In this paper,the contemporary understanding process of herbaceous plants and their contributions are elaborated.The systematic idea of"mountain,river,forest,field,lake,and grass are a community of life"has ...In this paper,the contemporary understanding process of herbaceous plants and their contributions are elaborated.The systematic idea of"mountain,river,forest,field,lake,and grass are a community of life"has led the grass to enter a new era of development.Broadly speaking,vegetation includes grassland,forest,crop,garden,etc.,while herbaceous vegetation is the most widely distributed on earth.From the macro and micro perspectives of soil and water ecology,this paper discusses the position and role of herbaceous vegetation in the earth's soil and water ecosystem,especially the fundamental position in mountain,river,forest,field,lake,grass and sand.Starting from the concept of soil and water ecology,the integrated protection and systematic management of mountain,river,forest,field,lake,grassland,and sand is proposed.Essentially,it is the protection and management of soil and water ecology,which summarizes various ecological systems on earth.The successful application of herbaceous plants in ecological restoration projects of mine has further enriched and developed the theory of soil and water ecology.展开更多
The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvl...The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvlang'variety under a continuous planting regime of one,four,and seven years,and a replanting regime of one and four years.Under the condition of continuous planting,with the increase of number of years,pH,ammonium nitrogen,and nitrate nitrogen decreased in the rhizosphere and non-rhizosphere soils,whereas organic matter,available phosphorus and potassium,enzyme activities,and the number of bacteria,fungi,and actinomycetes increased.Under the condition of replanting,with the increase of number of years,fungi and actinomycetes in both soils increased,while pH,organic matter,nutrients,enzyme activities,and bacterial number decreased.pH,organic matter,nutrient content,enzyme activity and the number of bacterial were lower in soil replanted for four years,whereas the abundance of fungi and actinomycetes was higher,altering the soil from“bacterial high-fertility”to“fungal low-fertility”with increasing years of replanting.The activity of antioxidant enzymes and MDA content in roots of peony in replanting were higher than those in continuous planting,while the content of osmotic regulatory substances in replanting was lower than that in continuous planting.The results showed that there were no obvious adverse factors in soil during seven years of continuous planting,and herbaceous peony could maintain normal growth and development.However,soils after four years of replanting were not suitable for herbaceous peony growth.Benzoic acid increased with years of replanting,which potentially caused replanting problems.This study provides a theoretical basis for understanding the mechanism of replanting problems in the herbaceous peony.展开更多
[Objectives] To explore the niche characteristics of herbaceous plants under Pinus tabuliformis plantation forest in the feldspathic sandstone area,and to provide basic data for maintaining biodiversity and community ...[Objectives] To explore the niche characteristics of herbaceous plants under Pinus tabuliformis plantation forest in the feldspathic sandstone area,and to provide basic data for maintaining biodiversity and community stability in the local P.tabuliformis plantation forest.[Methods] The types,quantity,average plant height,and coverage of various herbaceous plants were recorded by field survey in a well-growing P.tabulaeformis forest area.Based on the survey data,Shannon and Levins niche breadth index,Levins niche overlap index and ecological response were used to analyze the niche characteristics of herbaceous plants under P.tabulaeformis plantation forest.[Results]( i) There were 35 species of herbaceous plants in the P.tabulaeformis plantation forest in the feldspathic sandstone area.Among them,Stipa bungeiensis had the largest niche breadth indexes with better performance.Because of its strong adaptability,its community was in an obviously advantageous position.( ii) The overall niche width and niche overlap index were generally not high,and understory herb species showed differentiation.( iii) Among the understory herbaceous species,37.15% of the species were developed species,and 62.86% of the species were declining species.Among the 14 dominant species,11 were developmental species.The species with largest the resource occupancy were S.bungeiensis( 0.188 5),Heteropappus altaicus( 0.053 1),and Cleistogenes squarrosa( 0.037 9).[Conclusions] Competition among under herbaceous plants in P.tabulaeformis plantation forest in the feldspathic sandstone area was weak,and the community species had poor utilization of resources and environment.Most of the dominant herbaceous species were in the developing stage,indicating that the P.tabulaeformis plantation community tends to be relatively stable at the current stage.展开更多
Herbaceous plants are widely distributed on islands and where they exhibit spatial heterogeneity.Accurately identifying the impact factors that drive spatial heterogeneity can reveal typical island biodiversity patter...Herbaceous plants are widely distributed on islands and where they exhibit spatial heterogeneity.Accurately identifying the impact factors that drive spatial heterogeneity can reveal typical island biodiversity patterns.Five southern islands in the Miaodao Archipelago,North China were studied herein.The spatial distribution of herbaceous plant diversity on these islands was analyzed,and the impact factors and their degree of impact on spatial heterogeneity were identified using CCA ordination and ANOVA.The results reveal 114 herbaceous plant species,belonging to 94 genera from 34 families in the50 plots sampled.The total species numbers on different islands were significantly positively correlated with island area,and the average a diversity was correlated with human activities,while the(3 diversity among islands was more affected by island area than mutual distances.Spatial heterogeneity within islands indicated that the diversities were generally high in areas with higher altitude,slope,total nitrogen,total carbon,and canopy density,and lower moisture content,pH,total phosphorus,total potassium,and aspect.Among the environmental factors,pH,canopy density,total K,total P,moisture content,altitude,and slope had significant gross effects,but only canopy density exhibited a significant net effect.Terrain affected diversity by restricting plantation,plantation in turn influenced soil properties and the two together affected diversity.Therefore,plantation was ultimately the fundamental driving factor for spatial heterogeneity in herbaceous plant diversity on the five islands.展开更多
As one of the most sensitive regions to global climate change, alpine tundra in many places around the world has been undergoing dramatic changes in vegetation communities over the past few decades.Herbaceous plant sp...As one of the most sensitive regions to global climate change, alpine tundra in many places around the world has been undergoing dramatic changes in vegetation communities over the past few decades.Herbaceous plant species in the Changbai Mountains area have significantly expanded into tundra shrub communities over the past 30 yr.Soil microbial communities, enzyme activities, and soil nutrients are intertwined with this expansion process.In order to understand the responses of the soil microbial communities to such an expansion, we analyzed soil microbial community structures and enzyme activities in shrub tundra as well as areas with three different levels of herbaceous plant expansion.Our investigation was based on phospholipid fatty acid(PLFA) analysis and 96-well microtiter plates.The results showed that herbs have expanded greatly in the tundra, and they have become the dominant species in herbaceous plant expansion areas.There were differences for community composition and appearance among the shrub tundra and the mild expansion, moderate expansion, and severe expansion areas.Except for soil organic matter, soil nutrients were increased in herbaceous plant expansion areas, and the total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were greatest in moderate expansion areas(MOE), while soil organic matter levels were highest in the non-expanded areas(CK).The total soil PLFAs in the three levels of herbaceous plant expansion areas were significantly higher than those in the non-expanded areas, and total soil PLFAs were highest in the moderately expanded area and lowest in the severely expanded area(SEE).Bacteria increased significantly more than fungi and actinomycetes with herbaceous plant expansion.Soil hydrolase activities(β-1,4-glucosidase(βG) activity, β-1, 4-N-acetylglucosaminidase(NAG) activity, and acid phosphatase(aP) activity) were highest in MOE and lowest in the CK treatment.Soil oxidase activities(polyphenol oxidase(PPO) activities and peroxidase(PER) activities) were also highest in MOE, but they were lowest in the SEE treatment.The variations in total soil PLFAs with herbaceous plant expansion were mostly correlated with soil organic matter and available phosphorus concentrations, while soil enzyme activities were mostly correlated with the total soil nitrogen concentration.Our results suggest that herbaceous plant expansion increase the total soil PLFAs and soil enzyme activities and improved soil nutrients.However, soil microorganisms, enzyme activity, and nutrients responded differently to levels of herbaceous plant expansion.The soil conditions in mild and moderate expansion areas are more favorable than those in severe expansion areas.展开更多
In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic...In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic and herbaceous habit theoretically may have been well adopted by pioneer angiosperms, pre-Cretaceous herbs are missing hitherto, leaving the origin of herbs and evolution of herbaceous angiosperms mysterious. Here we report Juraherba bodae gen. et sp. nov, a whole plant herbaceous angiosperm, from the Middle Jurassic (〉164 Ma) at Daohugou Village, Inner Mongolia, China, a fossil Lagerst^itten that is worldwide famous for various fossil finds. The angiospermous affinity of Juraherba is ensured by its enclosed ovules/seeds. The plant is small but complete, with physically connected hairy root, stem, leaves, and fructifications. The Middle Jurassic age recommends Juraherba as the earliest record of herbaceous seed plants, demanding a refresh look at the evolutionary history of angiosperms.展开更多
Background:Herbs are an important part of the forest ecosystem,and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances.Based on the near-mature secondary coniferous...Background:Herbs are an important part of the forest ecosystem,and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances.Based on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone,this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of thinning.Results:The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity,they were mainly determined by seasonal changes.Across the entire growing season,the species with the highest importance values in thinning treatments included Carex pilosa,Aegopodium alpestre,Meehania urticifolia,and Filipendula palmata,which dominated the herb layer of the coniferous and broad-leaved mixed forest.The number of species,Margalef index,Shannon-Wiener index and Simpson index all had their highest values in May,and gradually decreased with months.Pielou index was roughly inverted“N”throughout the growing season.Thinning did not increase the species diversity.Thinning can promote the total biomass,above-and below-ground biomass.The number of plants per unit area and coverage were related to the total biomass,above-and below-ground biomass.The average height had a significantly positive correlation with herb biomass in May but not in July.However,it exerted a significantly negative correlation with herb biomass in September.The biomass in the same month increased with increasing thinning intensity.Total herb biomass,above-and below-ground biomass showed positive correlations with Shannon-Winner index,Simpson index and Pielou evenness index in May.Conclusions:Thinning mainly changed the light environment in the forest,which would improve the plant diversity and biomass of herb layer in a short time.And different thinning intensity had different effects on the diversity of understory herb layer.The findings provide theoretical basis and reference for reasonable thinning and tending in coniferous and broad-leaved mixed forests.展开更多
Patterns of biomass allocation among organs in plants are important because they influence many growth processes.The Yunnan-Guizhou Plateau(YGP)is considered to be one of the most sensitive areas in China to climate c...Patterns of biomass allocation among organs in plants are important because they influence many growth processes.The Yunnan-Guizhou Plateau(YGP)is considered to be one of the most sensitive areas in China to climate changes,but we know little about how current climatic gradients on the plateau influence plant biomass allocation.Gentiana rigescens and G.rhodantha,on the YGP,are important species because they are used in traditional Chinese medicines.We therefore analyzed the biomass allocation patterns of the two species across an elevation gradient(1000–2810 m a.s.l.)on the YGP to understand and predict the impact of climate change on these plant species.We found that the total biomass,reproductive biomass,vegetative biomass,aboveground biomass,and belowground biomass in G.rigescens were all significantly larger than those in G.rhodantha(p<0.05).However,for both species the aboveground biomass was nearly isometrically related to belowground biomass,regardless of elevation,mean annual temperature(MAT)ranging from 8.4℃t to 18.8℃t,and mean annual precipitation(MAP)ranging from 681 to 1327 mm,while the reproductive biomass was allometrically related to vegetative biomass.Intriguingly,there was a significant positive relationship(p<0.05)between the slope of the allometric scaling of reproductive and vegetative biomass and elevation among G.rigescens populations,i.e.plants growing at high elevationsallocate proportionately more biomass to reproduction at larger sizes and less at smaller sizes than plants growing at lower elevations.However,for G.rhodantha the reproductive allocation was negatively correlated with latitude.The results suggested different strategies in reproductive allocation in the two Gentiana plants on the YGP.Further studies are needed to investigate other environmental factors,such as nutrients and light,and genetic factors,in order to understand the trend of reproductive allometry along the environmental gradients.Our study has implications for the management and conservation practices of the two Gentiana species.展开更多
With Guiteyou 2 as the test mulberry variety, mulberry herbaceous cultivation field was established at the planting densities of 60 000,90 000 and 120 000 plants/hm2, respectively. Hybrid mulberry herbaceous cultivati...With Guiteyou 2 as the test mulberry variety, mulberry herbaceous cultivation field was established at the planting densities of 60 000,90 000 and 120 000 plants/hm2, respectively. Hybrid mulberry herbaceous cultivation test was conducted, with Tongxiangqing mulberry field of mid-fist-form at conventional planting density of 4 995 plants/hm2 as the control. The results showed that the leaf yield of herbaceous cultivation mulberry was closely related to the planting density. With the increasing planting density, the leaf yield per plant was decreasing, but the leaf yield per unit area of mulberry field was increasing. The annual leaf yield per unit area in the mulberry field with the average planting density of 120 000 plants/hm2 was 37 560 kg/hm2, 2.14 times of that of the control field. The moisture content of mulberry leaf in herbaceous cultivation field was 4.74% higher than the control; the contents of crude protein, crude fat, crude fiber and crude ash were 1.264%, 0.014%, 0.744% and 0.002%lower than the control, respectively. Comparison of leaf rearing with herbaceous cultivation mulberry and control mulberry showed that there was no significant difference in growth status of silkworm. The cocoon weight, cocoon shell weight, cocoon yield per 10 000 larvae, cocoon filament length and non-broken filament length of Chuanshan × Shushui were 12.81%, 14.29%, 13.85%, 5.95% and 7.68% lower than the control, respectively; but the percentage of common cocoons was 0.16% higher than the control; the cleanness and neatness were 0.2 and 1.25 points higher than the control;the filament size was 0.196 dtex lower than the control. The cocoon weight, cocoon shell weight, cocoon yield per 10 000 larvae, cocoon filament length and non-broken filament length of Jingsong × Haoyue were 11.06%, 10.20%, 11.53%, 9.46% and 9.03% lower than the control, respectively;but the percentage of common cocoons was 1.77% higher than the control; the cleanness and neatness were 0.12 and 2.50 points higher the control;and the filament size was 0.196 dtex lower than the control.展开更多
文摘In this paper,the contemporary understanding process of herbaceous plants and their contributions are elaborated.The systematic idea of"mountain,river,forest,field,lake,and grass are a community of life"has led the grass to enter a new era of development.Broadly speaking,vegetation includes grassland,forest,crop,garden,etc.,while herbaceous vegetation is the most widely distributed on earth.From the macro and micro perspectives of soil and water ecology,this paper discusses the position and role of herbaceous vegetation in the earth's soil and water ecosystem,especially the fundamental position in mountain,river,forest,field,lake,grass and sand.Starting from the concept of soil and water ecology,the integrated protection and systematic management of mountain,river,forest,field,lake,grassland,and sand is proposed.Essentially,it is the protection and management of soil and water ecology,which summarizes various ecological systems on earth.The successful application of herbaceous plants in ecological restoration projects of mine has further enriched and developed the theory of soil and water ecology.
基金supported by grants from the National Natural Science Foundation of China(Grant No.31670663).
文摘The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvlang'variety under a continuous planting regime of one,four,and seven years,and a replanting regime of one and four years.Under the condition of continuous planting,with the increase of number of years,pH,ammonium nitrogen,and nitrate nitrogen decreased in the rhizosphere and non-rhizosphere soils,whereas organic matter,available phosphorus and potassium,enzyme activities,and the number of bacteria,fungi,and actinomycetes increased.Under the condition of replanting,with the increase of number of years,fungi and actinomycetes in both soils increased,while pH,organic matter,nutrients,enzyme activities,and bacterial number decreased.pH,organic matter,nutrient content,enzyme activity and the number of bacterial were lower in soil replanted for four years,whereas the abundance of fungi and actinomycetes was higher,altering the soil from“bacterial high-fertility”to“fungal low-fertility”with increasing years of replanting.The activity of antioxidant enzymes and MDA content in roots of peony in replanting were higher than those in continuous planting,while the content of osmotic regulatory substances in replanting was lower than that in continuous planting.The results showed that there were no obvious adverse factors in soil during seven years of continuous planting,and herbaceous peony could maintain normal growth and development.However,soils after four years of replanting were not suitable for herbaceous peony growth.Benzoic acid increased with years of replanting,which potentially caused replanting problems.This study provides a theoretical basis for understanding the mechanism of replanting problems in the herbaceous peony.
基金Supported by the Science and Technology Plan Project of Inner Mongolia Autonomous Region"Study on the Ecological Restoration Technology System of Typical Watersheds in the Coarse Sand Concentrated Source Areas of the Yellow River"(201802106)。
文摘[Objectives] To explore the niche characteristics of herbaceous plants under Pinus tabuliformis plantation forest in the feldspathic sandstone area,and to provide basic data for maintaining biodiversity and community stability in the local P.tabuliformis plantation forest.[Methods] The types,quantity,average plant height,and coverage of various herbaceous plants were recorded by field survey in a well-growing P.tabulaeformis forest area.Based on the survey data,Shannon and Levins niche breadth index,Levins niche overlap index and ecological response were used to analyze the niche characteristics of herbaceous plants under P.tabulaeformis plantation forest.[Results]( i) There were 35 species of herbaceous plants in the P.tabulaeformis plantation forest in the feldspathic sandstone area.Among them,Stipa bungeiensis had the largest niche breadth indexes with better performance.Because of its strong adaptability,its community was in an obviously advantageous position.( ii) The overall niche width and niche overlap index were generally not high,and understory herb species showed differentiation.( iii) Among the understory herbaceous species,37.15% of the species were developed species,and 62.86% of the species were declining species.Among the 14 dominant species,11 were developmental species.The species with largest the resource occupancy were S.bungeiensis( 0.188 5),Heteropappus altaicus( 0.053 1),and Cleistogenes squarrosa( 0.037 9).[Conclusions] Competition among under herbaceous plants in P.tabulaeformis plantation forest in the feldspathic sandstone area was weak,and the community species had poor utilization of resources and environment.Most of the dominant herbaceous species were in the developing stage,indicating that the P.tabulaeformis plantation community tends to be relatively stable at the current stage.
基金Supported by the National Special Fund for Basic Science and Technology of China(No.2012FY112500)the Public Science and Technology Research Funds Projects of Ocean in China(Nos.201305009,201505012)the Special Fund of Chinese Central Government for Basic Scientific Research Operations in Commonweal Research Institutes(No.FIO2015G13)
文摘Herbaceous plants are widely distributed on islands and where they exhibit spatial heterogeneity.Accurately identifying the impact factors that drive spatial heterogeneity can reveal typical island biodiversity patterns.Five southern islands in the Miaodao Archipelago,North China were studied herein.The spatial distribution of herbaceous plant diversity on these islands was analyzed,and the impact factors and their degree of impact on spatial heterogeneity were identified using CCA ordination and ANOVA.The results reveal 114 herbaceous plant species,belonging to 94 genera from 34 families in the50 plots sampled.The total species numbers on different islands were significantly positively correlated with island area,and the average a diversity was correlated with human activities,while the(3 diversity among islands was more affected by island area than mutual distances.Spatial heterogeneity within islands indicated that the diversities were generally high in areas with higher altitude,slope,total nitrogen,total carbon,and canopy density,and lower moisture content,pH,total phosphorus,total potassium,and aspect.Among the environmental factors,pH,canopy density,total K,total P,moisture content,altitude,and slope had significant gross effects,but only canopy density exhibited a significant net effect.Terrain affected diversity by restricting plantation,plantation in turn influenced soil properties and the two together affected diversity.Therefore,plantation was ultimately the fundamental driving factor for spatial heterogeneity in herbaceous plant diversity on the five islands.
基金Under the auspices of National Natural Science Foundation of China(No.41571078,41171072)Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains,Ministry of Education
文摘As one of the most sensitive regions to global climate change, alpine tundra in many places around the world has been undergoing dramatic changes in vegetation communities over the past few decades.Herbaceous plant species in the Changbai Mountains area have significantly expanded into tundra shrub communities over the past 30 yr.Soil microbial communities, enzyme activities, and soil nutrients are intertwined with this expansion process.In order to understand the responses of the soil microbial communities to such an expansion, we analyzed soil microbial community structures and enzyme activities in shrub tundra as well as areas with three different levels of herbaceous plant expansion.Our investigation was based on phospholipid fatty acid(PLFA) analysis and 96-well microtiter plates.The results showed that herbs have expanded greatly in the tundra, and they have become the dominant species in herbaceous plant expansion areas.There were differences for community composition and appearance among the shrub tundra and the mild expansion, moderate expansion, and severe expansion areas.Except for soil organic matter, soil nutrients were increased in herbaceous plant expansion areas, and the total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were greatest in moderate expansion areas(MOE), while soil organic matter levels were highest in the non-expanded areas(CK).The total soil PLFAs in the three levels of herbaceous plant expansion areas were significantly higher than those in the non-expanded areas, and total soil PLFAs were highest in the moderately expanded area and lowest in the severely expanded area(SEE).Bacteria increased significantly more than fungi and actinomycetes with herbaceous plant expansion.Soil hydrolase activities(β-1,4-glucosidase(βG) activity, β-1, 4-N-acetylglucosaminidase(NAG) activity, and acid phosphatase(aP) activity) were highest in MOE and lowest in the CK treatment.Soil oxidase activities(polyphenol oxidase(PPO) activities and peroxidase(PER) activities) were also highest in MOE, but they were lowest in the SEE treatment.The variations in total soil PLFAs with herbaceous plant expansion were mostly correlated with soil organic matter and available phosphorus concentrations, while soil enzyme activities were mostly correlated with the total soil nitrogen concentration.Our results suggest that herbaceous plant expansion increase the total soil PLFAs and soil enzyme activities and improved soil nutrients.However, soil microorganisms, enzyme activity, and nutrients responded differently to levels of herbaceous plant expansion.The soil conditions in mild and moderate expansion areas are more favorable than those in severe expansion areas.
基金supported by the National Basic Research Program of China(973 Program 2012CB821901)Team Program of Scientific Innovation and Interdisciplinary Cooperation,Chinese Academy of Sciences(2013-2015)+3 种基金National Natural Science Foundation of China (91114201,41172006) awarded to X.WState Forestry Administration of China(No.2005-122)Science and Technology Project of Guangdong(No. 2011B060400011)Special Funds for Environmental Projects of Shenzhen(No.2013-02) awarded to Z.J.L.
文摘In contrast to woody habit with secondary growth, truthful herbaceous habit lacking secondary growth is restricted to angiosperms among seed plants. Although angiosperms might have occurred as early as in the Triassic and herbaceous habit theoretically may have been well adopted by pioneer angiosperms, pre-Cretaceous herbs are missing hitherto, leaving the origin of herbs and evolution of herbaceous angiosperms mysterious. Here we report Juraherba bodae gen. et sp. nov, a whole plant herbaceous angiosperm, from the Middle Jurassic (〉164 Ma) at Daohugou Village, Inner Mongolia, China, a fossil Lagerst^itten that is worldwide famous for various fossil finds. The angiospermous affinity of Juraherba is ensured by its enclosed ovules/seeds. The plant is small but complete, with physically connected hairy root, stem, leaves, and fructifications. The Middle Jurassic age recommends Juraherba as the earliest record of herbaceous seed plants, demanding a refresh look at the evolutionary history of angiosperms.
基金financially supported by a grant from the National Key Research and Development Program of China(2017YFC0504102)the Science and Technology Program of Jilin Provincial Education Department(JJKH20180349KJ).
文摘Background:Herbs are an important part of the forest ecosystem,and their diversity and biomass can reflect the restoration of vegetation after forest thinning disturbances.Based on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone,this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of thinning.Results:The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity,they were mainly determined by seasonal changes.Across the entire growing season,the species with the highest importance values in thinning treatments included Carex pilosa,Aegopodium alpestre,Meehania urticifolia,and Filipendula palmata,which dominated the herb layer of the coniferous and broad-leaved mixed forest.The number of species,Margalef index,Shannon-Wiener index and Simpson index all had their highest values in May,and gradually decreased with months.Pielou index was roughly inverted“N”throughout the growing season.Thinning did not increase the species diversity.Thinning can promote the total biomass,above-and below-ground biomass.The number of plants per unit area and coverage were related to the total biomass,above-and below-ground biomass.The average height had a significantly positive correlation with herb biomass in May but not in July.However,it exerted a significantly negative correlation with herb biomass in September.The biomass in the same month increased with increasing thinning intensity.Total herb biomass,above-and below-ground biomass showed positive correlations with Shannon-Winner index,Simpson index and Pielou evenness index in May.Conclusions:Thinning mainly changed the light environment in the forest,which would improve the plant diversity and biomass of herb layer in a short time.And different thinning intensity had different effects on the diversity of understory herb layer.The findings provide theoretical basis and reference for reasonable thinning and tending in coniferous and broad-leaved mixed forests.
基金sponsored by the National Natural Science Foundation of China(81760684)the CAS 135 Program(2017XTBGF05)。
文摘Patterns of biomass allocation among organs in plants are important because they influence many growth processes.The Yunnan-Guizhou Plateau(YGP)is considered to be one of the most sensitive areas in China to climate changes,but we know little about how current climatic gradients on the plateau influence plant biomass allocation.Gentiana rigescens and G.rhodantha,on the YGP,are important species because they are used in traditional Chinese medicines.We therefore analyzed the biomass allocation patterns of the two species across an elevation gradient(1000–2810 m a.s.l.)on the YGP to understand and predict the impact of climate change on these plant species.We found that the total biomass,reproductive biomass,vegetative biomass,aboveground biomass,and belowground biomass in G.rigescens were all significantly larger than those in G.rhodantha(p<0.05).However,for both species the aboveground biomass was nearly isometrically related to belowground biomass,regardless of elevation,mean annual temperature(MAT)ranging from 8.4℃t to 18.8℃t,and mean annual precipitation(MAP)ranging from 681 to 1327 mm,while the reproductive biomass was allometrically related to vegetative biomass.Intriguingly,there was a significant positive relationship(p<0.05)between the slope of the allometric scaling of reproductive and vegetative biomass and elevation among G.rigescens populations,i.e.plants growing at high elevationsallocate proportionately more biomass to reproduction at larger sizes and less at smaller sizes than plants growing at lower elevations.However,for G.rhodantha the reproductive allocation was negatively correlated with latitude.The results suggested different strategies in reproductive allocation in the two Gentiana plants on the YGP.Further studies are needed to investigate other environmental factors,such as nutrients and light,and genetic factors,in order to understand the trend of reproductive allometry along the environmental gradients.Our study has implications for the management and conservation practices of the two Gentiana species.
基金Supported by Technology Research and Development Program of Nanchong,2015(No.15A0053)
文摘With Guiteyou 2 as the test mulberry variety, mulberry herbaceous cultivation field was established at the planting densities of 60 000,90 000 and 120 000 plants/hm2, respectively. Hybrid mulberry herbaceous cultivation test was conducted, with Tongxiangqing mulberry field of mid-fist-form at conventional planting density of 4 995 plants/hm2 as the control. The results showed that the leaf yield of herbaceous cultivation mulberry was closely related to the planting density. With the increasing planting density, the leaf yield per plant was decreasing, but the leaf yield per unit area of mulberry field was increasing. The annual leaf yield per unit area in the mulberry field with the average planting density of 120 000 plants/hm2 was 37 560 kg/hm2, 2.14 times of that of the control field. The moisture content of mulberry leaf in herbaceous cultivation field was 4.74% higher than the control; the contents of crude protein, crude fat, crude fiber and crude ash were 1.264%, 0.014%, 0.744% and 0.002%lower than the control, respectively. Comparison of leaf rearing with herbaceous cultivation mulberry and control mulberry showed that there was no significant difference in growth status of silkworm. The cocoon weight, cocoon shell weight, cocoon yield per 10 000 larvae, cocoon filament length and non-broken filament length of Chuanshan × Shushui were 12.81%, 14.29%, 13.85%, 5.95% and 7.68% lower than the control, respectively; but the percentage of common cocoons was 0.16% higher than the control; the cleanness and neatness were 0.2 and 1.25 points higher than the control;the filament size was 0.196 dtex lower than the control. The cocoon weight, cocoon shell weight, cocoon yield per 10 000 larvae, cocoon filament length and non-broken filament length of Jingsong × Haoyue were 11.06%, 10.20%, 11.53%, 9.46% and 9.03% lower than the control, respectively;but the percentage of common cocoons was 1.77% higher than the control; the cleanness and neatness were 0.12 and 2.50 points higher the control;and the filament size was 0.196 dtex lower than the control.