川西北高寒草地沙化土壤特征及治理模式探讨——以阿坝州红原县为例

通过对川西北高寒草地不同类型的沙化样地0—10cm,10～20cm和20～30cm土壤有机质、pH和含水量进行分析。结果表明：（1）随着沙化程度加重,土壤有机质含量和土壤含水量明显降低;（2）随着土层深度增加,土壤有机质含量降低;未沙化、轻度沙化样地的土壤含水量随土层深度增加而降低,重度沙化样地则相反;（3）中度和重度沙化样地土壤pH约7．0,未沙化和轻度沙化pH值在6．5左右;沙地土壤有机质与pH值呈显著负相关关系,沙化土壤有机碳与水分损失是一个正反馈。鉴于川西高寒草地特殊环境,探讨了选用适宜的多年生高原药用植物或者其他高价值资源植物作为固沙材料,将治沙与经济发展相结合,建立高寒沙化草地治理模式。     

不同植被恢复模式对红原沙化草地土壤理化性质的影响

草地沙化是川西北地区生态环境恶化的显著问题之一,红原县是川西北草地沙化的代表。土壤理化性质在沙化治理过程中变化显著,能表征治沙效果的好坏。通过研究草本红景天、灌木(沙棘)、灌草结合红柳和沙棘及燕麦草混植三种植被恢复模式恢复一年对土壤理化性质的影响,分析了不同的植被类型对沙化草地的恢复效果,为进一步优化沙化草地植被恢复的群落结构,提高植被恢复的有效性提供理论依据。结果表明:草本植物、灌木及灌草结合三种植被修复模式均能明显增加土壤孔隙度、含水量、p H、有机质、含氮量、含磷量和含钾量,降低土壤容重,以增加土壤肥力,其中灌草结合的植被恢复模式对土壤修复的效果最好。     

草地生态环境失调主因与控制对策的探讨

草地生态环境失调已成为当今世界面临的一个严重问题。随着草地生态的破坏,制约着草地畜牧业的稳定发展。据大量资料表明,虽然引起草地生态失调的原因是多方面的,如开垦草地,过度放牧、破坏植被等而造成草地退化、水土流失、沙化;但从全局来看,草地超载过牧是导致草地生态失调的根本原因。为此,作者通过对草地生态环境失调成因与危害的分析,提出了维护草地生态平衡的积极对策:①以草定畜,依法管理草地;②落实草场承包责任制,固定草地使用权;③建立完整的草地科学利用体系。逐步制止草地生态恶化,改善草地生态环境。     

青藏高原东部冻土环境变化的初步探讨

青藏高原东部是大片连续多年冻土、岛状冻土和深季节冻土的过渡和交错地带。属高寒、干旱及半干旱气候,受西北冷空气袭击,多大风,极易引起风蚀和之沙化,生态环境脆弱。目前由于不合理的利用草场资源,破坏了草场的生态平衡,造成大面积草场退化及沙化,致使多年冻土呈区域性退化状态,由此而引起一系列自然灾害,对畜牧业造成严重损失。草场退化十分严重近数十年来,高原东部地区(95°E以东)随着生产发展和人口急剧增长,掠夺式利用草场资源,使草地生态环境失调。随着冻土环境和生态平衡的破坏,严重影响和制约着本区畜牧业的稳定发展。据有关资料,虽然引起草地生态失调的原因,有如开垦草地、人类和啮齿类动物破坏植被等,但     

包头市达茂旗土地退化现状及其成因分析

通过对包头市达茂旗自然环境和社会经济状况的研究，得出其土地退化问题十分严重。主要表现为：风蚀沙化严重、土壤水蚀问题突出、草地退化趋势加剧、耕地肥力下降相当普遍、盐渍化问题不容忽视。针对土地可持续利用中存在的主要制约因素进行了深入分析，得出长期的自然和人为因素的综合干扰是导致土地退化的主要原因，以期为各级决策部门提供参考。     

对内蒙古东部偏远农村牧区中小学生的环境意识状况的调查

当前．随着现代农牧业生产的迅速发展，人们生活水平的日益提高．农村牧区环境污染和生态破坏已变得越来越严峻．普遍存在着过度放牧、“偷放偷耕”、滥伐滥采、草地“三化”(退化、沙化和碱化)等现象农村牧区的中小学生作为农村牧区未来的建设者，他们的环境意识     

基于Landsat／TM和ETM＋的理塘草地沙化趋势及其驱动力分析

文章利用1989、1994、2000和2005年的4期Landsat／TM，ETM＋遥感影像，在几何校正、辐射定标、大气校正的基础上计算了归一化植被指数（NDVI），建立最小二乘法线性回归方程对多时相NDVI进行同化处理，基于二分模型提取植被覆盖度并转换成荒漠化指数（DI），对理塘县城附近约103．1km2范围的分类研究结果表明：（1）分为无沙化、轻度、中度、重度和严重沙化5级，其中2005年中度、重度和严重沙化面积分别为2．562km2、2．925km2和1．576km2；中度沙化比1989年减少9．69％，重度和严重沙化分别增多35．79％和161．8％；（2）2005年中度以上沙化面积比1989年增加1．470km2，增加了26．3％，年增加率为1．47％；（3）沙化面积呈前期小、中期大幅增加、后期增加减缓的总体趋势；（4）降水量和风速因子的变化趋势有利于缓解沙化，气温变化趋势没有反映出对沙化的促进作用。人类活动是造成沙化趋于恶化的主要因素；（5）沙化增加趋势与同类研究结果一致。     

论《防沙治沙法》的预防为主、防治结合、综合治理原则

土地沙化是我国面临严重的环境问题之一。土地沙化及治沙活动的特点决定了预防为主原则的重要性。《防沙治沙法》专章规定了土地沙化的预防。本文着重论述了该原则确立的原因，具体的法律规定，并针对其立法缺陷提出了法律完善的建议和保障实施办法。     

浅析祁连山国家公园青海片区沙化土地动态变化

本文通过对2014年、2019年祁连山国家公园青海片区沙化土地面积数据进行对比分析，得出了2019年较2014年沙化土地面积略有增加，并从气候变化、人为因素方面分析了变化原因，同时提出了综合性结论及建议。     

孤独的战斗：关于沙尘暴的非主流叙事

京津沙尘暴，准确地说．应该叫尘暴。尘暴的粉尘主要来源于内蒙古中部地区大小不同的数百个干涸盐湖．而并非一直都在宣传的沙漠、沙地或退化草地、沙化土地等。国家投入巨资治理但未能做到对症下药。治理干盐湖要比治理沙漠和沙地等更为有效．最好的方法之一是种植碱蓬．区区一亿多的投资即可见效。新问题是科学研究的原动力．然而．现在科学研究的机构及体制却在排斥新问题。沙尘之源——干盐湖就是个新问题，该谁来管？由于无利可图．各个部门都悄悄走开了。     

Seed bank composition of open and overgrown calcareous grassland soils--a case study from Southern Belgium

The success of calcareous grassland recreation following abandonment depends to a large extent on the composition of the soil seed bank. We studied the species richness and composition of the seed bank along a chronosequence from well-developed calcareous grassland to scrub and forest vegetation, which had developed on calcareous grassland over the last 225 years. The seed bank density was highest in the calcareous grassland soils (930 seeds/m(2)). However, the seed bank was mainly composed of rather common species of nutrient poor grassland, which were poorly represented in the surface vegetation. There were no significant differences in soil seed bank density and species composition between the calcareous grassland and scrub vegetation that was less than 15 years old, largely because several grassland species had persisted in the scrub vegetation and were therefore able to replenish the soil seed bank. In contrast seed density and species richness declined significantly after 40 years of grassland abandonment. Indeed, forest soils had the lowest seed densities (214 seeds/m(2)) with only a few grassland species represented. This reflects the lack of grassland species in the field layer of the forest, and, therefore, the lack of seed production and seed bank replenishment. It is clear that recreation of calcareous grassland on long abandoned sites cannot rely on germination of target species from the seed bank alone. Even in the calcareous grassland soil, seeds of target species are not abundant as the majority produces transient seeds, which decay rapidly if they do not germinate immediately. Successful grassland recreation on such sites therefore may require seeds of target species to be introduced artificially (e.g. as seed mixtures, green hay, etc.). Alternatively, reinstatement of traditional practices, such as grazing or mowing, will increase the natural dispersal potential of these species, allowing population reestablishment in the long term.     

Habitat Acquisition Strategies for Grassland Birds in an Urbanizing Landscape

Habitat protection for grassland birds is an important component of open space land acquisition in suburban Chicago. We use optimization decision models to develop recommendations for land protection and analyze tradeoffs between alternative goals. One goal is to acquire (and restore if necessary) as much grassland habitat as possible for a given budget. Because a viable habitat for grassland birds consists of a relatively large core area with additional parcels of grassland habitat nearby, the second goal is to minimize total pairwise distance between newly protected parcels and large existing reserves. We also use the concept of an effective grassland habitat area, which considers influences that neighboring land covers have on grassland habitat suitability. We analyze how the parcels selected for protection change as total protected effective area is traded off against total distance. As area is weighted more heavily, the selected parcels are scattered and unconnected. As total distance is weighted more heavily, the selected parcels coalesce around core reserves but protect less area. The differences in selected parcels as we change the objective function weights are caused by the differences in price per unit of effective habitat area across parcels. Parcels located in close proximity to the existing cores have relatively high prices per hectare of effective grassland area as a consequence of high restoration costs and adverse influences from roads, urban areas and/or forestland. As a result, these parcels have lower priority for selection when the area objective is weighted more heavily for a given budget.     

新疆草原旅游资源可持续开发研究

新疆草原面积广阔、类型多样,旅游资源丰富,具有很大的发展潜力,但目前很少对新疆的草原旅游资源进行研究.分析了新疆草原旅游资源规模大、分布广、类型多样、民俗文化多元但自然生态和人文生态都极为脆弱等特征,对目前新疆草原旅游资源开发现状和存在的问题进行了全面和深入的探讨,提出了新疆草原旅游资源可持续开发的思路,以促进新疆草原地区旅游业发展.     

Assessing the spatial distribution of grassland age in a marginal European landscape

Grassland age is increasingly recognised to be an indicator for present-day biodiversity, e.g. plant species richness, and is also important for other landscape functions. We developed a methodological approach to systematically assess the spatial distribution of grassland age in marginal European landscapes. This approach - applied to the Lahn-Dill Highlands (1270 km(2)), a marginal landscape in Hesse, Germany - comprises three steps: (1) in a two-stage stratification process, we pre-stratified the study area according to recent land-cover patterns and their changes between 1955 and 1995 (stratification I) and classified grassland types by combining data on soil moisture, base-richness, and elevation (stratification II). From 50 grassland types, we randomly selected 1000 representative grassland patches. (2) We determined the age of these patches by means of aerial photograph interpretation of a chronosequence dating back to 1953 and classified each patch with respect to the age classes young (<18 years), mid-aged (18-47 years), and old (>47 years). (3) Based on this information, we calculated grassland type-specific probabilities for grassland patches to belong to the respective age classes. These probabilities were projected to districts by direct extrapolation. An exemplary validation of extrapolation results for two test areas was performed. The results revealed that 49% of the investigated patches were old grassland. The remaining patches were mid-aged (36%) or young grassland (15%). The extrapolation results indicated accordingly a predominance of old grassland at the district scale. Occurrences of mid-aged grassland were concentrated in districts with a pronounced land-cover change, whereas young grassland is apparently evenly distributed across the study area. Validation results suggest that our approach is suitable for a realistic estimation of grassland age in marginal European landscapes. The method may be applied in landscape models of various disciplines that rely on large-scale information on grassland age.     

吉林省西部草原资源的开发与利用

草原是吉林省西部最重要的植被类型，是区域自然资源比较优势的集中体现。长期以来，由于对草原掠夺式开发利用，导致草原严重退化，环境恶化，成为本区可持续发展的制约因素。摆脱吉林省西部生态灾难，大兴草业是最佳的战略选择。应用草地农业生态学原理，实施草业工程，通过草地畜牧业，饲料业，草坪业，草原旅游业的系统开发，是实现吉林省西部可持续发展的必由之路。     

氮沉降对草原凋落物分解的影响

大气氮沉降增加是全球变化的重要现象之一,草原生态系统对氮沉降增加的响应成为草地生态学的研究热点之一。凋落物分解是草原生态系统养分循环和能量流动的主要途径,氮沉降增加引起草原植物群落结构变化,导致凋落物质量、土壤肥力、土壤微生物和土壤动物的变化,最终影响凋落物的分解。本文综述了氮沉降对草原凋落物结构、化学组成和分解环境的影响等方面的国内外最新研究进展,讨论了需进一步加强研究的内容,以期为进一步拓展该领域研究的广度和深度、为全面分析和评估全球变化对草原生态系统的影响提供参考。     

Grassland Management Activity Data: Current Sources and Future Needs

Estimates of potential and actual C sequestration require areal information about various types of management activities. Forest surveys, land use data, and agricultural statistics contribute information enabling calculation of the impacts of current and historical land management on C sequestration in biomass (in forests) or in soil (in agricultural systems). Unfortunately little information exists on the distribution of various management activities that can impact soil C content in grassland systems. Limited information of this type restricts our ability to carry out bottom-up estimates of the current C balance of grasslands or to assess the potential for grasslands to act as C sinks with changes in management. Here we review currently available information about grassland management, how that information could be related to information about the impacts of management on soil C stocks, information that may be available in the future, and needs that remain to be filled before in-depth assessments may be carried out. We also evaluate constraints induced by variability in information sources within and between countries.It is readily apparent that activity data for grassland management is collected less frequently and on a coarser scale than data for forest or agricultural inventories and that grassland activity data cannot be directly translated into IPCC-type factors as is done for IPCC inventories of agricultural soils. However, those management data that are available can serve to delineate broad-scale differences in management activities within regions in which soil C is likely to change in response to changes in management. This, coupled with the distinct possibility of more intensive surveys planned in the future, may enable more accurate assessments of grassland C dynamics with higher resolution both spatially and in the number management activities.     

Property rights and grassland degradation: a study of the Xilingol pasture, Inner Mongolia, China

The semi-private property rights arrangement called the Household Production Responsibility System (HPRS) was started in the early 1980s in Xilingol pasture of Inner Mongolia (China), and stimulated the development of stockbreeding. The grassland has been degrading severely with increasing numbers of livestock. Based on a historical review of property rights regimes in Inner Mongolia and empirical surveys in Xilingol pasture during 2001-2003, this paper assesses the implementation of HPRS and its impacts on incomes of households as well as the environmental impact on the grassland. It was found that HPRS does not mitigate the "Tragedy of the Commons", instead it has exacerbated the situation. It was also found that co-management of grassland and livestock among a few households presents a sustainable use of grassland to develop livestock breeding. We conclude with the recommendation that small-scale collective property rights systems should be encouraged in Xilingol pasture of Inner Mongolia.     

秦皇岛市城市绿地对气候环境的调节作用

通过对秦皇岛草面、沥青表面、水泥表面和裸露地表4种表面温度观测的数据,分析了不同地表表面温度在夏季不同天气条件下温度的变化规律与差异,阐述了草地在城市气候环境调节中的作用。统计结果表明,夏季各表面温度从高到低的次序为:沥青、水泥、裸土和草面温度。在不同的地表面中,夜间基本均以草面温度最低。各表面的最低温度出现在日出前,各表面的平均最高温度出现在12～14时之间。在夏季晴朗的白天,中午各表面温度达到一日中的最高。草面的温度远低于沥青和水泥表面的温度,白天平均温度差异达到10.0℃左右。     

新疆草地资源特征与生态治理

从新疆草地资源发生条件分析其多样性,对草地退化进行了生态分析,提出了草地生态恢复的生态置换理论与实施方案。