Behavioral responses of bison and elk in Yellowstone to snowmobiles and snow coaches.

Managers of public lands are charged with protecting some of our most important natural resources and ecosystems, while providing for their use and enjoyment by visitors. Almost one million visitors entered Yellowstone National Park by motorized means on snowmobiles (87%) or snow coaches (13%) during 1992-2003. Most vehicles toured the central portion of the park where bison (Bison bison) and elk (Cervus elaphus) concentrate in geothermal areas. We sampled >6500 interactions between groups of these species and groups of snowmobiles and snow coaches (collectively, OSV, over-snow vehicles) during five winters (1999-2000, 2002-2004). Multinomial logits models were used to identify conditions leading to behavioral responses. Elk responded three times as often (52%) as bison (19%) during interactions with groups of snowmobiles and snow coaches due to increased vigilance responses (elk, 44%; bison, 10%). However, the frequency of higher-intensity movement responses by bison and elk were similar (6-7% travel, 1-2% flight, <1% defense) and relatively low compared to other studies of ungulates and snowmobile disturbance. The likelihood of active responses by bison and elk increased significantly if animals were on or near roads, groups were smaller, or humans approached. The likelihood of an active response by bison decreased within winters having the largest visitation, suggesting some habituation to snowmobiles and snow coaches. There was no evidence that snowmobile use during the past 35 years affected the population dynamics or demography of bison or elk. Thus, we suggest that regulations restricting levels and travel routes of over-snow vehicles (OSVs) were effective at reducing disturbances to bison and elk below a level that would cause measurable fitness effects. We recommend park managers consider maintaining OSV traffic levels at or below those observed during our study. Regardless, differing interpretations of the behavioral and physiological response data will continue to exist because of the diverse values and beliefs of the many constituencies of Yellowstone.     

Biodiversity consequences of alternative future land use scenarios in Greater Yellowstone.

Land use is rapidly expanding in the Greater Yellowstone Ecosystem, primarily from growth in the number of rural homes. There is a need to project possible future land use and assess impacts on nature reserves as a guide to future management. We assessed the potential biodiversity impacts of alternative future land use scenarios in the Greater Yellowstone Ecosystem. An existing regression-based simulation model was used to project three alternative scenarios of future rural home development. The spatial patterns of forecasted development were then compared to several biodiversity response variables that included cover types, species habitats, and biodiversity indices. We identified the four biodiversity responses most at risk of exurban development, designed growth management policies to protect these areas, and tested their effectiveness in two alternative future scenarios. We found that the measured biodiversity responses, including riparian habitat, elk winter range, migration corridors, and eight other land cover, habitat, and biodiversity indices, are likely to undergo substantial conversion (between 5% and 40%) to exurban development by 2020. Future habitat conversion to exurban development outside the region's nature reserves is likely to impact wildlife populations within the reserves. Existing growth management policies will provide minimal protection to biodiversity in this region. We identified specific growth management policies, including incentives to cluster future growth near towns, that can protect "at risk" habitat types without limiting overall growth in housing.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Effects of climate change on surface water management of Seyhan basin,Turkey

The goal of this study was to set-up the basis for climate change adaptation of water resources management policies in Seyhan River basin. The first priority was to identify the balances between water resources and water users with respect to existing and planned projects. In this respect various aspects of Seyhan basin were evaluated, including evaluation of existing water resources, determination of water demand of existing and planned projects, and water resources supply-demand characteristics. The global climate change model was downscaled to the basin scale, the results were associated with hydrometeorological monitoring network and finally the impact of climate change on surface water resources and demands were determined for specific projection years. Water resources management scenarios were developed to evaluate adaptation alternatives to climate change scenarios at the basin level. It was determined that even though there was no water stress in Seyhan basin in 2010, many parts of the basin were expected to suffer significant shortages over the coming years.     

Effects of river otter activity on terrestrial plants in trophically altered Yellowstone Lake

Animals that deposit aquatically derived nutrients on terrestrial landscapes link food webs and affect a variety of in situ processes. This phenomenon, however, is poorly documented in freshwater habitats, especially where species introductions have drastically changed an ecosystem's trophic structure. In this study, we used stable isotopes to document water-to-land nutrient transport by river otters (Lontra canadensis) around Yellowstone Lake, an ecosystem recently altered by nonnative species invasions. We then investigated the effects of otter fertilization on plant growth and prevalence at latrine (scent-marking) sites and evaluated how the recent changes to the lake's food web could influence these plant responses. Values of delta15N were higher on latrines compared to non-latrine sites in five of seven sample plant taxa. Additionally, latrine grasses had higher percentage N than those from non-latrines. Foliar delta15N positively related to fecal deposition rate for some plants, indicating that increased otter scent-marking led to a rise in these N values. Logistic regression models indicated that otters selected for well-shaded latrines with access to foraging. Atypical latrines, misclassified as non-latrines by the regression models, had values of delta15N similar to correctly classified latrines, suggesting that site effects alone cannot explain elevated N values at otter latrine sites. No difference in plant diversity or percent cover of N-fixing taxa occurred between latrine and nonlatrine sites, though specific genera did differ between site types. Measurements of shoot lengths indicated increased growth of some latrine currants (Ribes sp.). In Yellowstone Lake, a twofold reduction in otter numbers could result in an even greater decline in nutrient deposition at latrines, as otters may become less social in a system with decreased prey availability. Our results highlight the role of animals in linking aquatic and terrestrial habitats in inland freshwater systems and suggest that ongoing changes in the trophic structure of Yellowstone Lake could have unexpected ramifications well beyond the lake itself.     

Effects of Fishing on the Ecosystem Structure of Coral Reefs

Overfishing is considered one of the three most significant threats to coral reef ecosystems. Exponentially increasing human populations in the tropics have placed enormous demands upon reefs as a food source. At high intensities, termed ecosystem or Malthusian overfishing, fishing causes major direct and indirect effects on the community structure of fishes and other organisms. It reduces species diversity and leads to local extinctions not only of target species but also of other species not fished directly. Conceivably it could also lead to global extinctions. Loss of keystone species, such as predators of echinoderms, through fishing, can lead to major effects on reef processes, such as accretion of calcium carbonate. Ultimately, sustained heavy fishing may lead to loss of entire functional groups of species, resulting in impairment of the potentially important ecosystem functions provided by those groups. Overfishing has been shown to interact with other agents of disturbance to reduce the ability of reefs to recover from natural occurrences such as hurricanes. Effective management of fishing will require a deeper understanding of the effects of exploitation than we now possess. Research initiatives are underway to examine the responses of fish populations to fishing, generally responses to protection from fishing. There is, however, an urgent need to look beyond fish communities and to consider the entire reef ecosystem. Studies that integrate population and community biology with ecosystem processes will provide a much better understanding of the effects of biodiversity loss on reef function and will improve our ability to manage these complex systems.     

典型纳米材料的土壤微生物效应研究进展

纳米材料的大量生产和广泛应用使其不可避免地进入环境中,而土壤是人工纳米材料释放到环境的主要的汇。土壤中的微生物群落能敏感地反映土壤环境质量的变化,其对物质循环与能量转换具有极重要的生态学意义,然而纳米材料因其独特的物理化学特性,对土壤微生物群落及其功能的影响尚不明确。在参考纳米材料对微生物影响相关研究的基础上,总结了土壤中纳米材料的主要类型及来源,综述了典型纳米材料对土壤微生物群落结构、丰度、功能的影响及可能的影响机制,探讨了环境因子对人工纳米材料土壤生物效应的调控作用,对需要深入研究的方向进行了展望。     

高尔夫球场建设对生态系统影响分析及环境管理对策

通过对高尔夫球场建设过程、特点及主要生态环境影响因子分析，指出高尔夫球场建设需占用大量土地，尤其是农业生态区域，对地表形态、农业生产、水土流失、水环境等均有不同程度的不利影响，对落后地区社会经济具有带动作用。在以安徽元一高尔夫球场为例进行分析基础上，提出了高尔夫球场建设与运营管理的生态环境管理对策。     

化学污染物对珊瑚礁生态系统的影响研究进展

化学污染物是影响珊瑚礁生态系统健康的重要因素之一。近年来,中国沿海地区农业活动、城市工业化以及旅游业发展迅速,珊瑚礁区的环境污染问题日趋严重。珊瑚礁生态系统长期处于化学污染物的联合毒性作用下,生态风险日益增加,已受到国内外研究者的广泛关注。本文综述了该领域的重要研究进展,并从个体、细胞和分子水平重点介绍了化学污染物对珊瑚的影响,主要包括:(1)珊瑚礁对重金属和多环芳烃有明显的富集作用,可以作为该海域化学污染物污染水平的外在反映;(2)化学污染物对珊瑚幼体的影响程度比成体大;(3)抗氧化酶和特定的功能基因可被用作生物标记物(biomarker)来监测珊瑚礁生态系统的健康状况。最后,本文对我国珊瑚礁生态系统未来的研究方向进行了展望,建议在典型的珊瑚礁海域进行长期的生态学监测,并结合室内毒理学实验,筛选出敏感的生物标志物,评价珊瑚礁生态系统可能存在的生态风险,为今后珊瑚礁生态系统的保护和管理提供科学依据。     

Effects of Changes in Biodiversity on Ecosystem Function in Tropical Forests

Changing land use in the tropics has resulted in vast areas of damaged and degraded lands where biodiversity has been reduced. The majority of research on biodiversity has been focused on population and community dynamics and has rarely considered the ecosystem processes that are intimately related. We present a framework for examining the effects of changes in biodiversity on ecosystem function in natural, managed, and damaged tropical forests. Using a whole-ecosystem approach, the framework identifies key nutrient and energy cycling processes and critical junctures or pathways, termed interfaces, where resources are concentrated and transferred between the biotic and abiotic components of the ecosystem. Processes occurring at these interfaces, and the organisms or attributes participating in these processes, exert a strong influence on ecosystem structure. We use examples from Puerto Rico, Southern China, Dominica, and Nicaragua to illustrate how the functional diversity framework can be applied to critically examine the effects of changes in biodiversity on ecosystem function, and the relative success or failure of rehabilitation strategies. The few available data suggest that functional diversity, and not just species richness, is important in maintaining the integrity of nutrient and energy fluxes. High species richness, however, may increase ecosystem resiliency following disturbance by increasing the number of alternative pathways for the flow of resources. We suggest ways in which the framework of functional diversity can be used to design research to examine the effects of changes in biodiversity on ecosystem processes and in the design and evaluation of ecosystem management and land rehabilitation projects in the tropics.     

Effects of boreal forest management practices on the climate impact of CO2 emissions from bioenergy

In Life Cycle Assessment (LCA), carbon dioxide (CO₂) emissions from biomass combustion are traditionally assumed climate neutral if the bioenergy system is CO₂ flux neutral, i.e. the quantity of CO₂ released approximately equals the amount of CO₂ sequestered in biomass. This convention is a plausible assumption for fast growing biomass species, but is inappropriate for slower growing biomass, like forests. In this case, the climate impact from biomass combustion can be potentially underestimated if CO₂ emissions are ignored, or overestimated, if biogenic CO₂ is considered equal to anthropogenic CO₂. The estimation of the effective climate impact should take into account how the CO₂ fluxes are distributed over time: the emission of CO₂ from bioenergy approximately occurs at a single point in time, while the absorption by the new trees is spread over several decades. Our research target is to include this dynamic time dimension in unit-based impact analysis, using a boreal forest stand as case study. The boreal forest growth is modelled with an appropriate function, and is investigated under different forestry regimes (affecting the growth rate and the year of harvest). Specific atmospheric decay functions for biomass-derived CO₂ are then elaborated for selected combinations of forest management options. The contribution to global warming is finally quantified using the GWP_bio index as climate metric. Results estimates the effects of these practices on the characterization factor used for the global warming potential of CO₂ from bioenergy, and point out the key role played by the selected time horizon.