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1.
Int J Mol Sci ; 25(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38396759

RESUMO

Caragana, a xerophytic shrub genus widely distributed in northern China, exhibits distinctive geographical substitution patterns and ecological adaptation diversity. This study employed transcriptome sequencing technology to investigate 12 Caragana species, aiming to explore genic-SSR variations in the Caragana transcriptome and identify their role as a driving force for environmental adaptation within the genus. A total of 3666 polymorphic genic-SSRs were identified across different species. The impact of these variations on the expression of related genes was analyzed, revealing a significant linear correlation (p < 0.05) between the length variation of 264 polymorphic genic-SSRs and the expression of associated genes. Additionally, 2424 polymorphic genic-SSRs were located in differentially expressed genes among Caragana species. Through weighted gene co-expression network analysis, the expressions of these genes were correlated with 19 climatic factors and 16 plant functional traits in various habitats. This approach facilitated the identification of biological processes associated with habitat adaptations in the studied Caragana species. Fifty-five core genes related to functional traits and climatic factors were identified, including various transcription factors such as MYB, TCP, ARF, and structural proteins like HSP90, elongation factor TS, and HECT. The roles of these genes in the ecological adaptation diversity of Caragana were discussed. Our study identified specific genomic components and genes in Caragana plants responsive to heterogeneous habitats. The results contribute to advancements in the molecular understanding of their ecological adaptation, lay a foundation for the conservation and development of Caragana germplasm resources, and provide a scientific basis for plant adaptation to global climate change.


Assuntos
Caragana , Caragana/genética , Perfilação da Expressão Gênica/métodos , Transcriptoma , Genes de Plantas , Fenótipo , Repetições de Microssatélites
2.
BMC Plant Biol ; 22(1): 85, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35216546

RESUMO

BACKGROUND: For better understanding the mechanism of Reaumuria soongarica community formation in a salt stressed grassland ecosystem, we designed a field experiment to test how leaves salt secretion changes the competitive relationship between species in this plant communities. RESULTS: Among the three species (R. soongarica, Stipa glareosa and Allium polyrhizum) of the salt stressed grassland ecosystem, the conductivity of R. soongarica rhizosphere soil was the highest in five soil layers (0-55 cm depth). The high soil conductivity can increase the daily salt secretion rate of plant leaves of R. soongarica. In addition, we found the canopy size of R. soongarica was positively related to the distance from S. glareosa or A. polyrhizum. The salt-tolerance of R. soongarica was significantly higher than the other two herbs (S. glareosa and A. polyrhizum). Moreover, there was a threshold (600 µS/cm) for interspecific competition of plants mediated by soil conductivity. When the soil conductivity was lower than 600 µS/cm, the relative biomass of R. soongarica increased with the soil conductivity increase. CONCLUSIONS: The efficient salt secretion ability of leaves increases soil conductivity under the canopy. This leads the formation of a "saline island" of R. soongarica. Meanwhile R. soongarica have stronger salt tolerance than S. glareosa and A. polyrhizum. These promote the competitiveness of R. soongarica and inhibit interspecies competition advantage of the other two herbs (S. glareosa and A. polyrhizum) in the plant community. It is beneficial for R. soongarica to establish dominant communities in saline regions of desert grassland.


Assuntos
Folhas de Planta/metabolismo , Sais/metabolismo , Tamaricaceae/fisiologia , Allium/fisiologia , China , Clima Desértico , Pradaria , Poaceae/fisiologia , Rizosfera , Salinidade , Tolerância ao Sal , Solo/química , Tamaricaceae/crescimento & desenvolvimento
3.
Ecol Lett ; 24(10): 2054-2064, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34319652

RESUMO

Livestock grazing is a major driver shaping grassland biodiversity, functioning and stability. Whether grazing impacts on grassland ecosystems are scale-dependent remains unclear. Here, we conducted a sheep-grazing experiment in a temperate grassland to test grazing effects on the temporal stability of productivity across scales. We found that grazing increased species stability but substantially decreased local community stability due to reduced asynchronous dynamics among species within communities. The negative effect of grazing on local community stability propagated to reduce stability at larger spatial scales. By decreasing biodiversity both within and across communities, grazing reduced biological insurance effects and hence the upscaling of stability from species to communities and further to larger spatial scales. Our study provides the first evidence for the scale dependence of grazing effects on grassland stability through biodiversity. We suggest that ecosystem management should strive to maintain biodiversity across scales to achieve sustainability of grassland ecosystem functions and services.


Assuntos
Ecossistema , Pradaria , Animais , Biodiversidade , Ovinos
4.
Int J Mol Sci ; 22(21)2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34769324

RESUMO

Organisms have evolved effective and distinct adaptive strategies to survive. Stipa grandis is a representative species for studying the grazing effect on typical steppe plants in the Inner Mongolia Plateau. Although phenotypic (morphological and physiological) variations in S. grandis in response to long-term grazing have been identified, the molecular mechanisms underlying adaptations and plastic responses remain largely unknown. Here, we performed a transcriptomic analysis to investigate changes in gene expression of S. grandis under four different grazing intensities. As a result, a total of 2357 differentially expressed genes (DEGs) were identified among the tested grazing intensities, suggesting long-term grazing resulted in gene expression plasticity that affected diverse biological processes and metabolic pathways in S. grandis. DEGs were identified in RNA-Seq and qRT-PCR analyses that indicated the modulation of the Calvin-Benson cycle and photorespiration metabolic pathways. The key gene expression profiles encoding various proteins (e.g., ribulose-1,5-bisphosphate carboxylase/oxygenase, fructose-1,6-bisphosphate aldolase, glycolate oxidase, etc.) involved in these pathways suggest that they may synergistically respond to grazing to increase the resilience and stress tolerance of S. grandis. Our findings provide scientific clues for improving grassland use and protection and identifying important questions to address in future transcriptome studies.


Assuntos
Adaptação Fisiológica , Regulação da Expressão Gênica de Plantas , Herbivoria , Proteínas de Plantas/metabolismo , Poaceae/genética , Transcriptoma , Animais , Pradaria , Proteínas de Plantas/genética , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , Ovinos
5.
Proc Biol Sci ; 287(1928): 20200675, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32486982

RESUMO

Biotic mechanisms associated with species diversity are expected to stabilize communities in theoretical and experimental studies but may be difficult to detect in natural communities exposed to large environmental variation. We investigated biotic stability mechanisms in a multi-site study across Inner Mongolian grassland characterized by large spatial variations in species richness and composition and temporal fluctuations in precipitation. We used a new additive-partitioning method to separate species synchrony and population dynamics within communities into different species-abundance groups. Community stability was independent of species richness but was regulated by species synchrony and population dynamics, especially of abundant species. Precipitation fluctuations synchronized population dynamics within communities, reducing their stability. Our results indicate generality of biotic stability mechanisms in natural ecosystems and suggest that for accurate predictions of community stability in changing environments uneven species composition should be considered by partitioning stabilizing mechanisms into different species-abundance groups.


Assuntos
Pradaria , Animais , Biodiversidade , China , Ecossistema , Gerbillinae , Dinâmica Populacional
6.
Ecol Appl ; 28(1): 201-211, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29034532

RESUMO

Large herbivores have pronounced effects on nutrient cycling in grasslands. These organisms are known to alter the quality and quantity of plant production as well as the amounts and quality of plant litter and animal wastes. The generalization that the relative quality of detritus inputs is enhanced by herbivores is well known, but how this process is affected by diet selection processing and feces production of different large herbivores remains largely unstudied. Here, we measured how these differences for cattle and sheep on a dry grassland might influence nitrogen (N) mineralization from feces. We found that cattle of larger body size tended to select the low quality grass Stipa grandis as their major food source. In contrast, the subdominant grass Leymus chinensis, with relatively high N content, was a majority in the diet of smaller sheep, when palatable forbs were insufficient in the field. This diverse diet quality resulted in a C:N ratio of cattle feces that was higher than that of sheep feces. Relatively higher labile C availability in the cattle feces, namely relatively higher cellulose/hemicellulose contents, promoted microbial growth and in turn accelerated cattle feces decomposition. A surprise finding was that the feces from cattle mineralized about twice as much N as feces from sheep, despite the latter having slightly higher N content. From a grassland productivity perspective, increasing the proportion of large body-sized species in grazing herbivore assemblages perhaps is beneficial to forage productivity and nutrient recycling by the rapid degradation of feces.


Assuntos
Ciclo do Carbono , Fezes/química , Pradaria , Herbivoria , Ciclo do Nitrogênio , Animais , Bovinos , Ovinos , Microbiologia do Solo
7.
ScientificWorldJournal ; 2014: 765907, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24959627

RESUMO

In recent decades, degradation of ecosystem in the steppe region of the Inner Mongolia Plateau, especially in riparian floodplain wetlands, has become a significant ecological crisis. Not uncommonly, with the increasing of livestock in the Inner Mongolian steppe region, a riparian floodplain wetland is becoming a hotspot area of grazing for local herdsmen. Hence, it is essential to understand degradation mechanisms of riparian floodplain wetland ecosystems caused by extensive grazing. In this study, the spatial distribution of soil compaction, salinity, total nitrogen, total phosphorus, organic carbon, and microbial biomass C and N were investigated. The results showed that grazing led to an increase in soil compaction and soil surface salinity, which significantly lowered levels of total N, P, and TOC in the soil surface. Grazing decreased soil microbial biomass C and N concentration in the lower riparian floodplain wetland, whereas it significantly increased soil microbial biomass C and N concentration in the higher riparian floodplain wetland. Elevation differences in the riparian floodplain wetland increased spatial heterogeneity in the soil and thus resulted in different influence of grazing on wetland soils and ecosystem. Therefore, elevation differences and grazing intensity were the main factors controlling soil characteristics in the riparian floodplain wetland of this region.


Assuntos
Solo/química , Áreas Alagadas , Carbono/análise , China , Ecossistema , Pradaria , Nitrogênio/análise
8.
Front Plant Sci ; 15: 1294895, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38645388

RESUMO

Livestock presence impacts plant biodiversity (species richness) in grassland ecosystems, yet extent and direction of grazing impacts on biodiversity vary greatly across inter-annual periods. In this study, an 8-year (2014-2021) grazing gradient experiment with sheep was conducted in a semi-arid grassland to investigate the impact of grazing under different precipitation variability on biodiversity. The results suggest no direct impact of grazing on species richness in semi-arid Stipa grassland. However, increased grazing indirectly enhanced species richness by elevating community dominance (increasing the sheltering effect of Stipa grass). Importantly, intensified grazing also regulates excessive community biomass resulting from increased inter-annual wetness (SPEI), amplifying the positive influence of annual humidity index on species richness. Lastly, we emphasize that, in water-constrained grassland ecosystems, intra-annual precipitation variability (PCI) was the most crucial factor driving species richness. Therefore, the water-heat synchrony during the growing season may alleviate physiological constraints on plants, significantly enhancing species richness as a result of multifactorial interactions. Our study provides strong evidence for how to regulate grazing intensity to increase biodiversity under future variable climate patterns. We suggest adapting grazing intensity according to local climate variability to achieve grassland biodiversity conservation.

9.
Ecol Evol ; 14(2): e10993, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38380069

RESUMO

The desert ecosystem of the Qinghai-Tibet Plateau (QTP) is an important component of China's desert ecosystem. Studying the mechanisms shaping the taxonomic, phylogenetic, and functional beta diversity of plant communities in the QTP desert will help us to promote scientific conservation and management of the region's biodiversity. This study investigated the effects of environmental (including altitude, climate factors, and soil factors) and geographic distances on three facets of beta diversity as well as their turnover and nestedness components based on field survey data. The results showed that turnover components dominate the three facets of beta diversity. However, the turnover contributions to phylogenetic and functional beta diversity were lower than for taxonomic beta diversity. Environmental distance had a greater influence than geographic distance, with the former uniquely explaining 15.2%-22.8% of beta diversity and the latter explaining only 1.7%-2.4%. Additionally, the explanatory power of different factors for beta diversity differed between herbs and shrubs, with environmental distance being more important for the latter. Distance-based redundancy analysis suggested that soil total potassium content had a substantial impact on the beta diversity of three dimensions, with mean temperature of the coldest month and soil total phosphorus content having a substantial impact on taxonomic and functional beta diversity as well. Our results support that environmental sorting plays a predominant role in shaping plant community composition across QTP desert ecosystems. To maintain the plant diversity of this region, it is crucial to prioritize the conservation of its diverse environmental conditions and actively mitigate its degradation by anthropogenic pressures.

10.
Sci Total Environ ; 899: 165636, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37487897

RESUMO

Plant functional traits can elucidate the response of plant communities and ecosystems to biotic and abiotic disturbances. However, whether livestock consume more aboveground biomass (AGB) in communities dominated by species with 'acquisitive' traits or in communities where biodiversity is high is not well known. Here, we measured 22 functional traits of the grazing communities and control communities in a Mongolian Plateau desert steppe. The effects of grazing on AGB, CWM traits, species diversity, and functional diversity (FD) were analysed, furthermore, we estimated the grazing impact by using the log response ratio (LRR, an increasing value shows a higher grazing impact) and investigated the correlations between the LRR, plant growth, and community-weighted mean (CWM) traits and diversity indices. We found that grazing significantly increased the CWM dry matter content and carbon-to­nitrogen ratio and decreased the CWM height, specific leaf area (SLA), and nitrogen and phosphorus contents. The AGB decreased, while species diversity and FD increased under grazing treatments. Additionally, we found that plant traits and biodiversity could predict the response of AGB to grazing, the LRR was higher in patches dominated by species with 'acquisitive' foliage and in patches with higher biodiversity; in these patches, plant growth was lower. In the study area, the response of CWM traits to grazing suggests an avoidance strategy, which may be more conducive for adapting to low resource utilization environments. Also, the relationship between the CWM traits and the LRR indicated that the effect of grazing on AGB was mainly related to the selective foraging of herbivores. In addition, patches preferred by livestock may not recover quickly, leading to slow growth and thus reduced biomass under grazing treatments after prolonged grazing.


Assuntos
Biodiversidade , Ecossistema , Animais , Biomassa , Plantas , Gado , Nitrogênio , Pradaria
11.
Front Plant Sci ; 14: 1275018, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38148860

RESUMO

Phylogenetic analysis provides crucial insights into the evolutionary relationships and diversification patterns within specific taxonomic groups. In this study, we aimed to identify the phylogenetic relationships and explore the evolutionary history of Stipa using transcriptomic data. Samples of 12 Stipa species were collected from the Qinghai-Tibet Plateau and Mongolian Plateau, where they are widely distributed, and transcriptome sequencing was performed using their fresh spikelet tissues. Using bidirectional best BLAST analysis, we identified two sets of one-to-one orthologous genes shared between Brachypodium distachyon and the 12 Stipa species (9397 and 2300 sequences, respectively), as well as 62 single-copy orthologous genes. Concatenation methods were used to construct a robust phylogenetic tree for Stipa, and molecular dating was used to estimate divergence times. Our results indicated that Stipa originated during the Pliocene. In approximately 0.8 million years, it diverged into two major clades each consisting of native species from the Mongolian Plateau and the Qinghai-Tibet Plateau, respectively. The evolution of Stipa was closely associated with the development of northern grassland landscapes. Important external factors such as global cooling during the Pleistocene, changes in monsoonal circulation, and tectonic movements contributed to the diversification of Stipa. This study provided a highly supported phylogenetic framework for understanding the evolution of the Stipa genus in China and insights into its diversification patterns.

12.
Front Plant Sci ; 13: 870526, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212278

RESUMO

The impact of global climate change on ecosystem structure has attracted much attention from researchers. However, how climate change and meteorological conditions influence community phylogenetic structure remains poorly understood. In this research, we quantified the responses of grassland communities' phylogenetic structure to long- and short-term meteorological conditions in Inner Mongolia, China. The net relatedness index (NRI) was used to characterize phylogenetic structure, and the relationship between the NRI and climate data was analyzed to understand the dynamics of community phylogenetic structure and its relationship with extreme meteorological events. Furthermore, multiple linear regression and structural equation models (SEMs) were used to quantify the relative contributions of meteorological factors before and during the current growing season to short-term changes in community phylogenetic structure. In addition, we evaluated the effect of long-term meteorological factors on yearly NRI anomalies with classification and regression trees (CARTs). We found that 1) the degree of phylogenetic clustering of the community is relatively low in the peak growing season, when habitat filtering is relatively weak and competition is fiercer. 2) Extreme meteorological conditions (i.e., drought and cold) may change community phylogenetic structure and indirectly reduce the degree of phylogenetic clustering by reducing the proportion of dominant perennial grasses. 3) Meteorological conditions before the growing season rather than during the current growing season explain more variation in the NRI and interannual NRI anomalies. Our results may provide useful information for understanding grassland community species assembly and how climate change affects biodiversity.

13.
Elife ; 112022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36206306

RESUMO

Extending knowledge on ecosystem stability to larger spatial scales is urgently needed because present local-scale studies are generally ineffective in guiding management and conservation decisions of an entire region with diverse plant communities. We investigated stability of plant productivity across spatial scales and hierarchical levels of organization and analyzed impacts of dominant species, species diversity, and climatic factors using a multisite survey of Inner Mongolian grassland. We found that regional stability across distant local communities was related to stability and asynchrony of local communities. Using only dominant instead of all-species dynamics explained regional stability almost equally well. The diversity of all or only dominant species had comparatively weak effects on stability and synchrony, whereas a lower mean and higher variation of precipitation destabilized regional and local communities by reducing population stability and synchronizing species dynamics. We demonstrate that, for semi-arid temperate grassland with highly uneven species abundances, the stability of regional communities is increased by stability and asynchrony of local communities and these are more affected by climate rather than species diversity. Reduced amounts and increased variation of precipitation in the future may compromise the sustainable provision of ecosystem services to human well-being in this region.


Assuntos
Ecossistema , Pradaria , Animais , Biodiversidade , Clima , Gerbillinae , Humanos , Plantas
14.
Artigo em Inglês | MEDLINE | ID: mdl-33806311

RESUMO

Accurate monitoring of grassland vegetation dynamics is essential for ecosystem restoration and the implementation of integrated management policies. A lack of information on vegetation changes in the Wulagai River Basin restricts regional development. Therefore, in this study, we integrated remote sensing, meteorological, and field plant community survey data in order to characterize vegetation and ecosystem changes from 1997 to 2018. The residual trend (RESTREND) method was utilized to detect vegetation changes caused by human factors, as well as to evaluate the impact of the management of pastures. Our results reveal that the normalized difference vegetation index (NDVI) of each examined ecosystem type showed an increasing trend, in which anthropogenic impact was the primary driving force of vegetation change. Our field survey confirmed that the meadow steppe ecosystem increased in species diversity and aboveground biomass; however, the typical steppe and riparian wet meadow ecosystems experienced species diversity and biomass degradation, therefore suggesting that an increase in NDVI may not directly reflect ecosystem improvement. Selecting an optimal indicator or indicator system is necessary in order to formulate reasonable grassland management policies for increasing the sustainability of grassland ecosystems.


Assuntos
Ecossistema , Rios , Biomassa , China , Monitoramento Ambiental , Pradaria , Humanos
15.
J Plant Res ; 123(4): 509-17, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20130954

RESUMO

Climate change is known to influence interannual variation in grassland aboveground net primary productivity (ANPP), or seasonal biomass, but direct, long-term ground observations are rare. We present a 22-year (1982-2003) measurement series from the Inner Mongolia grassland, China, to examine the effect of climate change on interannual variations in ANPP and monthly aboveground biomass (MAB). ANPP exhibited no increase over 1982-2003 but there was an association with previous-year precipitation. MAB in May increased by 21.8% from 47.8 g m(-2) (averaged for 1982-1984) to 58.2 g m(-2) (2001-2003), whereas there was no significant variation in June, July and August, and a decrease of 29.7% in September. The MAB increase in May was correlated with increases in precipitation and temperature in the preceding months. These findings suggest that the effects of climate change on grassland production vary throughout the growing season, with warmer and wetter springs resulting in increased biomass early in the growing season, and drier falls causing a decrease in biomass late in the growing season.


Assuntos
Biomassa , Mudança Climática , Poaceae/crescimento & desenvolvimento , Estações do Ano , China , Chuva , Análise de Regressão , Temperatura , Fatores de Tempo
16.
Sci Total Environ ; 739: 139958, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758943

RESUMO

The ecological environment in China's arid and semi-arid regions has been improving over the past few decades. Using the Mu Us Sandy Land (MUSL) as a case study, we examine the consequent climate feedbacks and the impacts of revegetation on regional climate by incorporating high-resolution remote-sensing vegetation data into the WRF-Noah model. From 2001 to 2010, although a small portion of the grassland was degraded in MUSL, vegetation overall improved, with green fraction and leaf area index increased and surface albedo decreased. The model simulation suggests a cooling of the near-surface temperature by 0.12-0.32 °C on average and up to >0.5 °C in summer, with a reduction in nighttime minimum of 0.15-0.46 °C and in daytime maximum of <0.13 °C. The cooling is accompanied by a slight increase in 2-m air humidity. The near-surface cooling and wetting are induced by revegetation-enhanced evapotranspiration, but they have insignificant effect on the local precipitation. The results of this study imply that while revegetation has positive effects on the ecological systems in MUSL, it bears the cost of an increase in evapotranspiration of 51 mm per summer, which may exacerbate the water shortages in the region.


Assuntos
Ecossistema , Areia , China , Mudança Climática , Clima Desértico
17.
Sci Total Environ ; 718: 137252, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32325613

RESUMO

The relationships between biodiversity and ecosystem functioning (BEF) have been extensively studied over past decades. However, the environmental factors affecting their relationships, and how their relationships vary under the influence of environmental factors, remain controversial. Studying the BEF relationships in natural/wild environments is of great significance for devising strategies in biodiversity conservation and ecosystem functioning. Using the data from 75 sites on the Mongolian Plateau steppe, we analyzed the relationship between species richness and biomass with general linear models (GLMs) and linear mixed models (LMMs), and analyzed the variation in the species richness-biomass relationships under environmental conditions by the partial least square path modeling (PLSPM). The results showed that de Martonne aridity index affected both species richness and community biomass in parallel, and that hydrothermal coupling conditions were more important direct impact factors for aboveground biomass. However, the significant species richness-biomass relationships became weaker when the effects of environmental factors (i.e. climate and soil properties) were present. Climate humidity was the most important factor in mediating the relationship between species richness and community biomass. Our research suggested that species richness-biomass relationships are weak in the natural grasslands of the Mongolian Plateau, and that this may be due to the differences in the regional-scale environment and changes in species interactions. We recommend that a more comprehensive understanding of the relationship between diversity and biomass requires further research within broader environmental gradients.


Assuntos
Biodiversidade , Biomassa , Umidade , Solo
18.
Sci Bull (Beijing) ; 65(13): 1125-1136, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36659164

RESUMO

Vegetation maps are important sources of information for biodiversity conservation, ecological studies, vegetation management and restoration, and national strategic decision making. The current Vegetation Map of China (1:1000000) was generated by a team of more than 250 scientists in an effort that lasted over 20 years starting in the 1980s. However, the vegetation distribution of China has experienced drastic changes during the rapid development of China in the last three decades, and it urgently needs to be updated to better represent the distribution of current vegetation types. Here, we describe the process of updating the Vegetation Map of China (1:1000000) generated in the 1980s using a "crowdsourcing-change detection-classification-expert knowledge" vegetation mapping strategy. A total of 203,024 field samples were collected, and 50 taxonomists were involved in the updating process. The resulting updated map has 12 vegetation type groups, 55 vegetation types/subtypes, and 866 vegetation formation/sub-formation types. The overall accuracy and kappa coefficient of the updated map are 64.8% and 0.52 at the vegetation type group level, 61% and 0.55 at the vegetation type/subtype level and 40% and 0.38 at the vegetation formation/sub-formation level. When compared to the original map, the updated map showed that 3.3 million km2 of vegetated areas of China have changed their vegetation type group during the past three decades due to anthropogenic activities and climatic change. We expect this updated map to benefit the understanding and management of China's terrestrial ecosystems.

19.
PLoS One ; 14(8): e0221177, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31425547

RESUMO

Wetlands are one of the most critical resources in Inner Mongolia Plateau. However, the region has experienced severe wetland loss in the context of global change. To quantify the dynamic change and the related driving forces, we extracted wetland information using multi-temporal Landsat images between 1993 and 2013 using ArcGIS platform and man-machine interactive interpretation. Dynamically changing characteristics for the past 20 years were analyzed, including wetland types and spatial distribution patterns of the wetlands in Inner Mongolia. We also performed correlation analysis and generalized linear models to quantify the contribution of natural and human factors to the changes in natural wetland area. Our results indicated that the total area of wetlands was 42421.2 km2 in 1993, and decreased to 38912.4 km2 in 2013, a decline ratio of 8.3%. Meanwhile, all types of wetlands showed a trend of transformation into non-wetlands. Anthropogenic factors led to the loss of natural wetlands in Inner Mongolia. In grasslands, mining coal was the dominant driver for natural wetland loss, while in arable lands, agricultural encroachment and irrigation were the primary driving forces. These findings can provide meaningful information for improving sustainable wetlands management strategies according to local conditions in different sub-regions.


Assuntos
Conservação dos Recursos Naturais , Monitoramento Ambiental/métodos , Análise Espaço-Temporal , Áreas Alagadas , Agricultura/estatística & dados numéricos , China , Conjuntos de Dados como Assunto , Modelos Lineares , Mineração/estatística & dados numéricos , Imagens de Satélites/estatística & dados numéricos , Interface Usuário-Computador
20.
Sci Total Environ ; 675: 642-650, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31035202

RESUMO

Grassland ecosystems are one of the most important terrestrial ecosystems in the world, producing essential both goods and ecosystem services (ES) for human beings. The Inner Mongolian steppe is a major grassland ecosystem in Northern China, covering 13.5% of the northern Chinese grassland area, and playing important ecological roles for the adjacent region of the capital Beijing-Tianjin-Hebei. Quantification of grassland ES under the different utilization patterns is vital for the maintenance of multiple ES and mitigation against ES loss in this region. We made a manipulative experiment with four grazing intensities (grazing exclusion, GE; light grazing intensity, LG; medium grazing intensity, MG; heavy grazing intensity, HG). We then quantified the intensities of eight different grassland ES (1. herbage intake, HT; 2. biodiversity conservation, BI; 3. soil nutrient retention, SN; 4 soil carbon stocks SC; 5. soil erosion prevention, SEP; 6. soil water storage, SWC; 7. potential nutrient recycling, PNC; 8. carbon sequestration from atmosphere. CS) and total ES via a series of field measurements. Pearson coefficients and trade-offs index were used to access the above ES relationships and degree of trade-offs between ES. Grazing intensities significantly (p < 0.05) affected the grassland intensities of 'regulating', 'culture' and 'provisioning' services, but the 'supporting' services. We found three types of relationships (trade-offs, synergy or neutral) have been found in this study. Trade-offs occurred between 'provisioning' and 'regulating' services. Although GE management presented significantly higher intensity of total ES (0.64) than LG (0.52), LG management significantly weakened the trade-offs between 'provisioning' and 'regulating' services (Trade-offs index 0.22) in comparison with GE (Trade-offs index 11.02). Our study suggests, therefore, that LG is the most suitable grassland utilization practice in the Inner Mongolian steppe.

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