毛乌素沙地植被水分利用效率的时空格局

水分利用效率（WUE）是衡量生态系统碳水循环耦合程度的重要指标,明晰其动态变化规律有助于判断区域植被生态建设是否与当地的自然条件相适应。利用基于CASA（Carnegie-Ames-Stanford Approach）模型得到的植被净初级生产力（NPP）数据和MODIS系列产品中的蒸散发（ET）数据,估算了2001—2016年毛乌素沙地植被的WUE,并探讨了其时空演变特征及与气象因子的关系。结果显示：（1）WUE的多年平均值为0.62 gC·mm^-1·m^-2,空间上自东向西递减,在不同植被类型间表现为栽培植物>灌丛>草甸>草原>荒漠;（2）WUE以0.009 gC·mm^-1·m^-2·a^-1的速率上升,东部地区变化尤为显著,NPP的快速增长是WUE呈增加趋势的主要原因;（3）WUE与各气象因子的相关程度由大至小依次为太阳辐射、降水量、风速和气温,分布在西部地区的荒漠植被WUE受气象因子影响最小。经过一系列生态建设工程的治理,毛乌素沙地大部分地区自2001年以来NPP和WUE均呈增加趋势,即生态系统在变“绿”的同时还实现了水分的高效利用,有利于当地生态环境的健康发展;但在水热条件较差的中西部地区,新建设的植被生长缓慢且导致蒸散发产生强烈变化,使WUE呈减少趋势,暴露出植被建设规模与水资源承载能力不匹配的问题,需引起格外重视。     

Response of the water use efficiency of natural vegetation to drought in Northeast China

Drought has become a problem that is universally faced by global terrestrial ecosystems. Northeast China is located in a region sensitive to global climate changes, and one of the main impacts of climate changes in Northeast China is manifested as drought in growing seasons. This study analyzes the spatio-temporal evolution law of the water use efficiency (WUE) of the main natural vegetation (i.e., cold-temperate coniferous forests, temperate pine-broad-leaved mixed forests, warm-temperate deciduous broad-leaved forests, and grasslands) in Northeast China based on public MODIS data products, including MCD12Q1, MOD15A2H, MOD16A2, and MOD17A3H, and meteorological data from 2002 to 2013. The influence of drought events on the WUE of different vegetation types and their response to drought events are also investigated. The study findings are as follows: (1) drought in Northeast China frequently occurs in the regions stretching from 114.55°E to 120.90°E, and the percentage of drought area among the forests is lower than that among the grasslands during these years; (2) the annual average WUE of the natural vegetation ranges from 0.82 to 1.08 C/kg^-1H₂O, and the WUE of forests (0.82 to 1.08 C/kg^-1H₂O) is universally higher than that of grasslands (0.84 to 0.99 C/kg^-1H₂O); (3) in 2008, the regions where the WUE in drought conditions is higher than that in normal water conditions account for 86.11% of the study area, and a significant linear positive correlation is found between the WUE in drought conditions and the WUE in normal water conditions, whereas the degree of drought does not influence the WUE of the natural vegetation in an obviously linear manner; and (4) the WUE for the cold-temperate coniferous forests and temperate pine-broad-leaved mixed forests with a high ET or low NPP is more likely to rise in drought conditions; the WUE for the grasslands with a low Evapotranspiration (ET), Net Primary Production (NPP), and Leaf Area Index (LAI) is more likely to rise in drought conditions; and the ET, NPP, and LAI have no significant influence on the WUE for the warm-temperate deciduous broad-leaved forests in drought conditions. This study contributes to improving the evaluation of the influence of drought on natural ecosystems.     

Cartographic Methods for Determining the Qibla

Abstract

Islam is an important topic in human and regional geography instruction, and major textbooks include maps showing Islam's core and rapid expansion diffusion, along with the number of pilgrims to Mecca from different countries. Determining the qibla, the sacred direction for daily prayer, and the distance to Mecca are additional topics that link human geography, Islamic mathematical geography, and modern geographic information science. Recently discovered Persian instruments used a retro-azimuthal map projection devised by medieval Muslim mathematicians to compute the qibla and distance to Mecca from anywhere within the seventeenth century realm of Islam. Modern global maps that allow the qibla and distance to Mecca to be determined from all populated areas on earth are added to the Persian instruments.     

Cartographic assessment of pollution of forest ecosystems on the Baikal natural territory by technogenic emissions

The implementation of these authors’ original approaches in generating maps of forest pollution and vital status of forest stands in a large region is outlined. The maps so far developed can be considered basic, reflecting the phenomena to be subsequently monitored in order to make justified forecasts of the state of forest vegetation on territories exposed to pollution, including under changes of the level and character of emission load.     

The principles of forecasting the geom structure of the Prebaikalia under climate change

We consider some methodological principles of forecasting changes in the geom structure of the Prebaikalia’s territory under climatic warming. A forecast is made by using a GIS that was created on the basis of the landscape map for the southern part of East Siberia. The identified spatial connections of geoms, the characteristic altitudes at which each geom is located, and the location structures of geom units in altitude serve as a basis for forecasting.     

植被生态用水结构及绿水资源消耗效用——以黄河三门峡地区为例

以黄河三门峡地区为研究对象,构建适用于流域尺度植被生态用水估算的生态水文模型,对三门峡地区20世纪50年代以来植被生态用水量进行了定量模拟,得到研究区植被生态用水时空结构差异.在此基础上,对三门峡地区不同植被类型绿水资源消耗效用进行了分析,提出该区域植被结构调整方案.结果表明:三门峡地区植被生态用水量自20世纪50年代以来,由于气候和土地利用状况的变化,总体呈现出降低-稳定-上升的趋势;生态用水空间结构主要表现在不同植被类型下生态用水量差异上:林地最大,其次为农作物、灌丛,草地最小;林地高效消耗比例最大,其次为草地和灌丛,农用地最小.基于不同植被类型绿水资源消耗效用分析,提出三门峡地区植被结构调整方案.在一定水资源消耗量状况下,减少无效和低效消耗量,增加高效消耗量,是缓解该地区生产、生活、生态用水矛盾,提高总体生态效益的重要途径.     

Vegetation as a factor in the system of natural environment preservation of Prebaikalia

A central role in the formation of the natural environment of Prebaikalia is played by vegetation having the environment-forming and environment-protective functions. Nowadays, it is experiencing ever increasing anthropogenic impacts which lead to disturbances in its structure and decrease its ecological potential. This creates certain challenges of a local and regional character, because the main territory of the region is within the zone of atmospheric influence and within the western portion of the central ecological zone of the Baikal natural territory focus on preserving the ecosystem of Lake Baikal as the UNESCO World Natural Heritage site. Therefore, the main direction of nature conservation activity aimed at improving the quality of the region’s natural environment remains focused on the preservation and recovery and of its primary vegetation. Some measures are suggested concerning ecologically oriented nature management in Prebaikalia. We have defined the goals for the scientific accompaniment of the measures for the preservation of vegetation as an important factor of the environmental quality. The paper demonstrates the effectiveness of integrated study into the entire florocenotic diversity of modern vegetation, its evolutionary-genetic basis and the ecological and dynamical potentials of plant communities for the purposes of forecasting the ecologically oriented development of the region’s natural environment. The recommendations are formulated in accordance with the State Ecological Program for the period until 2030. The map entitled “Protection of vegetation in Prebaikalia (recommendations for optimization of the ecological policy)” has been developed, which provides information on territories with a different environmental quality having regard to the ecological potential. The legend includes the following parts of the map: special preservation of primary vegetation (full and partial), recovery of disturbed vegetation (active and passive recovery of primary forests), and economic rational (ecologically oriented) use of vegetation.     

Ecological water demand of natural vegetation in the lower Tarim River

We have appraised the relationships between soil moisture, groundwater depth, and plant species diversity in the lower reaches of the Tarim River in western China, by analyzing field data from 25 monitoring wells across eight study sites and 25 permanent vegetation survey plots. It is noted that groundwater depth, soil moisture and plant species diversity are closely related. It has been proven that the critical phreatic water depth is five meters in the lower reaches of the Tarim River. We acquired the mean phreatic evaporation of different groundwater levels every month by averaging the two results of phreatic evaporation using the Qunk and Averyanov formulas. Based on different vegetation types and acreage with different groundwater depth, the total ecological water demand (EWD) of natural vegetation in 2005 was 2.4×108 m3 in the lower reaches of the Tarim River. Analyzing the monthly EWD, we found that the EWD in the growth season (from April to September) is 81% of the year’s total EWD. The EWD in May, June and July was 47% of the year’s total EWD, which indicates the best time for dispensing artificial water. This research aims at realizing the sustainable development of water resources and provides a scientific basis for water resource management and sound collocation of the Tarim River Basin.     

Advances in monitoring vegetation and land use dynamics in the Sahel

Vegetation dynamics of the West African Sahel has attracted great scientific interest over the last 40?years because of the dramatic inter-decadal variability observed in the resource base of the region directly impacting on the livelihoods of the West African population. From farmers to pastoralists, agro-pastoralists and forest-users, all depend on the availability of vegetation resources and are affected by fluctuations in the available vegetation resource. Vegetation dynamics are controlled by both natural and human factors, including climate change and variability, increased concentration of CO₂ in the atmosphere, grazing pressure, bush fires and agricultural expansion or contraction. The use of satellite data in combination with field data played a major role in the monitoring of vegetation dynamics and land use in the Sahel, since the mega drought of the 1970s and the 1980s. This paper briefly reviews the advance of satellite-based monitoring of vegetation dynamics over these 40?years. We discuss the promises of current and likely future data sources and analysis tools, as well as the need to strengthen in situ data collection to support and validate satellite-based vegetation and land use monitoring and modelling.     

Assessing the thermal regime of soils in the depressions of the Prebaikalia and Northern Transbaikalia

Long-term data from meteorological stations have been used in assessing the thermal state of the soil layer in large depressions of the Prebaikalia and Northern Transbaikalia. We examine the characteristics of temperature distribution in depth over an annual cycle for seasonally frozen and permafrost soils. For the Baikalian type depressions we carried out a spatial differentiation of the lowest and highest (having regard to the temperature lag) mean monthly soil temperatures. It is concluded that within a single depression the thermal regime of the soil fluctuates over a very broad range. On the other hand, an identical situation with the temperature regime can occur in different depressions.     

The Evolutionary-Genetic Basis of Structural-Cenotic Diversity of Modern Vegetation in Prebaikalia

An assessment is made of the uniqueness of modern vegetation in Prebaikalia as a biogeographical entity. It is shown that its complex structural-cenotic diversity is represented on the new universal geobotanical map of vegetation at a scale of 1:500 000. The map legend, constructed on the principles of V. B. Sochava’s multidimensional and multistage structural-dynamical classification of plant communities, displayed more than 160 cenotic subdivisions of vegetation of Prebaikalia representing its different types. An analysis is made of the development paths of vegetation for assessing its evolutionary potential. The study revealed the main stages of philocenogenesis in the Late Cainozoic. Its main directions have been revealed, which are important for understanding the characteristics of the region’s modern vegetation cover. The heterogeneity and heterochronicity of modern cenotic diversity of vegetation is shown. Emphasis is placed on the evolutionary processes of vegetation of Prebaikalia in the Holocene which can last for at least 40 thousand years. In this connection, it is proposed to change interpretation of the Holocene Optimum as an optimum for the evolution of the dark-coniferous taiga of Siberia. It is shown that the genetic linkages of the cenotic structure of modern vegetation cover in Prebaikalia are clearly pronounced via regional-typological categories of vegetation reflecting profound links of modern vegetation with natural-geographical regions where its philogenetic processes were taking place in interaction with the general evolution of the natural environment. An analysis is made of the significance of the floristic and cenotic boundaries having an important biogeographical significance. Such boundaries, on the one hand, are the footprint of the past evolutionary processes in vegetation, and in the natural environment as a whole, and, on the other, indicate the dynamical potential of possible changes in vegetation under global climate change.     

塔里木河下游植被生态需水量(英文)

We have appraised the relationships between soil moisture,groundwater depth, and plant species diversity in the lower reaches of the Tarim River in western China,by analyzing field data from 25 monitoring wells across eight study sites and 25 permanent vegetation survey plots.It is noted that groundwater depth,soil moisture and plant species diversity are closely related.It has been proven that the critical phreatic water depth is five meters in the lower reaches of the Tarim River.We acquired the mean phreatic evaporation of different groundwater levels every month by averaging the two results of phreatic evaporation using the Qunk and Averyanov formulas.Based on different vegetation types and acreage with different groundwater depth,the total ecological water demand(EWD)of natural vegetation in 2005 was 2.4×108m 3in the lower reaches of the Tarim River.Analyzing the monthly EWD,we found that the EWD in the growth season(from April to September)is 81%of the year's total EWD.The EWD in May,June and July was 47%of the year's total EWD,which indicates the best time for dispensing artificial water.This research aims at realizing the sustainable development of water resources and provides a scientific basis for water resource management and sound collocation of the Tarim River Basin.     

我国软木工业的现状及发展策略

<正> 世界软木原料主要采自欧洲栓皮栎(Quercus suber L.)的外皮,通称栓皮或软木,是一种十分珍贵、稀有的资源,在世界上仅产于西地中海沿岸的国家和地区。我国也有性能相似、数量可观的软木资源,主产于栓皮栎树的外皮,也有极少量的黄波椤(Phellodendron amurense Rupr.)的外皮。     

The influence of water regulation on vegetation in the lower Heihe River

Water regulation has been carried out by the Heihe River Bureau since 2000, which aims to address the existing eco-environmental problems in the lower Heihe River. In the past nine years, great changes in spatial-temporal distribution of water resources took place in the lower Heihe River. In order to objectively evaluate the influence of water regulation on the eco-environment, the changes of groundwater table, typical vegetation, landscape types as well as East Juyan Lake have been analyzed in the lower Heihe River, by means of field surveys and remote sensing. These results indicate that there are obvious effects of water regulation on the eco-environment, which has been improved toward sustainability in the lower Heihe River.     

The influence of water regulation on vegetation in the lower Heihe River

Water regulation has been carried out by the Heihe River Bureau since 2000, which aims to address the existing eco-environmental problems in the lower Heihe River. In the past nine years, great changes in spatial-temporal distribution of water resources took place in the lower Heihe River. In order to objectively evaluate the influence of water regulation on the eco-environment, the changes of groundwater table, typical vegetation, landscape types as well as East Juyan Lake have been analyzed in the lower Heihe River, by means of field surveys and remote sensing. These results indicate that there are obvious effects of water regulation on the eco-environment, which has been improved toward sustainability in the lower Heihe River.     

海南省生态环境综合评价制图方法

介绍以景观生态学理思想为指导,以多因素综合评价为主要方法,以遥感与地理信息系统为手段,编绘海南生态环境评价图的方法。在生态环境制图的基础上,对海南省生太环境质量作了评价分析。对于区域生态环境评价及生态环境动态监测具借鉴意义。     

黄土高原植被降水利用效率对植被恢复/退化的响应

基于2000-2014年MODIS NDVI数据及气象数据,运用累计降水利用效率变化差异（CRD,cumulative rain use efficiency differences）估算模型和基于地形要素降水量插值法,探讨2000-2014年黄土高原RUE（降水利用效率rain use efficiency）对植被变化的响应,以期为黄土高原生态可持续发展提供数据支撑。结果表明：黄土高原大部分地区植被覆盖得以改善,其面积约占总面积的81%,区域边缘植被覆盖退化严重。黄土高原降水利用效率RUE与累计NDVI的相关性总体表现为“东南呈正相关,西北为负相关”的空间格局,全区相关系数以正相关为主。黄土高原CRD与植被变化趋势的相关性显著,其中,植被退化背景下,植被退化程度越严重,RUE越低;植被恢复背景下,RUE受“退耕还林还草”作用显著,2000-2005年,RUE呈上升趋势,2007年后,随着退耕还林还草政策的工作重心转移,RUE呈波动变化。     

Prehistoric aboriginal impacts on Australian vegetation: an assessment of the evidence

To what extent were Australian vegetation patterns in 1788 a product of human activity? Pollen and charcoal evidence which addresses this question is reviewed. I discuss the nature of the evidence, particularly the difficulties involved in establishing relationships between charcoal and fire history, and between fire history and human activity. I then address the broader question from the perspectives of both time and space by examining three key periods which might be expected to provide relevant evidence: (i) the time of initial human colonisation of the continent; (ii) the late Holocene, when Aboriginal population densities are thought to have increased substantially; and (iii) the last 200 years, when Aboriginal influences on the landscape have been mostly removed. Impacts are likely to have been different in different environments, with vegetation types vulnerable to fire showing the most marked changes. I conclude with a discussion of ways alternative interpretations have been utilised by competing groups in land management debates.     

科尔沁沙地沙丘植被对丘间低地水体的影响北大核心CSCD

在流动沙丘以建立固沙植被的方式向固定沙丘转化的过程中,植被将改变沙丘水分再分配过程,影响沙丘的水文调节功能,甚至可能引起沙丘生态系统水资源失衡。为探明植被对沙丘水文调解功能的影响,以科尔沁沙地不同植被盖度的沙丘-丘间地水体组合体为研究对象,于2021年生长季开展了沙丘植被盖度、丘间低地水体变化特征、气象因素的动态观测,以期明确沙丘植被变化对丘间低地水体的影响。结果表明:(1)沙丘植被盖度影响沙丘水分对外补给能力,随着沙丘表面固沙植被盖度增加,单位面积沙丘对外水分补给能力降低,表现为流动沙丘(58.25 mm)>半固定沙丘(24.75 mm)>固定沙丘(14.87 mm),占同期降水量的比例分别为21.39%、9.09%、5.46%。(2)生长季流域降水补给量、植被盖度、气温显著影响沙丘对丘间低地水体的水分补给量,丘间低地水体获补量与流域降水补给量显著正相关,与植被盖度、气温极显著负相关。(3)依据水量平衡原理推导出沙丘水分对外补给量(Y)与影响因素(降水补给量X_(1),植被盖度X_(2),平均气温X_(3))的关系模型,Y=1052.737+0.1X_(1)-11.459X_(2)-37.585X_(3),R2=0.641。可根据模型预测沙丘水分对外补给量,为流动沙丘生物治理模式的合理选择提供支持。     

Reconstructing the vegetation of forest and alpine-steppe landscapes in the southwestern part of Tuva since the Late Glacial period till the present

On the basis of the spore-pollen, lithological and radiocarbon analysis of sediments from two lakes lying on a high-mountain plateau in the southwestern part of Tuva, the changes in vegetation, climate and landscapes have been reconstructed from 14645 years ago till the present.