Host-parasite interactions in oligotrophic stream ecosystems: the roles of life-history strategy and ecological niche

Biodiversity in fluvial ecosystems is under pressure as a consequence of their degradation. Conservation strategies for endangered freshwater molluscs and for salmonid fishes have been proposed but they are typically poorly integrated. Here, we examined for the first time the genetic structure of a critically endangered obligate mollusc invertebrate parasite, the freshwater pearl mussel ( Margaritifera margaritifera ), and its vertebrate host fish, the brown trout ( Salmo trutta m. fario ), in European headwater streams. We compared genetic differentiation and diversity with productivity and ecological habitat features of both species in nine different European streams from the drainage systems of the Danube, Elbe, Weser, Tuuloma, Kemijoki and Aulne. Genetic differentiation was more pronounced in pearl mussel than in brown trout, although the drainage-specific patterns were generally similar. Genetic diversity of host and parasite was negatively correlated. The most oligotrophic, postglacially colonized areas represented genetic diversity hotspots with high conservation priority for pearl mussels, whereas their host fish displayed low diversity in these areas. This pattern can be explained by differences in the ecological niches and in the life-history strategies of both species. These results question the effectiveness of single-species approaches in the conservation of genetic aquatic resources and suggest that genetic information from species with different life-history strategies, such as invertebrates and fish, should be considered simultaneously for geographical conservation prioritization in stream ecosystems.     

基于系统保护规划方法东北生物多样性热点地区和保护空缺分析

根据东北地区生物多样性特征,利用系统保护规划方法和国际上常用的保护规划软件C- plan,计算了规划单元的不可替代性值,确定了区域生物多样性热点地区,并根据保护区分布现状进行了生物多样性保护空缺分析.结果显示,东北地区不可替代性较高的热点地区有4个,分别是:(1)长白山西北部林区,(2)大兴安岭北段山地区,(3)大兴安岭南部森林与草原过渡区,(4)松嫩平原中部湿地区. 在优先、一般、非优先3个等级中,需要优先保护地区的总面积是19.49×104km2,约占区域总面积的20.91%.同时,根据已建保护区分布情况研究发现,区域内存在3个明显的保护空缺,即长白山西北部林区、大兴安岭北段山地区和大兴安岭南段森林草原过渡区.建议新建和扩建保护区,同时建立生态廊道把相应的保护区关联起来,以实现区域内生物多样性保护目标.     

The integration of biodiversity and climate change: A contextual assessment of the carbon farming initiative

Summary The Carbon Farming Initiative (CFI) allows the creation of tradable Australian Carbon Credit Units (ACCUs) derived from across the ecosystem sector via project‐level baseline and credit activities: it is the first national offset scheme in the world to broadly include farming and forestry projects. Because these activities have the potential to produce both biodiversity and climate change benefits, a crucial outcome is for widespread uptake of the policy. However, the design, complexity and cost of the CFI project development process, and low prices as a result of ACCUs trading in the voluntary market, will all likely militate against this. This article shows how international politics and policy surrounding the Kyoto Protocol have influenced the design of the CFI, with its potential to proliferate complex and narrow methodologies and counter‐productive approaches to integrity standards such as permanence. The article shows that despite the pressing need to integrate biodiversity and climate change considerations as equally important challenges, their global integration remains poorly articulated. Biodiversity considerations are also not integrated into the CFI but, rather, are dealt with indirectly through safeguard measures that avoid perverse incentives and unintended harm, and as an optional co‐benefit via the development of an index. This article suggests that we need to move past the shackles of Kyoto towards streamlined and standardized approaches such as risk‐based assessments and the use of regional baselines. Using regionally specific baselines such as for avoided deforestation would allow landholders to opt‐in to regional‐scale mitigation opportunities. Activities that Australia accounts for, such as reforestation and deforestation, should also be able to opt‐in for coverage under the Clean Energy Act (and out of the voluntary carbon market) to obtain a secure price.     

Gallery Forest or Herbaceous Wetland? The Need for Multi‐Target Perspectives in Riparian Restoration Planning

Much riparian restoration focuses on establishment of gallery forests, with relatively limited effort to restore herbaceous wetlands as key components of riparian landscape mosaics. Multiple reasons for this include inherent cultural or esthetic preferences, greater availability of scientific knowledge to support riparian forest restoration, and choices of ecological indicators commonly used for monitoring and assessment. Yet riparian herbaceous wetlands have declined dramatically as a result of river regulation and agricultural development, leading to losses of important habitats and ecosystem services that differ from those provided by gallery forests. As an alternative to a single‐minded focus on tree establishment, we advocate restoration of diverse and dynamic habitat mosaics in the context of natural variability of flow and sediment regimes. Landscape context should inform active restoration activities at the local scale, such that riparian forests are not planted in ecologically inappropriate sites. Models are needed to match life history requirements of particular wetland herbaceous plant species with details of flow and sediment transport regimes. We emphasize the importance of herbaceous wetlands as a critical and often overlooked component of riparian ecosystems, and the need for both passive and active restoration of fluvial marshes, sloughs, wet meadows, alkali meadows, off‐channel ephemeral ponds, and other critical floodplain communities associated with herbaceous plant dominance.     

基于MaxEnt模型的三江源区草地濒危保护植物热点区识别

三江源地处全球生物多样性热点之一的青藏高原腹地, 是高寒草地生物多样性的集中分布区。但过去几十年中, 人为干扰和气候变化等因素导致高寒草地严重退化, 草地生物多样性受到极大威胁。本研究利用最大熵(MaxEnt)模型模拟了三江源区40种濒危保护植物当前及未来气候变化情景下的热点分布区。根据最大熵模型估计结果统计, 目前三江源濒危保护植物的热点区面积89,438 km², 主要分布于三江源东部和南部, 其中濒危物种大于30种的最热点地区面积485 km², 主要分布于囊谦县、玉树市、班玛县、久治县和河南县。未来在增温增湿的气候变化情景下, 最大熵模型模拟的三江源区草地濒危保护植物的热点区将向西北部扩大, 有利于植物多样性的维持和提升。然而, 模型模拟还发现, 在囊谦县、玉树市、班玛县、久治县和河南县等县市, 均有濒危保护植物大于25种以上的热点区域未被重点保护区覆盖, 总面积为4,423 km²。这一区域被划分为可开展畜牧生产活动的一般保护区, 受到人为干扰的可能性较大, 应予以更多关注与保护。