中国沿海水生生物污染数据集及食用水产品的健康危害评估

沿海区域是污染物的汇集区域,污染物的生态风险和健康危害广受关注.亟需开展污染物的监测,评估污染的生态风险.已有研究提供了不同水域不同水生生物中各类污染物的含量数据,但尚缺乏系统的沿海区域生物体污染物含量的数据集,无法为沿海区域生态风险及其人体健康危害评估提供数据支撑.本研究通过CNKI、Web of Science和P...     

Use of Riparian Buffer Strips as Movement Corridors by Forest Birds

We conducted a 3-year field experiment to measure the frequency of bird movements through riparian buffer strips before and after harvesting of adjacent forest. Our study was conducted in the boreal mixed wood forest of Alberta and was designed to determine empirically whether songbirds use riparian buffer strips of forest connecting forest reserves as corridors and if they move along these buffer strips more frequently than they cross adjacent clearcuts. We used mist nets to obtain an index of the frequency of bird movement in the forest, and we observed bird movements across adjacent clearcuts for comparison. We predicted that the frequency of movement would be greater (1) in buffer strips after harvesting of adjacent forest than before harvesting, (2) in buffer strips than across clearcuts and, (3) in buffer strips than at control sites (lakeshore forest with no adjacent clearcuts). After adjusting for year-to-year variation in abundance, we found that capture rates increased significantly from pre- to post-harvest, but only for juveniles. Capture rates of adults decreased immediately after harvesting, probably because of the removal of an adjacent source of birds that previously moved through the lakeside forest. Movement rates of forest species in clearcuts were significantly lower than capture rates in the forest. The number of adults captured was positively correlated with the number of territories in the buffer strips, indicating that most birds captured were probably residents. The number of local territories was a poor predictor of juvenile captures, supporting the notion that juveniles were likely dispersing individuals. Our results indicate that buffer strips enhanced movements of juveniles (i.e., acted as corridors) and maintained movement rates of adults. Furthermore, there appeared to be a threshold distance between reserves below which birds may be less reluctant to fly across openings, making corridor use less important.     

粤北星子河水生生物体内重金属污染特征及健康风险

本文分析了粤北星子河12种水生生物样品中Cd、Cr、Cu、Pb、Ni和Zn等6种金属元素的含量水平。利用综合污染指数法和目标危害系数法对水生生物中重金属的污染特征及其健康风险进行评价。结果表明:不同水生生物对重金属的富集程度存在明显差异,重金属的含量水平从低到高顺序依次为:CdNiPbCrCuZn;鱼类富集重金属明显低于贝类。在贝类样品中,Cr、Pb和Zn的含量均出现超标现象。鱼类重金属综合污染指数低于1,属于微污染;而田螺重金属综合污染指数大于1,属于轻度污染水平。不同鱼类中重金属的复合健康危害系数(TTHQ)均小于1,且每周评估摄入量(EDI)均远低于暂定每周允许摄入量(PTWI),居民通过鱼类摄入重金属的健康风险较低;田螺中重金属对人的复合健康危害系数大于1,长期食用田螺存在较高的健康风险,风险较高的重金属元素为Cr、Pb和Zn。     

稀有鮈鲫作为水生模式生物的研究及探讨

我国本土水生生物稀有鮈鲫(Gobiocypris rarus Ye et Fu,1983年)是一种优良的试验用鱼,具备成为模式生物必要条件。本文总结了稀有鮈鲫生物生态学研究情况,分析了稀有鮈鲫在多个应用领域与模式生物斑马鱼、青鳉存在的不足和差距,同时借鉴发达国家推动模式生物的实践经验,提出了针对性建议。     

稀有鮈鲫作为水生模式生物的研究及探讨

我国本土水生生物稀有鮈鲫(Gobiocypris rarus Ye et Fu,1983年)是一种优良的试验用鱼,具备成为模式生物必要条件。本文总结了稀有鮈鲫生物生态学研究情况,分析了稀有鮈鲫在多个应用领域与模式生物斑马鱼、青鳉存在的不足和差距,同时借鉴发达国家推动模式生物的实践经验,提出了针对性建议。     

生态恢复对退化河岸植物群落的作用 ——以重庆九龙外滩河岸带生态恢复为例

河岸带是陆地生态系统与水生生态系统之间的过渡地带,受人类干扰的威胁较大.长江是流经重庆都市区的主要河流,主城区两江四岸部分河岸硬化,河岸生态功能退化或丧失,生物多样性降低.本文以重庆主城区九龙外滩的河岸带为研究区域,通过调查,采用Ward最小方差法对植物群落类型进行划分,比较了生态恢复区域和自然区域的植物群落特征及优势...     

Habitat Split as a Cause of Local Population Declines of Amphibians with Aquatic Larvae

Abstract:  Most amphibian species have biphasic life histories and undergo an ontogenetic shift from aquatic to terrestrial habitats. In deforested landscapes, streams and forest fragments are frequently disjunct, jeopardizing the life cycle of forest-associated amphibians with aquatic larvae. We tested the impact of habitat split—defined as human-induced disconnection between habitats used by different life-history stages of a species—on four forest-associated amphibian species in a severely fragmented landscape of the Brazilian Atlantic Forest. We surveyed amphibians in forest fragments with and without streams (referred to as wet and dry fragments, respectively), including the adjacent grass-field matrix. Our comparison of capture rates in dry fragments and nearby streams in the matrix allowed us to evaluate the number of individuals that engaged in high-risk migrations through nonforested habitats. Adult amphibians moved from dry fragments to matrix streams at the beginning of the rainy season, reproduced, and returned at the end of the breeding period. Juveniles of the year moved to dry fragments along with adults. These risky reproductive migrations through nonforested habitats that expose individuals to dehydration, predation, and other hazards may cause population declines in dry fragments. Indeed, capture rates were significantly lower in dry fragments compared with wet fragments. Declining amphibians would strongly benefit from investments in the conservation and restoration of riparian vegetation and corridors linking breeding and nonbreeding areas.     

Birds as Suppliers of Seed Dispersal in Temperate Ecosystems: Conservation Guidelines from Real‐World Landscapes

Abstract: Seed dispersal by animals is considered a pivotal ecosystem function that drives plant‐community dynamics in natural habitats and vegetation recovery in human‐altered landscapes. Nevertheless, there is a lack of suitable ecological knowledge to develop basic conservation and management guidelines for this ecosystem service. Essential questions, such as how well the abundance of frugivorous animals predicts seeding function in different ecosystems and how anthropogenic landscape heterogeneity conditions the role of dispersers, remain poorly answered. In three temperate ecosystems, we studied seed dispersal by frugivorous birds in landscape mosaics shaped by human disturbance. By applying a standardized design across systems, we related the frequency of occurrence of bird‐dispersed seeds throughout the landscape to the abundance of birds, the habitat features, and the abundance of fleshy fruits. Abundance of frugivorous birds in itself predicted the occurrence of dispersed seeds throughout the landscape in all ecosystems studied. Even those landscape patches impoverished due to anthropogenic disturbance received some dispersed seeds when visited intensively by birds. Nonetheless, human‐caused landscape degradation largely affected seed‐deposition patterns by decreasing cover of woody vegetation or availability of fruit resources that attracted birds and promoted seed dispersal. The relative role of woody cover and fruit availability in seed dispersal by birds differed among ecosystems. Our results suggest that to manage seed dispersal for temperate ecosystem preservation or restoration one should consider abundance of frugivorous birds as a surrogate of landscape‐scale seed dispersal and an indicator of patch quality for the dispersal function; woody cover and fruit resource availability as key landscape features that drive seedfall patterns; and birds as mobile links that connect landscape patches of different degrees of degradation and habitat quality via seed deposition.