Estimation of Economic and Ecological Value of Raising Sheep in Pastoral Area

Tibetan sheep is a unique breed of livestock in Alpine pastoral areas,which is one of the main economic pillars of animal husbandry in pastoral areas,in order to analyze and compare the estimated the economic and ecological benefits of Tibetan sheep under different feeding modes,this paper used a simplified model from multiple angles of animal production,economics and Ecology,The results show that:(i)Under the traditional grazing condition,the annual income of raising one ewe is only 23.4 yuan;(ii)Under the high-efficiency breeding mode,the average income of ewes bred by high-efficiency technology was 168 yuan/(head·year),which was 7 times higher than that of ewes under traditional grazing;each lamb could produce an indirect economic benefit of 500 yuan;(iii)The ecosystem service value affected by each Tibetan sheep through grassland was above 150000 yuan.

Trophic niche and adaptation in highland lizards:sex has greater influences than species matching

The plateau environments are typically arid,cool,and high altitude,posing formidable challenges to wildlife survival due to resource scarcity and harsh conditions.Unraveling ecological adaptability in severe conditions requires a deeper understanding of the niche characteristics of plateau species.Trophic niche,which is a comprehensive indicator describing the energy acquisition strategy of animals,remains relatively understudied in plateau species.Here,by combining stable isotopes and morphological data,we quantified the trophic niches of two allopatric lizard species(Phrynocephalus vlangalii and P.erythrurus)that live in the hinterland of the Qinghai–Tibetan Plateau,and explored how their trophic niches correlate with morphological and environmental factors.While both trophic niche and morphological traits were similar between species,noteworthy distinctions were observed between male and female Phrynocephalus lizards.The morphological traits associated with predation(i.e.limb length and head size)and reproduction(i.e.abdomen length),annual mean temperature,and sex played influential roles in shifting trophic niches.These results imply that sexual dimorphism may facilitate inter-sex divergence in resource utilization,leading to trophic niche variations in the highland lizards.Furthermore,extreme environmental stress can constrain interspecific divergence in morphological and trophic traits.Our findings illustrate the dynamic variations of trophic niches in highland lizards,contributing to a more comprehensive understanding of the adaptation strategies employed by lizard species in plateau environments.

青藏高原植被结构变化反映环境变迁

草地植被结构对于其生产和生态功能至关重要,但大尺度信息严重匮乏.本研究结合多源遥感数据和深度学习,在区域尺度上厘清了青藏高原高寒草地基于群系的植物群落结构空间格局,并比较了其历史变化.过去40年,高寒草甸在高寒草地中的比例从50%上升到69%,反映了变暖变湿的环境变化.此外,高寒草甸和高寒草原中高山嵩草草甸和紫花针茅草原的优势度分别增强到76%和92%.其中,气候因子驱动了紫花针茅草原近些年的分布;高山嵩草草甸近些年的分布则并非完全由气候驱动,人类活动可能起重要作用.本研究首次探索了区域尺度植被结构特征与历史变化,为认识青藏高原草地变化的驱动力及其空间异质性提供了新视角.

重新认知青藏高原围栏禁牧的作用

围栏禁牧是中国政府为恢复青藏高原等地退化草地而采取的一项重要政策.然而,关于围栏对高寒草地生态系统功能和服务及其对牧民生计的影响,人们的认识还很有限.本研究荟萃分析和基于问卷的调查显示,围栏禁牧时间长达4年和8年的时间里可以有效地促进高寒草甸以及草原的地上植被生长,更长时间的围栏并没有带来任何生态和经济效益.研究还发现,围栏限制了野生动物的活动范围,增加了非围栏地区的放牧压力,降低了牧民的满意度,且给地区和国家政府带来了巨大的财政成本.因此,建议在适当的情况下,应鼓励传统的游牧方式来利用草地,在严重退化的草地上应采用短期围栏(4~8年),在重要的野生动物栖息地应避免使用围栏,特别是受保护的大型哺乳动物分布的区域.研究结果可为青藏高原草地可持续管理提供一定的参考.

Using balance of seasonal herbage supply and demand to inform sustainable grassland management on the Qinghai–Tibetan Plateau

To mitigate the impacts of grassland degradation on the Qinghai–Tibetan Plateau(QTP), in recent decades China has been implementing large-scale conservation programs and has invested about 42 billion CNY(7 billion USD). However, these programs are faced with major challenges involving trade-offs between ecological function, livestock production and income of pastoralists.Scientific assessments, as well as technical and policy issues, have not fully captured the complex ecological,social and economic dynamics of the challenges facing grassland management on the QTP. Pastoral livestock production on the QTP is characterized by imbalance in both quality and quantity between livestock seasonal nutrient requirements and herbage production, which forces pastoralists to keep larger numbers of livestock for longer periods, leading to overgrazing. To solve these problems, an integrated crop-livestock system is promoted to improve the efficiency of livestock production and conserve natural grassland as well for a sustainable system for the QTP.

Patterns of plant diversity at high altitudes on the Qinghai-Tibetan Plateau

To describe the biodiversity patterns of plants along an altitudinal gradient on the Qinghai-Tibetan Plateau and to clarify the bias in plant specimen records at high altitude.Methods We conducted a large-scale investigation of vegetation at a wide range of altitudes,focusing on a high-altitudinal range(3200-5200 m)at different locations on the Qinghai-Tibetan Plateau.We then compared the altitudinal distribution of plant species obtained from our field investigation with that in plant specimen records from published sources and an online database.Important Findings Our data provide evidence that altitude plays a large role in regulating species composition on the Qinghai-Tibetan Plateau.We could not,however,detect a clear relationship between altitude and species richness,although a weak monotonically increasing trend of richness was detected with increasing altitude.According to specimen records,most species have been sampled at a wide range of altitudes,and the average range of 145 species is>2000 m.Despite this wide range,more than half of the species we observed were at higher altitudes than the specimen records indicate.High-altitude areas have probably been so poorly sampled that only a small fraction of the resident species has been recorded.This study clearly shows the regional bias of specimen records in the Qinghai-Tibetan Plateau.

优化围栏管理措施以实现青藏高原可持续发展目标

The Tibetan Plateau is characterized by extreme weather,harsh environment,and high sensitivity to climate warming and human activities[1].Once degraded,it is difficult to rehabilitate the ecosystems in this region because of the unique environment.Consequently,alpine grassland ecosystems of the Tibetan Plateau play important roles in regional ecological security and economic development.Nevertheless,alpine grasslands have been experiencing serious degradation owing to the escalating impact of overgrazing and climate change in recent years[2].

Phosphorus does not alleviate the negative effect of nitrogen enrichment on legume performance in an alpine grassland

Aims Nitrogen(N)-fixing legumes,despite being highly phosphorus(P)-demanding,constitute an important plant functional group and play key roles in N-poor ecosystems such as alpine grasslands.However,legume performance,including biomass,abundance and species richness,is expected to change,because anthropogenic activities have drastically increased soil N and P availability world-wide.We conducted a field experiment to assess the effects of N and P addition,alone and in combination,on legume performance in an alpine grassland,and identified and clarified the mechanisms underlying these changes.Methods A three year field experiment of N addition(10 g N m−2 year−1),P addition(5 g P m−2 year−1),and N+P combined addition(both N and P,same amounts as solo treatments)was conducted in an alpine grassland on the tibetan Plateau in china from 2011 to 2013.Effects of nutrient addition were assessed at the community level(above-ground net primary production(ANPP),height and light intensity),functional group level(biomass,species richness,relative height,relative coverage and relative density of legumes)and species level(foliar N,P concentration of two legumes).Important findings Overall,adding N alone significantly increased ANPP by 20.82%,but adding P alone did not;whereas,addition of N and P together resulted in a large increase in ANPP(+37.03%)than addition of either alone,indicating potential co-limitation of alpine grasslands.In contrast,adding P alone significantly promoted legume perfor-mance as measured by 65.22%increase in biomass and 58.45%increase in relative abundance,while adding N alone reduced leg-ume performance as measured by 39.54%decrease in biomass and 50.36%in relative abundance.combining P and N addition did not mitigate the negative effect of N addition on legume performance and,surprisingly,suppressed legume biomass by 53.14%and relative abundance by 63.51%.N and P addition altered the balance of light competition between grasses and legumes as indicated by the changes in light levels,plant heights and litter accumulation.However,there were no obvious changes in legume species richness in response to N and P within our experimental timeframe.this study provides further evidence of the importance of P as a co-limiting nutrient in alpine grasslands,contrary to the traditional view that N limitation predominates in such regions.the contrasting effects of N and P addition on legume performance provide important insights into potential changes in legume performance in nutrient-limited grasslands following N and P enrichment under climate change,with implications for nutrient management in alpine grasslands.

The role of herbivores in the grassland carbon budget for Three-Rivers Headwaters region,Qinghai-Tibetan Plateau,China

Background:An accurate assessment of the carbon budget is a crucial part of projecting future climate change and its impact on ecosystems.Grasslands foster multiple ecological functions including support for wild animals and livestocks.Herbivores intake forage biomass carbon,then digest and metabolize,and finally retain some carbon.The carbon processes have not been well quantified,resulting in uncertainties in the estimation of regional carbon budgets for grassland ecosystems.Methods:An animal metabolic carbon flux model was developed for herbivores in the Three-Rivers Headwaters region of China.The forage intake and metabolic carbon rates were estimated through metabolic body weight and daily digested measures for the main herbivore species.Results:The carbon intake was 5.52 Tg C year−1(45%)from partial aboveground biomass(12.2 Tg C year−1),in which 39.31%was released into the atmosphere by respiration CO_(2),43.77%was returned to the ecosystem as feces and urine,and 16.96%was retained in herbivores for population regeneration or for human well-being.Conclusions:This study,as the first research on this topic,quantified the carbon flux of herbivores and found livestock accounts for a major part of consumed carbon on grasslands,which is important for understanding regional carbon budgets to mitigate and adapt to climate change over grasslands worldwide.

Contrasting altitudinal patterns of leaf UV reflectance and absorbance in four herbaceous species on the Qinghai-Tibetan Plateau

Aims Alpine plants have to cope with intense ultraviolet(UV)radiation and its altitudinal changes.It has been argued that leaf UV reflec-tance and absorbance should play a central role in acclimation and adaptation to changes in UV radiation,but evidence is lim-ited from high altitudinal ecosystems.In this study,we assessed whether leaf UV reflectance and leaf pigments jointly vary with altitude in alpine broadleaved herbaceous species.The primary hypothesis is that leaves with higher UV reflectance should have lower UV absorbance and/or lower contents of photosynthetic pigments.Methods Leaf UV reflectance,leaf UV absorbance and photosynthetic pig-ments(chlorophyll a and b,carotenoids)were examined in four broadleaved herbaceous species in relation to their habitat alti-tudes.The leaf surface reflectance and leaf extract absorbance at wavelengths of 305 and 360 nm were measured to examine the leaf optical and photochemical characteristics in the UV-B and UV-A bands,respectively.The species included Saussurea katochaete Maxim.,Saussurea pulchra Lipsch.,Anaphalis lactea Maxim.and Rheum pumilum Maxim.,which are distributed along the same slope from 3200 to 4200 m in the Qilian Mountains,Qinghai-Tibetan Plateau.Important Findings The leaf UV absorbance was approximately twice as high at 305 nm(UV-B)than at 360 nm(UV-A)for all species except R.pumilum.Among the four species,the leaf UV absorbance was the highest and almost all values were within 2-6 Abs cm^(−2)(absorbance cm^(−2))in S.pulchra,but the lowest(frequently<1 Abs cm^(−2))were observed in R.pumilum.Only R.pumilum showed significantly higher values at higher elevations.Leaf UV reflectance was generally higher at higher elevations for all species except for A.lactea,and exhibited much larger altitudinal variations compared to leaf UV absorbance.Anaphalis lactea showed a very high UV reflectance even at low altitudes.Among the four species,photosynthetic pigments tended to decrease with an increase in leaf UV reflectance but increased with leaf UV absorbance.The study suggests that leaf UV reflec-tance,rather than leaf UV absorbance,plays a more active role in acclimation to altitudinal changes in UV radiation,and a high investment in leaf UV reflectance may limit the accumulation of photosynthetic pigments in alpine plants.

Long-term warming does not affect soil ecoenzyme activity and original microbial nutrient limitation on the Qinghai-Tibet Plateau

Microbes play an important role in the carbon cycle and nutrient flow of the soil ecosystem.However,the response of microbial activities to long-term warming over decades is poorly understood.To determine how warming changes ecoenzyme activity and microbial nutrient limitation,we conducted a long-term,21 years,experiment,on the Qinghai–Tibet Plateau.We selected typical grass-and shrub-covered plots,used fiberglass open-top chambers(OTCs)to raise the temperature,conducted soil sampling at different depths,studied the response of nutrient-acquiring enzyme activity and stoichiometry,and conducted vector analysis of stoichiometry.Our results showed that long-term warming did not have a notable effect on the activity of nutrient-acquiring enzymes or enzymatic stoichiometry.However,Spearman correlation analysis indicated a significant and positive correlation between ecoenzyme activity and the available nutrients and microbial biomass in soil.Vector analysis of stoichiometry showed phosphorus limitation for all soil microbes at different depths,regardless of whether the soil experienced warming.These changes in enzymatic stoichiometry and vector analysis suggested that microbial nutrient limitation was not alleviated substantially by long-term warming,and warming did not considerably affect the stratification of microbial nutrient limitation.Our research has also shown that long-term warming does not significantly change soil ecoenzyme activity and original microbial nutrient limitation at different soil depths within the OTUsʼimpact range.These results could help improve understanding of microbial thermal acclimation and response to future long-term global warming.

Toward a sustainable grassland ecosystem worldwide

Globally,grasslands,covering about 40%of the Earth’s land area,are vital for supporting important ecosystem functions,services,and livelihoods of millions of humans.Currently,grassland degradation is a major threat to the maintenance of ecological services,1 food security,and sustainable development,and directly hinders the global efforts with meeting goals and targets such as the The UN Decade on Ecosystem Restoration and Sustainable Development Goals(SDGs).Remote sensing approaches have the advantages of spanning large geographical areas withmultiple spatial,spectral,and temporal resolutions.In global scale,remote sensing methods used normalized difference vegetation index to determine net primary productivity(NPP),which still is the effectivemethod to indicate grassland conditions.To master the general situation of grassland,we analyzed the global spatial-temporal variation of NPP from 2001 to 2019 at the pixel level across the globe.As presented in Figure 1A,the NPP values of global grasslands showed an obvious variation trend,which indicated a considerable distribution pattern of spatial heterogeneity.The decreasing and increasing trend in grassland NPP covered approximately 25.3%and 74.5%of the total grassland area,respectively.