The Effect of Fragment Shape and Species' Sensitivity to Habitat Edges on Animal Population Size

Abstract:  Habitat fragmentation causes extinction of local animal populations by decreasing the amount of viable "core" habitat area and increasing edge effects. It is widely accepted that larger fragments make better nature reserves because core-dwelling species have a larger amount of suitable habitat. Nevertheless, fragments in real landscapes have complex, irregular shapes. We modeled the population sizes of species that have a representative range of preferences for or aversions to habitat edges at five spatial scales (within 10, 32, 100, 320, and 1000 m of an edge) in a nation-wide analysis of forest remnants in New Zealand. We hypothesized that the irregular shapes of fragments in real landscapes should generate statistically significant correlations between population density and fragment area, purely as a "geometric" effect of varying species responses to the distribution of edge habitat. Irregularly shaped fragments consistently reduced the population size of core-dwelling species by 10–100%, depending on the scale over which species responded to habitat edges. Moreover, core populations within individual fragments were spatially discontinuous, containing multiple, disjunct populations that inhabited small spatial areas and had reduced population size. The geometric effect was highly nonlinear and depended on the range of fragment sizes sampled and the scale at which species responded to habitat edges. Fragment shape played a strong role in determining population size in fragmented landscapes; thus, habitat restoration efforts may be more effective if they focus on connecting disjunct cores rather than isolated fragments.     

Effects of prenatal yolk androgens on armaments and ornaments of the ring-necked pheasant

Mothers may profoundly affect offspring phenotype and performance by adjusting egg components, including steroid hormones. We studied the effects of elevated prenatal testosterone (T) exposure in the ring-necked pheasant on the expression of a suite of male and female traits, including perinatal response to stress, immune response, growth, and secondary sexual traits. Prenatal T levels were increased by injecting the yolk of unincubated eggs with physiological doses of the hormone. Yolk T injection resulted in a reduced length of male tarsal spurs, a trait which positively predicts male success in intra- and intersexual selection and viability, whereas no direct effect on male wattle characteristics or plumage traits of either sex was observed. Female spur length was also negatively affected by T, but to a lesser extent than in males. In addition, the covariation between male secondary sexual traits, which are reliable quality indicators, differed between T and control males, suggesting that the manipulation may have altered the assessment of overall male quality by other males and females. In conclusion, the negative effects of elevated yolk T on spur length, a trait which positively predicts male fitness, coupled with the lack of effects on growth or other traits in both sexes, provided limited evidence for mothers being subjected to a trade-off between positive and negative consequences of yolk T deposition on offspring traits and suggest that directional selection for reduced yolk T levels may occur in the ring-necked pheasant.     

RAPD markers suggest genotypic effects on forager specialization in a eusocial wasp

Genetic variability within insect societies may provide a mechanism for increasing behavioral diversity among workers, thereby augmenting colony efficiency or flexibility. In order to assess the possibility that division of labor has a genetic component in the eusocial wasp Polybia aequatorialis, I asked whether the genotypes of workers within colonies correlated with behavioral specialization. Workers specialized by foraging for one of the four materials (wood pulp, insect prey, nectar, or water) gathered by their colonies. I collected foragers on 2 days from each of three colonies and identified the material the foragers were carrying when collected. I produced random amplified polymorphic DNA (RAPD) markers from the genomic DNA of these foragers and estimated genotypic similarity of foragers based on sharing of variable RAPD marker bands. Contingency tests on 20 variable loci per colony showed statistically significant (P <0.05) biases in RAPD marker frequencies among forager types in the three colonies. Patterns of association of RAPD marker bands with specializations were constant in two colonies, but changed between collection days in one colony. RAPD marker biases suggest that division of labor among workers includes a genetic component in P. aequatorialis. Colony-level selection on variation in division of labor is a possible factor favoring the evolutionary maintenance of high genotypic variability (low relatedness) in epiponine wasp colonies and in other eusocial insects. Received: 18 July 1995/Accepted after revision: 1 October 1995     

An environmental approach for used oil management in Asian cities: a Bangkok' s experience

This paper addresses increasing concern about the pollution threat of used oil being illegally dumped and the impact of oil on air pollution and freshwater ecosystems in Asian countries. Used oil is a very serious waste management problem. These results call for management action such as maximising the collection and recovery of used oil. The Thai government recognizes the need to recycle used oil and has been active in encouraging programs to accomplish this goal. Thus unless new approaches and incentives are developed, used oil generation may become an increasing serious problem to our environment. The purpose of this study is to examine the technical and economic feasibility, of recycling used oils. In addition, this paper briefly discusses the problems to be overcome and outlines potential mechanisms for providing the necessary disposal controls in order to maximize the protection to public health and environmental quality from potential hazards posed by used lube oil disposal.     

累积影响评价的原则和框架

累积影响评价是针对项目环境影响评价极少考虑若干活动累积影响的缺陷和适应可持续发展的要求而发展起来，而建立累积影响评价的原则和呆对提高其有效性具有重要意义，在分析和总结有关文献的基础上，根据累积影响评价的特征，提出了累积影响评价的原则和框架，以指导和规范累积影响评价的实践。     

The effects of managerial and employee attributions for corporate social responsibility initiatives

Although corporate social responsibility (CSR) can affect employees, we know little about how it affects them. Employees' interpretation of CSR is important because of the paradoxical nature of CSR. When firms operate in ways that seem counter to their nature (i.e., pursuit of social good rather than profit), the causal attributions of affected employees are crucial to understanding their work‐related behavior, as is the role of contextual factors such as leadership processes in shaping these attributions. Drawing from attribution and social learning theories, we develop a multilevel social influence theory of how CSR affects employees. We integrate managers as second observers in the baseline actor (i.e., firm)—observer (i.e., employee) dyad, whereas most attribution theory research has focused on single actor–observer dyads. Multisource field data collected from 427 employees and 45 managers were analyzed using hierarchical linear modeling. Managers' genuine (self‐serving) CSR attributions are positively related to employees' genuine (self‐serving) CSR attributions; and the strength of the relationship between managers' and employees' genuine CSR attributions depends on managers' organizational tenure. Employees' genuine CSR attributions also are positively related to employee advocacy, whereas—interestingly—employees' self‐serving CSR attributions do not appear to harm employee advocacy. Copyright © 2017 John Wiley & Sons, Ltd.     

PM2.5的健康危害、毒理效应与作用机制的研究

大气颗粒物对人体健康的影响在世界范围内引起关注,尤其是细粒子（PM_2.5,fine particulate matter）因粒径小、成分复杂,对人体健康的影响尤为突出。PM_2.5的毒理效应与作用机制是当前研究的热点,分析其研究现状与存在问题能更好地把握其核心领域并开展更进一步的研究。基于文献检索与分析,系统梳理了PM_2.5危害导致的疾病类型;介绍了PM_2.5毒理研究的主要实验手段;讨论当前认知的PM_2.5毒理效应（包括PM_2.5不同组分、不同来源、不同季节的影响）;汇总PM_2.5毒理作用机制研究方法的原理、特点、检测指标与测定方法,解析目前研究认为的五种主要的PM_2.5毒理作用机制。在分析已有研究成果的基础之上,就PM_2.5毒理实验、方法和研究内容方面存在的不足进行讨论,并提出今后需要重点开展的研究方向,以期为PM_2.5健康危害的准确评估和有效防治提供科学依据。     

环境规制对碳排放时空格局演变的作用路径研究——基于东北三省地级市实证分析

基于2005-2016年东北三省36个地级市面板数据,定性分析环境规制与碳排放的时空格局演变特征,并利用中介效应分析法定量研究环境规制对碳排放的影响及作用路径。结果表明：（1）从各城市对比来看,环境规制强度呈现出明显的市域差异,碳排放量呈先增加后减小态势。（2）从空间格局来看,环境规制强度呈现由北向南逐渐增强的态势,区域间差异逐渐增大。环境规制的高水平类型分布集中,城市数量最多;低水平类型均位于黑龙江省北部,城市数量最少。碳排放量的高水平类型集中分布在辽东半岛以及大庆市和吉林市等石油型、冶金型城市,低水平类型城市数量呈波动增加,主要分布在东北北部,且向南逐渐扩散。（3）东北三省严格的环境规制不仅直接抑制碳排放,也可以通过优化产业结构和精简粗放投资间接抑制碳排放,地方政府竞争则会减弱环境规制对碳排放的抑制效应。     

1种钝化剂对3种水稻生长影响及降镉效果的研究

为了考察钝化剂对不同程度污染土壤及不同水稻品种的适应性,采用盆栽试验研究了2种程度镉污染农田土壤(轻度污染土壤和重度污染土壤)中钝化剂的修复效果以及3个品种水稻对镉的吸收。结果表明:添加钝化剂后,2种污染程度土壤的pH值在不同时期均显著提高(轻度污染土壤pH值提高了0. 18～0. 73,重度污染土壤pH值提高了0. 42～0. 71),土壤中pH值与土壤有效态Cd呈负相关性(轻度污染土壤的pH值与土壤有效态Cd相关系数为0. 77;重度污染土壤的pH值与土壤有效态Cd的相关系数为0. 91)。2种程度镉污染土壤分蘖期和成熟期的有效态Cd在施加钝化剂后明显降低(轻度污染土壤有效态Cd在分蘖期的最大降幅为30. 69%,在成熟期的最大降幅为25. 69%;重度污染土壤有效态Cd在分蘖期的最大降幅为6%,在成熟期的最大降幅为7. 5%)。糙米总Cd在施加钝化剂后也明显降低(轻度污染土壤的糙米总Cd降低幅度为59. 46%～66. 67%,重度污染土壤的糙米总Cd降低幅度为18. 71%～57. 60%)。施加钝化剂对水稻株高、叶绿素、有效穗、生物量及产量无显著性差异。此外,3个水稻品种的糙米Cd富集系数有一定的差异,2种污染程度土壤中水稻生长有差异。因此,钝化剂对3种水稻品种均具有降镉效果,且对3种水稻生长无负面影响。钝化剂对水稻生长轻度镉污染土壤的修复效果优于重度污染土壤的修复效果,施用钝化剂能使轻度污染土壤中糙米总Cd达标,不能使重度污染土壤中糙米总Cd达标;轻度污染土壤中水稻生长效果明显优于重度污染土壤中水稻生长。