Effects of Harvesting Flowers from Shrubs on the Persistence and Abundance of Wild Shrub Populations at Multiple Spatial Extents

Abstract: Wildflower harvesting is an economically important activity of which the ecological effects are poorly understood. We assessed how harvesting of flowers affects shrub persistence and abundance at multiple spatial extents. To this end, we built a process‐based model to examine the mean persistence and abundance of wild shrubs whose flowers are subject to harvest (serotinous Proteaceae in the South African Cape Floristic Region). First, we conducted a general sensitivity analysis of how harvesting affects persistence and abundance at nested spatial extents. For most spatial extents and combinations of demographic parameters, persistence and abundance of flowering shrubs decreased abruptly once harvesting rate exceeded a certain threshold. At larger extents, metapopulations supported higher harvesting rates before their persistence and abundance decreased, but persistence and abundance also decreased more abruptly due to harvesting than at smaller extents. This threshold rate of harvest varied with species’ dispersal ability, maximum reproductive rate, adult mortality, probability of extirpation or local extinction, strength of Allee effects, and carrying capacity. Moreover, spatial extent interacted with Allee effects and probability of extirpation because both these demographic properties affected the response of local populations to harvesting more strongly than they affected the response of metapopulations. Subsequently, we simulated the effects of harvesting on three Cape Floristic Region Proteaceae species and found that these species reacted differently to harvesting, but their persistence and abundance decreased at low rates of harvest. Our estimates of harvesting rates at maximum sustainable yield differed from those of previous investigations, perhaps because researchers used different estimates of demographic parameters, models of population dynamics, and spatial extent than we did. Good demographic knowledge and careful identification of the spatial extent of interest increases confidence in assessments and monitoring of the effects of harvesting. Our general sensitivity analysis improved understanding of harvesting effects on metapopulation dynamics and allowed qualitative assessment of the probability of extirpation of poorly studied species.     

Motivations Influencing the Adoption of Conservation Easements

Abstract: The use of conservation easements as a conservation mechanism for private land has increased greatly in the past decade; conservation easements now protect over 15 million ha across the United States from residential and commercial development. We used a mailed survey and in‐depth telephone interviews to determine factors that motivate private landowners in Iowa, Illinois, Michigan, Ohio, and Wisconsin (U.S.A.) to place conservation easements on their properties. The mailed survey asked about characteristics of landowners, their properties, and their opinions on 9 factors related to the decision to place an easement. A follow‐up telephone interview was completed with 19 mail‐survey participants to gain an in‐depth understanding of the action and to triangulate the results with the questionnaire. Place attachment, which is a measure of personal connection to a location or property, was the greatest motivation for implementation of an easement. Results of a principal components analysis suggested contributing to the public good underlaid several of the strong motivational factors for participation. Financial reasons were the lowest ranked motivational factor; however, financial concerns may facilitate placement of an easement that would otherwise not be realized. We believe that our results may be transferable to places where land protected by easements is not dominated by traditional farming (row crops, pastures, and hay), timber harvesting, or nonextractive uses (e.g., habitat for wild animals, recreation, and protection of ecosystem services).     

Characterization of a limestone in a batch fluidized bed reactor for sulfur retention under oxy-fuel operating conditions

CO₂ and SO₂ are some of the main polluting gases emitted into atmosphere in combustion processes using fossil fuel for energy production. The former is one of the major contributors to build-up the greenhouse effect implicated in global climate change and the latter produces acid rain. Oxy-fuel combustion is a technology, which consists in burning the fuel with a mix of pure O₂ and recirculated CO₂. With this technology the CO₂ concentration in the flue gas may be enriched up to 95%, becoming possible an easy CO₂ recovery. In addition, oxy-fuel combustion in fluidized beds allows in situ desulfurization of combustion gases by supplying calcium based sorbent.In this work, the effect of the principal operation variables affecting the sulfation reaction rate in fluidized bed reactors (temperature, CO₂ partial pressure, SO₂ concentration and particle size) under typical oxy-fuel combustion conditions have been analyzed in a batch fluidized bed reactor using a limestone as sorbent. It has been observed that sulfur retention can be carried out by direct sulfation of the CaCO₃ or by sulfation of the CaO (indirect sulfation) formed by CaCO₃ calcination. Direct sulfation and indirect sulfation operating conditions depended on the temperature and CO₂ partial pressure. The rate of direct sulfation rose with temperature and the rate of indirect sulfation for long reaction times decreased with temperature. An increase in the CO₂ partial pressure had a negative influence on the sulfation conversion reached by the limestone due to a higher temperature was needed to work in conditions of indirect sulfation. Thus, it is expected that the optimum temperature for sulfur retention in oxy-fuel combustion in fluidized bed reactors be about 925–950 °C. Sulfation reaction rate rose with decreasing sorbent particle size and increasing SO₂ concentration.     

Do biodiversity indices behave as expected from traits of constituent species in simulated scenarios?

It is believed that diversity of plant communities has a positive effect on their productivity. The benefits of diversity are described by “biodiversity indices”, comparing yield of mixtures with yields of monocultures of constituent species. These indices are supposed to capture also the main mechanisms leading to increased yield. We have constructed a spatially explicit individual based model, simulating even-aged stand development, and compared the behaviour of selected biodiversity indices (overyielding, selectivity and complementarity) with expectations based on life history traits of constituent species. The results are based on comparisons of two species mixtures with corresponding monocultures. We designed three scenarios of changes in the two species life history differentiation, and compared the behaviour of the indices with expectation based on it. In the first scenario, selectivity was driven by increasing size inequality of the two species, mostly in accordance with expectations. The second scenario presents increasing shade tolerance of the smaller species that increased complementarity, again mostly as expected. In the last scenario, shortening of length of stress tolerance of the weaker species surprisingly increased values of the biodiversity indices. For each setting, we varied sowing density and spatial pattern of the constituent species. The behaviour of the indices was influenced by both factors, but the effect of density was more pronounced. In particular, at high sowing densities, the most important interactions happened in the very early stages of mixture development, and the behaviour of the indices was often counter-intuitive.     

Enhancing Conservation,Ecosystem Services,and Local Livelihoods through a Wildlife Premium Mechanism

We propose the wildlife premium mechanism as an innovation to conserve endangered large vertebrates. The performance‐based payment scheme would allow stakeholders in lower‐income countries to generate revenue by recovering and maintaining threatened fauna that can also serve as umbrella species (i.e., species whose protection benefits other species with which they co‐occur). There are 3 possible options for applying the premium: option 1, embed premiums in a carbon payment; option 2, link premiums to a related carbon payment, but as independent and legally separate transactions; option 3, link premiums to noncarbon payments for conserving ecosystem services (PES). Each option presents advantages, such as incentive payments to improve livelihoods of rural poor who reside in or near areas harboring umbrella species, and challenges, such as the establishment of a subnational carbon credit scheme. In Kenya, Peru, and Nepal pilot premium projects are now underway or being finalized that largely follow option 1. The Kasigau (Kenya) project is the first voluntary carbon credit project to win approval from the 2 leading groups sanctioning such protocols and has already sold carbon credits totaling over $1.2 million since June 2011. A portion of the earnings is divided among community landowners and projects that support community members and has added over 350 jobs to the local economy. All 3 projects involve extensive community management because they occur on lands where locals hold the title or have a long‐term lease from the government. The monitoring, reporting, and verification required to make premium payments credible to investors include transparent methods for collecting data on key indices by trained community members and verification of their reporting by a biologist. A wildlife premium readiness fund would enable expansion of pilot programs needed to test options beyond those presented here. Mejora de la Conservación, Servicios del Ecosistema y Calidad de Vida Local Mediante un Mecanismo de Compensación de Vida Silvestre     

Understanding and Estimating Effective Population Size for Practical Application in Marine Species Management

Abstract: Effective population size (N_e) determines the strength of genetic drift in a population and has long been recognized as an important parameter for evaluating conservation status and threats to genetic health of populations. Specifically, an estimate of N_e is crucial to management because it integrates genetic effects with the life history of the species, allowing for predictions of a population's current and future viability. Nevertheless, compared with ecological and demographic parameters, N_e has had limited influence on species management, beyond its application in very small populations. Recent developments have substantially improved N_e estimation; however, some obstacles remain for the practical application of N_e estimates. For example, the need to define the spatial and temporal scale of measurement makes the concept complex and sometimes difficult to interpret. We reviewed approaches to estimation of N_e over both long‐term and contemporary time frames, clarifying their interpretations with respect to local populations and the global metapopulation. We describe multiple experimental factors affecting robustness of contemporary N_e estimates and suggest that different sampling designs can be combined to compare largely independent measures of N_e for improved confidence in the result. Large populations with moderate gene flow pose the greatest challenges to robust estimation of contemporary N_e and require careful consideration of sampling and analysis to minimize estimator bias. We emphasize the practical utility of estimating N_e by highlighting its relevance to the adaptive potential of a population and describing applications in management of marine populations, where the focus is not always on critically endangered populations. Two cases discussed include the mechanisms generating N_e estimates many orders of magnitude lower than census N in harvested marine fishes and the predicted reduction in N_e from hatchery‐based population supplementation.     

A behavior based safety approach at a Kuwait research institution

INTRODUCTION: Behavior based safety (BBS) initiatives are the current trend toward improving safety performance. METHOD: This study outlines the framework of the BBS process and summarizes several behavioral safety approaches to accident prevention. RESULTS: Although most of the published research has focused on the improvement of safe behavior in industry, this study is the first to apply the current approach of behavior based safety in a research/educational setting. An experiment conducted at a research institution demonstrated the effectiveness of a well-designed behavior based safety process. A follow-up study indicated that the BBS produced a lasting effect for the experimental group. IMPACT ON INDUSTRY: Results from this study can be the driving force to implement behavior-based safety processes into educational, research, and training organizations.     

常用聚氨酯硬泡外墙外保温系统的点燃特性研究

基于锥形量热仪实验,对常用的聚氨酯硬泡外墙外保温系统的点燃特性进行了实验研究。所研究的系统种类包括粘贴保温板薄抹灰外墙外保温系统,瓷砖饰面粘贴保温板外墙外保温系统,胶粉浆料复合保温板外墙外保温系统和保温装饰板外墙外保温系统。实验结果显示,聚氨酯硬泡保温板和聚氨酯硬泡外墙外保温系统都可由热厚型点燃描述。在防护层对点燃时间的抑制效果方面,胶粉聚苯颗粒复合保温板系统最好,瓷砖饰面系统稍差但明显好于5mm和3mm厚防护层的薄抹灰系统,铝板保温装饰板系统最差。     

基于Web的安全法规符合性评估系统

在分析安全法规符合性评估现状和存在问题的基础上,提出基于Web的安全法规符合性评估系统的技术框架.通过将辨识的安全法规按要素分类、给出量化评估指标体系,构建基于web的安全法规符合性评估系统,实现法规数据库检索、指标体系的计算机辅助定量评估、多人联评、移动终端现场评估、自动生成报告等功能.并以某测井企业为例,开发了安全法规符合性评估系统并已投入使用.应用结果表明,基于web的设计和移动终端的应用使得该系统表现出较好的现场应用性,该系统可提高企业安全法规符合性评估效率,是提高企业安全生产保障能力及满足政府监管要求的有效途径.     

基于磁场理论的矿岩加载损伤破坏表征研究

充填体与围岩的相互力学作用,除了接触带表壁附近可以通过贴置电阻应变片的方式进行应变值测量外,接触面及接触带附近的损伤破坏情况不易监测。基于此,应用磁场理论,将磁粉加入到配比试样中,充磁之后进行加载试验。通过特斯拉计测量试样表壁在加载过程中的磁感应强度变化,建立由表及里的损伤破坏联系规律。试验结果表明:加了磁粉的配比试样,在加载过程中各监测点处的磁感应强度值变化明显,特别是在内部裂纹扩展至临空面处的磁感应强度几乎减小至0.2 mT以下;而试样在加载过程中,各监测点的磁感应强度值随着压密破坏而变化;在未破坏时,不同区域有较一致的随试样内部压密相应磁感应强度增大的变化规律,而在试样加载破坏后,不同监测点磁感应强度变化起伏较大。