Based on the MODIS NDVI product data source of Xilingol from 2010 to 2019, we use the pixel dichotomous model to retrieve the vegetation coverage in our study. The spatiotemporal changes of the vegetation cover were analyzed in the model by using the meteorological data from researched sites or the vicinal meteorological stations for evaluating the meteorological influence on the vegetation cover changes. Based on this, an evaluation method was established to estimate the relative influences of the climate changes and anthropogenic activities. The main conclusions are as follows: (1) Fractional vegetation cover in Xilingol was decreased from the northeast to the southwest. (2) The overall trend in Xilingol fractional vegetation cover in the 10-year period shows a fluctuating increasing trend. (3) An opposite distribution pattern was detected between mean precipitation and mean temperature in the study site. (4) Compared with temperature, annual precipitation has a higher correlation with fractional vegetation cover in the study site and is the main climatic factor that affects vegetation growth in the study site. (5) During the 10-year period in the study site, anthropogenic human activities have slightly greater inhibitory effects on vegetation growth than promoting effects. (6) Climate change is a major factor to accelerate grassland degradation from 2010 to 2019 in vegetation degradation regions. The promotion effect of precipitation on vegetation coverage is obviously higher than the limitation of human activities, which leads to the increase of vegetation coverage in 2010–2019.

根据河北省草地资源资产清查的需求,开发了河北省草地资源资产信息管理平台.该平台基于GIS信息系统,运用文件地理数据库(GDB),实现草地资源数据快速输入、存储、处理、查询、提取等功能,达到规范草地资源资产数据管理机制、简化草地资源动态监测流程、提高处理草地资源动态监测数据效率的目的 ,为相关部门提供草地资源综合分析、动态监测和管理规划等服务.

为全面掌握草原资源基础数据,分析评价草原资源及其生态状况,提供内蒙古草原生态现状调查的理论依据和技术指导,在已有工作的基础上结合先进的调查技术,提出了一整套包括“3S”技术、样点布设技术、地面调查技术、数据获取技术、遥感解译技术、模型估算技术、精度验证技术和数据库技术在内的草原生态现状调查的关键技术集成方法.

为了解草原矿区土壤碳(C)、氮(N)、磷(P)含量及生态化学计量特征,以锡林浩特胜利煤田周围草原为研究对象,研究不同距离、不同方向土壤C、N、P含量及化学计量特征.结果表明:1)土壤有机碳、全氮、全磷含量在4.0 km处最高,碳磷比(C/P)、氮磷比(N/P)在4.0 km处最高,碳氮比(C/N)在0 km处最高;2)有机碳含量在东向最高,全氮含量在东向和北向最高,全磷含量在北向最高;3)土壤有机碳含量与全氮含量、全磷含量、碳氮比、碳磷比、氮磷比,全氮含量与全磷含量、碳磷比、氮磷比,碳氮比与碳磷比,碳磷比与氮磷比呈极显著正相关(P＜0.01);碳氮比与氮磷比呈显著负相关(P＜0.05).试验表明,土壤碳、氮、磷含量、碳磷比最高值出现在4.0 km处,碳氮比最高值出现在0 km处,而土壤中磷元素迁移速度较慢,因此推测露天开采煤炭形成的粉尘促进了无机碳的扩散和转换.

资源信息的整合、挖掘,建立以数据库系统为基础的信息平台是草原资源利用和保护的迫切任务.西藏草原资源信息平台以目前国际上高度认可且极具发展潜力的对象化设计方法及专业开发工具为研发框架和手段.以西藏第二次草原普查的数据资料为基础,研发出一套通用性、稳定性和兼容性较强,并能够满足西藏地区草原资源信息管理需要的应用系统平台.西藏草原资源的GIS数据库管理功能的实现,创建了我国高海拔、大尺度草原信息快速获取与精准制图成套技术方法,提升了草原资源数据管理的精准度和工作效率,满足草原资源监管、宏观调控和社会化服务的需要.

[Objective] The aim was to accurately and truly reflect the changes in structure and function of the desert steppe ecosystem in Inner Mongolia. [Method] The desert steppe in Damao Banner was taken as the object of study,the change of vegetation coverage,grassland produc-tivity and carrying capacity in recent more than 30 years was studied by using 3S technology. [Result] The coverage of grassland vegetation in Damao Banner was increased by 2% compared with in the initial period of 2000;the productivity of grassland in Damao Banner decreased from south to north,which was higher than that in 2003;the carrying capacity of Damao Banner grassland was increasing compared with the 1980s and in the initial period of 2000. [Conclusion] The result provides theoretical basis for Inner Mongolia to make up ecological management decision.

我国北方荒漠草原地区生态环境总体上具有结构简单、易受干扰、自我调节能力差等特点.因此,在全球气候变化的大背景下,由于农业与牧业之间的激烈竞争,加之区内气候波动、人类活动干扰等诸多因素,对荒漠草原地区的生态环境和结构产生了重大影响.为了能准确和真实的反映我国北方荒漠草原地区生态系统的结构和功能的变化,该文选定达茂旗为研究对象,通过对草地退化结构变化、草地等和级结构变化的研究,得出以下结论:(1)相比20世纪80年代达茂旗退化、沙化、盐渍化草地,以及重度退化和重度盐渍化草地相比20世纪80年代都有所减少;(2)达茂旗草地等级由低一级的草地向高一级的草地逐渐演变;(3)达茂旗草地质量相比20世纪80年代有所降低.

近年来剧烈的人类活动和自然因素变化致使生态系统退化,表现为草地植被退化、生物种类单一、土壤物理性质变差等.为了探讨内蒙古典型草地生态系统的结构和功能变化,以呼伦贝尔典型草原退牧还草工程区为研究对象,采用成对取样方法(围栏内-围栏外)对退牧还草工程区禁牧和休牧两种干扰方式下植被恢复过程中物种多样性、地上生物量、土壤容重和水分等的变化特征进行了研究,以期为草地的合理利用和管理提供理论依据.结果表明:(1)不同干扰方式对草地物种多样性和地上生物量有明显影响,物种的多样性指数和丰富度指数在禁牧区分别为1.73和7.59,在休牧区为1.47和5.70,全部表现为禁牧区>休牧区(P<0.05).地上生物量则相反,在禁牧区和休牧区分别为36.34 g·m-2和42.83 g·m-2,表现为禁牧区<休牧区;(2)不同干扰方式对草地土壤物理性状有明显影响,但不同指标对干扰方式的响应不同.禁牧有利于土壤含水量的积累,放牧导致土壤紧实、容重增加,同一土层深度土壤含水量表现为禁牧区>休牧区,例如0～10 cm处土壤含水量在禁牧区和休牧区分别为4.57％和2.80％,禁牧区显著高于休牧区(P<0.05);土壤容重则相反,表现为禁牧区<休牧区.综上所述,不同的生态工程措施对草原生态系统有明显影响,禁牧有利于维持较高的物种多样性和维持较好的土壤物理性质,休牧可提高草原生产力,退牧还草工程对恢复草原生态功能起到了积极的作用.

氮、磷是维持草原生态健康的重要元素,其含量变化及分布特征,对草原放牧、草地生态管理具有重要的意义.以内蒙古锡林郭勒草原矿区为研究对象,采用多元逐步回归筛选与N/P比最为密切的高光谱波段,建立了基于高光谱反演草原矿区表层土壤N/P的BP神经网络模型.结果表明:1)通过多元逐步回归筛选出的70个波段,其中包括2个可见光波段和68个红外光波段;2)BP神经网络模型随着隐含层层数的增加,训练数据和测试数据的拟合优度先增大后减小,且隐含层层数为3时最大,分别为R 2tr=0.8727和R 2t=0.8842(P<0.0001);训练数据均方根误差先减小后增大,隐含层层数为3时最小,RMSE tr=0.0600,测试数据均方根误差在隐含层层数为3时,RMSE t=0.0882;3)节点数为6、3和10的3层隐含层BP神经网络模型在拟合和预测土壤N/P时的效果较好,可用于草原表层土壤N/P的快速预测.

About 400 million ha grassland in China is a large potential carbon sink.However,grassland carbon sequestration is not fully understood.This paper reviews the effects of meteorological factors(CO2,temperature and rainfall change),grassland management(grazing,native grassland conversion to cropland,mowing,fertilization,irrigation,reseeding,abandoned cropland,exclosure,establishment of artificial grassland and ploughing),and degradation on soil carbon content,to guide grassland management for carbon sequestration.Changes of temperature and precipitation play different roles in the function of grassland carbon sequestration,which should be taken into account in grassland management.Degraded grassland with low productivity and soil organic matter content and a worse soil physical and chemical environment has great carbon sequestration potential.Appropriate grassland management measures will greatly improve soil organic carbon.One report suggests that the application of exclosure in degraded grassland in China could sequester over 12.01 Tg C/year.Heavy grazing can reduce carbon sequestration due to changing grassland plant community diversity,net primary productivity reduction,lower litter production and nitrogen limitation in soil.Proper grazing management has been estimated to increase soil carbon storage.Native grassland conversion to cropland has caused negative carbon sequestration,as a result of soil erosion,soil organic matter decomposition and lower litter production.Because high mowing intensity reduced soil organic matter,proper mowing height and frequency,application of manure and fertilizer to balance nutrient loss was needed on hay grassland.Fertilization,reseeding,ploughing and irrigation increased soil organic matter storage by promoting revegetation and net primary productivity.Abandoned cropland and exclosure associated with fertilization and reseeding could promote restoration and soil nutrient content,and increase carbon sequestration efficiency.Carbon sequestration capability of forage was: mixed perennial legume and grasslegumeperennial grassannual grass.

In order to know well about the relationship between the space -time dynamics of vegetation covering in Hun-shandake Desert and the precipitation of its growing period and the temperature , we managed to obtain its law of the space -time dynamics change , by using calculating the vegetation covering of Zhenglan Banner Grassland with Pixel binary model method which is based on the data source from MODIS satellite of America .It was demonstrated that the coverage rates of vegetation fluctuated during 2000 to 2011 with highest value (47.4%) in 2004 and the lowest value (34.1%) in 2009. The mean rate of vegetation covering was 40.96% with a relatively small coefficient of variation (10.9%) during the 12 years.The higher coverage were mainly observed in grasslands around or inside the rivers and lakes of the sands and lower coverage were mainly observed in grasslands around northwest and eastern sand strip area .The coverage rate of vegetation had the positive linear correlation with the precipitation (R=0.674,P=0.016) and the negative linear relationship with the average temperature(R=0.627,P=0.029)vegetation growing period.

In order to measure the ratio and content of dietary plant species of sheep in Inner Mongolia desert steppes,different combinations of alkanes,long-chain alcohols and long-chain fatty acids were evaluated by gas chromatography for distinguishing species.Different combinations of alkanes,long-chain alcoholsand long-chain fatty acids were assessed by principal component analysis(PCA) and one-way ANOVA analysis.Results showed that plant wax compositions could be used as markers of distinguishing dietary plant species in desert steppes of Inner Mongolia.The combination of plant wax alkanes and long-chain alcohols was the best for estimating sheep intake and dietary composition.These results provided a pattern and method for assessing sheep intake and dietary composition in desert steppe.

Alfalfa (Medicago sativa L.) is a primary and widely cultivated forage crop in China. As a perennial leguminous grass, continuous planted alfalfa may influence carbon and nitrogen sequestration in soils. We evaluated the effect of alfalfa, planted for different lengths of time, and temperature and precipitation on soil organic carbon (SOC) and total nitrogen (TN) contents, and estimated soil SOC and TN inventories from 0-60 cm in three agro-pastoral ecotones of northern China. Alfalfa SOC and TN storage patterns were significantly different with increasing soil depths between the three regions of northern China. Continuous alfalfa grassland planted had a positive effect on accumulation of both SOC and TN in the Northwest region, whereas SOC storage peaked 6-7 years after planting in the Northeast and North region. Moreover, relatively higher TN storage appeared 7 years after planting in the Northeast and North regions. This study controlled as many factors as possible, but we caution that such temporal inferences could be artifacts of site selection. The regression analysis indicated that SOC and TN accumulation was mainly dependent on temperature (≥10°C of effective total accumulated temperature) in the North region. Precipitation in the growing season was the main limiting factor for SOC storage in the Northwest region and TN accumulation in the North regions. Therefore, the different climate factors affecting SOC and TN sequestration in alfalfa occurred at a regional scale.

The potential of grazing lands to sequester carbon must be understood to develop effective soil conservation measures and sustain livestock production. Our objective was to evaluate the effects of grazing on soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) in Typical steppe and Desert steppe ecosystems, which are both important grassland resources for animal grazing and ecological conservation in China, and to derive region-specific soil C changes associated with different stocking rates (ungrazed, UG; lightly grazed, LG; moderately grazed, MG; heavily grazed, HG). This study substantiated that significant higher SOC, TN and MBC appeared with the treatment of LG in typical steppe. From 2004 to 2010, grazing treatments increased soil carbon storage in desert steppe, which was partly due to the grazing history. The higher MBC concentration and MBC/SOC suggest a great potential for carbon sequestration in the desert steppe ecosystem. The greater MBC in desert steppe than typical steppe was mainly the result of higher precipitation and temperature, instead of soil substrate. The change of MBC and the strong positive relationships between MBC and SOC indicated that MBC in the soil was a sensitive index to indicate the dynamics of soil organic carbon in both steppes in Inner Mongolia of China.

An experiment was conducted about MDA dynamics of the last autumn cutting on alfalfa to different fall dormancy. The results showed that there was a reduction to MDA for different category alfalfa on Sep10th. There was a trend like reduction-increase-reduction in different dormancy alfalfa on Sep20th,Sep30th and Oct20th with the highest in next later March. There were two summites in different dormancy alfalfa on Oct20th and next later March,and it showed that the temperature change in later autumn led to the injury and the relationship between alfalfa regreen up in the next March because of a summit.

以内蒙古自治区天然草原为研究尺度,将草原植被盖度常规调查方法与地理信息系统(geographic information system,GIS)中反距离权重(inverse distance weighted,IDW)内插法结合应用,实现了由点到面信息的拓展,结果为:2008年内蒙古天然草原植被平均投影盖度为38.85%,较2007年同期提高了1.13%;其中,多年生植物投影盖度平均为28.80%,全区地表植被平均基盖度为13.21%.2008年内蒙古天然草原植被盖度情况总体好于去年.