A Matrix‐Calibrated Species‐Area Model for Predicting Biodiversity Losses Due to Land‐Use Change

Abstract: Application of island biogeography theory to prediction of species extinctions resulting from habitat loss is based on the assumption that the transformed landscape matrix is completely inhospitable to the taxa considered, despite evidence demonstrating the nontrivial influence of matrix on populations within habitat remnants. The island biogeography paradigm therefore needs refining to account for specific responses of taxa to the area of habitat “islands” and to the quality of the surrounding matrix. We incorporated matrix effects into island theory by partitioning the slope (z value) of species–area relationships into two components: γ, a constant, and σ, a measure of taxon‐specific responses to each component of a heterogeneous matrix. We used our matrix‐calibrated model to predict extinction and endangerment of bird species resulting from land‐use change in 20 biodiversity hotspots and compared these predictions with observed numbers of extinct and threatened bird species. We repeated this analysis with the conventional species–area model and the countryside species–area model, considering alternative z values of 0.35 (island) or 0.22 (continental). We evaluated the relative strength of support for each of the five candidate models with Akaike's information criterion (AIC). The matrix‐calibrated model had the highest AIC weight (w_i = 89.21%), which means the weight of evidence in support of this model was the optimal model given the set of candidate models and the data. In addition to being a valuable heuristic tool for assessing extinction risk, our matrix‐calibrated model also allows quantitative assessment of biodiversity benefits (and trade‐offs) of land‐management options in human‐dominated landscapes. Given that processes of secondary regeneration have become more widespread across tropical regions and are predicted to increase, our matrix‐calibrated model will be increasingly appropriate for practical conservation in tropical landscapes.     

Patterns of Citations of Open Access and Non‐Open Access Conservation Biology Journal Papers and Book Chapters

Abstract: Open access (OA) publishing, whereby authors, their institutions, or their granting bodies pay or provide a repository through which peer‐reviewed work is available online for free, is championed as a model to increase the number of citations per paper and disseminate results widely, especially to researchers in developing countries. We compared the number of citations of OA and non‐OA papers in six journals and four books published since 2000 to test whether OA increases number of citations overall and increases citations made by authors in developing countries. After controlling for type of paper (e.g., review or research paper), length of paper, authors’ citation profiles, number of authors per paper, and whether the author or the publisher released the paper in OA, OA had no statistically significant influence on the overall number of citations per journal paper. Journal papers were cited more frequently if the authors had published highly cited papers previously, were members of large teams of authors, or published relatively long papers, but papers were not cited more frequently if they were published in an OA source. Nevertheless, author‐archived OA book chapters accrued up to eight times more citations than chapters in the same book that were not available through OA, perhaps because there is no online abstracting service for book chapters. There was also little evidence that journal papers or book chapters published in OA received more citations from authors in developing countries relative to those journal papers or book chapters not published in OA. For scholarly publications in conservation biology, only book chapters had an OA citation advantage, and OA did not increase the number of citations papers or chapters received from authors in developing countries.     

Effects of Two Amphibian Pathogens on the Developmental Stability of Green Frogs

Abstract: Developmental instability, measured as fluctuating asymmetry (FA), is often used as a tool to measure stress and the overall quality of organisms. Under FA, it is assumed that control of symmetry during development is costly and that under stress the trajectory of development is disturbed, resulting in asymmetric morphologies. Amphibian emergent infectious diseases (EIDs), such as Ranavirus and chytrid fungus, have been involved in several mortality events, which makes them stressors and allows for the study of FA. We analyzed nine populations of green frogs (Rana clamitans) for the presence or absence of Ranavirus and chytrid fungus. Individuals were measured to determine levels of FA in seven traits under the hypothesis that FA is more likely to be observed in individuals infected by the pathogens. Significantly higher levels of FA were found in individuals with Ranavirus compared with uninfected individuals among all populations and all traits. We did not observe FA in individuals infected with chytrid fungus for any of the traits measured. Additionally, we observed a significant association between Ranavirus infection and levels of FA in both males and females, which may indicate this viral disease is likely to affect both sexes during development. Altogether, our results indicate that some EIDs may have far‐reaching and nonlethal effects on individual development and populations harboring such diseases and that FA can be used as a conservation tool to identify populations subject to such a stress.     

江苏省城乡结合部土地资源利用状况与对策

城乡结合部是城市向农村的过渡带。由于其独特的经济地理位置,使这一地带的土地资源呈现出协同效应活跃、恢复原状机会少、抗干扰能力低、边界变化速度快等生态脆弱性特征。由于人们长期不合理的开发活动,导致了结合部内土地资源数量锐减、质量下降、污染严重、投入减少、地面沉降等生态环境变异。迫使我们采取切实有效的措施,解决日趋严重的城乡结合部土地资源危机。     

CHLOROPHYLL-BIOMASS-NUTRIENT RELATIONSHIPS FOR NATURAL ASSEMBLAGES OF FLORIDA PHYTOPLANKTON1

Parallel determination of phytoplankton biomass and chlorophyll a concentration were made on spring and summer phytoplankton samples collected from 165 Florida lakes. There was a significant correlation between chlorophyll a concentration and phytoplankton biomass (r=0.80; P < 0.01). Chlorophyll content per unit phytoplankton biomass ranged over two orders of magnitude. Nitrogen seemed to be a major factor influencing the chlorophyll content of Florida algae. Multiple regression analyses indicated that phytoplankton biomass was dependent on both the total phosphorus and total nitrogen concentration. Nutrient-phytoplankton and Secchi-phytoplankton relationships for the Florida lakes had higher coefficients of determination if chlorophyll a concentrations rather than phytoplankton biomass data were used in regression analyses.     

煤矿居民区一氧化碳中毒事件

本文报导一起煤矿因地下燃煤产生的一氧化碳漏进入矿区居民住宅所引起的一氧化碳中毒事件。     

催化光度法测定中成药中痕量铬

研究了Cr（Ⅵ）催化H2O2氧化溴甲酚红（BR）的反应。在HAc-NaAc介质中，以溴化十六烷基吡啶（CPB）为增敏剂，测定波长为588nm，Cr(Ⅵ）浓度在0－0.06mg/L内与吸光度呈线性关系。该法用于中成药乌鸡白凤丸中铬含量的测定，结果令人满意。     

复杂岩溶矿床延深水平涌水量的预测

随着岩溶矿床的延深开采,矿坑涌水量的计算成为防治水害首先要解决的难题。文章创造性地采用国外广泛采用的岩溶水衰减动态分析法,选择了我国南方复杂岩溶含水层中有代表性的重庆市红岩煤矿,将丛林采区茅口组岩溶水动力单元和该单元南大巷(标高+370 m)的茅口灰岩岩溶含水层的主要排水点-1号突水点作为研究对象,建立了该单元岩溶含水层的计算模型-衰减动态(流量和水位)方程,求出了岩溶水动力单元水均衡、地下水储量计算和矿坑涌水量预测的水文地质参数:a、T、K、S、μ、Ie,建立了该单元岩溶裂隙-管道水的水均衡方程, 根据连续观察一个水文年以上的丰富地下水动态资料,预测了红岩煤矿370 m标高以下的延伸开采水平(295- 370 m)矿坑涌水量。     

滇池湖泊富营养化动力学模拟研究

针对滇池富营养化情况 ,利用实测资料 ,建立了叶绿素a、透明度、藻量与总氮、总磷之间的相关关系式 ,利用水动力学原理建立垂向平均化的水动力学模型 ,并对总氮、总磷及叶绿素a、透明度和藻量分布进行了模拟计算。对滇池湖泊富营养化的控制提供科学依据。     

模拟海洋全浸区环境下A517海工钢的腐蚀机理研究

目的 探究 A517 海工钢在海洋全浸区环境下的腐蚀机理。方法 通过模拟海洋全浸区腐蚀环境,利用失重法、SEM、EDS、XRD、电化学等测试技术,分析A517钢的腐蚀行为历程,并探讨其在全浸区的腐蚀机理。结果A517钢在厚度方向上的最大电位差为 13 mV,小于发生电偶腐蚀的最小电位差50mV,说明材料在厚度方向上的腐蚀敏感性一致。随浸泡时间的延长,腐蚀质量损失量逐渐增加,平均腐蚀速率先降低、后升高、最后趋于稳定,腐蚀速率约为 0.127 mm/a。结论 腐蚀动力初期主要是由溶解氧的极限扩散控制,后期则是腐蚀产物的氧化还原电荷转移控制。腐蚀首先在 Al₂O₃、MgO 等夹杂物处萌生扩展,腐蚀产物出现明显的分层现象,外锈层主要是疏松易脱落的γ-FeOOH,内锈层主要是致密均匀的 Fe₃O₄,同时锈层中还检测到了β-FeOOH和α-FeOOH的存在。锈层中存在大量微裂纹,削弱了产物膜的保护作用,促进了腐蚀的进行。