草原生态系统生态补偿机制研究:中德案例研究比较(英文)

目前,草地生态系统退化成为全球关注的问题。生态补偿机制(PES)是为了草地生态系统的恢复/保护,采取补贴或支付费用的方式,改变使用者资源利用方式的制度安排。科学、合理的生态补偿制度需要全面地考虑可能出现的风险和挑战:如环境效益的滞后性,不可预见的监督、管理成本和社会经济目标(足额补偿标准、公平)的实现。本文的目标是通过中德两国生态补偿措施的对比(选取中国内蒙古锡林郭勒盟,德国勃兰登堡州为案例区域进行研究),为今后中德两国的生态补偿理论和实践提供依据。研究着重以下四个方面进行分析:中德两国生态补偿的实施框架,目标人群,实施效果评估等。研究结果表明,由于缺乏有效的激励机制,农户作为最基层的执行单位和实施者,其参与的主动性不够,中德两国生态补偿措施实施的成效有待提高。基于研究结果,提出了今后生态补偿项目设计中,中国应侧重于项目实施的监控和管理制度;而德国应在空间目标规划和具体管理措施和方式等方面进行完善。     

A dynamic relationship between the leaf phenology and rainfall regimes of Hawaiian tropical ecosystems: A remote sensing approach

Hypertemporal MODIS time series data provide a unique opportunity to investigate a dynamic relationship between leaf phenology and the climatic pattern of diverse, cloud‐prone Hawaiian ecosystems. Harmonic analysis summarized the complex greenness signals of Hawaiian tropical ecosystems into two main phenological wave forms – a moisture‐limited and a light‐limited type. Greenness maximums occurred during the wet season in dry and mesic ecosystems, and during the dry season in wet forests. The magnitude and periodicity of greenness fluctuations were also rainfall‐dependent. The annual greenness amplitude increased with increasing mean annual precipitation (MAP) in dry and mesic ecosystems. In wetter environments where MAP was greater than 3000 mm, however, annual greenness amplitude decreased with MAP. Annual greenness periodicity was stronger in drylands than in wet forests, and it weakened as annual precipitation increased. This result shows that rainfall is less important as a limiting factor in wet forests than it is in drylands. Therefore, leaf phenology is not governed by rainfall seasonality as forest wetness increases in the region.     

Six decades of agricultural land use change in Bangladesh: Effects on crop diversity,productivity, food availability and the environment, 1948–2006

This paper provides a detailed analysis of agricultural land use change in Bangladesh over a 59‐year period (1948–2006) and examines how these have impacted crop diversity, productivity, food availability and the environment. The key findings of the analysis are: first, land use intensity has increased significantly over this period, mainly from the widespread adoption of a rice‐based Green Revolution technology package beginning in the early 1960s; second, contrary to expectation, crop diversity too has increased; third, although land productivity has increased significantly, declines in the productivity of fertilizers and pesticides raise doubts over sustaining agricultural growth; fourth, food availability has improved, with a reversal in the dietary energy imbalance in recent years despite a high population growth rate; and finally, the production environment has suffered with widespread soil nutrient depletion experienced in many agroecological regions. The policy implication points towards crop diversification as a desired strategy for agricultural growth to improve resource economy, productivity and efficiency in farming in Bangladesh.     

Continuity and change: Spatiotemporal land use dynamics on Bellona Island, Solomon Islands

Traditional agricultural land use systems in the humid tropics of the Southwest Pacific are, as elsewhere, affected by globalization processes. This paper analyzes the directions of change in the land use system of Bellona, a small outer island in the Solomon Islands. We focus on the human–environmental interaction that shapes land use patterns and practices in the context of theoretical lines of thought concerning intensification of agricultural systems in the tropics. Aerial photography from 1966 and satellite imagery from 2006 in conjunction with studies from the 1960s and a contemporary household survey reveal only minor changes in the agricultural system. Land use and land cover dynamics are related to agricultural strategies, demographic factors, institutional actors as well as biophysical drivers or constraints. Local agricultural production still contributes significantly to local subsistence but imported food has also become a major food source. Hence, land use has become partially disconnected from the local population pressure and therefore remains relatively stable while the larger livelihood portfolio has undergone significant diversification. At present, the agricultural system is a supplement to a range of strategies supporting the increasing number of people on the island. This explains why land use patterns continue relatively unchanged while livelihood and food supply strategies have changed.     

天山北麓山地-绿洲-荒漠生态系统净初级生产力空间分布格局及其季节变化

以天山北麓总面积达93 936 km~2的山地-绿洲-荒漠生态样带为例,利用生态-遥感光能利用率模型NPP-PEM,使用1 km分辨率SPOT/VEGETATION遥感等数据资料,估算了生态样带净初级生产力(NPP)空间分布及其季节变化.结果表明山地-绿洲-荒漠生态样带平均NPP为161.06 g C·m~(-2)·a~(-1),样带陆地生态系统年总碳吸收量或年总NPP累积量为15.081 Tg C(1Tg=10~(12)g),其中绿洲农田、山地草甸草原、平原荒漠草原和山地森林对的碳吸收贡献率分别为32.67%、28.16%、12.41%和9.15%.夏季是各类生态系统NPP增加量最大的季节,而沙漠由于早春短命植被覆盖而具有生长双峰现象.样带NPP空间分布及其季相变化特征是自然环境、地貌、气候以及人类生产活动长期共同作用和影响的结果,其中水热条件和基质是控制干旱区陆地生态系统NPP空间格局的决定因子.结果检验表明模拟效果较为合理,证明NPP-PEM模型在干旱生态系统的应用是可行的.研究为干旱区陆地生态系统碳循环研究开辟了途径,可为干旱区生态系统评估、监测和管理提供研究方法和参考依据.     

农用地产能核算的基础与方法研究——以河南省为例

为了探讨农用地产能的概念、核算的基础和方法,采用综合分析的方法,通过研究明确了农用地产能的概念和层次;探讨了农用地产能核算与农用地分等成果的关系,指出农用地分等成果是农用地产能核算的基础,农用地产能核算是农用地分等成果的应用与继续;可以依据农用地自然质量等指数核算农用地理论产能,依据农用地利用等指数核算可实现产能,依据农业统计数据核算实际产能,并进行了实证研究。研究认为:以不同层次的农用地分等成果为基础核算不同层次的产能是可行的。     

近50多年来澜沧江流域农业灌溉需水的时空变化

利用澜沧江流域云南境内8 个气象站1950s-2007 年的逐月气象数据,现状作物种植、农业耕作、田间水分管理等资料,应用Mann-Kendall 法和R/S 分析法,探索50 多年来流域区的干湿变化、农业灌溉定额转折变化趋势及分布规律。结果表明：年、季平均温度普遍地显著升高,降水量干季增加、湿季减少;大部分地区的参照作物腾发量ET0在年度及干、湿季都呈增加趋势,仅在流域中段大理、剑川、耿马的部分时段为减少,干湿指数大多数地区都是降低;水稻及农业综合灌溉需水定额从流域上游到下游逐渐呈减少、增-减并存到增加的趋势。气象因子、ET0、干湿指数、水稻灌溉及农业综合灌溉定额发生转折变异现象都集中在澜沧江中下段的耿马、思茅、景洪、勐腊等地,且时间系列的转折变异点在1960s-1990s 的各个时期均有出现。水稻灌溉定额随纬度方向变化的相关系数为0.513,随海拔高程变化为0.610,最高值出现在维西,最低值为勐腊;农业综合灌溉定额受作物种植结构和水稻种植面积的影响较大,二者相关系数达到0.826,但其与纬度、海拔的变化规律不明显,最高值在大理,最低值在维西。灌溉定额在小范围内的多样性变化,表明在纵向岭谷特殊环境对地表水汽输送、气温和气流场分布等的“通道-阻隔”作用下,澜沧江河谷农业灌溉需水量时空变化的复杂性。     

Remote sensing of ecosystem services: An opportunity for spatially explicit assessment

Ecosystem service is an emerging concept that grows to be a hot research area in ecology. Spatially explicit ecosystem service values are important for ecosystem service management. However, it is difficult to quantify ecosystem services. Remote sensing provides images covering Earth surface, which by nature are spatially explicit. Thus, remote sensing can be useful for quantitative assessment of ecosystem services. This paper reviews spatially explicit ecosystem service studies conducted in ecology and remote sensing in order to find out how remote sensing can be used for ecosystem service assessment. Several important areas considered include land cover, biodiversity, and carbon, water and soil related ecosystem services. We found that remote sensing can be used for ecosystem service assessment in three different ways: direct monitoring, indirect monitoring, and combined use with ecosystem models. Some plant and water related ecosystem services can be directly monitored by remote sensing. Most commonly, remote sensing can provide surrogate information on plant and soil characteristics in an ecosystem. For ecosystem process related ecosystem services, remote sensing can help measure spatially explicit parameters. We conclude that acquiring good in-situ measurements and selecting appropriate remote sensor data in terms of resolution are critical for accurate assessment of ecosystem services.     

Root properties of vegetation communities and their impact on the erosion resistance of river dikes

Predicted climate change and the associated sea level rise poses an increased threat of flooding due to wave overtopping events at sea and river dikes. To safeguard the land from flooding it is important to keep the soil erosion resistance at the dikes high. As plant roots can be very effective in reducing soil erosion rates by concentrated flow, the main goal of this study is to explore the variability in root system characteristics of five dike vegetation communities along the Scheldt River (Belgium) and to assess their effectiveness in controlling soil erosion rates during concentrated flow. This study is the first one to investigate systematically the erosion‐reducing potential of the root properties of representative dike vegetation communities in a temperate humid climate. Results show that the presence of Urtica dioica resulted in large differences in root length density (RLD) among dike vegetation communities. Observed RLD values in the topsoil ranged from 129 to 235 km m^‐3 for dike vegetation communities without U. dioica, while smaller values ranging from 22 to 58 km m^?3 were found for vegetation communities with U. dioica. The erosion‐reducing effect of the dike vegetation communities was estimated based on a global Hill curve model, linking the RLD to the soil detachment ratio (SDR; i.e. the ratio of the soil detachment rate for root‐permeated topsoils to the soil detachment rate for root‐free topsoils). Concentrated flow erosion rates are likely to be reduced to 13–16% of the erosion rates for root‐free topsoils if U. dioica is absent compared to 22–30% for vegetation communities with U. dioica. Hence, to maintain a high resistance of the soil against concentrated flow erosion it is important to avoid the overgrowth of grassland by U. dioica through an effective vegetation management. Copyright © 2016 John Wiley & Sons, Ltd.     

祁连山中部亚高山草地土壤呼吸及其组分研究

草地碳通量组分的区分及其与环境因子的关系是了解生态系统碳循环的重要环节。于2013年6-8月在祁连山中部亚高山草地开展了土壤呼吸及其组分研究,利用根去除法区分根系自养呼吸和土壤微生物异养呼吸。采用LI-8100土壤碳通量系统测定生态系统呼吸、土壤呼吸及土壤微生物呼吸速率,同时测定10cm处土壤温度和5cm处土壤湿度。分析呼吸速率和环境因子的昼夜变化动态,自养呼吸和异养呼吸速率占土壤呼吸速率的比例,呼吸速率与土壤温湿度及与生物量的关系。结果表明：生态系统呼吸、土壤呼吸和土壤微生物呼吸速率的日变化趋势均呈单峰型曲线,具体表现为生态系统呼吸（11.07μmol · m^-2 ·s^-1）>土壤呼吸（6.31μmol·m^-2·s^-1）>异养呼吸（4.92μmol·m^-2 ·s^-1）>自养呼吸（1.39μmol·m^-2·s^-1）;自养和异养呼吸速率分别占土壤呼吸速率的22.03%和77.97%;呼吸速率与10cm处土壤温度呈指数相关,Q₁₀值排序为：土壤微生物呼吸（Q₁₀=3.74）>土壤呼吸（Q₁₀=2.76）>生态系统呼吸（Q₁₀=2.49）,呼吸速率与5cm处土壤湿度呈显著线性负相关关系,双因素模型明显提高了呼吸速率与温湿度的相关性,能够分别解释土壤微生物呼吸,土壤呼吸和生态系统呼吸速率变异的89%,79%和62%;地上生物量和呼吸速率之间存在显著线性正相关关系,地下生物量与呼吸速率之间呈二次回归关系（P=0.01）,未刈割草地呼吸速率大于刈割草地土壤呼吸速率,刈割一年的土壤呼吸速率大于刈割两年的土壤呼吸速率。