Nitraria spp.,Reaumuria spp.and Caragana spp.)responded more markedly to climatic factors(precipitation and temperature)than that of herbs(Stipa spp.,Leymus spp.and Cleistogenes spp.),indicating higher sensitivity of shrubδ^(13)C to climatic changes.The most important factor regulating spatial variations of leafδ^(13)C in Tibetan Plateau was altitude,while it was precipitation in northern grasslands.Our results suggested that shrubs are more adapted to increasing drought in arid and semi-arid grassland.Controls of environmental factors on leafδ^(13)C depended on the most limiting factors in arid grassland(precipitation)and Tibetan grasslands(atmospheric CO_(2)concentration).展开更多
Aims Alien species are commonly considered as harmful weeds capa-ble of decreasing native biodiversity and threatening ecosystems.Despite this assumption,little is known about the long-term patterns of the native-alie...Aims Alien species are commonly considered as harmful weeds capa-ble of decreasing native biodiversity and threatening ecosystems.Despite this assumption,little is known about the long-term patterns of the native-alien relationships associated with human disturbed managed landscapes.This study aims to elucidate the commu-nity dynamics associated with a successional gradient in chilean Mediterranean grasslands,considering both native and alien species.Methods Species richness(natives and aliens separately)and life-form(annu-als and perennials)were recorded in four chilean post-agricultural grazed grasslands each covering a broad successional gradient(from 1 to 40 years since crop abandonment).A detrended correspondence analysis(DcA),mixed model effects analyses and cor-relation tests were conducted to assess how this temporal gradient influenced natives and aliens through community dynamics.Important Findings Our results show different life-form patterns between natives and aliens over time.Aliens were mainly represented by annuals(especially ruderals and weeds),which were established at the beginning of succession.Annual aliens also predominated at mid-successional stages,but in old grasslands native species were slightly more representative than alien ones within the community.In the late successional states,positive or no correlations at all between alien and native species richness suggested the absence of competition between both species groups,as a result of differ-ent strategies in occupation of the space.community dynamics over time constitute a net gain in biodiversity,increasing natives and maintaining a general alien pool,allowing the coexistence of both.Biotic interactions including facilitation and/or tolerance processes might be occurring in chilean post-agricultural grasslands,a fact that contradicts the accepted idea of the alien species as contenders.展开更多
文摘Adaptive fuzzy neural inference systems are used to illustrate the primary nodal number of plant life-forms. Categorization of two candidate areas is carried out using the water-energy dynamic (for Ecuador, South America) and Macedonia, Southern Europe), within which the life-form spectra are distributed. Genetic optimization methods are used to expand the primary nodal number to the complete number of life-form categories. The distribution of the elements exhibits a stochastic, binomial distribution and the utopia line and curve are summarized which enhance accuracy of the climatic data and of the consequent numbers of plant species occurrences. Expansion of the distribution of each life-form category is approximated within the Z utopia hyperplane with use of the functional approximation algorithm. This process gives additional structure and informative value to the Z plane, enhancing our ability to make informed policy decisions concerning species and ecosystem conservation.
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The Department of Biotechnology,New Delhi provided principal funding through a grant to US(BT/PR7928/NDB/52/9/2006)
文摘The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland evergreen rainforest' formation and exhibit striking similarities and conspicuous differences with the equatorial rainforests in Asia-Pacific as well as tropical seasonal rainforests in southwestern China near the Tropic of Cancer. We found these common attributes of the rainforests in Meghalaya: familial composition with predominance of Euphorbiaceae, Lauraceae, Meliaceae, Moraceae, Myrsiticaceae,Myrtaceae and Rubiaceae; deciduousness in evergreen physiognomy; dominance of mega-and mesophanerophytic life-forms; abundance of species with low frequency of occurrence(rare and aggregated species); low proportional abundance of the abundant species; and truncated lognormal abundance distribution. The levels of stand density and stand basal area were comparable with seasonal rainforests in southwestern China, but were lower than equatorial rainforests. Tropical Asian species predominated flora, commanding 95% of the abundance. The differences include overall low stature(height) of the forest, inconspicuous stratification in canopy, fewer species and individuals of liana, thicker understory,higher proportion of rare species, absence of locally endemic species and relatively greater dominance of Fagaceae and Theaceae. The richness of species per hectare(S) was considerably lower at higher latitudes in Meghalaya than in equatorial rainforests, but was comparable with seasonal rainforests. Shannon's diversity index(H’=4.40 nats for ≥10 cm gbh and 4.25 nats for ≥30 cm gbh) was lower on higher latitudes in Meghalaya in comparison to species-rich equatorial rainforests, but it was the highest among all lowland rainforests near the Tropic of Cancer.
基金The Fund of the Research Project of Korea Institute of Ocean Science&Technology under contract No.PEA0014the National Research Foundation of the Ministry of Science and ICT under contract Nos NRF-2020R1A2C2005970 and NRF-2017M3A9E4072753the Fund of the Korea Institute of Marine Science&Technology Promotion of the Ministry of Ocean and Fisheries under contract No.21210466。
文摘Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external wall.The relationship between their valve morphology and habitat means that diatoms can be used as bioindicators to characterize the aquatic environment.To estimate the differential distribution and diversity of diatom assemblages along the coastal line,we collected phytoplankton samples from 114 coastal sites of waters of R.O.Korea.We applied the unweighted pair-group technique using the arithmetic averages clustering method to cluster the sampling sites,apart from those where the biota consisted of other groups,such as dinoflagellates,into four regions:the Yellow Sea,South Sea,southern East Sea,and northern East Sea.Indicator species analysis in each region led to the selection of tychoplanktonic,chain-forming,attached species to substrates and psychrophilic indicator diatoms,respectively,each of which represented a planktonic lifestyle associated with one of the four regions.This study shows the diatom assemblages to serve as bioindicators of Korean coastal water in winter,and the subsequent seasonal survey will provide a starting point for the improved understanding of Korean diatom-based ecoregions,in both time and space.
基金National Basic Research Program of China(973 program,2014CB954400)the National Natural Science Foundation of China(31522010)State Key Laboratory of Forest and Soil Ecology(LFSE2013-13 and LFSE2015-18).
文摘Aims We aimed to quantify the variation of leafδ^(13)C along an arid and semi-arid grassland transect in northern China.We also evaluated the effects of environmental factors(i.e.precipitation,temperature and altitude)on the spatial variation of leafδ^(13)C in northern grasslands and Tibetan Plateau,China.Method We sampled leaves of plant species belonging to three herb genera(Stipa spp.,Leymus spp.and Cleistogenes spp.)and three shrub genera(Caragana spp.,Reaumuria spp.and Nitraria spp.)for carbon isotope analysis from 50 locations along a 3200-km arid and semiarid grassland transect in northern China.Leafδ^(13)C data in Tibetan Plateau and northern grasslands in China were also compiled from studies in literature.Important Findings Along the transect,leafδ^(13)C for C_(3)plants ranged from−28.0‰to−23.3‰,and from−16.3‰to−13.8‰for C_(4)plant Cleistogenes spp..The change in leafδ^(13)C ranged from−0.26‰to−3.51‰with every 100 mm increase of annual precipitation,and leafδ^(13)C of shrubs(Nitraria spp.,Reaumuria spp.and Caragana spp.)responded more markedly to climatic factors(precipitation and temperature)than that of herbs(Stipa spp.,Leymus spp.and Cleistogenes spp.),indicating higher sensitivity of shrubδ^(13)C to climatic changes.The most important factor regulating spatial variations of leafδ^(13)C in Tibetan Plateau was altitude,while it was precipitation in northern grasslands.Our results suggested that shrubs are more adapted to increasing drought in arid and semi-arid grassland.Controls of environmental factors on leafδ^(13)C depended on the most limiting factors in arid grassland(precipitation)and Tibetan grasslands(atmospheric CO_(2)concentration).
基金the Spanish Ministry of Science and Innovation for the financial support received for the present study,reference CGL2009-08718the Spanish Ministry of Education,Culture and Sport for the pre-doctoral FPU scholarship of the main author,reference AP2009-0518+1 种基金the support provided by Juan María Arenas,Javier Seoane,Nagore García and especially for the advice and suggestions provided by Greg Guerinthe assistance of the entire INIA-Cauquenes Institution in central Chile,especially the contributions by Teresa Aravena.
文摘Aims Alien species are commonly considered as harmful weeds capa-ble of decreasing native biodiversity and threatening ecosystems.Despite this assumption,little is known about the long-term patterns of the native-alien relationships associated with human disturbed managed landscapes.This study aims to elucidate the commu-nity dynamics associated with a successional gradient in chilean Mediterranean grasslands,considering both native and alien species.Methods Species richness(natives and aliens separately)and life-form(annu-als and perennials)were recorded in four chilean post-agricultural grazed grasslands each covering a broad successional gradient(from 1 to 40 years since crop abandonment).A detrended correspondence analysis(DcA),mixed model effects analyses and cor-relation tests were conducted to assess how this temporal gradient influenced natives and aliens through community dynamics.Important Findings Our results show different life-form patterns between natives and aliens over time.Aliens were mainly represented by annuals(especially ruderals and weeds),which were established at the beginning of succession.Annual aliens also predominated at mid-successional stages,but in old grasslands native species were slightly more representative than alien ones within the community.In the late successional states,positive or no correlations at all between alien and native species richness suggested the absence of competition between both species groups,as a result of differ-ent strategies in occupation of the space.community dynamics over time constitute a net gain in biodiversity,increasing natives and maintaining a general alien pool,allowing the coexistence of both.Biotic interactions including facilitation and/or tolerance processes might be occurring in chilean post-agricultural grasslands,a fact that contradicts the accepted idea of the alien species as contenders.