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Abstract: Drylands, which occupy more than 40% of the Earth's land surface, are highly susceptible to degradation. It is important to understand causes, mechanisms, and environmental consequences of dryland ecosystem degradation. Land use policies are known to play a critical role in driving land cover changes, as well as in mitigating land degradation and promoting sustainable development in drylands. We analyzed the effects of different policies on vegetation cover and the attitude of local people toward policy changes in Uxin county, Inner Mongolia, China, based on remote sensed Normalized Difference Vegetation Index (NDVI) time series and household surveys. Overall vegetation in the study area was found to recover during 1987–2007. Multilevel statistical modeling results demonstrated that NDVI, density of agricultural population, density of livestock, land use, accessibility to market, and mean annual precipitation all had significant effects on re-vegetation. Changes in land use policy, which restricted farmers and herdsmen in certain land use practices and eliminated rangeland overload, were found to be an important driver of vegetation recovery during 1997–2007. Local households in the area generally approve the policy but adjust it according to their cultural traditions or land use practices. [Copyright &y& Elsevier]

Productivity-species diversity relationships have been a controversial research topic in ecology with scale believed to be among the main reasons for discovering different relationships. We collected data on species diversity (richness) and productivity (peak above-ground biomass) of the Stipa breviflora association in the Inner Mongolia grassland to examine spatial scale dependency and possible underlying mechanisms responsible for the relationships found. One local and seven different landscape scales (the first level corresponds in extent to a 100 × 100 km area, which is increased consecutively by 100 km resulting in the 700 × 700 km area at the highest level) were considered. We found that: (1) unimodal relationships dominated the local scale, but this varied depending on the position along successional gradients; (2) a positive linear relationship was common at larger spatial scales; (3) biotic processes were the most likely primary factor underlying local scale unimodal relationships, but environmental heterogeneity (precipitation patterns) was the main determinant of relationships found at larger spatial scales; (4) our study contributed to other empirical evidence and predictions of theoretical models regarding scale dependency of productivity-species richness relationships; (5) while earlier research demonstrated positive linear species richness-productivity relationships across a number of ecological scales in the Inner Mongolia steppe, our study specifically tested a spectrum of geographical scales to confirm the scale-dependency of this relationship. Lastly, our study emphasized the critical role played by precipitation patterns in controlling biodiversity and grassland ecosystem functioning, which maintains the relatively high level of biodiversity and stable ecosystem processes. [ABSTRACT FROM AUTHOR]

Land use/land cover (LULC) change and climate change are interconnected factors that affect the ecological environment. However, there is a lack of quantification of the impacts of LULC change and climate change on landscape ecological risk under different shared socioeconomic pathways and representative concentration pathways (SSP-RCP) on the Mongolian Plateau (MP). To fill this knowledge gap and understand the current and future challenges facing the MP's land ecological system, we conducted an evaluation and prediction of the effects of LULC change and climate change on landscape ecological risk using the landscape loss index model and random forest method, considering eight SSP-RCP coupling scenarios. Firstly, we selected MCD12Q1 as the optimal LULC product for studying landscape changes on the MP, comparing it with four other LULC products. We analyzed the diverging patterns of LULC change over the past two decades and observed significant differences between Mongolia and Inner Mongolia. The latter experienced more intense and extensive LULC change during this period, despite similar climate changes. Secondly, we assessed changes in landscape ecological risk and identified the main drivers of these changes over the past two decades using a landscape index model and random forest method. The highest-risk zone has gradually expanded, with a 30% increase compared to 2001. Lastly, we investigated different characteristics of LULC change under different scenarios by examining future LULC products simulated by the FLUS model. We also simulated the dynamics of landscape ecological risks under these scenarios and proposed an adaptive development strategy to promote sustainable development in the MP. In terms of the impact of climate change on landscape ecological risk, we found that under the same SSP scenario, increasing RCP emission concentrations significantly increased the areas with high landscape ecological risk while decreasing areas with low risk. By integrating quantitative assessments and scenario-based modeling, our study provides valuable insights for informing sustainable land management and policy decisions in the region. • Landscape changes and associated ecological risks were simulated in the Mongolian Plateau. • The intensity and extent of land use change in Inner Mongolia are greater than in Mongolia. • Land-use changes generally led to increased landscape ecological risk (LER). • The high-risk area was observed to increase exponentially with higher future RCP concentrations. • The SSP2-RCP4.5 pathway was identified as the most favorable scenario for promoting sustainable development. [ABSTRACT FROM AUTHOR]

Grassland is one of the most widely-distributed ecosystems on Earth and provides a variety of ecosystem services. Grasslands, however, currently suffer from severe degradation induced by human activities, overgrazing pressure and climate change. In the present study, we explored the transcriptome response of Stipa breviflora, a dominant species in the desert steppe, to grazing through transcriptome sequencing, the development of simple sequence repeat (SSR) markers, and analysis of genetic diversity. De novo assembly produced 111,018 unigenes, of which 88,164 (79.41%) unigenes were annotated. A total of 686 unigenes showed significantly different expression under grazing, including 304 and 382 that were upregulated and downregulated, respectively. These differentially expressed genes (DEGs) were significantly enriched in the "alpha-linolenic acid metabolism" and "plant-pathogen interaction" pathways. Based on transcriptome sequencing data, we developed eight SSR molecular markers and investigated the genetic diversity of S. breviflora in grazed and ungrazed sites. We found that a relatively high level of S. breviflora genetic diversity occurred under grazing. The findings of genes that improve resistance to grazing are helpful for the restoration, conservation, and management of desert steppe. [ABSTRACT FROM AUTHOR]

Abstract Intensive anthropogenic land-use causes habitat loss and landscape homogenization, which leads to the decrease of biodiversity and ecosystem degradation. Therefore, it is important to study the influence of landscape heterogeneity on biodiversity. In this study, vegetation surveys conducted at 53 sites in the Tabu River basin, located at the agro-pastoral ecotone of Inner Mongolia of China, revealed 146 species. Species diversity was evaluated at three scales: species richness within patches (alpha diversity), between patches (beta diversity) and at the landscape scale (gamma diversity). We analyzed landscape heterogeneity (LH total) and its driving factors including environmental variables (LHDF env-var , such as precipitation and altitude), environmental heterogeneity (LHDF env-het) and human activities (LHDF hum). We used structural equation modeling (SEM) to evaluate the response of species richness to landscape heterogeneity at three scales and determined the relative contribution of driving factors in explaining species diversity at these scales. The results of the study are summarized as follows: 1) Alpha diversity was the dominant component of gamma diversity in the Tabu River basin in Inner Mongolia. 2) There is no significant correlation (P = 0.512) between alpha diversity and LH total ; with the increase of LH total beta and gamma diversities showed hump-shaped relationships. 3) LHDF env-het was the primary factor in maintaining alpha diversity, with heterogeneity of mean annual precipitation (MAP), temperature (MAT) and altitude (ALT) acting as three largest contributors. LHDF hum primarily contributed to the maintenance of beta diversity. 4) LHDF hum was the primary contributor to gamma diversity, and human activity exceeded threshold values for positive effects. Based on our findings we suggest liming agricultural use along the river to prevent reductions in species diversity. Graphical abstract Unlabelled Image Highlights • Alpha diversity was the dominant component of gamma diversity. • With the increase of LUI, beta and gamma diversities showed hump-shaped relationships. • Environmental heterogeneity was the primary factor in maintaining alpha diversity. • Human activity primarily contributed to the maintenance of beta diversity. • Intensive land-use drives homogenization of plant communities in this area. [ABSTRACT FROM AUTHOR]

The relationship between biodiversity and productivity has been a hot topic in ecology. However, the relative importance of taxonomic diversity and functional characteristics (including functional dominance and functional diversity) in maintaining community productivity and the underlying mechanisms (including selection and complementarity effects) of the relationship between diversity and community productivity have been widely controversial. In this study, 194 sites were surveyed in five grassland types along a precipitation gradient in the Inner Mongolia grassland of China. The relationships between taxonomic diversity (species richness and the Shannon-Weaver index), functional dominance (the community-weighted mean of four plant traits), functional diversity (Rao's quadratic entropy), and community aboveground biomass were analyzed. The results showed that (1) taxonomic diversity, functional dominance, functional diversity, and community aboveground biomass all increased from low to high precipitation grassland types; (2) there were significant positive linear relationships between taxonomic diversity, functional dominance, functional diversity, and community aboveground biomass; (3) the effect of functional characteristics on community aboveground biomass is greater than that of taxonomic diversity; and (4) community aboveground biomass depends on the community-weighted mean plant height, which explained 57.1% of the variation in the community aboveground biomass. Our results suggested that functional dominance rather than taxonomic diversity and functional diversity mainly determines community productivity and that the selection effect plays a dominant role in maintaining the relationship between biodiversity and community productivity in the Inner Mongolia grassland. [ABSTRACT FROM AUTHOR]

Climate change has significant effects on primary productivity and ecosystem function. To assess these effects in the Inner Mongolia Plateau of China, we analysed the 8 km normalized difference vegetation index (NDVI) time-series from the Global Inventory Monitoring and Modeling System (GIMMS) data set and characterized vegetation productivity between 1981 and 2011. We used canonical correspondence analysis (CCA) to elucidate the relationship between productivity and climatic factors for different vegetation types and model the response of productivity to climate change. We found the following. (1) Productivity in the study area exhibits high spatial heterogeneity while generally decreasing from northeast to southwest, which is mainly driven by precipitation patterns. (2) Most of the total variation (88.35%) of NDVI can be explained by precipitation and temperature. Around 46.19% of the total variation is explained solely by precipitation, 31.85% by temperature, and 10.31% by the precipitation and temperature interaction term. (3) Productivity of most ecosystems of the area increased gradually between 1981 and 2011. The central region of the Plateau is characterized by the high annual coefficient of variation (CV) of NDVI, which is mainly attributable to the desert steppe, the most sensitive ecosystem of the area. (4) Climate factors influence primary productivity differently in different vegetation zones of our study area. Primary productivity of forest and agricultural areas is explained mainly by temperature and steppe vegetation by precipitation. Desert vegetation is closely related to both precipitation and temperature. Not only did the study quantitatively assess the effects of climate changes on primary production, but it also provided an important basis for a comprehensive analysis of climate change on ecosystem function in the Inner Mongolia Plateau. [ABSTRACT FROM PUBLISHER]

• Stipa. breviflora originated on the northeastern QTP and the eastern Helan mountains. • S. breviflora originated in the late Miocene. • The genetic differentiation of S. breviflora was mainly caused by IBD. Historical and contemporary microevolutionary processes influence the extent and structure of genetic variation. Combining phylogeography and landscape genetics is an important approach for delineating the formation mechanisms about the patterns of genetic structures. Grassland ecosystems comprise approximately one-third of Earth's vegetative cover. The spatial distribution of genetic variations derived from dominant plant species in steppes is helpful to understand the origin and evolution of this kind of vegetation. In this paper, we took Stipa breviflora , a dominant species of desert steppe, as an example, and conducted the research on both chloroplast DNA sequences and microsatellite loci of populations. The results of analyzing haplotype and microsatellite diversity revealed that S. breviflora most probably originated from the region in eastern Helan Mountains and northeast of Qinghai-Tibet Plateau (QTP) during the late Miocene. The genetic variation distribution of the species was in accordance with the core-periphery hypothesis (CPH), i.e., populations located at the periphery of a species' range should have lower levels of genetic variation than those at the center of the range. Paleoclimatic fluctuations contributed to haplotype evolution, while geographical distance played an important role in driving contemporary genetic differentiation. Our findings highlight the complexity of intraspecific evolution and clarify the biogeographical history of desert steppes based on molecular signals. [ABSTRACT FROM AUTHOR]

Background: The redundancy hypothesis predicts that the species redundancy in a plant community enhances community stability. However, numerous studies in recent years questioned the positive correlation between redundancy and stability. Methodology: We explored the relationship between the species redundancy, functional redundancy and community stability in typical steppe grassland in Northern China by sampling grassland vegetation along a gradient of resource availability caused by micro-topography. We aimed to test whether community redundancy enhanced community stability, and to quantify the relative importance of species redundancy and functional redundancy in maintaining community stability. Results: Our results showed that the spatial stability of plant community production increases with increased supply of soil resources, and the functional redundancy instead of species diversity or species redundancy is correlated with the community stability. Our results supported the redundancy hypothesis and have implications for sustainable grassland management. [ABSTRACT FROM AUTHOR]

• The new grassland utilization unit is based on ecological site and STM. • New grassland utilization unit reflects both ecological and economic attributes. • Soil texture is the key factor of the grassland utilization unit. • New grassland utilization unit provides support for management and decision-making. Rational utilization of grassland is crucial to regional sustainable development, in which the classification of grassland utilization is the foundation. Traditional classification mainly focuses on a single attribute of grassland, and it is necessary to develop a new index to comprehensively classify grassland. Based on ecological site (ES) and state-and-transition model (STM) theory, 164 sample points of Inner Mongolia grassland were divided into four ecological sites and eight grassland utilization units by cluster analysis. We found that (1) the classification of grassland utilization based on ES and STM has a strict nested hierarchical structure; (2) soil texture is the main driving factor of grassland utilization units; and (3) the new grassland utilization unit integrates ecological and economic attributes, which is more suitable for grassland management. This new method, combined with remote sensing technology, will show great potential in regional grassland management. [ABSTRACT FROM AUTHOR]

Understanding the distribution pattern and maintenance mechanism of species diversity along environmental gradients is essential for developing biodiversity conservation strategies under environmental change. We have surveyed the species diversity at 192 vegetation sites across different steppe zones in Inner Mongolia, China. We analysed the total species diversity (γ diversity) and its composition (α diversity and β diversity) of different steppe types, and their changes along a precipitation gradient. Our results showed that (i) β diversity contributed more than α diversity to the total (γ) diversity in the Inner Mongolia grassland; the contribution of β diversity increased with precipitation, thus the species-rich (meadow steppe) grassland had greater contribution of β diversity than species-poor (desert steppe) grassland. (ii) All α, β and γ species diversity increased significantly (P<0.05) with precipitation, but their sensitivity to precipitation (diversity change per mm precipitation increase) was different between the steppe types. The sensitivity of α diversity of different steppe community types was negatively (P<0.05) correlated with mean annual precipitation, whereas the sensitivity of β and γ diversity showed no trend along the precipitation gradient (P>0.10). (iii) The α diversity increased logarithmically, while β diversity increased exponentially, with γ diversity. Our results suggest that for local species diversity patterns, the site species pool is more important in lower precipitation areas, while local ecological processes are more important in high precipitation areas. In addition, for β diversity maintenance niche processes and diffusion processes are more important in low and high precipitation areas, respectively. Our results imply that a policy of “multiple small reserves” is better than one of a “single large reserve” for conserving species diversity of a steppe ecosystem, and indicate an urgent need to develop management strategies for climate-sensitive desert steppe ecosystem. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions are the primary cause of global warming, and active development of renewable energy has become popular in resource utilization. Wind power, as the second largest renewable energy source, plays an important role in the power industry, and clarifying the carbon footprint and carbon emission intensity of wind farms is the basis for their rational use. Although the study of the carbon footprint of wind farms has attracted considerable attention, the characteristics of the carbon footprint and carbon emission intensity of wind farms in grassland areas compared with other types of wind farms have not been determined to date. As an important part of the world's largest Eurasian grassland, the installed capacity of wind farms in the grasslands of Inner Mongolia ranks first in China. In this study, the carbon footprint of the production, transportation, construction, operation, and disposal stages was evaluated by using the life cycle assessment method in a 49.5 MW wind farm in the Inner Mongolia grassland, and its carbon emission intensity was explored in depth. The results showed the following: (1) The carbon footprint of the wind farm in the grassland area was 18701.29 t, of which the construction stage accounted for the largest proportion at 56.74%, and the other stages, ranging from highest to lowest, were production, disposal, transportation, and operation stages, which were 28.18%, 12.08%, 2.76%, and 0.24%, respectively. (2) The carbon footprint of material recycling was 18726.53 t, and the reduced carbon emissions accounted for 50.03% of the total carbon emissions. (3) The carbon emission intensity of the wind farm was 6.57 g/kWh, which is approximately 148.45 times, 72.91 times, 127.85 times, and 3.50 times less than the carbon emission intensity of the four non-renewable energy sources of coal, natural gas, oil, and nuclear power, respectively. (4) Wind power have lower carbon emission intensities than the four renewable energy sources of hydropower, biomass, and photovoltaics. This study highlights the very important role played by system boundaries when employing life cycles to evaluate carbon footprints. Compared with offshore wind farms and non-grassland wind farms, grassland wind farms have the lowest carbon emission intensity. The promotion of wind farms has excellent potential in grassland areas. • Construction stage accounts the largest proportion of wind farm carbon footprint. • Grassland wind farms have the lowest carbon emission intensity. • System boundary plays an important role in employing life cycle assessment. [ABSTRACT FROM AUTHOR]

The accumulation of heat and moderate precipitation are the primary factors that are used by grasslands to trigger a green-up date. The accumulated growing degree-days (AGDD) requirement over the preseason is an important indicator of the response of grassland spring phenology to climate change. This study adopted the Normalized Difference Phenology Index (NDPI), which derived from the Moderate Resolution Imaging Spectroradiometer (MODIS), to extract annual green-up dates in the Hulun Buir grassland in China between 2001–2015. Our analysis indicated that the range (standard deviation) and trend for the green-up date were DOY (day of year) 104 to DOY 144 (10.6 days) and −2.0 days per decade. Nine point two percent of the study area had significant (p < 0.05) changes in AGDD requirements. The partial correlations between the AGDD requirements and chilling days (67.04%, pixels proportion) were negative and significant (p < 0.05). The partial correlations between the AGDD requirement and precipitation (28.87%) were positive and significant (p < 0.05). Finally, the partial correlation between the AGDD requirement and insolation (97.65%) were positive and significant (p < 0.05). The results of this study could reveal the response of vegetation to climate warming and contribute to improving the phenological mechanism model of different grassland types in future research. [ABSTRACT FROM AUTHOR]

Desertification is a major obstacle to global sustainable development, and effective monitoring and an understanding of its driving factors are important for prevention and remediation. Therefore, assessing the role of ecological restoration policies in desertification is extremely urgent, especially quantified policies contribution. Here, we quantify the desertification process in the Mu Us Desert (China) from 1986 to 2015 based on remote sensing images, and using panel data analysis to assess the relative roles of climate, socioeconomic development and ecological restoration as drivers of these dynamics based on meteorological record, socioeconomic statistics and input funds of ecological restoration projects. We found (1) that, between 1986 and 2015, desertification of the Mu Us Desert initially intensified, but then declined, with maximum desertification in 2005, and (2) that, ecological restoration policies represent the dominant factor underlying the mitigation of desertification (60.9%), with a smaller, negative role of socioeconomic development (37.2%) and low impact of climate (1.8%). (3) There was obvious spatial heterogeneity in desertification process, with varying patterns among the three provinces (Inner Mongolia, Shaanxi and Ningxia): Desertification in Inner Mongolia experienced two episodes of intensification and reversals, with the strongest desertification in 1990 and 2005, while it peaked in Shaanxi and Ningxia in 2000 and 2005, respectively, with recovery in the following years. (4) Considerable differences are observed in the three driving factors affecting the desertification dynamics at the provincial scale, with socioeconomic factors (36.4%) accounting for a slightly higher contribution than ecological restoration policies (34.8%) and climate factors (28.9%) in Inner Mongolia. The reversal of desertification has mainly driven by ecological restoration policies in Shaanxi (55.8%) and climatic factors in Ningxia (44.1%). This study reveals the desertification process, and detects the key role of ecological restoration policies in recovering from desertification by using quantitative policy data in the Mu Us Desert. Based on this, we suggest continuing to implement ecological restoration policy to maintain desertification recovery. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that plant diversity not only plays an important role in maintaining ecosystem functions but can also mediate the impact of climate change on ecosystem functions. However, the relative importance of multiple aspects of diversity at different scales remains unclear. In this study, we investigated species, functional, and phylogenetic aspects of diversity at α and β scales, and measured eight soil functions (aboveground productivity, soil organic carbon, total soil nitrogen, total soil phosphorus, soil available nitrogen, soil available phosphorus, soil carbon-nitrogen ratio, and soil nitrogen-phosphorus ratio) to comprehensively assess the relationship between multiple aspects and scales of plant diversity and soil multifunctionality along an aridity gradient across the grasslands of Inner Mongolia. Diversity at α and β scales explained soil multifunctionality synergistically. Functional diversity explained most of the soil multifunctionality, while phylogenetic diversity explained the least. Aridity had both direct effects on soil multifunctionality, and indirect effects mediated mainly by functional α and β diversity. These findings indicate that in addition to α diversity, β diversity also played an important role in maintaining soil multifunctionality, and was an important mediator for the adverse impact of aridity on soil multifunctionality. Our study highlights the critical role of β diversity, especially regarding functional traits, in predicting the consequences of the increasingly arid conditions in the Inner Mongolian grasslands. Unlabelled Image • Diversity at the α and β scales explained multifunctionality synergistically. • Functional diversity explained more of the variance in multifunctionality than species and phylogenetic diversity. • The indirect impacts of aridity on soil multifunctionality were mediated by functional diversity. [ABSTRACT FROM AUTHOR]