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1.
We studied the roles of soil moisture contents and vegetation structure in the spatial distribution of small mammals in the typical steppes of Inner Mongolia, China, using logistic and linear regressions of a data set collected in a 6-year study. Our results indicated that soil moisture contents remained in the most parsimonious models for Spermophilus dauricus, Cricetulus barabensis, Microtus maximowiczii, M. gregalis, and Ochotona daurica. The relative abundance of C. barabensis, M. maximowiczii, and O. daurica was inversely related to soil moisture contents, while that of M. gregalis and S. dauricus was positively related to soil moisture contents in logistic regressions. Linear regression analyses showed that soil moisture contents and the number of small mammal species were inversely related. The negative effects of wet soil were consistent at both small mammal population and community levels in the semi-arid steppes. Above-ground plant biomass and plant coverage also affected the spatial distribution of small mammals in the typical steppe of Inner Mongolia.  相似文献   

2.
蒙古高原中部气候变化及影响因素比较研究   总被引：4，自引：0，他引：4  
王菱  甄霖  刘雪林  王勤学 《地理研究》2008,27(1):171-180
利用蒙古国中部6个气象站1940~2004年和中国内蒙古自治区中部6个气象站1951~2004年的温度和降水资料,对两地的气候变化及其影响因素作了对比研究。结果表明:20世纪90年代与60年代相比,中国内蒙古6站平均升温1.35℃,蒙古国6站上升1.13℃,2000~2004年与60年代相比:中国内蒙古6站上升1.89℃,蒙古国则为1.37℃,中国内蒙古6站的升温速率高于蒙古国6站。对温度变化趋势作突变性检验,结果表明:温度发生突变时间是纬度较高地区早于纬度较低的地区,大城市早于中小城镇,城市化对温度变化影响比较明显。相对于温度变化,降水变化没有显著性的突变,但有周期变化,中国内蒙古降水变化有2.8年周期,蒙古国有4年、8年的周期,这可能因为中国内蒙古降水水汽主要来源于太平洋,而蒙古国降水的水汽主要来源于北冰洋。  相似文献   

3.
气候变化及其对植被净初级生产力的影响是全球变化研究的核心内容之一。基于空间化的CENTURY生物过程模型,分析1981-2010年内蒙古草地净初级生产力（NPP）的时空演变规律及其对关键气候因子的敏感性特征。结果表明：近30年内蒙古草地大部分区域NPP呈下降态势但趋势并不显著,全区平均降速约为1.17 g C/m2·a;NPP年代际变化时空差异较大,1980s至1990s约69.65%的区域NPP下降,1990s至2000s NPP下降加剧,下降面积较前者扩大了17.50%;NPP对降水与温度的敏感性特征空间异质性较强,但总体上区域降水减少可能是近30年内蒙古草地NPP下降的主要因素,温度升高同样会导致草地NPP下降,但作用程度较小。  相似文献   

4.
Spacing behavior is important to the population regulation and social organization of rodents. However, little is known regarding the factors influencing space use by rodent social groups. We tested the hypotheses that food resources in the typical steppe would be so abundant that food availability would not be a limiting factor of home-range sizes of social groups of Mongolian gerbils (Meriones unguiculatus). We also assessed the effects of social organization on the home-range size of social groups of gerbils, using capture-recapture methods. Home ranges of social groups of Mongolian gerbils did not differ in size between the breeding and non-breeding periods; however, home ranges overlapped more during the breeding period than during the non-breeding period. Overlap of home ranges might allow male gerbils to access female mates of neighboring colonies during the breeding period. Home-range sizes of social groups were positively related to number of males during the breeding period, but positively related to group size and number of females during the non-breeding period. Therefore, social organization influenced home-range sizes of social groups. Our hypothesis that food availability is not a limiting factor of space use by social groups of Mongolian gerbils from spring through autumn was supported.  相似文献   

5.
乌兰图雅 《地理学报》2021,76(7):1722-1731
内蒙古草原是蒙古高原草原带的南部组成部分,是我国北方重要的生态屏障,草原生态修复任务重、压力大。本文以蒙古高原典型草原乌珠穆沁—温都尔汗样带为例,以1988—2016年5期TM数据为信息源,获取2016年样带草地利用信息基础上,按国别和年限对样带草地利用特征进行分析,揭示草地主要干扰因素,探寻有效的修复途径和可借鉴的国际经验。研究发现：① 草地面积占样带95.05%,均匀覆盖于整个样带;其他用地类型占比均不大,但分布相对集中,其中耕地集中于样带西北部蒙古国段,工矿用地、沙地、盐碱地集中于样带东南部内蒙古段。② 1988—2016年样带耕地面积减幅最大,为35.71%,集中位于蒙古国段;草地、水域面积逐年减少,在中国境内、境外变化趋势相同,但内蒙古段草地减幅大于蒙古国段且多转为未利用地;工矿用地面积增幅最大,为初期的近367倍,集中分布于内蒙古段;盐碱地、沙地面积逐年增加,在中国境内、境外的变化幅度相当。③ 草地是高原主要土地利用类型,放牧是草地主要利用方式,开矿是除放牧以外中国草地的主要干扰因子,蒙古国则为垦殖,内蒙古的草地干扰远大于蒙古国。草地退化与干旱化是蒙古高原面临的主要生态环境问题,在中国境内尤为突出。  相似文献   

6.
Soil carbon sequestration and potential has been a focal issue in global carbon research. Under the background of global change, the estimation of the size as well as its change of soil organic carbon（SOC） storage is of great importance. Based on soil data from the second national soil survey and field survey during 2011–2012, by using the regression method between sampling soil data and remote sensing data, this paper aimed to investigate spatial distribution and changes of topsoil（0–20 cm） organic carbon storage in grasslands of Inner Mongolia between the 1980 s and 2010 s. The results showed that：（1） the SOC storage in grasslands of Inner Mongolia between the 1980 s and 2010 s was estimated to be 2.05 and 2.17 Pg C, with an average density of 3.48 and 3.69 kg C·m–2, respectively. The SOC storage was mainly distributed in the typical steppe and meadow steppe, which accounted for over 98% of the total SOC storage. The spatial distribution showed a decreased trend from the meadow steppe, typical steppe to the desert steppe, corresponding to the temperature and precipitation gradient.（2） SOC changes during 1982–2012 were estimated to be 0.12 Pg C, at 7.00 g C·m–2·yr–1, which didn＇t show a significant change, indicating that SOC storage in grasslands of Inner Mongolia remained relatively stable over this period. However, topsoil organic carbon showed different trends of carbon source/sink during the past three decades. Meadow steppe and typical steppe had sequestered 0.15 and 0.03 Pg C, respectively, served as a carbon sink; while desert steppe lost 0.06 Pg C, served as a carbon source. It appears that SOC storage in grassland ecosystem may respond differently to climate change, related to vegetation type, regional climate type and grazing intensity. These results might give advice to decision makers on adopting suitable countermeasures for sustainable grassland utilization and protection.  相似文献   

7.
The population structure, educational level and the livelihoods of 82 households of pastoral nomads, the organization of livestock husbandry and its impact on the grassland and forest ecosystems of the Dayan high valley (>2000 m a.s.l.) in the Mongolian Altai, western Mongolia, were surveyed using interviews and secondary information from official sources. Changes following the transition from centrally planned (before 1990) to market economy were analyzed. Two thirds of the monthly mean income of ca. 310 USD per nomad household is cash (ca. 55 USD) or non-cash (ca. 165 USD) income from livestock husbandry. Cashmere sale accounts for 70% of the cash income from livestock husbandry, which has led to a strong increase of goat numbers after 1990. Forests are used for livestock grazing, fuel wood collection, logging, and fruit collection. Livestock breeding and the seasonal migration of the nomad households are no longer organized by the government. To avoid transportation costs, two thirds of the families have reduced their seasonal migrations. This trend was favored by rising temperatures and earlier snowmelt during the last few decades, but resulted in a shortage of fodder and intensified forest use. Therefore, the use of grasslands and forests in the Mongolian Altai is no longer considered to be sustainable.  相似文献   

8.
This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index (NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series.  相似文献   

9.
内蒙古中西部春季沙尘暴年代际振荡及环流特征分析   总被引：6，自引：6，他引：0  
利用内蒙古中西部50个气象观测站1961—2000年春季沙尘暴日数资料,国家气候中心提供的北半球月平均500 hPa高度场网格尺度为10°(经度)×5°(纬度)的网格点资料、北半球500 hPa月平均环流特征量资料、东亚季风资料分析研究冬春季中高纬度大气环流的年代际尺度的演变特征及其对内蒙古中西部沙尘暴的影响,进一步揭示内蒙古中西部春季沙尘暴年代际变化的原因。结果表明：青藏高原位势高度、贝加尔湖地区位势高度、乌拉尔山地区位势高度、东亚冬季风、亚州经向环流、印缅槽、西太平洋副热带高压强度都对内蒙古中西部春季沙尘暴年代际振荡产生不同的影响。为内蒙古中西部春季沙尘暴的短期气候预测提供年代际尺度上的基本环流背景。  相似文献   

10.
内蒙古水土资源平衡及其水资源承载能力   总被引：14，自引：0，他引：14  
从资源平衡关系入手,定量计算了天然状态下内蒙古的水土资源平衡,揭示了内蒙古自然降水与作物水分需求的平衡关系;采用负载指数与承载力模型,计算了内蒙古的水资源利用潜力与承载能力,揭示了调控下内蒙古水资源支撑能力和保证程度.结果表明:内蒙古高原气候干旱,水分亏缺是自然降水条件下水土资源平衡的主要特征;内蒙古水资源承载力有限,当人均综合用水量达到较高水平时,平水年全区承载力接近超载临界值,偏枯水年全区水资源超载严重;内蒙古水资源承载能力盟市差异显著,水资源普遍短缺是区域人口发展的限制性特征.  相似文献   

11.
邵亚婷  王卷乐  严欣荣 《地理研究》2021,40(11):3029-3043
蒙古高原是中国重要的北方生态屏障。在全球气候变化的背景下,研究蒙古国植被物候变化特征对于认识蒙古国草地生态系统对气候变化的响应和促进区域畜牧业可持续发展具有重要意义。本研究利用非对称高斯拟合法对蒙古国2001—2019年MOD13Q1产品中的归一化植被指数（Normalized Differential Vegetation Index,NDVI）数据拟合,得到较为平滑的NDVI时间序列数据;基于TIMESAT平台,采用动态阈值法分析获得蒙古国连续19a植被物候数据。研究分析了蒙古国植被物候的空间分布及年际变化趋势,发现蒙古国植被返青期（Start of growing season,SOS）主要集中在110~150d,总体呈微弱推迟趋势,植被枯黄期（End of growing season,EOS）主要集中在270~310d,总体呈提前趋势,从而导致蒙古国生长季长度（Length of growing season,LOS）呈缩短趋势,且缩短时间最长可达2d以上。采用偏相关分析方法分析了植被物候对地形、降水、地表温度等地理要素的响应,表明蒙古国植被物候具有明显的空间异质性和海拔依赖性,不同植被物候对降水、地表温度（Land Surface Temperature,LST）的响应不同,SOS与日间LST呈显著正相关,EOS与夜间LST呈显著正相关,而LOS与年均降水呈显著负相关关系。  相似文献   

12.
2001-2010 年内蒙古植被覆盖度时空变化特征   总被引：65，自引：4，他引：61  
基于MODIS-NDVI 遥感数据反演了内蒙古地区2001-2010 年植被覆盖度的空间格局和变化规律, 并结合该地区同期降雨量和温度数据, 分别从不同空间和时间尺度上分析了森林生态区、草原生态区和荒漠生态区植被的年际变化和月际变化对气候变化的响应。结果表明:(1) 内蒙古植被覆盖度在空间上呈现东高西低的分布特征, 自西向东的变化速率为0.2/10°N, 10 年间森林、草原和荒漠生态区的年均植被覆盖度分别为0.57、0.4 和0.16;(2) 2001-2010年, 内蒙古植被覆盖度总体上呈上升趋势, 研究区内植被覆盖度极显著增加和显著增加的面积分别占总面积的11.25%和29.13%, 二者之和大于植被覆盖度极显著减少和显著减少的面积比例之和, 后者分别为7.65%和26.61%;(3) 在年际水平上, 内蒙古植被生长总体上与降雨量的关系更加密切, 而在月际水平上, 降雨量和温度对植被生长的影响作用相当, 说明年内植被生长更依赖于水热组合的共同作用, 而与单一气候因子的相关性降低;(4) 森林生态区植被覆盖度在年/月际水平上均与温度的相关性较强, 荒漠生态区植被覆盖度在年/月际水平上均与降雨量相关性较强, 而草原生态区植被覆盖度在年际水平上主要受降雨影响, 在月际水平上与二者相关性相当;(5) 草原区月植被覆盖度对降雨量的响应存在时滞效应。  相似文献   

13.
近54a蒙古高原降水变化趋势及区域分异特征   总被引：1，自引：0，他引：1       下载免费PDF全文
近半个世纪，有关全球气候的话题一直是科学界争论的焦点，拥有世界最大温带草原的蒙古高原降水变化是属于全球变化问题，又是其脆弱环境变化的最主要驱动因子之一。通过利用蒙古高原1961—2014年136个气象站点的月降水量数据，采用Sen’ s斜率法、Mann-Kendall趋势检验法和空间地统计方法，研究了该地区近54 a降水要素基本气候特征及其时空变化规律。结果表明：（1）近54 a蒙古高原年降水量呈减少趋势，趋势为-2.30 mm·（10 a）-1（P＞0.05），整体上年降水量东南及西北显著减少，东北及中南明显增加（2）夏季和秋季降水量呈减少趋势，趋势分别为-5.75 mm·（10 a）-1和-0.42 mm·（10 a）-1（P＞0.05）；春季和冬季降水量呈显著增加趋势，趋势分别为1.95 mm·（10 a）-1和0.50 mm·（10 a）-1（P<0.05）；季节降水量出现正负距平的年份和周期有所不同。（3）春季和冬季降水量呈增加趋势的站点居多，占全部站点的89.0%和84.6%，主要分布于高原东北部和中南部地区；夏季和秋季降水量呈减少趋势的站点居多，占全部站点的80.1%和57.4%，主要分布于高原东南部和西北部地区。为准确评估蒙古高原气候变化以及合理提出生态环境决策提供科学参考。  相似文献   

14.
The vegetation coverage dynamics and its relationship with climate factors on different spatial and temporal scales in Inner Mongolia during 2001-2010 were analyzed based on MODIS-NDVI data and climate data.The results indicated that vegetation coverage in Inner Mongolia showed obvious longitudinal zonality,increasing from west to east across the region with a change rate of 0.2/10°N.During 2001-2010,the mean vegetation coverage was 0.57,0.4 and 0.16 in forest,grassland and desert biome,respectively,exhibiting evident spatial heterogeneities.Totally,vegetation coverage had a slight increasing trend during the study period.Across Inner Mongolia,the area of which the vegetation coverage showed extremely significant and significant increase accounted for 11.25% and 29.13% of the area of whole region,respectively,while the area of which the vegetation coverage showed extremely significant and significant decrease accounted for 7.65% and 26.61%,respectively.On inter-annual time scale,precipitation was the dominant driving force of vegetation coverage for the whole region.On inter-monthly scale,the change of vegetation coverage was consistent with both the change of temperature and precipitation,implying that the vegetation growth within a year is more sensitive to the combined effects of water and heat rather than either single climate factor.The vegetation coverage in forest biome was mainly driven by temperature on both inter-annual and inter-monthly scales,while that in desert biome was mainly influenced by precipitation on both the two temporal scales.In grassland biome,the yearly vegetation coverage had a better correlation with precipitation,while the monthly vegetation coverage was influenced by both temperature and precipitation.In grassland biome,the impacts of precipitation on monthly vegetation coverage showed time-delay effects.  相似文献   

15.
Vegetation plays a significant role in global terrestrial ecosystems and in combating desertification. We analyzed vegetation change in Inner Mongolia of northern China using the Normalized Difference Vegetation Index(NDVI) from 1998 to 2013, which is an important composite of Chinese National Ecological Security Shelter. The correlation between vegetation growth and drought quantified using the Standardized Precipitation Evapotranspiration Index(SPEI) was also explored. Results show that vegetation in most of the study area has been rehabilitated to various degrees, especially in regions such as most of the Horqin Sandy Land, eastern Ordos Plateau, Hetao Plain, as well as the middle-northern Da Hinggan Ling Mountains. Vegetation improvement in spring was significant in most of the study area. Vegetation degradation was centrally distributed in Xilingol grassland close to the Sino-Mongolia border and abandoned croplands in Ulanqab Meng. Vegetation change trends and seasonal differences varied among different vegetation types. The biggest vegetation variation in the growing season was the belt-like distribution along those grasslands close to the precipitation isoline of 200 mm and the Sino-Mongolia border, but also variation in summer and autumn exist in obvious spatial differences between grasslands and forests. Drought largely influenced vegetation change of Inner Mongolia at 6-month scale or 12-month scale, except for forests of eastern Hunlun Buir Meng and deserts or gobi deserts of western Alxa Meng. Moreover,drought in the previous winter and early spring seasons had a lag effect on growing-season vegetation. Desert grassland was the most easily affected by drought in the study area. Anthropogenic activities have made great progress in improving local vegetation under the lasting drought background.  相似文献   

16.
樟子松固沙林带间植被恢复及其对林草界面作用的响应   总被引：1，自引：0，他引：1  
调查了海拉尔市巴音岱林场不同分布格局、不同带间距的人工樟子松林带内植被恢复过程及物种多样性的差异,分析了林草界面生态学效应,研究了林草界面对带间植被自然恢复的作用。结果表明,宽的带间距带内物种多样性和生物量变化曲线出现了两个高峰,而窄的带间距带内只有一个高峰,说明该地区林带之间距离不应小于12 m;当林带之间距离为16~28 m时草本物种多样性出现最大值。植被恢复效果表现为带间距12 m差于带间距24 m,虽然都差于天然植被,但边际效应大大地加速了群落演替的进程。研究区樟子松林草界面边缘效应影响域为20 m, 其小尺度范围内生境异质性也很明显。行带式造林带间距离不应大于40 m,超出边缘效应影响域不利于带间植被恢复。  相似文献   

17.
To explore the optimal land-use for soil carbon(C) sequestration in Inner Mongolian grasslands,we investigated C and nitrogen(N) storage in soil and soil fractions in 8 floristically and topographically similar sites which subjected to different land-use types(free-grazing,grazing exclusion,mowing,winter grazing,and reclamation).Compared with free-grazing grasslands,C and N storage in the 0-50 cm layer increased by 18.3%(15.5 Mg C ha-1) and 9.3%(0.8 Mg N ha-1) after 10-yr of grazing exclusion,respectively,and 21.9%(18.5 Mg C ha-1) and 11.5%(0.9 Mg N ha-1) after 30-yr grazing exclusion,respectively.Similarly,soil C and N storage increased by 15.3%(12.9 Mg C ha-1) and 10.2%(0.8 Mg N ha-1) after 10-yr mowing,respectively,and 19.2%(16.2 Mg C ha-1) and 7.1%(0.6 Mg N ha-1) after 26-yr mowing,respectively.In contrast,soil C and N storage declined by 10.6%(9.0 Mg C ha-1) and 11.4%(0.9 Mg N ha-1) after 49-yr reclamation,respectively.Moreover,increases in C and N storage mainly occurred in sand and silt fractions in the 0-10 cm soil layer with grazing exclusion and mowing.Our findings provided evidence that Inner Mongolian grasslands have the capacity to sequester C and N in soil with improved management practices,which were in the order:grazing exclusion > mowing > winter grazing > reclamation.  相似文献   

18.
内蒙古人口结构与区域经济耦合的关联分析   总被引：9，自引：1，他引：8  
毕其格  宝音  李百岁 《地理研究》2007,26(5):995-1004
本文在建立耦合系统评价指标体系的基础上,运用灰色关联分析法,构建了人口结构与区域经济交互作用的关联度模型和耦合度模型,揭示了内蒙古人口结构与区域经济耦合的主要因素及耦合关系,并从时空角度对耦合度的演变规律进行了分析。研究发现,内蒙古人口结构与区域经济系统要素耦合的机制复杂,而且关系密切;耦合度空间分布呈现与人口规模相反的规律,全区可划分为协调、磨合、拮抗和低水平耦合等4种类型。总体而言,内蒙古人口结构与区域经济耦合的空间分布基本以拮抗类型为主、低水平耦合次之,与1990年相比,2000年的耦合度呈现出上升的趋势;耦合度时序变动表现出一定的阶段性和波动性。  相似文献   

19.
We investigated how both droughts and dzuds (severe winter weather) control livestock mortality in a non-equilibrium steppe ecosystem of Mongolia, Gobi Three Beauty National Park. These steppe ecosystems have developed under high interannual variability of rainfall and nomadic grazing systems. Interannual precipitation variation was 39%, with 128 mm mean annual precipitation. The effect of climate variability and extreme events on livestock mortality is a critical aspect for the Mongolian economy. Analysis of drought and precipitation variability on livestock mortality rate was not significantly influenced by the index of mean annual precipitation and annual winter temperature. Overall, unlike hot dry regions, pastoral livestock mortality in the cold dry regions was affected more by dzuds and annual growing seasonal rain than by droughts. Dzuds can be frequent events, occurring as often as once every 2 and 3 years within a decade. The average annual livestock mortality for the combined drought and dzuds years (18%) was 4.8% greater than the years with dzuds alone, and 7% greater than in years with only drought. Thus livestock mortality appears to be more sensitive to dzuds than to droughts, and that dzuds contributes more to livestock mortality even years where combined drought and winter storms occur.  相似文献   

20.
《自然地理学》2013,34(6):505-518
Casual observations suggest that saguaro populations are densest in southeastern Arizona, although data have not been collected and no study has been done to address this topic. In addition, the topic of reproductive density has similarly never been addressed. Saguaro reproductive output is directly related to the number of adult individuals and the number of branches in the area. Thirty saguaro populations over their U.S. range were sampled to consider two variables: population density and reproductive stem density. Stepwise regression using climate and vegetation (e.g., availability of nurse plants) to predict density yielded tree + Ambrosia cover and maximum July precipitation. Nurse cover, however, is also influenced by summer rain. The partial correlation results suggest that high saguaro densities are linked with high quality nurse cover (i.e., not Larrea tridentata) in addition to summer rainfall. Total cover and mean annual precipitation are the best predictors of reproductive stem density. Mean annual precipitation may be a good predictor of reproductive stem density, because population density is linked with summer rain while branching is linked with winter rain. The plots were also divided into climatic regions. One-way ANOVA shows that the northeast (high winter precipitation) and west (dry) have lower saguaro densities than the southeast (high summer precipitation), while the northeast and southeast both have very high reproductive stem densities relative to the west. The warmer west is less susceptible to periodic freezing mortality, while previous work has shown that the southeast generally regenerates more successfully. Thus in the colder northeast, which is also outside of the primary summer rain and best nurse plant belt, low density populations seem to be maintained only with high reproductive density.  相似文献   

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