汾河源区生态系统服务价值的时空变化

运用GIS和遥感技术分析了汾河源区宁武县1990、2000、2010年的土地利用/覆被时空变化特征,并参照中国不同陆地生态系统单位面积服务价值,分析了该区域生态系统服务价值的时空变化。结果表明:1990-2010年,研究区生态系统服务价值共损失0.34×10⁸元,且损失量和损失幅度呈增加趋势;研究区东北到西南方向上的大片低海拔区域生态系统服务价值减幅较大,主要与该区域频繁的人类活动有关,而高海拔山区减幅较小或略有增加。气候暖干化、过度放牧和建设用地增加引起的草地和水域减少是导致研究区生态系统服务价值减少的主要原因。     

长江经济带农业发展的现状特征与模式转型

本文基于统计数据揭示长江经济带农业发展的现状特征,并结合农业农村发展范式及其演化的回顾,探讨新时期长江经济带农业发展模式转型及其基本策略。研究发现：长江经济带作为我国最重要的农业生产区域之一,近年来农业综合生产能力虽不断提升,但产品产量和产业产值占全国的比重呈下降趋势;农产品国际贸易呈现良好态势,但农产品加工业发展仍较薄弱;农业生产化学品投入强度不断提高,带来的环境问题函待解决;农业发展的新业态不断涌现,工资性收入成为农民收入的主体和动力源。新时期长江经济带的农业发展应充分吸收多功能农业生产和网络化乡村发展范式的有益成分,激发内生动力、整合外部动力,以全国粮食生产核心区、现代农业先行区、农产加工优势区、特色农业产业带为关键目标,实现“七大转变”,着力推进区域农业的多功能转型。深化相关改革、加大财政投入、鼓励创新创业、优化区域布局、加强区域合作、强化村镇建设是实现转型的重要保障。     

稻田生态系统服务价值测算方法与应用——以苏州市域为例

对稻田资源的生态服务价值重视不足是稻田保护工作的最大缺陷,导致了稻田资源流失严重。本文以苏州市水稻田为例,运用造林成本法、瑞典碳税法、制氧工业成本法、替代成本法、影子工程法、当量因子法等方法对稻田生态系统各项服务价值进行了测算。结果表明,苏州市域稻田生态系统服务净总价值量为60785.18×10⁵元,单位面积净价值量为73111.84 元/hm²。其中,正面总价值量为68485.93×10⁵元,环境效应负总价值量为7700.75×10⁵元,前者为后者的8.89 倍。从稻田生态系统服务价值各部分的比例看,其实物生产价值远远低于其生态经济价值,表明了作为人工湿地生态系统,稻田生态服务价值对社会经济的可持续发展具有十分重要的作用。研究结果将有助于确定稻田保护经济补偿标准,为各级政府出台相关政策提供思路和依据     

农业干旱监测研究进展与展望

本文全面分析了农业干旱的概念内涵及其与其他干旱类型之间的关系,进而从基于站点监测和基于遥感监测两个方面,系统梳理了国内外农业干旱监测的近今进展,对比了不同干旱监测指标的适用范围和局限性;同时,通过文献统计和重要文献引用揭示了国内外农业干旱监测研究的发展历程和最新进展,即农业干旱监测指标从传统的单一气象监测指标逐渐向气象与遥感相结合的综合监测指标转变。最后,在分析农业干旱监测现有挑战和困境的基础上,将农业干旱监测未来发展趋向归纳为5点展望,即进一步明晰农业干旱发生机理和受旱过程、识别农业干旱影响因素及其相互作用关系、构建多时空尺度农业干旱监测模型、耦合农业干旱定性表征与定量评估模型以及提高农业干旱监测模型中遥感数据的应用水平。     

The effects of land consolidation on the ecological connectivity based on ecosystem service value: A case study of Da’an land consolidation project in Jilin province

Land consolidation has a profound impact on landscape patterns and ecological functions at various scales through engineering and biological measures. In recent years, China invests more than 100 billion RMB yuan on land consolidation each year. To understand how land consolidation affects landscape patterns and ecosystems, we investigated the ecosystem service value and the ecological connectivity in a consolidated area of Da’an city from 2008 to 2014 using a revised ecological connectivity index. The results indicated that land consolidation has certain negative influences on the ecosystem services in this area. The total ecosystem service value will decrease by nearly 30% in the late stage of consolidation. This decrease is caused by the loss of ecosystem service of the wetland and grassland, despite a sensible increase of cultivated land. In addition, land consolidation could change the ecological connectivity as well as the land use structure. Up to 85% of the entire area will be in low connectivity in the late stage of consolidation, representing a 6.23% increase in the total coverage compared to pre-consolidation. Finally, the different connectivity landscape and their key areas can be identified by the revised ecological connectivity index effectively. This study is helpful to trace out the relationships between landscape pattern and ecological process, and provides insights for ecological planning and designing of land consolidation in this area. We suggest that more attentions should be paid to improve the quality and ecosystem service value per unit area of the landscape, to establish ecological compensation mechanism of wetland losses, and to create the ecological corridors along the least accumulated impendence surface in the key areas during land consolidation.     

Role of aeolian sediment accretion in the formation of heuweltjie earth mounds,western South Africa

The action of organisms in shaping landforms is increasingly recognized; the field of biogeomorphology and the conceptual framework of ecosystem engineering have arisen in response to the need for integrated studies of the interactions between biotic and abiotic components of landscapes. Pathways by which organisms influence landscape development may be complex. For example, primary change initiated by one biotic element may initiate a cascade of other changes that eventually produce a significant landscape modification. Mound‐like landforms in North America and southern Africa are widely cited examples of biogenic structures, yet there is considerable controversy regarding the processes responsible for their formation. Heuweltjies (Afrikaans for little hills) are circular mounds ranging from 10–30 m diameter and 0.5–2 m height and are widespread in western South Africa. Colonies of the termite (Microhodotermes viator) are typically associated with heuweltjies and some investigators have attributed heuweltjie formation to the direct action of termites in redistributing earthen materials. However, rather than being directly responsible in this way, termites simply create nutrient‐rich islands, which support denser vegetation, thereby inducing the localized accretion of aeolian sediments and upward growth of mounds. Contrasting soil features in heuweltjies in one locale indicate these processes have occurred throughout the late Quaternary. Geographic variation in sizes of mounds is explained in part by the local availability of sediments that can be mobilized and redistributed by the wind. Recognition of the operation of aeolian processes in the formation of heuweltjies has important implications for conservation. Any land use that diminishes the sediment‐trapping effect of vegetation on heuweltjies truncates the very process by which new aeolian materials can accrue and may promote irreversible erosion and landscape degradation. Copyright © 2014 John Wiley & Sons, Ltd.     

Environmental water quantity projections under market-driven and sustainability-driven future scenarios in the Narew basin,Poland

Abstract

The aim of this article is to assess the impact of four scenarios combining possible changes in climate, atmospheric carbon dioxide, land use and water use by 2050, on the specific set of ecologically relevant flow regime indicators that define environmental flow requirements in a semi-natural river basin in Poland. This aim is presented through a modelling case study using the Soil and Water Assessment Tool (SWAT). Indicators show both positive and negative responses to future changes. Warm projections from the IPSL-CM4 global climate model combined with sustainable land- and water-use projections (SuE) produce the most negative changes, while warm and wet projections from the MIROC3.2 model combined with market-driven projections (EcF) gave the most positive changes. Climate change overshadows land- and water-use change in terms of the magnitude of projected flow alterations. The future of environmental water quantity is brighter under the market-driven rather than the sustainability-driven scenario, which shows that sustainability for terrestrial ecosystems (e.g. more forests and grasslands) can be at variance with sustainability for riverine and riparian ecosystems (requiring sufficient amount and proper timing of river flows).

Editor D. Koutsoyiannis

Citation Piniewski, M., Okruszko, T., and Acreman, M.C., 2014. Environmental water quantity projections under market-driven and sustainability-driven future scenarios in the Narew basin, Poland. Hydrological Sciences Journal, 59 (3–4), 916–934.     

Environmental flows in India: towards sustainable water management

Abstract

The strong wet and dry seasons of tropical monsoon hydrology in India necessitate development of storage and flow diversion schemes for utilization of water to meet various social and economic needs. However, the river valley schemes may cause adverse flow-related impacts due to storage, flow diversion, tunnelling and spoil disposal. There may be critical reaches in which altered flows are not able to sustain the river channel ecology and riparian environment that existed prior to implementation of the storage and diversion schemes. In the past, environmental flows in India have usually been understood as the minimum flow to be released downstream from a dam as compensation for riparian rights, without considering the impacts on the river ecosystem. Rivers in India have been significantly influenced by anthropogenic activities over the past 60 years and have great social and religious significance to the vast population. This paper explores various aspects of past, present and future environmental flow assessment (EFA) in India highlighted by case studies from rivers across the nation. It demonstrates that multidisciplinary studies requiring expertise from a range of fields are needed for EFA, and that environmental flows are necessary for aquatic ecosystems to remain in a healthy state and for the sustainable use of water resources. The major focus areas for the development of EFA research in India are the creation of a shareable database for hydrological, ecological and socioeconomic data, developing hydrology–ecology relationships, evaluation of ecosystem services, addressing pollution due to anthropogenic activities and promotion of research on EFA. At the same time, efforts will be needed to develop new methods or refine existing methods for India.

Editor D. Koutsoyiannis; Guest editor M. Acreman

Citation Jain, S.K. and Kumar, P., 2014. Environmental flows in India: towards sustainable water management. Hydrological Sciences Journal, 59 (3–4), 751–769.     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases     

多年冻土区活动层土壤水分对不同高寒生态系统的响应

土地覆被变化对土壤水分的影响是生态水文学和流域水文学研究的关键问题,基于长江源典型多年冻土区不同高寒草地土壤水分的观测,结合降水、生物量（包括地上和地下）和土壤理化性质,研究了活动层土壤水分变化对不同高寒生态系统的响应. 结果表明：高寒草甸生物量、土壤养分含量均比高寒草原高,且对降水响应更为强烈,致使高寒草甸土壤水分变异性弱于高寒草原. 在土壤完全融化阶段,高寒草甸土壤活动层存在一个低含水层（50 cm左右）和两个相对高含水层（20 cm和120 cm）,但高寒草原土壤水分在活动层剖面上有随深度逐渐增大的一致性趋势;在秋季冻结过程中,高寒草甸土冻结起始日滞后于高寒草原土3~15 d;在春季融化阶段,高寒草原土更高的含冰量需要更多的融化潜热. 此外,表层土壤中（0~20 cm）,高寒草甸土比高寒草原土有更大的持水特性,而在活动层中下部则呈现完全相反的结果,不同高寒生态系统的演替改变了土壤的水热迁移过程.