Indicators Of Desertification Research Articles

Monitoring desertification processes using ecological indicators and providing management programs in arid regions of Iran

Abstract Desertification is a serious and perilous threat to natural ecosystems. Understanding the spatio-temporal characteristics of this process through the evaluation and monitoring of important indicators appears to be a challenging task. This research was carried out in arid regions of the northeast of Iran, with the objective of assessing desertification intensity and monitoring its progress over time. After collecting the basic data including climate, land use and land cover, roads of access, geology, demographics, pedology, land capability, and drainage network, desertification intensity was firstly assessed using the Iranian Model for Desertification Potential Assessment (IMDPA). Based on the results of the IMDPA model, important desertification indicators were selected and monitored in Geographic Information System (GIS). The results of the model were validated against ground-based data via the non-parametric Mann-Whitney test. The findings of desertification intensity assessment showed a moderate desertification intensity over approximately 41% of the central, northern and northwestern parts of the region. The agriculture criterion along with natural factors such as groundwater level fluctuations, salinity, and erosion had the greatest impact on the severity of desertification. Monitoring important and effective indices (over a 20-year period and in four 5-year intervals from 1995 to 2014) showed that drought, population growth, migration, land-use changes, vegetation degradation, soil erosion, groundwater level fluctuations, deterioration of groundwater quality and expansion of low-yield agricultural lands (2.75% increase in agricultural and residential lands over 2004–2014) led to an increased desertification intensity. Based on the status of desertification, a number of possible management programs were proposed for the study area. Accordingly, the implementation of some land degradation control programs such as replanting vegetation and compatible with salinity and drought are recommended to reduce desertification intensity in the study area.

Desertification: Inappropriate images lead to inappropriate actions

AbstractAmong policy institutions, researchers in other fields, and the public, there is an enduring misunderstanding of the nature of desertification. To a considerable extent, its meaning has been reduced to just two eye‐catching images: sand dunes encroaching on productive land and habitations and bare, cracked soil surfaces. Yet neither of these is an indicator of desertification—sometimes called dryland degradation. Rather desertification results in a wide range of changes, including erosion, loss of biodiversity, decline in soil fertility, and reduced carbon storage. Surprisingly, it is the pictures themselves, not the scientific literature, that have fixed this erroneous concept in the minds of even some who work in the field of land degradation. The results of this confusion include inappropriate management efforts, mistaken premises in research, and ill‐informed policies at local to global scales including misleading prognostications of institutions—even at the level of United Nations agencies.

Mapping desertification potential using life cycle assessment method: a case study in Lorestan Province, Iran

In recent year, desertification has become one of the most important environmental hazards all over the world, especially in developing countries such as Iran. Understanding the factors impacting on desertification and identifying the regions with high desertification potential are essential to control this phenomenon (i.e., desertification). The life cycle assessment (LCA) method is essential in assessing the desertification of ecosystems, especially for susceptible ecosystems with high degradation risks. The aim of the present study was to evaluate the desertification potential of Lorestan Province, Iran, based on the LCA method. We selected aridity, fire and dust as three indicators of desertification and collected data from 2000 to 2015. We divided the study area into 6 types of ecoregions according to the climate types (arid, semi-arid and dry sub-humid) and dominant species (Quercus brantii and Astragalus adscendens), and calculated the characteristic factor (CF) of each indicator (aridity, fire and dust) by combining the indicator layers and ecoregion layer of the study area. In a given ecoregion, the sum of CF values of aridity, dust and fire indicators represents the life cycle inventory (LCI) desertification value (the higher the LCI value, the greater the desertification potential). Then, we obtained the desertification potential map by combining and overlapping the ecoregions and the normalized indicators based on the LCA method. Aridity and fire exhibit significant impacts on desertification in the study area compared with dust. In the study area, semi-arid ecoregion with Quercus brantii as the dominant species is the largest ecoregion, while arid ecoregion with Quercus brantii as the dominant species is the smallest ecoregion. Arid ecoregion with Astragalus adscendens as the dominant species (LCI desertification value of 1.99) and dry sub-humid ecoregion with Quercus brantii as the dominant species (LCI desertification value of 0.79) show the highest and lowest desertification potentials, respectively. Furthermore, arid ecoregion with Quercus brantii as the dominant species also has a higher LCI desertification value (1.89), showing a high desertification potential. These results suggest the necessity of proper management and appropriate utilization in these ecoregions. In general, assessing desertification potential using the LCA method on a local and regional scale can possibly provide a new methodology for identifying and protecting areas with high degradation risks.

The Major Biophysical Indicators of Desertification in Arid and Semi arid regions of India

Desertification is a process of land degradation in arid, semi- arid and dry sub-humid regions due to climatic uncertainties and improper land management activities. The major desertification processes operating in arid and semi arid regions of India are soil erosion, vegetal degradation, salinization/alkalinisation, water logging, loss of soil fertility and uncontrolled mining. Identification of major biophysical indicators of desertification is necessary for periodical monitoring and preparation of strong combating plan. To investigate the biophysical indicators which are most effective in assessing the level of desertification vulnerability, a total of 17 biophysical indicators were studied in 13 sites of South India representing two different agro-ecological regions (AESR 8.3&3). Principal Component Analysis was employed to identify the effective indicators based on maximum loadings and Eigen value. Linear discriminant analysis was used to identify the most important and reliable indicators for assessing degree of desertification processes. The results showed that pH and organic carbon are the most reliable indicators for assessing the degree of desertification processes in South India.

Evaluating the desertification vulnerability of a semiarid landscape under different land uses with the environmental sensitivity index

AbstractThe objective of this study was to evaluate the desertification vulnerability of an approximately 1,000‐ha area in Anatolia, Turkey, comprising semiarid oak (Quercus spp.) and pine (Pinus spp.) forests and the adjacent cultivated lands by using the environmental sensitivity index (ESI). We calculated the ESI values for 632 randomly selected sites in the study area by entering the desertification indicators vegetation cover, plant type, soil depth, rock fragments, soil texture, slope gradient, drainage, parent material, mean annual precipitation, slope aspect, aridity index, land use intensity, and policy enforcement into the web‐based model Desertification Indicator System for Mediterranean Europe. The spatial structure of the ESI values was then evaluated using semivariograms and kriging‐interpolated surface maps. The mean ESI value was significantly greater in the cultivated areas (1.47; range = 1.25–1.61) than in the pine (1.32; 1.03–1.45) and oak (1.28; 1.18–1.57) forests (P < 0.01). The ESI was moderately spatially dependent in the oak forests and cultivated areas and strongly spatially dependent in the pine forests, as evidenced by the corresponding semivariograms. The ordinary kriging‐interpolated maps showed that most of the cultivated areas were critically vulnerable to desertification, whereas the majority of the forested areas were moderately vulnerable. We examined how the ESI values varied with soil organic matter (OM) content as an independent variable and found that the OM content was significantly moderately correlated with the ESI (n = 632, r = −0.51, P < 0.01), suggesting that the ESI could be used to evaluate the desertification vulnerability of similar landscapes across Turkey.

Reappraisal of Miocene eolian deposition in Tianshui Basin, China, based on an investigation of stratigraphy and provenance

Eolian deposition in China is intimately related to Asian desertification. The fine-grained sediments in the Cenozoic basins along the northeastern Tibetan Plateau are increasingly reported as eolian deposits due to their loess-like characteristics, thus extending the onset time of Asian desertification from the late Miocene to the early Miocene. However, the basin-scale stratigraphic correlation and geographic origin of these fine-grained sediments remain poorly investigated, limiting any interpretation of the transportation and paleoclimatic conditions responsible for their emplacement. This study combines analyses of detrital zircon U-Pb geochronology and heavy-mineral assemblages to present the first comprehensive stratigraphic and provenance study of Miocene sediments in the Tianshui Basin in northeastern Tibet. Comparison of results from 64 sand-sized and silt-sized samples from various sedimentary beds across the basin reveals that the main stratigraphic packages can be correlated basin-wide, confirming that the silt-sized sediments were a natural part of the basin fill. Statistical visualizations of the large data set from northern and western China clearly shows that the West Qinling Mountains are the main source of the Tianshui Basin silts. Contribution estimates corroborate this conclusion and eliminate the likelihood of substantial contributions from other mountains and drylands. Moreover, the significant differences between the Tianshui Basin silts and the Chinese Loess Plateau/Red Clay are reflected by their heavy-mineral compositions and euhedral zircon U-Pb ages. These provenance analyses strongly contradict the previous assumption of desert origin for the Tianshui Basin silts. Moreover, the northward transport of the Tianshui Basin silts conflicts with the prevailing dust pathway driven by the Asian westerlies and winter monsoons, which do not support the eolian interpretation for their formation. Consequently, we suggest that the Miocene Tianshui Basin silts cannot be used as an indicator of extensive desertification, in contrast with the suggestions of previous studies. This proposal undermines the corresponding hypothesis of an early Miocene onset of Asian interior desertification, and further raises questions about the validity of prevalent paleoclimatic interpretations drawn from fine-grained basin sediments.

Evaluation of indicators for desertification risk assessment in part of Thar Desert Region of Rajasthan using geospatial techniques

Desertification has emerged as a major economic, social and environmental problem in the western part of India. The best way of dealing with desertification is to take appropriate measures to arrest land degradation, especially in areas prone to desertification. This requires an early warning system for desertification based on scientific inputs. Hence, in the present study, an attempt has been made to develop a comprehensive model for the assessment of desertification risk in the Jodhpur district of Rajasthan, India, using 23 desertification indicators. Indicators including soil, climate, vegetation and socio-economic parameters were integrated into a GIS environment to get environmental sensitive areas (ESAs) to desertification. Desertification risk index (DRI) was calculated based on ESAs to desertification, the degree of land degradation and significant desertification indicators obtained from the stepwise multiple regression model. DRI was validated by using independent indicators such as soil organic matter content and cation exchange capacity. Multiple regression analysis shows that 16 indicators out of 23 were found to be significant for assessing desertification risk at a 99% confidence interval with \(R^{2}=0.83\). The proposed methodology provides a series of effective indicators that would help to identify where desertification is a current or potential problem, and what could be the actions to alleviate the problem over time.

An applied statistical method to identify desertification indicators in northeastern Iran

BackgroundDesertification could be considered ultimate consequence of land degradation in an ecosystem. Iran with more than 75% arid and semi-arid areas involves fragile and susceptible ecosystems to desertification. We applied a statistical algorithm including regression trees and random forest techniques for determining main factors affecting desertification based on ESAs in Taybad-Bakharz region at northeastern Iran.ResultsThe results indicated a significant correlation between the desertification hazard value with variables of wind erosion, precipitation, aridity index, technology development, slope index, vegetation state and land use changes.ConclusionsRegression trees and random forest techniques in desertification hazard provide an absolute estimation of the relationship between dependent and independent variables. We can use a robust base for further investigations and refined with findings from in-depth studies carried out at the local scale.

Desertification of landscapes in low mountainous and plain sloping foothills of Kur depression

As the result of utilization of modern landscapes for various purpose in low mountainous and plain sloping foothills (39.7%) of Kur depression (4036644 hectares) some desertification factors and desertification holes occurred and the danger of degradation of landscapes has increased. In this regard, there is a great need to explore the current state of desertification in the area. The main objective of the research is to determine the current state of the desertification process, mapping and defining the landscape areas that are subject to desertification in Kur mountainous lowland. Route-sectoral, comparison, evaluation, statistical interpretation, satellite image decoding methods and ArcGis software were used during the research. Particularly semi-stratified research methods for the determination of desertification indicators, desertification types and desertification rates have played a speci-al role. The following key findings were obtained during the research: Based on ArcGIS statistical analysis of databases of large scale electronic desalination maps that we have compiled, the areas of desertification of landscapes for the total area and separated physical-geographical regions have been identified and quantitative indicators have been compared. 46.1% of the landscape complex of the study area was not affected by desertification in practice. Deserted complexes at various levels make up 53.9% of the total area. Geographical distribution of desertification territories in the area depends on the characteristics of natural and anthropogenic desertification factors and the structural-genetic characteristics of landscapes. Development of desertification in the region is largely caused by active natural exodynamic processes in semi-desert, dry-steppe, arid-sparse forests and bush. In the modern landscape of the study area, sometimes all categories of desertification are observed within a landscape unit. The scientific achievements of the research. - For the first time, the area of deserted landscapes has been identified by indicators of desertification in terrain landscapes and factors that led to the formation and development of desertification habitats. - It was determined that 11.5% of landscapes were slightly, 16.1% moderately and 26.3% severely deserted in the study area. - NDVI Index based on LANDSAT-8 satellite images (2017) of the area is determined during separation of desertification holes and degradation rates in landscapes. Practical implications. The results obtained in the research can be used in landscape planning, preparation of meliorative action plans, efficient use of natural resources and implementation of a number of agricultural and environmental projects.

Fractal features of soil particle size in the process of desertification in desert grassland of Ningxia, China

The variation of soil properties, the fractal dimension of soil particle size, and the relationships between fractal dimension of soil particle size and soil properties in the process of desertification in desert grassland of Ningxia were discussed. The results showed that the fractal dimension (D) at different desertification stages in desert grassland varied greatly, the value of D was between 1.69 and 2.62. Except for the 10-20 cm soil layer, the value of D gradually declined with increa sing desertification of desert grassland at 0-30 cm soil layer. In the process of desertification in de-sert grassland, the grassland had the highest values of D , the volume percentage of clay and silt, and the lowest values of the volume percentage of very fine sand and fine sand. However, the mobile dunes had the lowest value of D , the volume percentage of clay and silt, and the highest value of the volume percentage of very fine sand and fine sand. There was a significant positive correlation between the soil fractal dimension value and the volume percentage of soil particles <50 μm, and a significant negative correlation between the soil fractal dimension value and the volume percentage of soil particles >50 μm. The grain size of 50 μm was the critical value for deciding the relationship between the soil particle fractal dimension and the volume percentage. Soil organic matter (SOM) and total nitrogen (TN) decreased gradually with increasing desertification of desert grassland, but soil bulk density increased gradually. Qualitative change from fixed dunes to semi fixed dunes with the rapid decrease of the volume percentage of clay and silt, SOM, TN and the rapid increase of volume percentage of very fine sand and fine sand, soil bulk density. Fractal dimension was significantly correlated to SOM, TN and soil bulk density. Fractal dimension 2.58 was a critical value of fixed dunes and semi fixed dunes. So, the fractal dimension of 2.58 could be taken as the desertification indicator of desert grassland.

Soil desiccation as indicator of desertification of forest–steppe ecosystems in the Barguzin depression

This article presents study data on the status of plant and soil cover in the Barguzin Depression related to soil desiccation as the result of a 3-year drought, which caused the death of natural pine forests and shelterbelts composed of pine and balsam poplar. The main factors of tree death, as well as the soil conditions that favor survival under long-term air drought, have been revealed. A negative trend in the development of forest steppes under climate aridization in the North Baikal region was determined.

Changes in soil organic carbon and its active fractions in different desertification stages of alpine-cold grassland in the eastern Qinghai–Tibet Plateau

In recent years, the desertification of alpine-cold grasslands has become increasingly serious in the Qinghai–Tibet Plateau in China, but it has not received the same amount of attention as has desertification in (semi)arid areas. Little is thus known about the change in soil organic carbon (SOC) during alpine-cold grassland desertification. To quantify the impacts of desertification on vegetation, SOC and its active fractions in alpine-cold grasslands, areas of light desertified grassland, medium desertified grassland, heavy desertified grassland, serious desertified grassland, and nondesertified grassland were selected as experimental sites in the eastern Qinghai–Tibet Plateau in China. The species number, height and coverage of vegetation were surveyed, and the soil particle fractions, SOC and SOC active fractions (including dissolved organic carbon (DOC), microbial biomass carbon (MBC), and labile organic carbon (LOC) were measured to a depth of 0–100 cm. The results showed that alpine-cold grassland desertification resulted in a significant reduction in vegetation cover, plant biomass, fine soil particles, SOC, DOC, LOC and MBC. The decreases in DOC, LOC and MBC were more rapid and apparent than were those in SOC, and the decrease in MBC was the most obvious among them. The rates of reduction in SOC concentrations accelerated as desertification progressed; most of the SOC was lost in the middle and later desertification stages, with lower losses during early desertification. The results indicate that active SOC fractions, particularly MBC, are more sensitive to desertification and can be used as sensitive indicators of desertification. Efforts to limit desertification and reduce SOC loss in alpine-cold grasslands should focus on early desertification stages and adopt strategies to prevent overgrazing and control the erosion of soil by wind.

Assessment of remote sensing-based classification methods for change detection of salt-affected areas (Biskra area, Algeria)

In the Wadi Biskra arid and semiarid areas, sustainable development is restricted by land degradation processes such as secondary salinization of soils. Being an important high-quality date production region of Algeria, this area needs continuous monitoring of desertification indicators, hence highly exposed to climate-related risks. Given the limited access to field data, appropriate methods were assessed for the identification and change detection of salt-affected areas, involving image interpretation and automated classifications employing Landsat imagery, ancillary and multisource ground truth data. First, a visual photointerpretation study of the land cover and land use classes was undergone according to acknowledged methodologies. Second, two automated classification approaches were developed: a customized decision tree classification (DTC) and an unsupervised one applied to the principal components of Knepper ratios composite. Five indices were employed in the DTC construction, among which also is a salinity index. The diachronic analysis was undergone for the 1984 to 2015 images (including seasonal approach), being supported by the interpreted land cover/land use map for error estimation. Considering also biophysical and socioeconomic data, comprehensive results are discussed. One of the most important aspects that emerged was that the accelerated expansion of agricultural land in the last three decades has led and continues to contribute to a secondary salinization of soils.

Assessing the progress of desertification of the southern edge of Chihuahuan Desert: A case study of San Luis Potosi Plateau

The aim of this study is to establish if the San Luis Potosi Plateau (SLPP), which is part of the southern edge of the Chihuahuan Desert, is generating desertification processes, indicating a progression of the desert toward the central part of Mexico. Therefore, we analyzed the temporal evolution of four environmental indicators of desertification: Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Iron Oxides Index (IO) and Surface Temperature (ST). Landsat TM images are used to cover a period from 1990 to 2011. A new equation of total balance is proposed to generate an image of the overall evolution of each factor which is applied to get a probability map of desertification. The evolution of NDVI, NDWI and IO shows a behavior almost stable over the time. In contrast, the ST shows a slight increase. The outcomes of this study confirm periods of vegetation re-greening and 8.80% of the SLPP has the highest probability to develop desertification. The most affected area is the portion west of the region, and the east and south are the least affected areas. The results suggest a slight advance of the desert, although most of the area doesn’t have the necessary conditions to develop desertification.

Plant species associated with different levels of species richness and of vegetation cover as indicators of desertification in Burkina Faso (West Africa)

Desertification is a major problem in Sudano-sahelian West Africa, including the loss of biodiversity and vegetation cover. The loss of related ecosystem services is having a severe impact on human wellbeing. To facilitate assessments of these aspects of desertification, we decided to find plant species suitable as indicators. Based on a large database of vegetation plot data for Burkina Faso, we identified species associated with high or low levels of species richness and vegetation cover by calculating average values of these measures from vegetation plots on which they occur. To account for the differences between the dry Sahel and the more humid Sudan, we separated the plots of our study area in three vegetation zones (Sahel, North Sudan, South Sudan). Furthermore, herbs and woody plants were analysed separately, as they were usually represented in different plot sizes in the primary data. For each combination of species richness or vegetation cover, vegetation zone and growth form we identified ten species indicating low and another ten species indicating high values and assigned indicator values based on the average values of these species in the relevés.

A mechanism of self‐organization in a desert with phytogenic mounds

AbstractPhytogenic mounds or nebkhas are formed by spatially isolated burial‐tolerant plants, which have been trapping windborne sediment within their canopies. They occur in drylands all over the world, and nebkha landscapes are considered intermediate between stable grasslands and unstable deserts with mobile dunes. Depending on the previous state of the landscape, they can thus be viewed both as indicators of desertification and as signs of stabilization. While individual nebkha mounds have been studied extensively, little is known about the organization of nebkha landscapes. In this study, we collected spatiotemporal data of vegetation and topography from four self‐made remotely sensed maps, created over a three‐year period from a study site in central Saudi Arabia dominated by the nebkha‐forming shrub Rhazya stricta Decne. Using logistic regressions and t tests, we found that the nebkha shrubs grow in topographic depressions, while they shrink on topographic highs and in locations with high nebkha densities. We propose that this spatial variation in nebkha growth is driven by water availability, as the few extreme rain events that typically make up the bulk of precipitation in deserts would spatially redistribute to topographic lows, and as nebkha density would positively correlate with competition for water. Our data suggest a novel mechanism of biogeomorphological self‐organization in deserts. The observed nebkha growth in depressions would lead to increased sedimentation on and in between the nebkhas owing to reduced wind speed, which after a time lag might transform depressions into topographic highs on which nebkhas tend to shrink because of water shortage. Shrinking nebkhas, in turn, could provoke soil erosion, on as well as in between the nebkha mounds, which may ultimately transform topographic highs into depressions, thereby closing the cycle of self‐organization.

Water harvesting model for improved rangeland productivity in Butana, Sudan

The above-ground biomass and floristic composition of Butana rangelands in Sudan were assessed in 2006 with field surveys covering 25 sites. The remote sensing data derived from Spot image for the same period was integrated to the field surveys to map the spatial distribution of biomass production (kg ha-1) using the perpendicular vegetation index. A rainfall map of the region was established from the meteorological data of the season and the digital elevation model. The rain use efficiency factor, which is the quotient of the annual pri­mary production (kg dry matter ha-1) of a season by rainfall (mm) of the same season, was used as a rangeland degradation and desertification indicator in Butana. To test the potential of water harvesting techniques on biomass produc­tion, two seasons’ experiments were conducted (2006 and 2007). Their results were used to simulate the potential of biomass production with water harvest­ing application through a general model that linked remote sensing output, field measurement and water harvesting results.

Assessing the robustness of spatial pattern sequences in a dryland vegetation model.

A particular sequence of patterns, 'gaps→labyrinth→spots', occurs with decreasing precipitation in previously reported numerical simulations of partial differential equation dryland vegetation models. These observations have led to the suggestion that this sequence of patterns can serve as an early indicator of desertification in some ecosystems. Because parameter values in the vegetation models can take on a range of plausible values, it is important to investigate whether the pattern sequence prediction is robust to variation. For a particular model, we find that a quantity calculated via bifurcation-theoretic analysis appears to serve as a proxy for the pattern sequences that occur in numerical simulations across a range of parameter values. We find in further analysis that the quantity takes on values consistent with the standard sequence in an ecologically relevant limit of the model parameter values. This suggests that the standard sequence is a robust prediction of the model, and we conclude by proposing a methodology for assessing the robustness of the standard sequence in other models and formulations.

Dynamics of Summer Moistening and Biophysical Parameters of Arid Pastures in the European Part of Russia in 2000–2014

The dynamics of moistening indices and biophysical parameters (MODIS data) of arid pastures is examined for the southeast of the European part of Russia in five-year periods over 2000–2014. It was found that the dynamics was heterogeneous both in the temporal and spatial dimensions. The maximal moisture decrease was noted in 2005–2009 in dry-steppe and semidesert pastures. During 2010–2014, the moisture levels continued to decrease, though less intensively compared to the previous five-year period. The dynamics of biophysical parameters is determined by changes in moistening and the degradation of pastures due to overgrazing. The period of 2005–2009 was noted for reduced NDVI, deterioration of the vegetation condi-tions (VCI), and the growth of albedo and surface temperature in dry-steppe and partly semidesert pastures. The following period was marked by a shift of maximal changes in biophysical parameters to the Kalmyk Republic and the right-bank of Astrakhan oblast. This resulted in the appearance of preconditions for new anthropogenic desertification in the territory of Kalmyk Republic, which was detected by the desertification indicator.

内蒙古生态系统质量空间特征及其驱动力

PDF HTML阅读 XML下载 导出引用 引用提醒 内蒙古生态系统质量空间特征及其驱动力 DOI: 10.5846/stxb201501290245 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金重点项目（40901289）；国家科技支撑计划课题（2011BAC09B08-02） Spatial patterns of ecosystem quality in Inner Mongolia and its driving forces analysis Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:植被作为生态系统的重要组成部分，联结着大气、水分和土壤等自然过程，其变化将直接影响该区域气候水文和土壤等状况，是区域生态系统质量变化的重要指示器。植被状况的好坏，主要通过生物量和植被覆盖度因子来表示。内蒙古自治区是我国北方生态环境问题十分严重的省份，弄清当前区域生态系统质量状况与变化及其近10年来变化的驱动因素，对分析与制定区域生态环境保护决策具有十分重要的意义。基于2000-2010年生物量和植被覆盖度，并结合地区植被区划数据，对内蒙古植被生态系统质量状况进行分析，并评估其与气候（降水、温度），人类活动（交通密度、农业发展、生态恢复工程）的相关关系，在此基础上探讨了气候和人类活动对近年来内蒙古生态系统质量变化的影响。结果表明：（1）内蒙古生态系统质量状况整体偏低，其中森林生态系统平均质量最高，灌丛、草原生态系统次之。空间分布呈明显的经度地带性，由东向西，质量逐渐降低。2000-2010年内蒙古生态系统质量总体上呈现缓慢增长趋势，但局部地区生态系统质量仍存在恶化，其中在107°E以东的草原和森林区域，生态系统质量变化十分剧烈。（2）近10年来内蒙古生态系统质量的变化与气候和人类活动的关系非常密切，其与降水、GDP1、化肥施用量、天保工程和退耕还草工程呈现明显的正相关。而与温度、道路密度和京津风沙治理工程呈现明显的负相关。其中，生态保护工程实施区域内和区域外的相关性存在显著的差异性。随着内蒙古社会经济的快速发展，人类活动对生态系统质量的影响逐渐加强，但降水仍是该地区生态系统质量的主要影响因子。（3）在内蒙古生态系统质量变化典型区域内，质量的增长主要是由于降水的增加、温度的降低、农业的发展、退耕还草工程的作用和交通发展的放缓。质量的降低则是因为降水的减少、温度的增加、农业发展缓慢和交通发展的加快所致。 Abstract:Vegetation is an important component of ecosystems, and it is involved in natural processes such as regional climate circulation, the hydrologic cycle, soil conditions, and other natural processes. It is also an important indicator of regional ecosystem quality change. Aboveground biomass and vegetation cover are important variables for describing vegetation quality and documenting ecosystem changes. Moreover, they are controlling factors in transpiration, photosynthesis, and other terrestrial processes, and are sensitive indicators of land degradation and desertification in arid and semi-arid regions. Aboveground biomass and vegetation cover have been used widely in the analysis of vegetation quality and changes. Inner Mongolia, an important province of northern China that is located mostly in arid and semi-arid areas, is undergoing a process of significant warming and drying, which could lead to serious ecological problems such as land degradation and desertification. Determining the driving cause of these problems has become a focus of vegetation research. Many researchers have attributed the degradation and desertification in northern China to long-term over-grazing, extensive cutting, and widespread conversion of grassland to cropland. Other studies have found that poor climate conditions, such as drought, severe wind erosion, temperature fluctuation, and winter precipitation are the primary cause of degradation and desertification. Nevertheless, some recent studies have shown that human activities can control the degradation in selected study regions of northern China. It is necessary to investigate current ecosystem quality and its response to climatic variation and human activities for a better understanding of the accumulated consèquences of changes in climate and human activities. In this study, combining remote sensing products (aboveground biomass and vegetation cover) with vegetation regionalization data, we quantified ecosystem quality in Inner Mongolia, and analyzed the effects of climate and human activities on spatial variations in quality change from 2000 to 2010. Our results indicated that overall ecosystem quality in Inner Mongolia is very low. Among the ecosystem types, the highest quality was exhibited in forest ecosystems, followed by shrub and grassland ecosystems, respectively. Ecosystem quality displayed evident spatial heterogeneities, divided according to latitude, and reduced gradually from east to west. There was a slight increase in ecosystem quality over the study period. However, degradation and desertification also existed in some regional areas. The spatial variation characteristics of ecosystem quality are formed by interactions between the influencing factors. The partial correlations among ecosystem quality and precipitation, GDP1, fertilizer, the natural forest protection project, and the returning farmland to grassland project were positive and statistically significant. By contrast, ecosystem quality was negatively correlated with temperature, road density, and the treatment of sand and wind sources. With the rapid development of the social economy of Inner Mongolia, the influence of human activities on ecosystem quality gradually increased, but precipitation was still the dominant factor that influenced the spatial variation characteristics of ecosystem quality. The main reasons for the improvement of ecosystem quality in a typical area were increasing precipitation, decreasing temperature, development of agriculture, returning farmland to grassland, and a slowing of traffic development. In addition, decreasing precipitation, increasing temperature, a slowdown of agricultural development, and a speeding up of traffic development led to degradation and desertification. These results provide specific information that may serve to strengthen the necessary public awareness about protecting and restoring ecosystems. 参考文献 相似文献 引证文献