Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate warming.The Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive ...Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate warming.The Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive to global climate warming.It is of great importance to study the changes in aboveground biomass and species diversity of alpine meadows on the QTP under predicted future climate warming.In this study,we selected an alpine meadow on the QTP as the study object and used infrared radiators as the warming device for a simulation experiment over eight years(2011-2018).We then analyzed the dynamic changes in aboveground biomass and species diversity of the alpine meadow at different time scales,including an early stage of warming(2011-2013)and a late stage of warming(2016-2018),in order to explore the response of alpine meadows to short-term(three years)and long-term warming(eight years).The results showed that the short-term warming increased air temperature by 0.31℃and decreased relative humidity by 2.54%,resulting in the air being warmer and drier.The long-term warming increased air temperature and relative humidity by 0.19℃and 1.47%,respectively,and the air tended to be warmer and wetter.The short-term warming increased soil temperature by 2.44℃and decreased soil moisture by 12.47%,whereas the long-term warming increased soil temperature by 1.76℃and decreased soil moisture by 9.90%.This caused the shallow soil layer to become warmer and drier under both short-term and long-term warming.Furthermore,the degree of soil drought was alleviated with increased warming duration.Under the long-term warming,the importance value and aboveground biomass of plants in different families changed.The importance values of grasses and sedges decreased by 47.56%and 3.67%,respectively,while the importance value of weeds increased by 1.37%.Aboveground biomass of grasses decreased by 36.55%,while those of sedges and weeds increased by 8.09%and 15.24%,respectively.The increase in temperature had a non-significant eff展开更多
This study addressed the floral component traits and biomass allocation patterns of Gentiana hexaphylla as well as the relationships of these parameters along an elevation gradient(approximately 3700 m, 3800 m, 3900 m...This study addressed the floral component traits and biomass allocation patterns of Gentiana hexaphylla as well as the relationships of these parameters along an elevation gradient(approximately 3700 m, 3800 m, 3900 m, and 4000 m) on the eastern Qinghai-Tibet Plateau. The plant height, floral characteristics, and biomass allocation of G. hexaphylla were measured at different altitudes after field sampling, sorting, and drying. Plant height was significantly greater at 3700 m than that at other elevations. Flower length was significantly greater at 4000 m than that at other elevations, whereas the flower length at low elevations showed no significant differences. Corolla diameter increased with altitude, although the difference was not significant between 3800 m and 3900 m. Variations in biomass accumulation, including the aboveground, photosynthetic organ, flower and belowground biomasses, showed non-linear responses to changes in altitude. The aboveground and photosynthetic organ biomasses reached their lowest values at 4000 m, whereas the belowground and flower biomassreached minimum values at 3700 m. The sexual reproductive allocation of G. hexaphylla also increased with altitude, with a maximum observed at 4000 m. These results suggest that external environmental factors and altitudinal gradients as well as the biomass accumulation and allocation of G. hexaphylla play crucial roles in plant traits and significantly affect the ability of this species to adapt to harsh environments. The decreased number of flowers observed at higher altitudes may indicate a compensatory response for the lack of pollinators at high elevations, which is also suggested by the deformed flower shapes at high altitudes. In addition, the individual plant biomass(i.e., plant size) had significantly effect on flower length and corolla diameter. Based on the organ biomass results, the optimal altitude for G. hexaphylla in the eastern Qinghai-Tibet Plateau is 3800 m, where the plant exhibits minimum propagule biomass and asexual reproduct展开更多
Background:Grasslands provide a wide range of ecosystem services(ESs).However,there is currently no method for easily diagnosing the level of ESs produced.Our aim was to develop ES indicators based on botanical survey...Background:Grasslands provide a wide range of ecosystem services(ESs).However,there is currently no method for easily diagnosing the level of ESs produced.Our aim was to develop ES indicators based on botanical surveys,which are readily available data and integrative of grassland spatiotemporal variability.Methods:Based on academic knowledge and expertise,we identified several simple vegetation criteria that we aggregated using a multicriteria analysis tool to construct indicators of the level of ESs provided by grasslands.In this study,the indicators were calculated from over 2000 botanical surveys spread over a wide biogeographical gradient.Results:Analyses of correlation between the various indicators show that“forage supply”and“diversity conservation”were not correlated.“Forage availability”and“nitrogen availability for the vegetation”were positively linked together and negatively linked to the robustness of the plant community to extreme events.A temporal approach highlights that the“biodiversity conservation”score decreased from 1970 to 2010 and that“nitrogen availability for the vegetation”was lower in 1970 and 1980 than in 2000 and 2010.Conclusions:These results show that our aggregation method based on a large data set of botanical surveys could be appropriate for studying temporal dynamics of ESs.展开更多
The impact of summer cattle grazing on water quality during three very different climatic years in the Sierra Nevada was investigated. Water year 2009 had near normal precipitation;2010 had late precipitation and snow...The impact of summer cattle grazing on water quality during three very different climatic years in the Sierra Nevada was investigated. Water year 2009 had near normal precipitation;2010 had late precipitation and snowmelt;and 2011 had 150% above normal precipitation. Surface waters were tested for pathogenic bacteria indicators fecal coliform, E. coli, and total coliform before and after cattle were released onto summer grazing allotments. Water samples were collected from meadow stream sites up to 6 weeks before and up to 6 weeks after cattle grazing began. Streams passing through ungrazed meadow served as controls. Eight sample sites were between 1694 m and 2273 m in elevation;one site was lower at 1145 m in elevation. Samples were transported within 6 hours to a water analysis laboratory, where samples were analyzed following standardized laboratory methods. Results showed that individual site and total mean concentrations of E. coli in surface waters were within regulatory standards before cattle arrived during each of the 3 study years. After the beginning of grazing, mean E. coli counts increased as follows: 2009 from 8 to 240 CFU/100mL, 2010 from 7 to 561 CFU/10mL;2011 from 7 to 657 CFU/100mL (p < 0.05 all years). Total coliform bacteria and fecal coliform concentrations showed the same pattern. This study shows that cattle grazing in the high elevation Sierra Nevada results in a significant increase in indicator bacteria. This impact on the watersheds occurs despite widely variable annual climatic conditions.展开更多
Urban areas are a major source of anthropogenic carbon dioxide (CO<sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">) emissions ...Urban areas are a major source of anthropogenic carbon dioxide (CO<sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">) emissions because of road traffic and local heating with natural gas, oil or coal. Rome is among the largest European cities (129,000 ha) with a large volume of green areas (69.6% of the total Municipality area). The CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> sequestration (CS) capability for the greenery extending for about 300 km</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> inside the area delimited by the Great Ring Road (GRA) in Rome was calculated combining satellite data with CS data measured in the field. Data from Sentinel-2 were collected and the Normalized Difference Vegetation Index (NDVI) was computed on a pixel-base. Three plant classes homogeneous in terms of annual NDVI profile were identified: deciduous trees (DT), evergreen trees (ET) and meadows (M) covering an area of 14,142.027 ha within the GRA, of which M had the highest percentage (48%), followed by DT (27%) and ET (25%). CS ranged from 428,241</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">492.9 </span><span style="font-family:Verdana;">T</span><span style="font-family:;" "=""><span style="font-family:Verdana;">ons CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> year</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (ET) to 263,072</span></span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;">460.6 Tons CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> year</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (M). The total CS of the greenery inside the GRA was 1049,490,355.4 Tons CO</span><sub><展开更多
Fish species composition and spatio-temporal variability of the community were studied in a tropical seagrass meadow located in a lagoon in the eastern part of North Sulawesi. The diversity of fish community in the se...Fish species composition and spatio-temporal variability of the community were studied in a tropical seagrass meadow located in a lagoon in the eastern part of North Sulawesi. The diversity of fish community in the seagrass meadows was relatively high, with the Shannon-Wiener index ranging from 1.57 to 3.69. The family Apogonidae was the most dominant in abundance(8.27 ind./(100 m2)) and biomass(28.49 g/(100 m2)). At the species level,Apogon lateralis and Sphaeramia orbicularis were the most dominant species in abundance and biomass,respectively. For spatial distribution on species, the end, middle and mouth of the lagoon clustered together as a whole, which may be due to the substrate types found in those zones. The fish species, fish abundance and fish biomass were greater in the dry and wet seasons than in the transition season, which is explained by the strong monsoon, which provides a more suitable environment and food for the fish. The maximum length of 93.10% of the captured species was less than their length at maturity, indicating that seagrass meadows are nursery habitats for many fishes. Therefore, protection of the seagrass meadows is essential for fisheries and sustainable resource utilization.展开更多
Aims Variations in vegetation spring phenology are widely attributed to temperature in temperate and cold regions.However,temperature effect on phenology remains elusive in cold and arid/semiarid ecosystems because so...Aims Variations in vegetation spring phenology are widely attributed to temperature in temperate and cold regions.However,temperature effect on phenology remains elusive in cold and arid/semiarid ecosystems because soil water condition also plays an important role in mediating phenology.Methods We used growing degree day(GDD)model and growing season index(GSI)model,coupling minimum temperature(T_(min))with soil moisture(SM)to explore the influence of heat requirement and hydroclimatic interaction on the start of carbon uptake period(SCUP)and net ecosystem productivity(NEP)in two alpine meadows with different precipitation regimes on the Qinghai-Tibet Plateau(QTP).One is the water-limited alpine steppe-meadow,and the other is the temperature-limited alpine shrub-meadow.Important Findings We observed two clear patterns linking GDD and GSI to SCUP:SCUP was similarly sensitive to variations in preseason GDD and GSI in the humid alpine shrub-meadow,while SCUP was more sensitive to the variability in preseason GSI than GDD in the semiarid alpine steppe-meadow.The divergent patterns indicated a balance of the limiting climatic factors between temperature and water availability.In the humid meadow,higher temperature sensitivity of SCUP could maximize thermal benefit without drought stress,as evidenced by the stronger linear correlation coefficient(R2)and Akaike’s information criterion(AIC)between observed SCUPs and those of simulated by GDD model.However,greater water sensitivity of SCUP could maximize the benefit of water in semiarid steppe-meadow,which is indicated by the stronger R2 and AIC between observed SCUPs and those of simulated by GSI model.Additionally,although SCUPs were determined by GDD in the alpine shrub-meadow ecosystem,NEP was both controlled by accumulative GSI in two alpine meadows.Our study highlights the impacts of hydroclimatic interaction on spring carbon flux phenology and vegetation productivity in the humid and semiarid alpine ecosystems.The results also suggest that water,together with temp展开更多
In the Garhwal of Uttarakhand, India, the Bhotiya, an ethnically and culturally distinct tribal group, were historically engaged in seasonal migration(i.e. transhumance) to take advantage of scarce mountain resources ...In the Garhwal of Uttarakhand, India, the Bhotiya, an ethnically and culturally distinct tribal group, were historically engaged in seasonal migration(i.e. transhumance) to take advantage of scarce mountain resources and trade relations with Tibet. This livelihood practice has all but disappeared.Households are adapting to these changing circumstances by engaging in the collection and sale of the valuable alpine medicinal fungus Ophiocordyceps sinensis, widely known as Cordyceps. The collection of this fungus has exploded, emerging as a lucrative yet high-risk livelihood strategy for many Bhotiya communities.The Bhotiyas' historic herding and trade-based interactions and knowledge of these alpine environments where Cordyceps are found uniquely positions them to access this valuable biological resource. Elsewhere in the Himalayan region, some households are earning as much as two-thirds of their income from the collection of Cordyceps; in China Cordyceps is now listed as an endangered species due to intense over-exploitation in the Tibetan Plateau.This paper seeks to fill the void in the scientific literature on the social, ecological and economic aspects of the emerging Cordyceps trade in the Garhwal. Our study investigates the socio-spatial dimensions of Cordyceps collection in the high alpine meadows. We document how a fusion of local knowledge and practice with alpine mountain systems has served to reinvigorate the economic integrity of mountain communities at a time of rapid socioeconomic change and to reimagine a new relationship between alpine resources and community well-being.The article offers suggestions to address the sustainability of both Cordyceps collection and livelihood activities which hinge on this fungus population. We find a need for(1) community-based conservation measures that are rooted in(2) secure resource access rights for local communities to continue sustainable collection and sale of Cordyceps and(3) participatory-and science-based processes for determining appropriate local collecti展开更多
Seagrass meadows are generally diverse in China and have become important ecosystem with essential functions.However,the seagrass distribution across the seawaters of China has not been evaluated,and the magnitude and...Seagrass meadows are generally diverse in China and have become important ecosystem with essential functions.However,the seagrass distribution across the seawaters of China has not been evaluated,and the magnitude and direction of changes in seagrass meadows remain unclear.This study aimed to provide a nationwide seagrass distribution map and explore the dynamic changes in seagrass population under global climate change.Simulation studies were performed using the modeling software MaxEnt with 58961 occurrence records and 27 marine environmental variables to predict the potential distribution of seagrasses and calculate the area.Seven environmental variables were excluded from the modeling processes based on a correlation analysis to ensure predicted suitability.The predicted area was 790.09 km^(2),which is much larger than the known seagrass distribution in China(87.65 km^(2)).By 2100,the suitable habitat of seagrass will shift northwest and increase to 923.62 km2.Models of the sum of the individual family under-pre-dicted the national distribution of seagrasses and consistently showed a downward trend in the future.Out of all environmental vari-ables,physical parameters(e.g.,depth,land distance,and sea surface temperature)contributed the most in predicting seagrass distri-butions,and nutrients(e.g.,nitrate,phosphate)ranked among the key influential predictors for habitat suitability in our study area.This study is the first effort to fill a gap in understanding the distribution of seagrasses in China.Further studies using modeling and biological/ecological approaches are warranted.展开更多
Rangelands occupy more than 80% of the agricultural land in Kyrgyzstan. At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basi...Rangelands occupy more than 80% of the agricultural land in Kyrgyzstan. At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people＇s livelihoods, rangeland degradation presents a threat for the majority of the population. We present for the first time an ecological assessment of different pasture types in a remote area of the Naryn Oblast, using vegetation and softs as indicators of rangeland conditions. We analysed the current degree of utilization （grazing pressure）, the amount of biomass, soil samples, and vegetation data, using cluster analysis as well as ordination techniques. Winter pastures （kyshtoo） are characterized by higher pH values （average of 7.27） and lower organic matter contents （average of 12.83%） compared to summer pastures （dzailoo） with average pH values of 6.03 and average organic matter contents of 21.05%. Additionally, summer pastures show higher above- ground biomass, and higher species richness and diversity. Our results support the hypothesis that winter pastures, which are located near settlements, suffer from over-utilisation, while the more distant summer pastures are subjected to much lower grazing pressure,展开更多
Agrarian system is well adapted in Himalayan eco-system. Hence, the people have adopted the traditional subsistence cereal farming and it becomes the main stay of Himalayan people. About 80 percent of the workable for...Agrarian system is well adapted in Himalayan eco-system. Hence, the people have adopted the traditional subsistence cereal farming and it becomes the main stay of Himalayan people. About 80 percent of the workable force is attached with agriculture and its allied practices, according to the census of 1991. Although, horticultural farming runs parallel with agriculture, its proportion in terms of land is quite less, resulted in a negligible place in the economy of the region. Human resources, mainly men are attached with national security after recruitment in Army. While, women play a vital and integrated role in maintaining the workable potential in the field of agriculture and are known as backbone of economy. An animal resource implies foremost and wider part in agricultural system and economy as well. Water resources are unutilized yet, while almost all the major rivers of our country are originated from and flowing through this region. Increasing population causes forest resources depletion. The economy of the region is rested either on 憈raditional cereal farming?or 憁oney order based?development, which could not take place due to its remoteness from the main streams of the country. The impact of modern technology with innovation in agricultural system remains impracticable due to unwillingness of people in one hand and on the other hand, adverse geographical conditions like topography, climate etc. which could not permit the uses of modern innovation in the field of agriculture. As for infra-structurally,this region is lacked behind, due to its inaccessibility. While, this region is bestowed with numerous rivers, many places for tourists and pilgrims, and huge forest resources. They might be used evenly in the development processes. The practice of tourism will help for the further development, particularly, in the wake of the newly born state, Uttaranchal. The present paper aims to evaluate the present potentiality of resources and their balanced utilization in the Pindar Basin. A precise study has been 展开更多
Aims Woody invasions into grasslands have increased globally due to changing land use,climate and introduced woody species,but spatial processes generating and sustaining these invasions are not well understood.To gai...Aims Woody invasions into grasslands have increased globally due to changing land use,climate and introduced woody species,but spatial processes generating and sustaining these invasions are not well understood.To gain insight into the patterns of spread of tree populations within grasslands,and to propose a full spatial analytical toolbox for studying native and non-native woody spe-cies spread when long-term data are not available,we tested if 50 years of grassland invasion in Western Carpathians by Norway spruce(Picea abies Karst.)proceeded by one of the two tradi-tionally competing hypotheses of species spread:(i)by frontier expansion,or(ii)by advanced groups established ahead of the population frontier.We also tested whether the pattern of invasion changed over time.Methods We analyzed the spatial demographic and genetic patterns of a Norway spruce population invading a Western Carpathian grass-land using ripley’s L(t)and genetic kinship coefficients(Fij).We mapped and genotyped spruce trees across the invasion front(from the invasion leading edge to fully colonized grassland near the source population)using three demographic classes(adults,juve-niles and seedlings)to approximate the temporal aspects of the invasion.We studied how the spatial patterns of invasion by indi-vidual demographic classes and their genetic kinship varied among adjacent plots established at different distances from the source population(ranging from 0 to 160 m,in 40-m distance increments).Important Findings Juveniles were positively genetically related to adults on fine scales(<4 m),suggesting that adults within the grassland acted as a seed source and accelerated early invasion.However,adults did not act as nucleation centers for the formation of advanced juvenile groups.Instead,geneti-cally unrelated juveniles formed groups independently of adults.These groups were small and separate at the leading edge but they increased in size and graded into a continuous zone near the source population.Thus,juvenile recruitment occurred as a 展开更多
On the basis of multifaceted investigations of approximately 600 phytosociological surveys of foxtail meadows taken in years 2002-2012 in river valleys with the assistance of the Braun-Blanquet method, the authors car...On the basis of multifaceted investigations of approximately 600 phytosociological surveys of foxtail meadows taken in years 2002-2012 in river valleys with the assistance of the Braun-Blanquet method, the authors carried out evaluation of the floristic composition with respect to phytosociological structure, floristic variability, degree of synanthropisation and life form structures. In addition, they ascertained the dependence of floristic variability of Alopecuretum pratensis phytocenoses on site conditions determined using： the phytoindication method and the laboratory analyses assessed the soil content of available forms of P and K and of Mg. The greatest areas among the recognised syntaxons are taken up by patches of a typical sub-association developed in fresh sites on soils of lightly acid reaction and moderate nitrogen availability. Floristic variability of Alopecuretum pratensis is characterised by： presence in the phytosociological structure of species characteristic for other syntaxons, floristic abundance and botanical structure, domination of species of the 1 st and 2nd degree of stability, high proportion of synanthropic species, values of the floristic diversity index （H＇）, natural and fodder score values. Geobotanical variability of foxtail meadows confirms difficulties with unequivocal determination of the systematic position of the Alopecuretum pratensis association.展开更多
In planning the George W.Bush Presidential Center in Dallas,Texas,former First Lady Laura Bush presented a very clear vision of what the Center should epitomize:“Because George was the first president of the new mill...In planning the George W.Bush Presidential Center in Dallas,Texas,former First Lady Laura Bush presented a very clear vision of what the Center should epitomize:“Because George was the first president of the new millennium,I wanted it to be forward and modern.”1 For the president and Mrs.Bush this meant making the building and landscape environmentally responsible,beautiful,and welcoming.In particular,their love of native Texas landscapes was an important framework for transforming the project’s urban site into a park that was sustainable and experientially rich for visitors.Sustainability was addressed from the start with smart planning that privileged contiguous parkland over impermeable surfaces and structures.Simultaneous consideration of every landscape component—-stormwater,plants,soil,topography,and more—netted cohesive natural systems that are better able to succeed with short-term establishment and provide enduring long-term health,the ultimate goals for a sustainable landscape.展开更多
基金This study was financially supported by the National Natural Science Foundation of China(41501219)the Applied Basic Research Project of Shanxi Province(2016021136)+2 种基金the National College Students'Innovative Entrepreneurial Training Plan Program of China(201910119007)the Research Project of Philosophy and Social Sciences in Colleges and Universities of Shanxi Province(2019W134)the Soft Science Research Project of Shanxi Province(2018041072-1).
文摘Ecosystems in high-altitude regions are more sensitive and respond more rapidly than other ecosystems to global climate warming.The Qinghai-Tibet Plateau(QTP)of China is an ecologically fragile zone that is sensitive to global climate warming.It is of great importance to study the changes in aboveground biomass and species diversity of alpine meadows on the QTP under predicted future climate warming.In this study,we selected an alpine meadow on the QTP as the study object and used infrared radiators as the warming device for a simulation experiment over eight years(2011-2018).We then analyzed the dynamic changes in aboveground biomass and species diversity of the alpine meadow at different time scales,including an early stage of warming(2011-2013)and a late stage of warming(2016-2018),in order to explore the response of alpine meadows to short-term(three years)and long-term warming(eight years).The results showed that the short-term warming increased air temperature by 0.31℃and decreased relative humidity by 2.54%,resulting in the air being warmer and drier.The long-term warming increased air temperature and relative humidity by 0.19℃and 1.47%,respectively,and the air tended to be warmer and wetter.The short-term warming increased soil temperature by 2.44℃and decreased soil moisture by 12.47%,whereas the long-term warming increased soil temperature by 1.76℃and decreased soil moisture by 9.90%.This caused the shallow soil layer to become warmer and drier under both short-term and long-term warming.Furthermore,the degree of soil drought was alleviated with increased warming duration.Under the long-term warming,the importance value and aboveground biomass of plants in different families changed.The importance values of grasses and sedges decreased by 47.56%and 3.67%,respectively,while the importance value of weeds increased by 1.37%.Aboveground biomass of grasses decreased by 36.55%,while those of sedges and weeds increased by 8.09%and 15.24%,respectively.The increase in temperature had a non-significant eff
基金sponsored by the National Natural Science Foundation (Grant No.313705594, 31400389)China Postdoctoral ScienceFoundation under Grant (2014M552385)the International Science & Technology Cooperation Program of China (Grant No. 2013DFR90670)
文摘This study addressed the floral component traits and biomass allocation patterns of Gentiana hexaphylla as well as the relationships of these parameters along an elevation gradient(approximately 3700 m, 3800 m, 3900 m, and 4000 m) on the eastern Qinghai-Tibet Plateau. The plant height, floral characteristics, and biomass allocation of G. hexaphylla were measured at different altitudes after field sampling, sorting, and drying. Plant height was significantly greater at 3700 m than that at other elevations. Flower length was significantly greater at 4000 m than that at other elevations, whereas the flower length at low elevations showed no significant differences. Corolla diameter increased with altitude, although the difference was not significant between 3800 m and 3900 m. Variations in biomass accumulation, including the aboveground, photosynthetic organ, flower and belowground biomasses, showed non-linear responses to changes in altitude. The aboveground and photosynthetic organ biomasses reached their lowest values at 4000 m, whereas the belowground and flower biomassreached minimum values at 3700 m. The sexual reproductive allocation of G. hexaphylla also increased with altitude, with a maximum observed at 4000 m. These results suggest that external environmental factors and altitudinal gradients as well as the biomass accumulation and allocation of G. hexaphylla play crucial roles in plant traits and significantly affect the ability of this species to adapt to harsh environments. The decreased number of flowers observed at higher altitudes may indicate a compensatory response for the lack of pollinators at high elevations, which is also suggested by the deformed flower shapes at high altitudes. In addition, the individual plant biomass(i.e., plant size) had significantly effect on flower length and corolla diameter. Based on the organ biomass results, the optimal altitude for G. hexaphylla in the eastern Qinghai-Tibet Plateau is 3800 m, where the plant exhibits minimum propagule biomass and asexual reproduct
文摘Background:Grasslands provide a wide range of ecosystem services(ESs).However,there is currently no method for easily diagnosing the level of ESs produced.Our aim was to develop ES indicators based on botanical surveys,which are readily available data and integrative of grassland spatiotemporal variability.Methods:Based on academic knowledge and expertise,we identified several simple vegetation criteria that we aggregated using a multicriteria analysis tool to construct indicators of the level of ESs provided by grasslands.In this study,the indicators were calculated from over 2000 botanical surveys spread over a wide biogeographical gradient.Results:Analyses of correlation between the various indicators show that“forage supply”and“diversity conservation”were not correlated.“Forage availability”and“nitrogen availability for the vegetation”were positively linked together and negatively linked to the robustness of the plant community to extreme events.A temporal approach highlights that the“biodiversity conservation”score decreased from 1970 to 2010 and that“nitrogen availability for the vegetation”was lower in 1970 and 1980 than in 2000 and 2010.Conclusions:These results show that our aggregation method based on a large data set of botanical surveys could be appropriate for studying temporal dynamics of ESs.
文摘The impact of summer cattle grazing on water quality during three very different climatic years in the Sierra Nevada was investigated. Water year 2009 had near normal precipitation;2010 had late precipitation and snowmelt;and 2011 had 150% above normal precipitation. Surface waters were tested for pathogenic bacteria indicators fecal coliform, E. coli, and total coliform before and after cattle were released onto summer grazing allotments. Water samples were collected from meadow stream sites up to 6 weeks before and up to 6 weeks after cattle grazing began. Streams passing through ungrazed meadow served as controls. Eight sample sites were between 1694 m and 2273 m in elevation;one site was lower at 1145 m in elevation. Samples were transported within 6 hours to a water analysis laboratory, where samples were analyzed following standardized laboratory methods. Results showed that individual site and total mean concentrations of E. coli in surface waters were within regulatory standards before cattle arrived during each of the 3 study years. After the beginning of grazing, mean E. coli counts increased as follows: 2009 from 8 to 240 CFU/100mL, 2010 from 7 to 561 CFU/10mL;2011 from 7 to 657 CFU/100mL (p < 0.05 all years). Total coliform bacteria and fecal coliform concentrations showed the same pattern. This study shows that cattle grazing in the high elevation Sierra Nevada results in a significant increase in indicator bacteria. This impact on the watersheds occurs despite widely variable annual climatic conditions.
文摘Urban areas are a major source of anthropogenic carbon dioxide (CO<sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">) emissions because of road traffic and local heating with natural gas, oil or coal. Rome is among the largest European cities (129,000 ha) with a large volume of green areas (69.6% of the total Municipality area). The CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> sequestration (CS) capability for the greenery extending for about 300 km</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> inside the area delimited by the Great Ring Road (GRA) in Rome was calculated combining satellite data with CS data measured in the field. Data from Sentinel-2 were collected and the Normalized Difference Vegetation Index (NDVI) was computed on a pixel-base. Three plant classes homogeneous in terms of annual NDVI profile were identified: deciduous trees (DT), evergreen trees (ET) and meadows (M) covering an area of 14,142.027 ha within the GRA, of which M had the highest percentage (48%), followed by DT (27%) and ET (25%). CS ranged from 428,241</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">492.9 </span><span style="font-family:Verdana;">T</span><span style="font-family:;" "=""><span style="font-family:Verdana;">ons CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> year</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (ET) to 263,072</span></span><span style="font-family:Verdana;">,</span><span style="font-family:;" "=""><span style="font-family:Verdana;">460.6 Tons CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> year</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (M). The total CS of the greenery inside the GRA was 1049,490,355.4 Tons CO</span><sub><
基金The China-Indonesia Maritime Cooperation Fund Project "China-Indonesia Bitung Ecological Station Establishment"the National Natural Science Foundation of China under contract Nos 41676096 and 41506123+3 种基金the Biodiversity of Coastal Ecosystem,Kema,North Sulawesithe Scientific Research Foundation of Third Institute of Oceanography,SOA under contract No.2015024the National Key Research and Development Program of China under contract Nos 2017YFC1405101 and2017YFC0506105the Public Science and Technology Research Funds Projects of Ocean under contract No.201505009
文摘Fish species composition and spatio-temporal variability of the community were studied in a tropical seagrass meadow located in a lagoon in the eastern part of North Sulawesi. The diversity of fish community in the seagrass meadows was relatively high, with the Shannon-Wiener index ranging from 1.57 to 3.69. The family Apogonidae was the most dominant in abundance(8.27 ind./(100 m2)) and biomass(28.49 g/(100 m2)). At the species level,Apogon lateralis and Sphaeramia orbicularis were the most dominant species in abundance and biomass,respectively. For spatial distribution on species, the end, middle and mouth of the lagoon clustered together as a whole, which may be due to the substrate types found in those zones. The fish species, fish abundance and fish biomass were greater in the dry and wet seasons than in the transition season, which is explained by the strong monsoon, which provides a more suitable environment and food for the fish. The maximum length of 93.10% of the captured species was less than their length at maturity, indicating that seagrass meadows are nursery habitats for many fishes. Therefore, protection of the seagrass meadows is essential for fisheries and sustainable resource utilization.
基金supported by the National Natural Science Foundation of China(31870406,41661144045)the State Key Research and Development Program(2016YFC0502001,2017YFA0604801).
文摘Aims Variations in vegetation spring phenology are widely attributed to temperature in temperate and cold regions.However,temperature effect on phenology remains elusive in cold and arid/semiarid ecosystems because soil water condition also plays an important role in mediating phenology.Methods We used growing degree day(GDD)model and growing season index(GSI)model,coupling minimum temperature(T_(min))with soil moisture(SM)to explore the influence of heat requirement and hydroclimatic interaction on the start of carbon uptake period(SCUP)and net ecosystem productivity(NEP)in two alpine meadows with different precipitation regimes on the Qinghai-Tibet Plateau(QTP).One is the water-limited alpine steppe-meadow,and the other is the temperature-limited alpine shrub-meadow.Important Findings We observed two clear patterns linking GDD and GSI to SCUP:SCUP was similarly sensitive to variations in preseason GDD and GSI in the humid alpine shrub-meadow,while SCUP was more sensitive to the variability in preseason GSI than GDD in the semiarid alpine steppe-meadow.The divergent patterns indicated a balance of the limiting climatic factors between temperature and water availability.In the humid meadow,higher temperature sensitivity of SCUP could maximize thermal benefit without drought stress,as evidenced by the stronger linear correlation coefficient(R2)and Akaike’s information criterion(AIC)between observed SCUPs and those of simulated by GDD model.However,greater water sensitivity of SCUP could maximize the benefit of water in semiarid steppe-meadow,which is indicated by the stronger R2 and AIC between observed SCUPs and those of simulated by GSI model.Additionally,although SCUPs were determined by GDD in the alpine shrub-meadow ecosystem,NEP was both controlled by accumulative GSI in two alpine meadows.Our study highlights the impacts of hydroclimatic interaction on spring carbon flux phenology and vegetation productivity in the humid and semiarid alpine ecosystems.The results also suggest that water,together with temp
基金funded in part by the College of Forestry and Conservation at the University of Montana,MissoulaThe logistical support and research assistance provided by the Mountain Shepherds Initiative and the Nanda Devi Campaign based in Uttarakhand were paramount
文摘In the Garhwal of Uttarakhand, India, the Bhotiya, an ethnically and culturally distinct tribal group, were historically engaged in seasonal migration(i.e. transhumance) to take advantage of scarce mountain resources and trade relations with Tibet. This livelihood practice has all but disappeared.Households are adapting to these changing circumstances by engaging in the collection and sale of the valuable alpine medicinal fungus Ophiocordyceps sinensis, widely known as Cordyceps. The collection of this fungus has exploded, emerging as a lucrative yet high-risk livelihood strategy for many Bhotiya communities.The Bhotiyas' historic herding and trade-based interactions and knowledge of these alpine environments where Cordyceps are found uniquely positions them to access this valuable biological resource. Elsewhere in the Himalayan region, some households are earning as much as two-thirds of their income from the collection of Cordyceps; in China Cordyceps is now listed as an endangered species due to intense over-exploitation in the Tibetan Plateau.This paper seeks to fill the void in the scientific literature on the social, ecological and economic aspects of the emerging Cordyceps trade in the Garhwal. Our study investigates the socio-spatial dimensions of Cordyceps collection in the high alpine meadows. We document how a fusion of local knowledge and practice with alpine mountain systems has served to reinvigorate the economic integrity of mountain communities at a time of rapid socioeconomic change and to reimagine a new relationship between alpine resources and community well-being.The article offers suggestions to address the sustainability of both Cordyceps collection and livelihood activities which hinge on this fungus population. We find a need for(1) community-based conservation measures that are rooted in(2) secure resource access rights for local communities to continue sustainable collection and sale of Cordyceps and(3) participatory-and science-based processes for determining appropriate local collecti
基金supported by the National Key R&D Program of China(No.2019YFC1408405-02)the National Natural Science Foundation of China(No.6207070555)the Youth Foundation of the Shandong Academy of Sciences(No.2019QN0026).
文摘Seagrass meadows are generally diverse in China and have become important ecosystem with essential functions.However,the seagrass distribution across the seawaters of China has not been evaluated,and the magnitude and direction of changes in seagrass meadows remain unclear.This study aimed to provide a nationwide seagrass distribution map and explore the dynamic changes in seagrass population under global climate change.Simulation studies were performed using the modeling software MaxEnt with 58961 occurrence records and 27 marine environmental variables to predict the potential distribution of seagrasses and calculate the area.Seven environmental variables were excluded from the modeling processes based on a correlation analysis to ensure predicted suitability.The predicted area was 790.09 km^(2),which is much larger than the known seagrass distribution in China(87.65 km^(2)).By 2100,the suitable habitat of seagrass will shift northwest and increase to 923.62 km2.Models of the sum of the individual family under-pre-dicted the national distribution of seagrasses and consistently showed a downward trend in the future.Out of all environmental vari-ables,physical parameters(e.g.,depth,land distance,and sea surface temperature)contributed the most in predicting seagrass distri-butions,and nutrients(e.g.,nitrate,phosphate)ranked among the key influential predictors for habitat suitability in our study area.This study is the first effort to fill a gap in understanding the distribution of seagrasses in China.Further studies using modeling and biological/ecological approaches are warranted.
基金funded by BMBF(Bundesministerium für Bildung und Forschung,Germany)(Ff E_IB-074)the context of the joint project TRANSPAST
文摘Rangelands occupy more than 80% of the agricultural land in Kyrgyzstan. At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people＇s livelihoods, rangeland degradation presents a threat for the majority of the population. We present for the first time an ecological assessment of different pasture types in a remote area of the Naryn Oblast, using vegetation and softs as indicators of rangeland conditions. We analysed the current degree of utilization （grazing pressure）, the amount of biomass, soil samples, and vegetation data, using cluster analysis as well as ordination techniques. Winter pastures （kyshtoo） are characterized by higher pH values （average of 7.27） and lower organic matter contents （average of 12.83%） compared to summer pastures （dzailoo） with average pH values of 6.03 and average organic matter contents of 21.05%. Additionally, summer pastures show higher above- ground biomass, and higher species richness and diversity. Our results support the hypothesis that winter pastures, which are located near settlements, suffer from over-utilisation, while the more distant summer pastures are subjected to much lower grazing pressure,
文摘Agrarian system is well adapted in Himalayan eco-system. Hence, the people have adopted the traditional subsistence cereal farming and it becomes the main stay of Himalayan people. About 80 percent of the workable force is attached with agriculture and its allied practices, according to the census of 1991. Although, horticultural farming runs parallel with agriculture, its proportion in terms of land is quite less, resulted in a negligible place in the economy of the region. Human resources, mainly men are attached with national security after recruitment in Army. While, women play a vital and integrated role in maintaining the workable potential in the field of agriculture and are known as backbone of economy. An animal resource implies foremost and wider part in agricultural system and economy as well. Water resources are unutilized yet, while almost all the major rivers of our country are originated from and flowing through this region. Increasing population causes forest resources depletion. The economy of the region is rested either on 憈raditional cereal farming?or 憁oney order based?development, which could not take place due to its remoteness from the main streams of the country. The impact of modern technology with innovation in agricultural system remains impracticable due to unwillingness of people in one hand and on the other hand, adverse geographical conditions like topography, climate etc. which could not permit the uses of modern innovation in the field of agriculture. As for infra-structurally,this region is lacked behind, due to its inaccessibility. While, this region is bestowed with numerous rivers, many places for tourists and pilgrims, and huge forest resources. They might be used evenly in the development processes. The practice of tourism will help for the further development, particularly, in the wake of the newly born state, Uttaranchal. The present paper aims to evaluate the present potentiality of resources and their balanced utilization in the Pindar Basin. A precise study has been
基金Slovak Grant Agency for Science(VEGA)(1/0126/03,1/0437/03,1/0362/13).
文摘Aims Woody invasions into grasslands have increased globally due to changing land use,climate and introduced woody species,but spatial processes generating and sustaining these invasions are not well understood.To gain insight into the patterns of spread of tree populations within grasslands,and to propose a full spatial analytical toolbox for studying native and non-native woody spe-cies spread when long-term data are not available,we tested if 50 years of grassland invasion in Western Carpathians by Norway spruce(Picea abies Karst.)proceeded by one of the two tradi-tionally competing hypotheses of species spread:(i)by frontier expansion,or(ii)by advanced groups established ahead of the population frontier.We also tested whether the pattern of invasion changed over time.Methods We analyzed the spatial demographic and genetic patterns of a Norway spruce population invading a Western Carpathian grass-land using ripley’s L(t)and genetic kinship coefficients(Fij).We mapped and genotyped spruce trees across the invasion front(from the invasion leading edge to fully colonized grassland near the source population)using three demographic classes(adults,juve-niles and seedlings)to approximate the temporal aspects of the invasion.We studied how the spatial patterns of invasion by indi-vidual demographic classes and their genetic kinship varied among adjacent plots established at different distances from the source population(ranging from 0 to 160 m,in 40-m distance increments).Important Findings Juveniles were positively genetically related to adults on fine scales(<4 m),suggesting that adults within the grassland acted as a seed source and accelerated early invasion.However,adults did not act as nucleation centers for the formation of advanced juvenile groups.Instead,geneti-cally unrelated juveniles formed groups independently of adults.These groups were small and separate at the leading edge but they increased in size and graded into a continuous zone near the source population.Thus,juvenile recruitment occurred as a
文摘On the basis of multifaceted investigations of approximately 600 phytosociological surveys of foxtail meadows taken in years 2002-2012 in river valleys with the assistance of the Braun-Blanquet method, the authors carried out evaluation of the floristic composition with respect to phytosociological structure, floristic variability, degree of synanthropisation and life form structures. In addition, they ascertained the dependence of floristic variability of Alopecuretum pratensis phytocenoses on site conditions determined using： the phytoindication method and the laboratory analyses assessed the soil content of available forms of P and K and of Mg. The greatest areas among the recognised syntaxons are taken up by patches of a typical sub-association developed in fresh sites on soils of lightly acid reaction and moderate nitrogen availability. Floristic variability of Alopecuretum pratensis is characterised by： presence in the phytosociological structure of species characteristic for other syntaxons, floristic abundance and botanical structure, domination of species of the 1 st and 2nd degree of stability, high proportion of synanthropic species, values of the floristic diversity index （H＇）, natural and fodder score values. Geobotanical variability of foxtail meadows confirms difficulties with unequivocal determination of the systematic position of the Alopecuretum pratensis association.
文摘In planning the George W.Bush Presidential Center in Dallas,Texas,former First Lady Laura Bush presented a very clear vision of what the Center should epitomize:“Because George was the first president of the new millennium,I wanted it to be forward and modern.”1 For the president and Mrs.Bush this meant making the building and landscape environmentally responsible,beautiful,and welcoming.In particular,their love of native Texas landscapes was an important framework for transforming the project’s urban site into a park that was sustainable and experientially rich for visitors.Sustainability was addressed from the start with smart planning that privileged contiguous parkland over impermeable surfaces and structures.Simultaneous consideration of every landscape component—-stormwater,plants,soil,topography,and more—netted cohesive natural systems that are better able to succeed with short-term establishment and provide enduring long-term health,the ultimate goals for a sustainable landscape.
