筛选菌种酶催化降解微囊藻毒素的特点

从云南滇池底泥中筛选出1株能够高效降解微囊藻毒素(Microcystins,MCs)的纯菌种.该菌无细胞提取液能进行降解MC-RR和MC-LR的酶促反应,并有最终产物的积累.在pH 6～8范围内酶对MC-RR和MC-LR的催化降解活性较高,Cu²⁺、Mn²⁺和Zn²⁺对降解MCs的酶促反应没有明显的促进作用.     

主成分分析法在水节霉生长水体水质评价中的应用

基于SPSS主成分分析法对海浪河流域水节霉生长水体水质进行评价.在12月份,对海浪河流域10个断面的水质指标进行评价,结果表明,英雄桥和斗银河口断面污染较严重,主要污染物为氮和有机物,其余断面水质较好,基本满足功能需求;同时对水节霉惟一生长地河夹村大坝连续进行6个月的水质监测,结果表明,在冰封期的1～2月份,该断面污染...     

灌水和生物炭施用对水稻土呼吸温度敏感性的影响

水稻田的生态系统呼吸和温度敏感性(Q10)在稻田生态系统温室气体排放等方面有非常重要的作用.本文采用静态暗箱/气相色谱法,研究间歇灌溉和淹水灌溉两种方式下不施肥(CK)、单施化肥(NPK)、10 t·hm-2生物炭+化肥(LBC)、20t·hm-2生物炭+化肥(MBC)和40 t·hm-2生物炭+化肥(HBC)这5个处理的稻田生态系统呼吸和Q10的变化规律.结果表明:①淹水灌溉下生态系统呼吸的温度敏感系数Q10分别为4. 45 (CK)、7. 40 (NPK)、6. 44 (LBC)、4. 58 (MBC)和3. 87(HBC). 5个处理下淹水灌溉比间歇灌溉均显著降低了稻田生态系统的Q10值(P 0. 01),CK、NPK、LBC、MBC和HBC在淹水灌溉下分别比在间歇灌溉下降低了48. 6%、55. 2%、67. 9%、70. 3%和70. 8%;②两种灌溉条件下,化肥与生物炭配施相比不施肥处理均增加了稻田生态系统的呼吸,但不同的生物炭施入水平,对生态系统呼吸的促进作用差异不显著;③化肥与中、低量生物炭配施相比不施肥均增加了稻田生态系统呼吸的温度敏感性(P 0. 05),但MBC和HBC处理均比NPK处理降低了稻田生态系统的Q10值,稻田生态系统呼吸的温度敏感性随着生物炭施入水平的增加而减小.     

油指纹多元统计分析在鉴别地表水石油类污染来源中的应用研究

采用油指纹多元统计方法,对嘉兴市杭州塘和长山河水系沿岸加油站9个不同来源的轻质柴油进行了分类鉴别,并考察了风化的影响.结果表明:仅基于GC-MS谱图,很难对不同轻质柴油的来源进行鉴别;但基于GC-MS谱图,提取正构烷烃及多环芳烃特征比值,进一步采用多元统计方法,可以对不同来源的轻质柴油进行区分.考虑实际水环境中油污染物会风化,向河水中投入两种轻质柴油,考察了不同初始浓度和不同风化时间下的油指纹变化,发现油污染物初始浓度为0.5 mg·L~(-1)时,所有特征比值在风化过程中均极不稳定,无法用于分类鉴别;油污染物初始浓度达到1.0 mg·L~(-1)及以上时,特征比值C_(17)/Pr、C_(18)/Ph在风化5 d内可用作油指纹的鉴别指标,5 d后无法用于鉴别;特征比值Pr/Ph、(C_(19)+C_(20))/(C_(21)+C_(22))、CPI受风化时间影响小,始终可以作为油指纹鉴别的特征指标.     

Pollution,habitat loss,fishing, and climate change as critical threats to penguins

Cumulative human impacts across the world's oceans are considerable. We therefore examined a single model taxonomic group, the penguins (Spheniscidae), to explore how marine species and communities might be at risk of decline or extinction in the southern hemisphere. We sought to determine the most important threats to penguins and to suggest means to mitigate these threats. Our review has relevance to other taxonomic groups in the southern hemisphere and in northern latitudes, where human impacts are greater. Our review was based on an expert assessment and literature review of all 18 penguin species; 49 scientists contributed to the process. For each penguin species, we considered their range and distribution, population trends, and main anthropogenic threats over the past approximately 250 years. These threats were harvesting adults for oil, skin, and feathers and as bait for crab and rock lobster fisheries; harvesting of eggs; terrestrial habitat degradation; marine pollution; fisheries bycatch and resource competition; environmental variability and climate change; and toxic algal poisoning and disease. Habitat loss, pollution, and fishing, all factors humans can readily mitigate, remain the primary threats for penguin species. Their future resilience to further climate change impacts will almost certainly depend on addressing current threats to existing habitat degradation on land and at sea. We suggest protection of breeding habitat, linked to the designation of appropriately scaled marine reserves, including in the High Seas, will be critical for the future conservation of penguins. However, large‐scale conservation zones are not always practical or politically feasible and other ecosystem‐based management methods that include spatial zoning, bycatch mitigation, and robust harvest control must be developed to maintain marine biodiversity and ensure that ecosystem functioning is maintained across a variety of scales. Contaminación, Pérdida de Hábitat, Pesca y Cambio Climático como Amenazas Críticas para los Pingüinos     

Identifying correlates of success and failure of native freshwater fish reintroductions

Reintroduction of imperiled native freshwater fish is becoming an increasingly important conservation tool amidst persistent anthropogenic pressures and new threats related to climate change. We summarized trends in native fish reintroductions in the current literature, identified predictors of reintroduction outcome, and devised recommendations for managers attempting future native fish reintroductions. We constructed random forest classifications using data from 260 published case studies of native fish reintroductions to estimate the effectiveness of variables in predicting reintroduction outcome. The outcome of each case was assigned as a success or failure on the basis of the author's perception of the outcome and on whether or not survival, spawning, or recruitment were documented during post‐reintroduction monitoring. Inadequately addressing the initial cause of decline was the best predictor of reintroduction failure. Variables associated with habitat (e.g., water quality, prey availability) were also good predictors of reintroduction outcomes, followed by variables associated with stocking (e.g., genetic diversity of stock source, duration of stocking event). Consideration of these variables by managers during the planning process may increase the likelihood for successful outcomes in future reintroduction attempts of native freshwater fish. Identificación de Correlaciones de Éxito y Fracaso de Reintroducciones de Peces de Nativos Agua Dulce     

Selecting cost‐effective areas for restoration of ecosystem services

Selection of areas for restoration should be based on cost‐effectiveness analysis to attain the maximum benefit with a limited budget and overcome the traditional ad hoc allocation of funds for restoration projects. Restoration projects need to be planned on the basis of ecological knowledge and economic and social constraints. We devised a novel approach for selecting cost‐effective areas for restoration on the basis of biodiversity and potential provision of 3 ecosystem services: carbon storage, water depuration, and coastal protection. We used Marxan, a spatial prioritization tool, to balance the provision of ecosystem services against the cost of restoration. We tested this approach in a mangrove ecosystem in the Caribbean. Our approach efficiently selected restoration areas that at low cost were compatible with biodiversity targets and that maximized the provision of one or more ecosystem services. Choosing areas for restoration of mangroves on the basis carbon storage potential, largely guaranteed the restoration of biodiversity and other ecosystem services. Selección de Áreas Rentables para la Restauración de Servicios Ambientales     

Improving Environmental and Social Targeting through Adaptive Management in Mexico's Payments for Hydrological Services Program

Natural resource managers are often expected to achieve both environmental protection and economic development even when there are fundamental trade‐offs between these goals. Adaptive management provides a theoretical structure for program administrators to balance social priorities in the presence of trade‐offs and to improve conservation targeting. We used the case of Mexico's federal Payments for Hydrological Services program (PSAH) to illustrate the importance of adaptive management for improving program targeting. We documented adaptive elements of PSAH and corresponding changes in program eligibility and selection criteria. To evaluate whether these changes resulted in enrollment of lands of high environmental and social priority, we compared the environmental and social characteristics of the areas enrolled in the program with the characteristics of all forested areas in Mexico, all areas eligible for the program, and all areas submitted for application to the program. The program successfully enrolled areas of both high ecological and social priority, and over time, adaptive changes in the program's criteria for eligibility and selection led to increased enrollment of land scoring high on both dimensions. Three factors facilitated adaptive management in Mexico and are likely to be generally important for conservation managers: a supportive political environment, including financial backing and encouragement to experiment from the federal government; availability of relatively good social and environmental data; and active participation in the review process by stakeholders and outside evaluators. Mejorando los Objetivos Ambiental y Social Mediante el Manejo Adaptativo en el Programa de Pagos por Servicios Hidrológicos en México