Roads,Interrupted Dispersal,and Genetic Diversity in Timber Rattlesnakes

Abstract: Anthropogenic habitat modification often creates barriers to animal movement, transforming formerly contiguous habitat into a patchwork of habitat islands with low connectivity. Roadways are a feature of most landscapes that can act as barriers or filters to migration among local populations. Even small and recently constructed roads can have a significant impact on population genetic structure of some species, but not others. We developed a research approach that combines fine‐scale molecular genetics with behavioral and ecological data to understand the impacts of roads on population structure and connectivity. We used microsatellite markers to characterize genetic variation within and among populations of timber rattlesnakes (Crotalus horridus) occupying communal hibernacula (dens) in regions bisected by roadways. We examined the impact of roads on seasonal migration, genetic diversity, and gene flow among populations. Snakes in hibernacula isolated by roads had significantly lower genetic diversity and higher genetic differentiation than snakes in hibernacula in contiguous habitat. Genetic‐assignment analyses revealed that interruption to seasonal migration was the mechanism underlying these patterns. Our results underscore the sizeable impact of roads on this species, despite their relatively recent construction at our study sites (7 to 10 generations of rattlesnakes), the utility of population genetics for studies of road ecology, and the need for mitigating effects of roads.     

Effectiveness of Community Forestry in Prey Long Forest,Cambodia

Cambodia has 57% forest cover, the second highest in the Greater Mekong region, and a high deforestation rate (1.2%/year, 2005–2010). Community forestry (CF) has been proposed as a way to reduce deforestation and support livelihoods through local management of forests. CF is expanding rapidly in Cambodia. The National Forests Program aims to designate one million hectares of forest to CF by 2030. However, the effectiveness of CF in conservation is not clear due to a global lack of controlled comparisons, multiple meanings of CF, and the context‐specific nature of CF implementation. We assessed the effectiveness of CF by comparing 9 CF sites with paired controls in state production forest in the area of Prey Long forest, Cambodia. We assessed forest condition in 18–20 randomly placed variable‐radius plots and fixed‐area regeneration plots. We surveyed 10% of households in each of the 9 CF villages to determine the proportion that used forest products, as a measure of household dependence on the forest. CF sites had fewer signs of anthropogenic damage (cut stems, stumps, and burned trees), higher aboveground biomass, more regenerating stems, and reduced canopy openness than control areas. Abundance of economically valuable species, however, was higher in control sites. We used survey results and geographic parameters to model factors affecting CF outcomes. Interaction between management type, CF or control, and forest dependence indicated that CF was more effective in cases where the community relied on forest products for subsistence use and income. Efectividad de la Silvicultura Comunal en el Bosque Prey Long, Camboya     

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     

Assessing the Potential Impact of Cane Toads on Australian Snakes

Abstract:   Cane toads ( Bufo marinus ) are large, highly toxic anurans that were introduced into Australia in 1937. Anecdotal reports suggest that the invasion of toads into an area is followed by dramatic declines in the abundance of terrestrial native frog-eating predators, but quantitative studies have been restricted to nonpredator taxa or aquatic predators and have generally reported minimal impacts. Will toads substantially affect Australian snakes? Based on geographic distributions and dietary composition, we identified 49 snake taxa as potentially at risk from toads. The impact of these feral prey also depends on the snakes' ability to survive after ingesting toad toxins. Based on decrements in locomotor (swimming) performance after ingesting toxin, we estimate the LD₅₀ of toad toxins for 10 of the at-risk snake species. Most species exhibited a similar low ability to tolerate toad toxins. Based on head widths relative to sizes of toads, we calculate that 7 of the 10 taxa could easily ingest a fatal dose of toxin in a single meal. The exceptions were two colubrid taxa (keelbacks [  Tropidonophis mairii ] and slatey-grey snakes [  Stegonotus cucullatus ]) with much higher resistance to toad toxins (up to 85-fold) and one elapid (swamp snakes [  Hemiaspis signata ]) with low resistance but a small relative head size and thus low maximum prey size. Overall, our analysis suggests that cane toads threaten populations of approximately 30% of terrestrial Australian snake species.     

Genetic Structure of Herpetofauna on Halmahera Island,Indonesia: Implications for Aketajawe‐Lolobata National Park

Abstract: Genetic variation within species—a priority for biodiversity conservation—is influenced by natural selection, demography, and stochastic events such as genetic drift. We evaluated the role of these factors in 14 codistributed species of reptiles and amphibians on the Indonesian island of Halmahera by testing whether their molecular variation was correlated with geographic distance, ecology, riverine barriers, or Halmahera's paleoisland precursors. We found support for isolation by distance effects in four species. Two of these four were also significantly affected either by rivers or by ecology. A fifth species was significantly affected by ecology and a sixth was significantly affected by Halmahera's paleoislands. [Correction added after publication 9 December 2009: the previous sentence was edited for clarity.] These findings—the most comprehensive survey of multispecies genetic variation on Halmahera to date—bode well for the efficacy of the recently established Aketajawe‐Lolobata National Park in conserving a substantial component of vertebrate genetic variation on this island. Future success of conservation efforts will depend crucially, of course, on funding for and enforcement of conservation management of this park.     

Measurement of Genetic Variation in Endangered Populations: Bandicoots (Marsupialia: Peramelidae) as an Example

Abstract. Attempts to monitor the genetic variation of endangered populations by the use of blood protein electrophoresis often suffer from three drawbacks: a small sample of loci, lack of control populations with "normal" variation, and, sometimes, difficulty in confirming inheritance of electromorphs.
An endangered isolate (Hamilton, Victoria) of the eastern barred bandicoot, Perameles gunnii, was compared with a widespread, dense, conspecific population in Tasmania. A previous study of the effective size of the siolate suggested that the loss of variation should be detectable by protein electrophoresis if average heterozygosity () was approximately 0.057 in widespread, dense populations and 20 to 50 individuals from each population were analysed for 25 or more loci. However, no genetic variation was detected within or between samples.
Similar studies proposed as a baseline for monitioring genetic variation could be equally powerless to detect changes in variation, even with quite high values. The analysis of variation in DNA is expected to avoid many of the problems associated with blood protein studies.
This study highlights the importance of a control population. Analysis of the Hamilton population alone might have led us to concludce that the recent population crash has been responsible for the low variation; however, this conclusion is not warranted, because = 0 in the much larger Tasmania population.     

PRIVACY REGULATION AND PLACE ATTACHMENT: PREDICTING ATTACHMENTS TO A STUDENT FAMILY HOUSING FACILITY

Although similar processes and functions have been proposed for privacy regulation and place attachment, little theoretical or empirical work encompasses both constructs. In the present study, a theoretical model relates privacy regulation to place attachment in the home. According to this model, the home setting may either facilitate or inhibit privacy regulation with family. When regulation is facilitated, family functioning and feelings of control should be enhanced, promoting attachments to the home.Questionnaire data from student family apartment residents supported this model. Residents who reported greater ease in regulating privacy with family also reported greater apartment attachment. Analyses suggested that this relationship was mediated by family functioning and feelings of control. Similar relationships were found for three different types of attachment.By bridging across concepts often treated separately, the model supported in this study suggests new directions for theoretical and empirical study, and new applications for housing policy and design.     

黄河流域夏季水质量评价及管理对策

为了有效保护黄河水资源,促进黄河流域绿色发展,本研究在黄河流域上、中、下游贵德、兰州、三门峡和东营地点分别采样,分析p H、溶解氧、固体悬浮物、氨氮、硝态氮、总氮、亚硝态氮、总有机碳、总无机碳、总碳、总磷、化学需氧量、五日生化需氧量、粪大肠菌群、挥发酚含量变化趋势,并进行水质综合评价。结果发现:(1)固体悬浮物变化呈现东营兰州三门峡贵德;(2)氨氮、硝态氮、总氮、总有机碳、总无机碳、总碳、总磷、化学需氧量、五日生化需氧量、粪大肠菌群变化趋势依次为三门峡兰州东营贵德;(3)亚硝态氮和挥发酚含量变化趋势为兰州三门峡东营贵德;(4)综合水质评价结果为贵德水质好于东营,东营水质好于兰州,兰州好于三门峡。研究表明邻近城市和大型支流汇入点下游河段是黄河氮污染的主要来源,流域各省各级政府领导,要认真学习习总书记提出的"绿水青山就是金山银山"的生态思想,要入脑入心,严格科学减排,"一定要把黄河的事情办好"。