With the aggravation of global change, the response and adaptation of the unique ecosystem in Qinghai-Tibet Plateau to global change have been increasingly concerned by scientific community day by day, which makes the...With the aggravation of global change, the response and adaptation of the unique ecosystem in Qinghai-Tibet Plateau to global change have been increasingly concerned by scientific community day by day, which makes the sensitivity and fragility of this ecosystem in response to global change widely recognized by scholars. On the basis of introducing the present research process on the degenerate mechanisim, measures of and approaches to recovery, carbon cycle and primary productivity toward global change, we put forward several propositions on studying the alpine grassland ecosystem in Northern Tibetan Plateau.展开更多
In this paper, an updated vegetation map of the permafrost zone in the Qinghai-Tibet Plateau (QTP) was delineated. The vegetation map model was extracted from vegetation sampling with remote sensing (RS) datasets ...In this paper, an updated vegetation map of the permafrost zone in the Qinghai-Tibet Plateau (QTP) was delineated. The vegetation map model was extracted from vegetation sampling with remote sensing (RS) datasets by decision tree method. The spatial resolution of the map is 1 km×1 kin, and in it the alpine swamp meadow is firstly distinguished in the high-altitude areas. The results showed that the total vegetated area in the permafrost zone of the QTP is 1,201,751 km2. In the vegetated region, 50,260 km2 is the areas of alpine swamp meadow, 583,909 km2 for alpine meadow, 332,754 km2 for alpine steppe, and 234,828 km2 for alpine desert. This updated vegetation map in permafrost zone of QTP could provide more details about the distribution of alpine vegetation types for studying the vegetation mechanisms in the land surface processes of highaltitude areas.展开更多
In this article, we mainly analysis the soil carbon storage of the alpine grassland under different land uses in Qinghai-Tibet Plateau. The samples of this investigation include six experimental fields which are fence...In this article, we mainly analysis the soil carbon storage of the alpine grassland under different land uses in Qinghai-Tibet Plateau. The samples of this investigation include six experimental fields which are fenced mowing grassland, artificial grassland, winter and spring grazing meadowland, summer and autumn mild grazing land, summer and autumn moderate grazing pasture and summer and autumn severe grazing land and seven soil layers included 0 cm-5 cm, 5 cm-10 cm, 10 cm-20 cm, 20 cm-30 cm, 30 cm-50 cm, 50 cm-70 cm and 70 cm-100 cm. The results show that the soil carbon storage in different soil layers will gradually reduce and the difference was remarkable (P 〈 0.05). What is more, the soil carbon storage of alpine grassland under different land uses has following sequence: winter and spring grazing grassland 〉 summer and autumn mild grazing land 〉 artificial grassland 〉 summer and autumn moderate grazing meadowland 〉 summer and autumn severe grazing pasture 〉 fenced mowing meadow, and the significant difference between them is remarkable (P 〈 0.05).展开更多
The species-area relationship (SAR) is one of the most fundamental concepts in community ecology and is helpful for biodiversity conservation. However, few studies have systematically addressed this topic for differ...The species-area relationship (SAR) is one of the most fundamental concepts in community ecology and is helpful for biodiversity conservation. However, few studies have systematically addressed this topic for different alpine grassland types on the Tibetan Plateau, China. We explored whether the plant composition of different functional groups affects the manner in which species richness inereases with increasing area at scales ≤ 1.0 m^2. We also compared species richness (S) within and across forbs, legumes, sedges and grasses, with sampling subplot area (A) increasing from 0.0625 m^2 to 1.0 m^2 between alpine meadow and steppe communities. We applied a logarithmic function (S = b0 + b1 ln A) to determine the slope and intercept of SAR curves within and across functional groups. The results showed that the logarithmic relationship holds true between species richness and sampling area at these small scales. Both the intercept and slope of the logarithmic forbs-area curves are significantly higher than those for the three other functional groups (P 〈 0.05). Forb accounts for about 91.9 % of the variation in the intercept and 75.0% of the variation in the slope of the SAR curve when all functional groups' data were pooled together. Our results indicated that the different SAR patterns should be linked with species dispersal capabilities, environmental filtering, and life form composition within alpine grassland communities. Further studies on the relationship between species diversity and ecosystem functions should specify the differential responses of different functional groups to variations in climate and anthropogenic disturbances.展开更多
Deposited in plant cells and their intercellular space,phytoliths,a special form of silica,could be used to determine information on plant structure and physiology especially their size and content.With the hypothesis...Deposited in plant cells and their intercellular space,phytoliths,a special form of silica,could be used to determine information on plant structure and physiology especially their size and content.With the hypothesis that phytolith in plant would change under variable climate and environment,the dominant plant species in Songnen grassland,guinea grass(Leymus chinensis),was treated by an open-top chamber(OTC) to elevate CO2 concentration,infrared heaters,and artificial nitrogen(N) addition for three years from 2006–2008.Phytoliths were extracted by wet-ashing method and analyzed by variance analysis and so on.We found that the responses to elevated CO2 are complicated,and warming is positive while N addition is negative to the deposition of phytoliths in L.chinensis leaves.Especially,warming could reduce the negative impact of N addition on phytolith in L.chinensis.The short cell's taxonomic in graminea is significant because of no disappearance with simulated environmental changes.The phytolith originated in the long cell and plant intercellular space are more sensitive to elevated CO2 concentration,warming,and N addition,and could become some new indicators for environmental changes.In conclusion,different phytolith types have various responses to simulated warming,N addition and elevated CO2 concentration.展开更多
An increasing number of consumers demanding health foods have favoured poultry meat from natural production system. Amino acid and mineral elements are essential nutrient, required for numerous metabolic functions, wh...An increasing number of consumers demanding health foods have favoured poultry meat from natural production system. Amino acid and mineral elements are essential nutrient, required for numerous metabolic functions, which are provided partly by the poultry. The objective of this study was to evaluate amino acid and mineral composition in meat of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau. Eighty, 28-day-old Qinjiaoma male broilers were introduced into a rangeland where there was a dense population of grasshoppers (treatment GC). Control chicken were reared under intensive condition and given a maize-soybean diet (treatment CC). At 91 days of age, 24 birds from each treatment were slaughtered. Fresh breast meats were packaged and refrigerated for determination. The results indicated that dietary grasshoppers and rearing condition significantly (P 〈 0.05) affected some amino acid and mineral elements composition. Aspartic, arginine, threonine, isoleucine and lysine were higher in the muscles from GC than those from CC, and the similar trend were also found in the content of total amino acid and essential amino acid. While tryptophan and methionine were lower (P 〈 0.05) in meat from GC than that from CC. Effect of diets and rearing condition on mineral elements was also observed, the concentration of sodium, phosphorus and iron were higher (P 〈 0.05) in muscle from GC, while calcium was higher in muscle from CC. In conclusion, the meat in free-range broilers fed on grasshoppers has the richer amino acid and mineral elements.展开更多
This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications mini...This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer (4-1-4), an initial herbicide (Pasture Gard, Dow Agro) application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza (L.) Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.展开更多
Several abiotic and biotic factors were investigated as possible predictors of local species richness in two sub-alpine grasslands of Jenna and Belles Mountains in Northern Greece.For species richness modelling a hier...Several abiotic and biotic factors were investigated as possible predictors of local species richness in two sub-alpine grasslands of Jenna and Belles Mountains in Northern Greece.For species richness modelling a hierarchical modelling framework based on generalized additive models was adopted.The two sub-alpine grasslands differed in aspect,altitude and soil parent material(volcanic origin,mostly trachyte,and andesite(TA) for Jenna and metamorphic rocks,mostly gneiss(G) for Belles).12 fenced squared plots,16 m2 each,were used per grassland,where soil properties,herbage production,species presence and cover of grasses,legumes and forbs were estimated.Mean herbage production was significantly affected by slope and altitude,soil K content and floristic composition as expressed by an ordination axis.Soil p H,floristic composition and average herbage production were significant predictors of forbs and total species richness.For the former,soil N content and for the latter the occurrence of Agrostis capillaris,were also included as significant terms in the predictive model.Thepredictors for grasses species richness were N content,having a positive effect,and average herbage production.In all cases higher species richness was predicted for intermediate values of average herbage production.Differential responses were found between forbs and grasses.The predictors of their species richness were different while for the case of the common predictor(N) the responses of the two groups were also different(grasses species numbers increase and forbs species numbers decreased with increasing N).Maximum species richness of grasses was observed at relatively low production levels while forbs species richness maximized at relatively high production levels.展开更多
Enclosure is one of the most widely used management tools for degraded alpine grassland on the northern Tibetan Plateau, but the responses of different types of grassland to enclosure may vary, and research on these r...Enclosure is one of the most widely used management tools for degraded alpine grassland on the northern Tibetan Plateau, but the responses of different types of grassland to enclosure may vary, and research on these responses can provide a scientific basis for improving ecological conservation. This study took one site for each of three grassland types(alpine meadow, alpine steppe and alpine desert) on the northern Tibetan Plateau as examples, and explored the effects of enclosure on plant and soil nutrients by comparing differences in plant community biomass, leaf-soil nutrient content and their stoichiometry between samples from inside and outside the fence. The results showed that enclosure can significantly increase all aboveground biomass in these three grassland types, but it only increased the 10–20 cm underground biomass in the alpine desert. Enclosure also significantly increased the leaf nutrient content of the dominant plants and contents of total nitrogen(N), total potassium(K), and organic carbon(C) in 10–20 cm soil in alpine desert, thus changing the stoichiometry between C, N and P(phosphorus). However, enclosure significantly increased only the N content of dominant plant leaves in alpine steppe, while other nutrients and stoichiometries of both plant leaves and soil did not show significant differences in alpine meadow and alpine steppe. These results suggested that enclosure has differential effects on these three types of alpine grasslands on the northern Tibetan Plateau, and the alpine desert showed the most active ecological conservation in the responses of its soil and plant nutrients.展开更多
As an important biomarker, fatty acids(FAs) have been extensively used to trace the origin of organic matter in sediments and soils. However, studies of the distribution and abundance of FAs in alpine grassland soils ...As an important biomarker, fatty acids(FAs) have been extensively used to trace the origin of organic matter in sediments and soils. However, studies of the distribution and abundance of FAs in alpine grassland soils are still rare, especially on the Qinghai-Tibetan Plateau(QTP), the highest plateau in the world, which contributes sediments to many large rivers in Asia. This study investigates the composition, distribution and source of FAs with increasing soil depths from 17 typical alpine grassland sites in the QTP. The most abundant FAs included the ubiquitous C16 FA and even-numbered long-chain FAs(C20–C30), indicating mixed inputs from microbial and higher plant sources. Source apportionment showed that higher plants were the dominant contributor of FAs(approximately 40%) in QTP soils. The abundance of FAs decreased with soil depth, with the highest value(1.08±0.09 mg/g C) at a 0–10 cm depth and the lowest value(0.46±0.12 mg/g C) at a 50–70 cm depth, due to much lower plant inputs into the deeper horizons. The total concentration of FAs was negatively correlated to the mean annual temperature(MAT; P<0.05) and soil p H(P<0.01), suggesting that the preservation of FAs was favored in low-MAT and low-p H soils on the QTP. The abundance of fresh C source FAs increased significantly with the mean annual precipitation(MAP; P<0.05), indicating that high MAP facilitates the accumulation of fresh FAs in QTP soils. Other environmental parameters, such as the soil mineral content(aluminum and iron oxide), microbial community composition as well as litter quality and quantity, may also exert a strong control on the preservation of FAs in QTP soils and warrant further research to better understand the mechanisms responsible for the preservation of FAs in QTP soils.展开更多
基金Supported by National Key Technology R&D Program(2006BAC01A04 2007BAC06B01)National Natural Science Foundation of China(40771121)~~
文摘With the aggravation of global change, the response and adaptation of the unique ecosystem in Qinghai-Tibet Plateau to global change have been increasingly concerned by scientific community day by day, which makes the sensitivity and fragility of this ecosystem in response to global change widely recognized by scholars. On the basis of introducing the present research process on the degenerate mechanisim, measures of and approaches to recovery, carbon cycle and primary productivity toward global change, we put forward several propositions on studying the alpine grassland ecosystem in Northern Tibetan Plateau.
基金supported by the National Natural Science Foundation of China (Grant No.41101055)the Hundred Talents Program of the Chinese Academy of Sciences granted to Tonghua Wu (Grant No.51Y251571)the “National Basic Research Program of China (973 Program)” (Grant No.2010CB951402)
文摘In this paper, an updated vegetation map of the permafrost zone in the Qinghai-Tibet Plateau (QTP) was delineated. The vegetation map model was extracted from vegetation sampling with remote sensing (RS) datasets by decision tree method. The spatial resolution of the map is 1 km×1 kin, and in it the alpine swamp meadow is firstly distinguished in the high-altitude areas. The results showed that the total vegetated area in the permafrost zone of the QTP is 1,201,751 km2. In the vegetated region, 50,260 km2 is the areas of alpine swamp meadow, 583,909 km2 for alpine meadow, 332,754 km2 for alpine steppe, and 234,828 km2 for alpine desert. This updated vegetation map in permafrost zone of QTP could provide more details about the distribution of alpine vegetation types for studying the vegetation mechanisms in the land surface processes of highaltitude areas.
文摘In this article, we mainly analysis the soil carbon storage of the alpine grassland under different land uses in Qinghai-Tibet Plateau. The samples of this investigation include six experimental fields which are fenced mowing grassland, artificial grassland, winter and spring grazing meadowland, summer and autumn mild grazing land, summer and autumn moderate grazing pasture and summer and autumn severe grazing land and seven soil layers included 0 cm-5 cm, 5 cm-10 cm, 10 cm-20 cm, 20 cm-30 cm, 30 cm-50 cm, 50 cm-70 cm and 70 cm-100 cm. The results show that the soil carbon storage in different soil layers will gradually reduce and the difference was remarkable (P 〈 0.05). What is more, the soil carbon storage of alpine grassland under different land uses has following sequence: winter and spring grazing grassland 〉 summer and autumn mild grazing land 〉 artificial grassland 〉 summer and autumn moderate grazing meadowland 〉 summer and autumn severe grazing pasture 〉 fenced mowing meadow, and the significant difference between them is remarkable (P 〈 0.05).
基金supported by the Chinese Academy of Sciences (Grant Nos.XDB03030401,KZCXZ-XB3-08)the State Scholarship Fund of the China Scholarship Council (Grant No.201400260118)the International Postdoctoral Exchange Fellowship Program 2014 by the Office of China Postdoctoral Council (Grant No.20140041)
文摘The species-area relationship (SAR) is one of the most fundamental concepts in community ecology and is helpful for biodiversity conservation. However, few studies have systematically addressed this topic for different alpine grassland types on the Tibetan Plateau, China. We explored whether the plant composition of different functional groups affects the manner in which species richness inereases with increasing area at scales ≤ 1.0 m^2. We also compared species richness (S) within and across forbs, legumes, sedges and grasses, with sampling subplot area (A) increasing from 0.0625 m^2 to 1.0 m^2 between alpine meadow and steppe communities. We applied a logarithmic function (S = b0 + b1 ln A) to determine the slope and intercept of SAR curves within and across functional groups. The results showed that the logarithmic relationship holds true between species richness and sampling area at these small scales. Both the intercept and slope of the logarithmic forbs-area curves are significantly higher than those for the three other functional groups (P 〈 0.05). Forb accounts for about 91.9 % of the variation in the intercept and 75.0% of the variation in the slope of the SAR curve when all functional groups' data were pooled together. Our results indicated that the different SAR patterns should be linked with species dispersal capabilities, environmental filtering, and life form composition within alpine grassland communities. Further studies on the relationship between species diversity and ecosystem functions should specify the differential responses of different functional groups to variations in climate and anthropogenic disturbances.
基金Under the auspices of National Natural Science Foundation of China(No.40971116,41471164,31170303,31270366)Ministry of Environmental Protection Foundation for Public Welfare Project(No.201109067)National Undergraduate Training Programs for Innovation and Entrepreneurship(No.201410200074)
文摘Deposited in plant cells and their intercellular space,phytoliths,a special form of silica,could be used to determine information on plant structure and physiology especially their size and content.With the hypothesis that phytolith in plant would change under variable climate and environment,the dominant plant species in Songnen grassland,guinea grass(Leymus chinensis),was treated by an open-top chamber(OTC) to elevate CO2 concentration,infrared heaters,and artificial nitrogen(N) addition for three years from 2006–2008.Phytoliths were extracted by wet-ashing method and analyzed by variance analysis and so on.We found that the responses to elevated CO2 are complicated,and warming is positive while N addition is negative to the deposition of phytoliths in L.chinensis leaves.Especially,warming could reduce the negative impact of N addition on phytolith in L.chinensis.The short cell's taxonomic in graminea is significant because of no disappearance with simulated environmental changes.The phytolith originated in the long cell and plant intercellular space are more sensitive to elevated CO2 concentration,warming,and N addition,and could become some new indicators for environmental changes.In conclusion,different phytolith types have various responses to simulated warming,N addition and elevated CO2 concentration.
文摘An increasing number of consumers demanding health foods have favoured poultry meat from natural production system. Amino acid and mineral elements are essential nutrient, required for numerous metabolic functions, which are provided partly by the poultry. The objective of this study was to evaluate amino acid and mineral composition in meat of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau. Eighty, 28-day-old Qinjiaoma male broilers were introduced into a rangeland where there was a dense population of grasshoppers (treatment GC). Control chicken were reared under intensive condition and given a maize-soybean diet (treatment CC). At 91 days of age, 24 birds from each treatment were slaughtered. Fresh breast meats were packaged and refrigerated for determination. The results indicated that dietary grasshoppers and rearing condition significantly (P 〈 0.05) affected some amino acid and mineral elements composition. Aspartic, arginine, threonine, isoleucine and lysine were higher in the muscles from GC than those from CC, and the similar trend were also found in the content of total amino acid and essential amino acid. While tryptophan and methionine were lower (P 〈 0.05) in meat from GC than that from CC. Effect of diets and rearing condition on mineral elements was also observed, the concentration of sodium, phosphorus and iron were higher (P 〈 0.05) in muscle from GC, while calcium was higher in muscle from CC. In conclusion, the meat in free-range broilers fed on grasshoppers has the richer amino acid and mineral elements.
文摘This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer (4-1-4), an initial herbicide (Pasture Gard, Dow Agro) application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza (L.) Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.
基金The Greek Ministry of Agriculture is gratefully acknowledged for their support
文摘Several abiotic and biotic factors were investigated as possible predictors of local species richness in two sub-alpine grasslands of Jenna and Belles Mountains in Northern Greece.For species richness modelling a hierarchical modelling framework based on generalized additive models was adopted.The two sub-alpine grasslands differed in aspect,altitude and soil parent material(volcanic origin,mostly trachyte,and andesite(TA) for Jenna and metamorphic rocks,mostly gneiss(G) for Belles).12 fenced squared plots,16 m2 each,were used per grassland,where soil properties,herbage production,species presence and cover of grasses,legumes and forbs were estimated.Mean herbage production was significantly affected by slope and altitude,soil K content and floristic composition as expressed by an ordination axis.Soil p H,floristic composition and average herbage production were significant predictors of forbs and total species richness.For the former,soil N content and for the latter the occurrence of Agrostis capillaris,were also included as significant terms in the predictive model.Thepredictors for grasses species richness were N content,having a positive effect,and average herbage production.In all cases higher species richness was predicted for intermediate values of average herbage production.Differential responses were found between forbs and grasses.The predictors of their species richness were different while for the case of the common predictor(N) the responses of the two groups were also different(grasses species numbers increase and forbs species numbers decreased with increasing N).Maximum species richness of grasses was observed at relatively low production levels while forbs species richness maximized at relatively high production levels.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19050502,XDA20010201)The National Key Research Projects of China(2017YFA0604801,2016YFC0502001)The National Natural Science Foundation of China(31770477)。
文摘Enclosure is one of the most widely used management tools for degraded alpine grassland on the northern Tibetan Plateau, but the responses of different types of grassland to enclosure may vary, and research on these responses can provide a scientific basis for improving ecological conservation. This study took one site for each of three grassland types(alpine meadow, alpine steppe and alpine desert) on the northern Tibetan Plateau as examples, and explored the effects of enclosure on plant and soil nutrients by comparing differences in plant community biomass, leaf-soil nutrient content and their stoichiometry between samples from inside and outside the fence. The results showed that enclosure can significantly increase all aboveground biomass in these three grassland types, but it only increased the 10–20 cm underground biomass in the alpine desert. Enclosure also significantly increased the leaf nutrient content of the dominant plants and contents of total nitrogen(N), total potassium(K), and organic carbon(C) in 10–20 cm soil in alpine desert, thus changing the stoichiometry between C, N and P(phosphorus). However, enclosure significantly increased only the N content of dominant plant leaves in alpine steppe, while other nutrients and stoichiometries of both plant leaves and soil did not show significant differences in alpine meadow and alpine steppe. These results suggested that enclosure has differential effects on these three types of alpine grasslands on the northern Tibetan Plateau, and the alpine desert showed the most active ecological conservation in the responses of its soil and plant nutrients.
基金supported by the Chinese National Key Development Program for Basic Research (Grant Nos. 2014CB954003 & 2015CB954201)the National Natural Science Foundation of China (Grant Nos. 31370491 & 41503073)+1 种基金National 1000 Young Talents Programthe "Strategic Priority Research Program-Climate Change: Carbon Budget and Relevant Issues" of the Chinese Academy of Sciences (Grant No. XDA05050404)
文摘As an important biomarker, fatty acids(FAs) have been extensively used to trace the origin of organic matter in sediments and soils. However, studies of the distribution and abundance of FAs in alpine grassland soils are still rare, especially on the Qinghai-Tibetan Plateau(QTP), the highest plateau in the world, which contributes sediments to many large rivers in Asia. This study investigates the composition, distribution and source of FAs with increasing soil depths from 17 typical alpine grassland sites in the QTP. The most abundant FAs included the ubiquitous C16 FA and even-numbered long-chain FAs(C20–C30), indicating mixed inputs from microbial and higher plant sources. Source apportionment showed that higher plants were the dominant contributor of FAs(approximately 40%) in QTP soils. The abundance of FAs decreased with soil depth, with the highest value(1.08±0.09 mg/g C) at a 0–10 cm depth and the lowest value(0.46±0.12 mg/g C) at a 50–70 cm depth, due to much lower plant inputs into the deeper horizons. The total concentration of FAs was negatively correlated to the mean annual temperature(MAT; P<0.05) and soil p H(P<0.01), suggesting that the preservation of FAs was favored in low-MAT and low-p H soils on the QTP. The abundance of fresh C source FAs increased significantly with the mean annual precipitation(MAP; P<0.05), indicating that high MAP facilitates the accumulation of fresh FAs in QTP soils. Other environmental parameters, such as the soil mineral content(aluminum and iron oxide), microbial community composition as well as litter quality and quantity, may also exert a strong control on the preservation of FAs in QTP soils and warrant further research to better understand the mechanisms responsible for the preservation of FAs in QTP soils.