Sociological edge effects: Spatial distribution of human impact in suburban forest fragments

Suburban forest fragments often experience heavy recreational and waste disposal use, with considerable damage to the vegetation. To suggest strategies for conservation of the forest flora, spatial distributions of human impact were described in 40 fragmentary stands in northern New Castle County, Delaware. The distribution of human impact showed a significant bias to the forest edge, with 95% of localized damage occurring in the first 82 m. Forms of impact related to lawn maintenance fell significantly closer to the edge than impacts related to recreation and showed the strongest edge orientation. Edge distances of campsites, vandalized trees, and firewood gathering were negatively correlated with distance to the nearest graded road, indicating the importance of road access. Several forms of impact were also clustered near footpaths, although distance to paths was independent of edge distance in all cases. In terms of penetration of the forest and severity of damage, human impact greatly exceeds natural edge effects reported for this community. These findings suggest that damage may be minimized by limiting road access and avoiding the creation of small forest fragments.     

Temporary alteration of local social structure in a threatened population of Cuban iguanas (Cyclura nubila)

In small, insular populations, behavioral patterns that lead to increased variance in individual reproductive success can accelerate loss of genetic variation. Over a 1-year period, we documented behavior and hormone levels in a breeding group of adult Cuban iguanas (Cyclura nubila) at Guantánamo Bay. Male dominance was associated with body and head size, display behavior, testosterone levels, home-range size, and proximity to females. Based on their success in agonistic encounters, we ranked males in a linear dominance hierarchy. During the subsequent breeding season, we conducted a removal experiment in which the five highest-ranking males were temporarily relocated from the study site. Although we were unable to assess reproductive success directly, previously lower-ranking males assumed control of vacated territories, won more fights, and increased their proximity to females in the absence of the dominant males. When it results in greater mating opportunities for otherwise socially suppressed individuals, temporary alteration of local social structure may help limit erosion of genetic variation in small, insular populations. Electronic Publication     

嘉善水源保护地污染源分布与水源保护措施

嘉善县域近年地下水大量开采产生了系列问题,这使得寻找新水源地成为嘉善重大的社会经济问题.经过反复论证,嘉善县确定以太浦河作为新取水口,分设二个地表水水厂,统一供水.该取水工程的建设运行,不但要求加强上游来水水质的监测和评价,而且周围水环境的基础标准也必须同步提高.调查嘉善境内太浦河沿岸地区的基本情况并分析影响该区域水质量的主要污染因素,有利于针对性地提出水源保护的相关措施,控制污染,保证水质.     

辽河保护区坑塘湿地恢复技术研究

辽河保护区在清河口—马虎山段100多km河道上的沙坑为建设坑塘湿地提供了基本条件,阐述了辽河保护区坑塘湿地恢复方法、水系连通技术、生态系统恢复技术及建设工程设计方案。在铁岭段、沙宝台段和石佛寺段建设30个坑塘湿地,通过修建宽2~3 m的连通渠实现坑与坑及坑与河道之间的水系流动,可形成三大坑塘湿地群。通过湿地下垫面整治、植被恢复、生境恢复及水文调控与管理恢复坑塘湿地生态系统,通过河流湿地水网建设和水生植物群落重建工程进行坑塘湿地建设,能够实现对干流悬浮物、COD_Cr和氨氮的有效去除,增加蓄水量909万m³,有效改善辽河流域生态环境。     

Application of function analysis to bathing areas in the Maltese Islands

On a small island such as Malta where many developers and policy makers place a large emphasis on social use and develoment values, which encourages recreational/industrial development, it is often hard to promote the monetary value of coastal conservation due to strong competition with the large tourism industry. An assessment of the ecological (conservation) and economic (use/development) values of four popular Maltese bathing areas (Mellieha, St. George’s, Ramla and Ghajn Tuffieha Bay) was carried out by evaluating their ability to provide a number of functions. This is dependent on the environments’ inherent characteristics within the context of locally applicable time and space functions. Function Analysis is an innovative technique able to provide a means for assessing changes in environmental quality of an area and evaluating the sustainability of applied management regimes. This paper is a first example of an application of the Functional Analysis approach in Malta. Local application of this technique indicates a need for additional refinement in application to coastal areas. Analysis showed that St. George’s, had the lowest conservation value, Ramla and Ghajn Tuffieha bay had the highest conservation values, Mellieha Bay had high conservation value and use/development potential. In this context, conservation value is understood to reflect values of biodiversity, information/knowledge and environmental quality.     

秦皇岛市水土保持工作存在的问题及对策

自水保法颁布实施以来,秦皇岛市的水土保持工作取得了巨大成效;全市共出台县级以上水土保持规范性文件15个;工程建设力度不断加大,综合治理水土流失面积1 619 km2;宣传教育活动深入开展,人们的水保意识普遍增强。然而,在新形势下还存在着宣传不到位、投入不足、治理思路老化、重治理轻预防、执法队伍素质低等诸多问题。因此,针对我市目前水土保持工作存在的问题,提出六项保证措施,推进水土保持工作健康发展。     

Human-mediated dispersal of aquatic invertebrates with waterproof footwear

Human-mediated dispersal has rarely been considered in wetland conservation strategies at regional scales, yet high concern exists about this aspect for (inter-)national management considering invasive species in other aquatic systems. In this context, we aim at understanding the role of human-mediated dispersal by footwear in protected wetlands with high conservation value. Zooplankton and zoobenthos were sampled in 13 shallow lakes in central Spain and, at the same time, mud attached to waders was collected and later cultured in deionized water under laboratory conditions for 4 weeks. Two-hundred and four individuals belonging to 19 invertebrate taxa were recovered after hatching; Ostracoda (84 %), Cladocera (53 %), Copepoda (30 %), Anostraca (30 %), and Notostraca (7 %) were the most frequent groups among the hatched crustaceans. NMDS and PERMANOVA analyses showed significant differences between the dispersed (via footwear) and the source active metacommunity, suggesting different dispersal abilities among the species found. Human vectors facilitate dispersal among protected lakes, which could eventuality lead to biotic homogenization and faster spread of non-indigenous species. Preservation strategies and education campaigns associated to target humans in close contact with water bodies should be imperative in conservation management of protected lakes.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0689-x) contains supplementary material, which is available to authorized users.     

Integration of Land-Sharing and Land-Sparing Conservation Strategies Through Regional Networking: The Mesoamerican Biological Corridor as a Lifeline for Carnivores in El Salvador

Nations with little remaining natural habitat and small extent are challenged when trying to achieve biodiversity targets. We show that the Central American nation of El Salvador cannot viably sustain populations of 87 % of its extant carnivores, especially in the case of large-bodied species with low population densities. Current land-sparing strategies will not suffice; therefore we propose that land-sharing strategies be implemented in tandem with protected areas to expand current conservation efforts via new regional networks. In Central America such a network can be established by linking international protected area systems in a way that implements the existing vision for the Mesoamerican Biological Corridor. Specifically, we propose a re-envisioning of the Mesoamerican Biological Corridor in which land-sharing practices are adopted throughout the agricultural matrix while ensuring formal protection of the remaining natural habitat. Such an integration of land-sparing and land-sharing could result in the creation of an effective network of protected areas, thereby increasing the probability of safeguarding species with populations that overlap national borders.     

Isolated Ficus trees deliver dual conservation and development benefits in a rural landscape

Many of the world’s rural populations are dependent on the local provision of economically and medicinally important plant resources. However, increasing land-use intensity is depleting these resources, reducing human welfare, and thereby constraining development. Here we investigate a low cost strategy to manage the availability of valuable plant resources, facilitated by the use of isolated Ficus trees as restoration nuclei. We surveyed the plants growing under 207 isolated trees in Assam, India, and categorized them according to their local human-uses. We found that Ficus trees were associated with double the density of important high-grade timber, firewood, human food, livestock fodder, and medicinal plants compared to non-Ficus trees. Management practices were also important in determining the density of valuable plants, with grazing pressure and land-use intensity significantly affecting densities in most categories. Community management practices that conserve isolated Ficus trees, and restrict livestock grazing and high-intensity land-use in their vicinity, can promote plant growth and the provision of important local resources.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0645-9) contains supplementary material, which is available to authorized users.     

The effect of metal pollution on the population genetic structure of brown trout (Salmo trutta L.) residing in the River Hayle, Cornwall, UK

The River Hayle in south-west England is impacted with metals and can be divided into three regions depending on the copper and zinc concentrations: a low-metal upper section; a highly-contaminated middle section and a moderately contaminated lower section. Hayle river water is toxic to metal-naive brown trout, but brown trout are found in the upper and lower regions. The study aimed to evaluate the population genetic structure of River Hayle brown trout and to determine if the highly-contaminated section acts as a chemical barrier to migration. Population genetic analysis indicated that metals were not a barrier to gene flow within the river, but there was a high level of differentiation observed between fish sampled at two sites in the upper region, despite being separated by only 1 km. The metal tolerance trait exhibited by this brown trout population may represent an important component of the species genetic diversity in this region.