地表火对宝天曼栎类森林生态系统服务功能的影响研究

2008年4月至2010年6月采用时间序列代替空间序列的方法,对宝天曼栎类森林生态系统服务功能受地表火影响在不同时间的涵养水源、保育土壤、固碳释氧、生物保育、积累营养物质、负离子提供和森林病虫害防治等7个方面进行了初步评估。结果表明,地表火干扰造成宝天曼栎类森林生态系统服务功能损失的价值在时间序列上依次为1年是24.95万元.hm-2,5年是11.68万元.hm-2,10年是4.91万元.hm-2,15年是0.68万元.hm-2;各项服务功能价值量损失排序为保育土壤>涵养水源>病虫害防治>固碳释氧>积累营养物质>净化大气>生物保育,其中保育土壤和涵养水源两项的损失占总损失量的70%左右,这表明地表火主要影响宝天曼栎类森林生态系统中的保育土壤和涵养水源功能。     

Turbidity‐induced changes in emergent effects of multiple predators with different foraging strategies

Abstract – In natural systems, prey frequently interact with multiple predators and the outcome often cannot be predicted by summing the effects of individual predator species. Multiple predator interactions can create emergent effects for prey, but how those change across environmental gradients is poorly understood. Turbidity is an environmental factor in aquatic systems that may influence multiple predator effects on prey. Interactions between a cruising predator (largemouth bass Micropterus salmoides) and an ambush predator (muskellunge Esox masquinongy) and their combination foraging on a shared prey (bluegill Lepomis macrochirus) were examined across a turbidity gradient. Turbidity modified multiple predator effects on prey. In clear water, combined predators consumed in total more prey than expected from individual predator treatments, suggesting risk enhancement for prey. In moderately turbid water, the predators consumed fewer prey together than expected, suggesting a risk reduction for prey. At high turbidity, there were no apparent emergent effects; however, the cruising predator consumed more prey than the ambush predator, suggesting an advantage for this predator. Understanding multiple predator traits across a gradient of turbidity increases our understanding of how complex natural systems function.     

Dietary plasticity in Arctic charr (Salvelinus alpinus) in response to long‐term environmental change

Corrigan LJ, Winfield IJ, Hoelzel AR, Lucas MC. Dietary plasticity in Arctic charr (Salvelinus alpinus) in response to long‐term environmental change.
Ecology of Freshwater Fish 2011: 20: 5–13. © 2010 John Wiley & Sons A/S Abstract –  In the face of widespread environmental change impacts, there is a need to better understand mechanisms promoting flexibility and resilience of ecosystem components to such change to inform strategies for conservation. Glacial relict species are especially vulnerable to such changes. We investigated the behavioural responses of a native, glacial relict species, Arctic charr (Salvelinus alpinus) to long‐term environmental changes. It was hypothesised that changes in feeding behaviour would occur as a key intermediary to reduction in habitat availability (through climate change and eutrophication) or competitive interactions [with introduced roach (Rutilus rutilus)]. Stomach content analysis was used to assess the diet of 199 charr caught from Windermere, United Kingdom, in the months of March, June, September and November 2003–2007. The results were compared to data from 1940 to 1951 prior to the environmental changes and revealed a marked increase in the contribution of benthic invertebrates in the present diet. Stable isotope analysis confirms the results of the stomach analysis, suggesting that the charr have switched their diet from zooplanktivory towards benthivory. We discuss the possibility that habitat modification and roach population expansion in Windermere have contributed to changes in charr diet. Complementary studies suggest that this diet shift is more likely to be a response to the increasing roach population than to habitat modification; however, further study in Windermere would be required to elucidate the exact mechanism. Long‐term data sets such as these provide information that is useful for determining the directivity of ecological change and the capability of species to respond to change.     

内蒙古岩画中的动物群落结构及其生态环境的研究——以阴山和乌兰察布两地岩画对比研究为例

动物岩画是内蒙古地区古代动物的图解,通过岩画中的动物群落结构对比,可以推测相同地域范围内,不同时期的动物分布情况,进而推断当地的自然环境变迁的过程。     

风险厌恶下的供应链收益共享契约协调模型研究

收益共享契约是实现供应链系统绩效改善或完美协调的一种机制.考虑了零售商与供应商分别具有风险厌恶决策偏好情况下，在随机市场需求下建立了由单供应商和单零售商组成的二级供应链的收益共享契约模型，并对模型进行了分析，揭示了供应商和零售商的风险厌恶决策偏好对收益共享契约参数的影响.研究结果表明：当销售商（供应商）的风险厌恶控制在一定程度内时，通过调整收益共享契约参数，可以保证供应链的协调.     

天气衍生品的运作机制与精算定价

天气衍生品是为了规避天气风险给天气敏感行业带来收入的不稳定性而兴起的创新型风险管理工具，其实质是通过衍生合约对天气风险进行分割、重组和交易的证券化产品。不同于传统金融衍生品，天气衍生品的价值取决于温度、湿度或降雨量等天气指数。本文在分析天气衍生品市场发展的基础上，重点探讨了最常见的天气期货和天气期权的运作机制及其精算定价。     

依靠科学推进黄平县林业生态建设

贵州省黄平县是少数民族聚居的国家重点扶贫山区农业县。依据县情,依靠科学谋划林业生态建设。从黄平县的实际情况出发,对今后发展黄平县林业生态建设提出了一些建议。     

葶苈子药材生态适宜性区划研究

对全国葶苈子药材的生态适宜性开展评价,为优质葶苈子药材的栽培与选育提供理论依据。通过网络资料查阅和实地采集,收集了葶苈子药材共839个样点信息,其中播娘蒿430个样点,独行菜409个样点,综合55个生态因子,应用GIS和Maxent模型分析葶苈子药材在全国的生态适宜性分布。建立的Maxent模型预测效果良好(训练集和验证集特征曲线下面积均大于0.9),影响全国葶苈子药材生态适宜性的主要环境因子是降雨、温度、海拔、酸碱度、植被类型、土壤亚类等;全国内中药葶苈子最适宜生境主要集中在河北、河南、山西、山东、陕西、宁夏、甘肃南部、四川西部等地。对葶苈子分布区进行了生长等级划分,为葶苈子药材资源的调查研究、人工种植、划分优质产地、资源调查提供理论依据。     

广西畜禽现代生态养殖场认证存在问题及对策

为深化生态文明建设成效,推动生态养殖业的整体发展,广西自2016年开始实施畜禽现代生态养殖场认证工作,要求2020年全区90%规模养殖场都需要与现代生态养殖标准所符合。目前广西畜禽现代生态养殖场认证工作成效显著,在较大程度上推动现代生态养殖业的整体发展。但依然有一些问题存在于畜禽现代生态养殖场认证工作中,相关部门及人员需加强重视,及时探索针对性的对策。