Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmen...Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale.展开更多
Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored varia...Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.展开更多
Plant life form diversity and its direct gradient analysis on a larger scale climate change gradient were tested, based on the data from Northeast China Transect platform. The results showed that the species numbers, ...Plant life form diversity and its direct gradient analysis on a larger scale climate change gradient were tested, based on the data from Northeast China Transect platform. The results showed that the species numbers, life form richness and life form diversity were relative higher at the eastern forests and the ecotone between typical vegetation, while those on the meadow grasslands and typical steppes were lower. Although plant life forms can reflect the climate variations, life form diversity is not consistent with the major global gradient along the NECT.展开更多
A study was conducted to identify plant species,diversity,life form and relevant species to Mediterranean climate,Irano-Torunian and Sahara-Sindian in Postband region（N 27°58＇4＂-28°2＇16＂,E 53°17＇3...A study was conducted to identify plant species,diversity,life form and relevant species to Mediterranean climate,Irano-Torunian and Sahara-Sindian in Postband region（N 27°58＇4＂-28°2＇16＂,E 53°17＇34＂-53°22＇30＂）.In total,95 species belonging to 29 families and 69 genera of flora were surveyed and identified from December 2006 to June 2008.Composite and Gramineae were important families in terms of species frequency.According to Raunkiaer＇s system and using X^2 tests,the life-form spectrum showed that therophytes accounted for 47% of all species,and hemicryptophytes for 31%,phanerophytes for 12%,chamaeophyte for 7%,and cryptophytes for 3%.In geographical distribution,29% species with the most frequency belonged to Irano-Torunian region.Results show that therophytes were more than normal spectrum and phaneropytes were less than normal spectrum,which was in agreement with data obtained in arid climate.展开更多
Antioxidant systems are vital in life activities of macrophytes.Species with diff erent life forms need to cope with distinct environments by modifying physiological characters,especially antioxidant systems.In order ...Antioxidant systems are vital in life activities of macrophytes.Species with diff erent life forms need to cope with distinct environments by modifying physiological characters,especially antioxidant systems.In order to find diff erences among life forms and consequence of lake eutrophication,we studied three antioxidant enzymes activity(superoxide dismutase(SOD),ascorbate oxidase(APX)and catalase(CAT))and total soluble phenolics(TP)content in leaves of 26 macrophyte species in September 2013 in Lake Erhai,China.We found that antioxidation varied accordingly with life forms.The activities of SOD and APX in emergent macrophytes(EM)and floating-leaved macrophytes(FM)were much lower than those of submerged macrophytes(SM).On the contrary,TP content was much higher in EM and FM species.There was a negative correlation between TP and antioxidant enzyme activities(CAT and APX).The results suggested that EM and FM species rely on phenolics might to adapt to adverse environments(higher herbivores predation pressure and UV radiation intensity),while SM species more rely on antioxidant enzymes possibly due to lower demand for antioxidation and/or lack of light and inorganic C availability for phenolics synthesis.We also found FM species represent highest fitness in term of antioxidant system,which would lead to overgrowth of FM species and littoral zone bogginess during lake eutrophication.Finally,it is necessary to carry out the verification experiment under the control condition in the later stage,especially for the dominant ones in eutrophic lakes,to understand the exact adaptive mechanisms of them.展开更多
Biomass allocation patterns among plant species are related to their adaptive ecological strategies. Ephemeral, ephemeroid and annual plant life forms represent three typical growth strategies of plants that grow in a...Biomass allocation patterns among plant species are related to their adaptive ecological strategies. Ephemeral, ephemeroid and annual plant life forms represent three typical growth strategies of plants that grow in autumn and early spring in the cold deserts of China. These plants play an important role in reducing wind velocity in the desert areas. However, despite numerous studies, the strategies of biomass allocation among plant species with these three life forms remain contentious. In this study, we conducted a preliminary quadrat study during 2014–2016 in the southern part of the Gurbantunggut Desert, China, to investigate the allocation patterns of above-ground biomass(AGB) and below-ground biomass(BGB) at the individual level in 17 ephemeral, 3 ephemeroid and 4 annual plant species. Since ephemeral plants can germinate in autumn, we also compared biomass allocation patterns between plants that germinated in autumn 2015 and spring 2016 for 4 common ephemeral species. The healthy mature individual plants of each species were sampled and the AGB, BGB, total biomass(TB), leaf mass ratio(LMR) and root/shoot ratio(R/S) were calculated for 201 sample quadrats in the study area. We also studied the relationships between AGB and BGB of plants with the three different life forms(ephemeral, ephemeroid and annual). The mean AGB values of ephemeral, ephemeroid and annual plants were 0.806, 3.759 and 1.546 g/plant, respectively, and the mean BGB values were 0.106, 4.996 and 0.166 g/plant, respectively. The mean R/S value was significantly higher in ephemeroid plants(1.675) than in ephemeral(0.154) and annual(0.147) plants. The mean LMR was the highest in annual plants, followed by ephemeroid plants and ephemeral plants, reflecting the fact that annual plants allocate more biomass to leaves, associated with their longer life span. Biomass of ephemeral plants that germinated in autumn was significantly higher than those of corresponding plants that germinated in spring in terms of AGB, BGB and TB. However, the R/S value was similar in plants that germinated in autumn and spring. The slope of regression relationship between AGB and BGB differed significantly among the three plant life forms. These results support different biomass allocation hypotheses. Specifically, at the individual level, the AGB and BGB partitioning supports the allometric hypothesis for ephemeroid and annual plants and the isometric hypothesis for ephemeral plants.展开更多
The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and...The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum. Species were categorized as plant habit, height and length of growth-cycle and life-form classes according to Raunkiaer＇s system. The results show that in total of 68 species at grazed site, hemicryptophytes （He） accounted for 50.00% species, followed by cryptophytes （26.47%）, chamaephytes （16.18%）, phanemphytes （4.41%） and therophytes （2.94%）. At the ungrazed site in 65 plant species, hemicryptophytes （He） accounted fo＇r 49.23% species, cryptophytes （26.15%）, chamaephytes （15.38%）, phanerophytes （6.15%） and ther6phytes （3.08 % species）. In general, hemicrptophyte are dominant^in both sites i.e. graged and ungrazed. Growth form categories were classified as forbs, shrubs, grasses and sedges＇and undershrubs, according to plant habit and height. On the basis of length of the growth cycle, species were categorized as plant species of short growth cycle, intermediate growth cycle and long growth cycle. The short forbs of plant habit and height, had the highest emergence, and grasses and sedges had the lowest emergence in representative species. Percentage of species with long growth cycle was highest in both sites.展开更多
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
为探究呈岛屿间断分布的中国特有种油叶柯〔Lithocarpus konishii(Hayata)Hayata〕的群落结构、区系特征及多样性,在其分布区广东担杆岛、香港及海南文昌设置13个典型样地(总面积5800 m 2)并开展群落学调查,分析其群落的物种组成、结构...为探究呈岛屿间断分布的中国特有种油叶柯〔Lithocarpus konishii(Hayata)Hayata〕的群落结构、区系特征及多样性,在其分布区广东担杆岛、香港及海南文昌设置13个典型样地(总面积5800 m 2)并开展群落学调查,分析其群落的物种组成、结构特征、区系特征、物种多样性及类型。结果表明:13个油叶柯样地物种组成丰富,共有维管植物200种(含种下等级,下同),隶属于74科162属,其中海南文昌样地的物种数(140种)远多于香港和广东担杆岛样地。从生活型看,13个油叶柯样地中乔木、灌木、草本和藤本分别有41、85、57和17种,占比分别为20.5%、42.5%、28.5%和8.5%。从地理成分看,13个油叶柯样地植物群落在科和属水平均以泛热带和热带亚洲分布为主,热带性质明显。多样性分析结果显示:油叶柯样地灌木层的物种多样性指数总体高于乔木层和草本层。基于乔木层重要值的聚类分析结果,13个油叶柯样地的植物群落划分为油叶柯+鹅掌柴林〔Form.L.konishii+Heptapleurum heptaphyllum(Linn.)Y.F.Deng〕、台湾相思+油叶柯林(Form.Acacia confusa Merr.+L.konishii)、油叶柯+文昌锥林(Form.L.konishii+Castanopsis wenchangensis G.A.Fu et C.C.Huang)3类,与地理分布相吻合。综上所述,油叶柯群落为具热带特性的常绿阔叶林,但因处于次生演替不稳定阶段,亟需制定针对性保护策略以维持生态系统稳态。展开更多
基金supported by the National Key Research and Development Program of China(2023YFF0805602)National Natural Science Foundation of China(32225032,32001192,32271597)+1 种基金the Innovation Base Project of Gansu Province(2021YFF0703904)the Science and Technology Program of Gansu Province(24JRRA515,22JR5RA525,23JRRA1157).
文摘Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale.
文摘Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change.
文摘Plant life form diversity and its direct gradient analysis on a larger scale climate change gradient were tested, based on the data from Northeast China Transect platform. The results showed that the species numbers, life form richness and life form diversity were relative higher at the eastern forests and the ecotone between typical vegetation, while those on the meadow grasslands and typical steppes were lower. Although plant life forms can reflect the climate variations, life form diversity is not consistent with the major global gradient along the NECT.
文摘A study was conducted to identify plant species,diversity,life form and relevant species to Mediterranean climate,Irano-Torunian and Sahara-Sindian in Postband region（N 27°58＇4＂-28°2＇16＂,E 53°17＇34＂-53°22＇30＂）.In total,95 species belonging to 29 families and 69 genera of flora were surveyed and identified from December 2006 to June 2008.Composite and Gramineae were important families in terms of species frequency.According to Raunkiaer＇s system and using X^2 tests,the life-form spectrum showed that therophytes accounted for 47% of all species,and hemicryptophytes for 31%,phanerophytes for 12%,chamaeophyte for 7%,and cryptophytes for 3%.In geographical distribution,29% species with the most frequency belonged to Irano-Torunian region.Results show that therophytes were more than normal spectrum and phaneropytes were less than normal spectrum,which was in agreement with data obtained in arid climate.
基金Supported by the State Key Laboratory of Freshwater Ecology and Biotechnology(No.2016FBZ08)the Natural Science Foundation of Jiangxi Province(No.2015ZBBF6008)the National Natural Science Foundation of China(No.31200356)
文摘Antioxidant systems are vital in life activities of macrophytes.Species with diff erent life forms need to cope with distinct environments by modifying physiological characters,especially antioxidant systems.In order to find diff erences among life forms and consequence of lake eutrophication,we studied three antioxidant enzymes activity(superoxide dismutase(SOD),ascorbate oxidase(APX)and catalase(CAT))and total soluble phenolics(TP)content in leaves of 26 macrophyte species in September 2013 in Lake Erhai,China.We found that antioxidation varied accordingly with life forms.The activities of SOD and APX in emergent macrophytes(EM)and floating-leaved macrophytes(FM)were much lower than those of submerged macrophytes(SM).On the contrary,TP content was much higher in EM and FM species.There was a negative correlation between TP and antioxidant enzyme activities(CAT and APX).The results suggested that EM and FM species rely on phenolics might to adapt to adverse environments(higher herbivores predation pressure and UV radiation intensity),while SM species more rely on antioxidant enzymes possibly due to lower demand for antioxidation and/or lack of light and inorganic C availability for phenolics synthesis.We also found FM species represent highest fitness in term of antioxidant system,which would lead to overgrowth of FM species and littoral zone bogginess during lake eutrophication.Finally,it is necessary to carry out the verification experiment under the control condition in the later stage,especially for the dominant ones in eutrophic lakes,to understand the exact adaptive mechanisms of them.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20020101)the National Natural Science Foundation of China(31400394)
文摘Biomass allocation patterns among plant species are related to their adaptive ecological strategies. Ephemeral, ephemeroid and annual plant life forms represent three typical growth strategies of plants that grow in autumn and early spring in the cold deserts of China. These plants play an important role in reducing wind velocity in the desert areas. However, despite numerous studies, the strategies of biomass allocation among plant species with these three life forms remain contentious. In this study, we conducted a preliminary quadrat study during 2014–2016 in the southern part of the Gurbantunggut Desert, China, to investigate the allocation patterns of above-ground biomass(AGB) and below-ground biomass(BGB) at the individual level in 17 ephemeral, 3 ephemeroid and 4 annual plant species. Since ephemeral plants can germinate in autumn, we also compared biomass allocation patterns between plants that germinated in autumn 2015 and spring 2016 for 4 common ephemeral species. The healthy mature individual plants of each species were sampled and the AGB, BGB, total biomass(TB), leaf mass ratio(LMR) and root/shoot ratio(R/S) were calculated for 201 sample quadrats in the study area. We also studied the relationships between AGB and BGB of plants with the three different life forms(ephemeral, ephemeroid and annual). The mean AGB values of ephemeral, ephemeroid and annual plants were 0.806, 3.759 and 1.546 g/plant, respectively, and the mean BGB values were 0.106, 4.996 and 0.166 g/plant, respectively. The mean R/S value was significantly higher in ephemeroid plants(1.675) than in ephemeral(0.154) and annual(0.147) plants. The mean LMR was the highest in annual plants, followed by ephemeroid plants and ephemeral plants, reflecting the fact that annual plants allocate more biomass to leaves, associated with their longer life span. Biomass of ephemeral plants that germinated in autumn was significantly higher than those of corresponding plants that germinated in spring in terms of AGB, BGB and TB. However, the R/S value was similar in plants that germinated in autumn and spring. The slope of regression relationship between AGB and BGB differed significantly among the three plant life forms. These results support different biomass allocation hypotheses. Specifically, at the individual level, the AGB and BGB partitioning supports the allometric hypothesis for ephemeroid and annual plants and the isometric hypothesis for ephemeral plants.
文摘The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum. Species were categorized as plant habit, height and length of growth-cycle and life-form classes according to Raunkiaer＇s system. The results show that in total of 68 species at grazed site, hemicryptophytes （He） accounted for 50.00% species, followed by cryptophytes （26.47%）, chamaephytes （16.18%）, phanemphytes （4.41%） and therophytes （2.94%）. At the ungrazed site in 65 plant species, hemicryptophytes （He） accounted fo＇r 49.23% species, cryptophytes （26.15%）, chamaephytes （15.38%）, phanerophytes （6.15%） and ther6phytes （3.08 % species）. In general, hemicrptophyte are dominant^in both sites i.e. graged and ungrazed. Growth form categories were classified as forbs, shrubs, grasses and sedges＇and undershrubs, according to plant habit and height. On the basis of length of the growth cycle, species were categorized as plant species of short growth cycle, intermediate growth cycle and long growth cycle. The short forbs of plant habit and height, had the highest emergence, and grasses and sedges had the lowest emergence in representative species. Percentage of species with long growth cycle was highest in both sites.
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.
