Spatio-temporal patterns of satellite-derived grassland vegetation phenology from 1998 to 2012 in Inner Mongolia,China

Spatio-temporal variations of vegetation phenology, e.g. start of green-up season(SOS) and end of vegetation season(EOS), serve as important indicators of ecosystems. Routinely processed products from remotely sensed imagery, such as the normalized difference vegetation index(NDVI), can be used to map such variations. A remote sensing approach to tracing vegetation phenology was demonstrated here in application to the Inner Mongolia grassland, China. SOS and EOS mapping at regional and vegetation type(meadow steppe, typical steppe, desert steppe and steppe desert) levels using SPOT-VGT NDVI series allows new insights into the grassland ecosystem. The spatial and temporal variability of SOS and EOS during 1998–2012 was highlighted and presented, as were SOS and EOS responses to the monthly climatic fluctuations. Results indicated that SOS and EOS did not exhibit consistent shifts at either regional or vegetation type level; the one exception was the steppe desert, the least productive vegetation cover, which exhibited a progressive earlier SOS and later EOS. Monthly average temperature and precipitation in preseason(February, March and April) imposed most remarkable and negative effects on SOS(except for the non-significant impact of precipitation on that of the meadow steppe), while the climate impact on EOS was found to vary considerably between the vegetation types. Results showed that the spatio-temporal variability of the vegetation phenology of the meadow steppe, typical steppe and desert steppe could be reflected by the monthly thermal and hydrological factors but the progressive earlier SOS and later EOS of the highly degraded steppe desert might be accounted for by non-climate factors only, suggesting that the vegetation growing period in the highly degraded areas of the grassland could be extended possibly by human interventions.     

Effects of converting natural grasslands into planted grasslands on ecosystem respiration: a case study in Inner Mongolia,China

With increasingly intensifying degradation of natural grasslands and rapidly increasing demand of high quality forages, natural grasslands in China have been converted into planted grasslands at an unprecedented rate and the magnitude of the conversion in Inner Mongolia is among the national highest where the areal extent of planted grasslands ranks the second in China. Such land-use changes(i.e., converting natural grasslands into planted grasslands) can significantly affect carbon stocks and carbon emissions in grassland ecosystems. In this study, we analyzed the effects of converting natural grasslands into planted grasslands(including Medicago sativa, Elymus cylindricus, and M. sativa+E. cylindricus) on ecosystem respiration(F_(eco)) in Inner Mongolia of China. Diurnal F_(eco) and its components(i.e., total soil respiration(F_(ts)), soil heterotrophic respiration(F_(sh)) and vegetation autotrophic respiration(F_(va))) were measured in 2012(27 July to 5 August) and 2013(18 July to 25 July) in the natural and planted grasslands. Meteorological data, aboveground vegetation data and soil data were simultaneously collected to analyze the relationships between respiration fluxes and environmental factors in those grasslands. In 2012, the daily mean F_(eco) in the M. sativa grassland was higher than that in the natural grassland, and the daily mean F_(va) was higher in all planted grasslands(i.e., M. sativa, E. cylindricus, and M. sativa+E. cylindricus) than in the natural grassland. In contrast, the daily mean F_(ts) and F_(sh) were lower in all planted grasslands than in the natural grassland. In 2013, the daily mean F_(eco), F_(ts) and F_(va) in all planted grasslands were higher than those in the natural grassland, and the daily mean F_(sh) in the M. sativa+E. cylindricus grassland was higher than that in the natural grassland. The two-year experimental results suggested that the conversion of natural grasslands into planted grasslands can generally increase the F_(eco) and the increase in F_(eco) is more pronounced when the plantation becomes more mature. The results also indicated that F_(sh) contributed more to F_(eco) in the natural grassland whereas F_(va) contributed more to F_(eco) in the planted grasslands. The regression analyses show that climate factors(air temperature and relative humidity) and soil properties(soil organic matter, soil temperature, and soil moisture) strongly affected respiration fluxes in all grasslands. However, our observation period was admittedly too short. To fully understand the effects of such land-use changes(i.e., converting natural grasslands into planted grasslands) on respiration fluxes, longer-term observations are badly needed.     

近50年内蒙古中东部地区春夏季干旱特征分析

选取内蒙古地区累年平均降水量>200mm的75个气象站点1961～2010年逐日平均气温、逐日降水量资料,基于综合气象干旱指数(CI指数)计算方法,建立了各站历年春季和夏季CI指数序列。利用EOF方法,分析了内蒙古中东部地区春季和夏季干旱的时空分布特征,得出:1)内蒙古中东部地区春旱和夏旱均分为三种类型,且均具有全区一致干旱或不旱型、东西反相干旱型和南北反相干旱型的分布规律。但春季和夏季干旱或反向干旱的中心分布区域略有不同。2)内蒙古中东部地区春季干旱均出现在1980a以前,1980a后全区性的春季重旱减少,但局部重旱有所增加。夏旱在1980a以后呈两年或以上持续发展的态势,且近年来全区性夏旱发生频率增高、强度增加。3)内蒙古地区气候变暖出现在20世纪80年代中期之后。气候变暖后内蒙古地区降水分配格局发生了变化,使内蒙古中东部地区春季干旱减轻,而夏旱加重,应引起相关部门的重视。     

内蒙古东部地区与东三省区域旅游合作的思考

旅游业在区域经济发展中占有举足轻重的地位,内蒙古与东三省的区域旅游合作为双方带来前所未有的机遇,通过对内蒙古东部地区与东三省区域旅游合作现状的分析,发现双方合作中存在着发展状况不平衡,权利分散不便于协调、约束,各参与主体过分依赖骨干城市,合作中缺少新产品的涌现,企业动力不足,政府行为取代企业行为等诸多问题,针对双方合作...     

公元1-2000年内蒙古草原ANPP序列的重建及特征研究——基于CENTURY模型

利用高精度的中国西部公元1-2000年温度和降水变化序列及CENTURY模型,重建公元1-2000年内蒙古荒漠草原、典型草原和草甸草原地上净初级生产力(ANPP)序列,利用小波分析探讨了不同草原生产力周期变化特征及与气候要素之间的相关性。结果表明:1)3类草原ANPP波动大体相似,其中在魏晋和明清小冰期出现明显低值期,在公元600-1200年出现长达600年左右的高值期;2)不同草原ANPP波动有所不同,典型草原ANPP居中变幅最大,荒漠草原ANPP最低变幅次之,草甸草原最高且变幅最小;3)3类草原ANPP均存在准280a和准60a振荡周期,草甸草原ANPP还存在准150a振荡周期。4)降水和温度对草原ANPP有重大影响,但在不同类型的草原影响不同。典型草原和荒漠草原主要受降水控制,草甸草原受降水和温度共同控制。     

Attribution of explanatory factors for change in soil organic carbon density in the native grasslands of Inner Mongolia,China

The variation in soil organic carbon density(SOCD) has been widely documented at various spatial and temporal scales. However, an accurate method for examining the attribution of explanatory factors for change in SOCD is still lacking. This study aims to attribute and quantify the key climatic factors, anthropogenic activities, and soil properties associated with SOCD change in the native grasslands of Inner Mongolia, China, by comparing data between the 1960s and the 2010s. In 2007 and 2011, we resampled 142 soil profiles which were originally sampled during 1963–1964 in the native grasslands of Inner Mongolia. SOCD was determined in A horizon(eluvial horizon) of the soil. We selected the explanatory factors based on a random forest method, and explored the relationships between SOCD change and each of the explanatory factors using a linear mixed model. Our results indicated that the change in SOCD varied from the east to the west of Inner Mongolia, and SOCD was 18% lower in the 2010s than in the 1960s. The lower SOCD in the 2010s may primarily be attributed to the increasing in mean annual water surface evaporation, which explained approximately 10% and 50% of the total variation and explainable variation in the change in SOCD, respectively. The sand content of the soil is also a significant explanatory factor for the decrease in SOCD, which explained about 4% and 21% of the total variation and explainable variation in the change in SOCD, respectively. Furthermore, the collection of quantitative information on grazing frequency and duration may also help to improve our understanding of the anthropogenic factors that govern the change in SOCD.     

Change features of time-series climate variables from 1962 to 2016 in Inner Mongolia,China

Detecting change features of climate variables in arid/semi-arid areas is essential for understanding related climate change patterns and the driving and evolution mechanism between climate and arid/semi-arid ecosystems.This paper takes Inner Mongolia of China,a unique arid/semi-arid ecosystem,as the study area.We first detected trend features of climate variables using the linear trend analysis method and then detected their trend-shift features using the breaks for additive seasonal and trend method based on the time-series of monthly precipitation and monthly mean temperature datasets from 1962 to 2016.We analyzed the different change features of precipitation and temperature on a regional scale and in different ecological zones to discover the spatial heterogeneity of change features.The results showed that Inner Mongolia has become warmer-wetter during the past 54 years.The regional annual mean temperature increased 0.4°C per decade with a change rate of 56.2%.The regional annual precipitation increased 0.07 mm per decade with a slightly change rate of about 1.7%,but the trend was not statistically significant.The warmer trend was contributed by the same positive trend in each season,while the wetter trend was contributed by the negative trend of the summer precipitation and the positive trend of the other three seasons.The regional monthly precipitation series had a trend-shift pattern with a structural breakpoint in the year 1999,while the regional monthly mean temperature series showed an increasing trend without a periodical trend-shift.After the year 2000,the warmer-wetter trend of the climate in Inner Mongolia was accelerated.The late 20th century was a key period,because the acceleration of the wetter trend in some local zones(I and II)and the alleviation of the warmer trend in some local zones(Ⅶ,Ⅷand IX)occurred simultaneously.Moreover,the change features had a strong spatial heterogeneity,the southeastern and southwestern of Inner Mongolia went through a warmer-drier trend compared with the other areas.The spatio-temporal heterogeneity of the climate change features is a necessary background for various types of research,such as regional climate change,the evolution of arid/semi-arid ecosystems,and the interaction mechanisms between climate and arid/semi-arid ecosystems based on earth-system models in Inner Mongolia.     

内蒙古自治区森林碳储量及其动态变化

利用内蒙古森林资源清查资料,依据不同森林类型生物量和蓄积量之间的回归方程,估算了内蒙古自治区不同时段的森林生物量和碳储量,并分析其动态变化特征。结果表明：在1977-2003年间内蒙古森林面积由1.10×10^7hm^2增加到1.61×10^7hm^2,每年森林面积平均增长率为1.85%;森林碳储量由378.86TgC...     

Abrupt temperature change and a warming hiatus from 1951 to 2014 in Inner Mongolia,China

An abrupt temperature change and a warming hiatus have strongly influenced the global climate.This study focused on these changes in Inner Mongolia, China. This study used the central clustering method, Mann-Kendall mutation test and other methods to explore the abrupt temperature change and warming hiatus in three different temperature zones of the study region based on average annual data series.Among the temperature metrics investigated, average minimum temperature(Tnav) shifted the earliest,followed by average temperature(Tnv) and average maximum temperature(Txav). The latest change was observed in summer(1990 s), whereas the earliest was observed in winter(1970 s). Before and after the abrupt temperature change, Tnav fluctuated considerably, whereas there was only a slight change in Txav.Before and after the abrupt temperature change, the winter temperature changed more dramatically than the summer temperature. Before the abrupt temperature change, Tnav in the central region(0.322°C/10 a)and west region(0.48°C/10 a) contributed the most to the increasing temperatures. After the abrupt temperature change, Tnav in winter in the central region(0.519°C/10 a) and in autumn in the west region(0.729°C/10 a) contributed the most to the temperature increases. Overall, in the years in which temperature shifts occurred early, a warming hiatus also appeared early. The three temperature metrics in spring(1991)in the east region were the first to exhibit a warming hiatus. In the east region, Txav displayed the lowest rate of increase(0.412°C/a) in the period after the abrupt temperature change and before the warming hiatus,and the highest rate of increase after the warming hiatus.     

Ammonia emissions from soil under sheep grazing in Inner Mongolian grasslands of China

Ammonia (NH3) emission and redeposition play a major role in terrestrial nitrogen (N) cycles and can also cause environmental problems, such as changes in biodiversity, soil acidity, and eutrophication. Previous field grazing experiments showed inconsistent (positive, neutral, and negative) NH3 volatilization from soils in response to varying grazing intensities. However, it remains unclear whether, or to what extent, NH3 emissions from soil are affected by increasing grazing intensities in Inner Mongolian grasslands. Using a 5-year grazing experiment, we investigated the relationship between NH3 volatilization from soil and grazing pressure (0.0, 3.0, 6.0, and 9.0 sheep/hm2 ) from June to September of 2009 and 2010 via the vented-chamber method. The results show that soil NH3 volatilization was not significantly different at different grazing intensities in 2009, although it was higher at the highest stocking rate during 2010. There was no significant linear relationship between soil NH3 volatilization rates and soil NH4+-N, but soil NH3 volatilization rates were significantly related to soil water content and air temperature. Grazing intensities had no significant influence on soil NH3 volatilization. Soil NH3 emissions from June to September (grazing period), averaged over all grazing intensities, were 9.6±0.2 and 19.0±0.2 kg N/hm2 in 2009 and 2010, respectively. Moreover, linear equations describing monthly air temperature and precipitation showed a good fit to changes in soil NH3 emissions (r=0.506, P=0.014). Overall, grazing intensities had less influence than that of climatic factors on soil NH3 emissions. Our findings provide new insights into the effects of grazing on NH3 volatilization from soil in Inner Mongolian grasslands, and have important implications for understanding N cycles in grassland ecosystems and for estimating soil NH3 emissions on a regional scale.     

内蒙古阿拉善盟2000年土地沙漠化遥感监测

以阿拉善盟2000年TM卫星影像遥感信息为主要依据,根据中国北方土地沙漠化动态分类系统,在遥感影像上进行解译和面积量算,获得了阿拉善盟2000年土地沙漠化状况:沙漠化土地总面积3666232.9hm2,占土地总面积的15.48%。阿拉善盟主要的沙漠化类型为沙丘活化或流沙入侵(1846880hm2)、灌丛(草地)沙漠化(735369.5hm2)、砾质沙漠化(1064944hm2)和耕地沙漠化(19039hm2)。沙丘活化或流沙入侵主要分布在阿拉善左旗境内,巴丹吉林沙漠与腾格里沙漠和乌兰布和沙漠之间的一些低山丘陵和荒漠干草原上;灌丛(草地)沙漠化主要分布在阿拉善东部;砾质沙漠化主要分布在阿拉善盟的西部,尤其以额济纳旗最多;耕地沙漠化主要集中在额济纳绿洲。     

Persistence of four dominant psammophyte species in central Inner Mongolia of China under continual drought

Clarifying the persistence time of seedlings of dominant species under continual drought will help us understand responses of ecosystems to global climate change and improve revegetation efforts.Drought tolerance of four dominant psammophytic shrub species occurring in different environments was studied in the semi-arid areas of Inner Mongolian grasslands.Seedlings of Hedysarum laeve,Caragana korshinskii,Artemisia sphaerocephala and Artemisia ordosica were grown under four air temperature regimes(night/day:12.5/22.5℃,15/25℃,17.5/27.5℃ and 20/30℃)within climate(air temperature and humidity)controlled,naturally lit glasshouses with a night/day relative humidity of 70%/50%.Pots were watered to field capacity for each temperature treatment.Soil water condition was monitored by weighting each pot every day using an electronic balance.Date of seedling death for each treatment was recorded and the dead plants were harvested.Plant dry weights were determined after oven drying at 80℃ for 3 days.Two Artemisia species had higher growth rates than H.laeve and C.korshinskii,and the growth of all four species increased with increasing temperatures.The two Artemisia species had the highest leaf biomass increment,followed by C.korshinskii,and then H.laeve.Shoot biomass increment was higher for A.ordosica and C.korshinskii,intermediate for A.sphaerocephala and lowest for H.laeve.C.korshinskii had the highest root biomass increment.The final soil water content at death for all four species varied from 1% to 2%.C.korshinskii,A.sphaerocephala,H.laeve and A.ordosica survived for 25-43,24-41,26-41,and 24-37 days without watering,respectively.C.korshinskii,A.sphaerocephala,H.Laeve,and A.ordosica seedlings survived longer at the lowest temperatures(12.5/22.5℃)than at the highest temperatures(20/30℃)by 18,17,15 and 13 days,respectively.Increased climatic temperatures induce the death of seedlings in years with long intervals between rainfall events.The adaptation of seedlings to droughts should be emphasized in revegetation efforts in the Ordos Plateau,Inner Mongolia.     

内蒙古大兴安岭林区森林碳储量及其动态变化研究

基于内蒙古大兴安岭林区第四次至第六次复查期(1994-2008年)的森林资源数据,利用不同森林类型生物量和蓄积量之间的回归方程,估算大兴安岭林区森林生物量和碳储量,分析大兴安岭林区森林碳储量和碳密度变化规律。结果表明:在近15年间,大兴安岭林区森林面积呈持续增长的趋势,此期间森林碳储量也呈逐渐增加的趋势,其值变化规律为350.052 TgC(第六次复查)>330.468 TgC(第五次复查)>285.431 TgC(第四次复查)。不同复查期的森林碳密度变化规律为第六次复查>第四次复查>第五复查。从林龄方面来看,三次复查期内,森林碳储量变化规律为中龄林>成熟林>近熟林>过熟林>幼龄林,碳密度的变化规律为过熟林>成熟林>近熟林>中龄林>幼龄林。落叶松林和桦木林是大兴安岭林区的主要森林类型,在15年复查期内,落叶松林和桦木林面积、生物量和碳储量均呈逐渐增加的趋势,其中落叶松林的贡献率最大。     

太阳能风能化石能耦合采暖改善内蒙古西部草原民居冬季室内温度与热舒适性

为改善内蒙古西部草原民居冬季室内温度和热舒适性,选取102户草原民居对居住人员情况、冬季采暖方式、室内热舒适情况、家庭用能情况进行调研,对室内外的空气温度进行实测。构建太阳能风能化石能耦合采暖模型,并利用Design-Builder软件对室内各空间温度和室内热舒适性进行模拟,并与现有的连灶炕+土暖气采暖方式进行比较。研究结果表明:太阳能风能化石能耦合采暖方式在不开启反烧炉的情况下比现有采暖方式在最冷月室内平均温度提高2.26℃,热舒适满意度提高48.76个百分点;在开启反烧煤炉系统并每日平均燃烧3kg煤炭的情况下比传统采暖方式在最冷月室内平均温度提高4.23℃,热舒适满意度提高61.2个百分点,室内温度和热舒适性得到显著改善。为今后该地区草原民居采暖方式的选择和太阳能风能资源的利用提供一定的借鉴。     

内蒙古自治区地热资源分布特征与潜力评价

立足内蒙古地热地质条件,分析了全区地热田分布规律、形成机理,进行全区地热资源量计算、地热资源开发利用模式研究。针对不同地热区和热储类型确定了隆起山地对流型和山前平原、沉积盆地型地热田两种类型的计算方法与参数进行潜力评估。结果表明:内蒙古地热资源总量为1.99×1016k J。实际开采热量4.60×1011KJ/a,可替代的常规能源量2.6×104t/a,可减少CO2气体排放量6.24×104t/a、可减少SO2气体的排放量443.89t/a,可减少氮氧化物(NOx)排放量156.67t/a,可减少悬浮质粉尘208.89t/a,可减少固体废弃物排放量(以每年多少吨煤渣计量)2.62×103t/a。     

甘肃、内蒙古西部与青海近代积温变化趋势分析

利用甘肃、内蒙古西部与青海省45个站点的月平均气温资料,计算了1960-2000年稳定通过O℃(T≥0℃)和稳定通过10℃(71≥10℃)的积温,并对其变化趋势及突变进行了分析.结果表明:研究区的积温存在明显的变化趋势,20世纪80-90年代以来,积温呈波浪式上升;积温的大小与持续期的长短关系密切,两者变化趋势相吻合;且由于各区地理位置的不同,积温和持续期由北向南呈现梯度变化,曲线变化趋势大致相同,而Ⅲ区(青海南部)的积温与持续期变化趋势则明显不同于I区(内蒙古、甘肃)、Ⅱ区(青海).最后采用Mann-Kendall方法对I.Ⅱ,Ⅲ区内T≥0℃及71≥10℃的积温变化进行了突变分析,得出此3个区突变时间大致发生在1996年附近,其后气温上升趋势加快.     

内蒙古典型草原区土壤氮储量分布研究

基于野外调查数据、气象站观测数据和草原放牧统计数据,利用相关分析和逐步回归方法识别区域土壤氮储量的主要影响因素,建立了土壤氮储量与放牧压力指数和降雨两个影响变量的地理加权多元回归克里金模型,并利用该模型预测了内蒙古典型草原土壤氮储量的空间分布。结果表明:降水和放牧压力指数与土壤氮储量具有显著的相关关系;研究区域0-50cm土壤氮储量在0.01kg·m-2和1.56kg·m-2之间;土壤氮储量空间分布整体上呈自东北向西南递减的特征。区域降水减少对土壤氮储量累积具有不利的影响,而通过降低草原载畜率或采用草场封育措施降低放牧压力则有助于提高区域土壤氮储量。     

内蒙古糖甜菜叶斑病菌的多样性分析

采用ERIC-PCR,BOX-PCR和ITS的分析方法,对分离自我国内蒙古自治区5个市的21个糖甜菜叶斑病菌菌株进行多样性分析,并与其他12种病原细菌进行比较。ERIC-PCR揭示,在相似性80%上所有参试菌株分为26簇,而BOX-PCR只得到20个簇,暗示这两种短重复序列在基因组中的分布不同;将两者电泳图谱结合,得到介于上述两者间的结果,分为23个簇;在相似率达87%时,ITS分析将21个糖甜菜叶斑病菌菌株分成7簇。3种分析方法相互验证,均说明内蒙古糖甜菜叶斑病菌基因组存在显著多样性。ERIC和BOX聚类证明了糖甜菜叶斑病菌与短小杆菌属(Curtobacterium)亲缘关系较近,与其他属细菌亲缘关系较远。研究证明,ERIC和BOX扩增基因组DNA指纹比ITS图谱具有更强的多样性。     

MERSI资料在内蒙古草原牧草产量估测中的应用研究

利用卫星遥感资料估测天然草地生产力是草地生态学和草地管理学的研究热点。内蒙古草原面积大、类型多、具有重要的生态和生产功能,实时监测其草地生产力变化十分必要。由于风云3号极轨气象卫星资料具有迅速、覆盖面广、不受地面条件限制等优点,文中将内蒙古自治区气象局42个生态监测站点2008～2010年6～8月份的风云3号卫星MERSI遥感数据和同步的牧草产量实测数据相结合,引入MERSI-NDVI概念,建立了基于MERSI-NDVI估测内蒙古草原牧草产量的估测模型,并对模型的可靠性进行了检验。结果表明:基于风云3号极轨气象卫星资料提取的MERSI-NDVI与内蒙古草原牧草产量具有较高的相关性,利用MERSI-NDVI遥感估测天然草地牧草产量是可行的;基于MERSI-NDVI构建的三个类型草地遥感估产模型精度在65.32%～88.84%之间,其精度可以满足宏观测产的要求。不仅适合大面积监测估产,还可用于局部地域牧草产量的定点估产。     

包头地区晚第四纪沉积地层与环境演化

对包头地区BT1-1孔沉积岩芯进行了系统的岩性、地层年龄和沉积相的分析。结果表明:该钻孔剖面揭露了中更新世末期(130ka BP)以来的沉积地层,可划分为3个地层段:全新统(Qh):0-16.9m,为河流相沉积,底部年龄为11.9ka B.P.;上更新统(Qp3):16.9-84.2m,为一套河湖相交替沉积,底部年龄为118.5ka B.P.;中更新统顶部(Qp22未见底):84.2-101.1m,为湖相沉积,底部年龄为130.6ka B.P.。包头地区晚第四纪沉积环境经历了从湖泊环境-河湖交替环境-以河流环境为主的演化过程。128.2-126.4ka B.P.期间,由于气候寒冷干旱、湖盆萎缩而形成的盐湖沉积(芒硝层)是该区湖相沉积的一个标志层。