The optimal balance of defence investment strategies in clonal colonies of social aphids

Social aphid species provide ideal systems to study the ecological influences upon the evolution of sociality because they consist of discrete colonies which are entirely clonal and therefore devoid of any genetic conflict over altruistic behaviour. Although selfishness can be discounted as an obstacle preventing the evolution of altruistic defenders, the vast majority of aphid species are not social. To examine the key life-history and ecological characteristics that interact to facilitate social evolution, we designed a matrix population model based on the natural history of one of the unique aphid species with soldiers, Pemphigus spyrothecae. In addressing the life-history factors, our special interest was to examine the optimal trade-off faced by colonies that can increase their defence investment by producing defenders at birth and/or increasing the duration of the defensive stage. The level and period of exposure to predation and a declining colony birth rate were key factors that selected for social defence. The model demonstrated that, in species which have soldiers that can facultatively develop to make a direct contribution to colony fitness, temporal extension of the soldier stage is a key mechanism of increasing defence investment. This extension is particularly favoured when predation is high and the lifetime of a colony is long. An increase in production of defenders at birth was favoured when mortality due to predation was strongly biased towards defenders. The model suggests that, in species which have the defensive flexibility of choosing whether soldiers remain as such, there is little requirement for flexibility in the morph allocations made at birth. All these predictions were found to be fully compatible with the available empirical data.     

对我国基层环境执法后督察机制建设的思考

介绍了我国基层环保部门执法后督察取得的成效、存在问题，并提出对策建议。     

Drain of the Yellow River at Shandong Section: Causes and Countermeasures

1Harmful impacts of the drain of the Yellow RiverAccording to existing hydrographic records,the drain of the Yellow River (hereinafter referred toas the Drain) has the following three features.(1 ) The annual starting date of the Drain has beenadvancing.(2 ) The drain season has been prolonging.(3) The drain section has been extendingtoward the upper reaches of the Yellow River.In 1 997,the Yellow River suffered a drain of 2 2 6days atthe locality of L ijin County,Shandong Province and o…     

岩溶泉口沉积物有机碳的来源及环境指示意义

灵水湖为岩溶大泉出口形成的水体,具有优良的水质和几乎恒定的水温,但近年来水生生态系统却发生退化,湖底水草几近绝迹。为了寻找退化原因,利用沉积物的有机碳及其同位素、总氮、烧失量、C/N比值环境代用指标,以及~(210)Pb测年来重建过去环境。结果显示,灵水湖沉积物具有稳定的沉积速率(1.769 cm/a),1957~2013年,δ~(13)C_(org)在-29.6‰~-20.3‰之间波动,与TOC有很好的负相关关系,C/N显示有机碳主要来源于内源的湖泊生物;1960至1990年期间,降雨量、气温和湖水最高水位与δ~(13)C_(org)均有一定的对应关系,是此阶段影响有机碳碳同位素的主要因素;而1990至2013年,尽管有机碳主要来源不变,但与降雨量、气温和湖水水位等无明显对应关系,说明影响此阶段有机碳碳同位素的还有人类活动等其它原因。总结该区水生环境演化模型,认为区域尺度的人类活动是导致局部尺度(泉口)环境变化的主要原因。     

综放俯采支架选型及坚硬顶板垮落规律研究

坚硬顶板垮落对采场液压支架具有一定的冲击作用。为了研究河北冀中能源股份有限公司葛泉矿东井1197工作面综放俯采大青灰岩顶板垮落规律和控制,对综放俯采四柱支架进行了力学分析,结果表明：四柱支架后柱容易处于受拉状态,不利于综放俯采的顶板控制,两柱支架更为合适。利用YTJ20型岩层探测记录仪对大青灰岩顶板的节理裂隙情况进行了观测,观测结果显示：顶板裂隙比较发育。现场实测的采场液压支架工作阻力表明,选用的ZF3200/26/16两柱支撑掩护式支架合适。且大青灰岩比较坚硬,但能随采随冒,悬顶几乎不存在,无需进行顶板处理。     

Evaluating Alternative Strategies for Minimizing Unintended Fitness Consequences of Cultured Individuals on Wild Populations

Artificial propagation strategies often incur selection in captivity that leads to traits that are maladaptive in the wild. For propagation programs focused on production rather than demographic contribution to wild populations, effects on wild populations can occur through unintentional escapement or the need to release individuals into natural environments for part of their life cycle. In this case, 2 alternative management strategies might reduce unintended fitness consequences on natural populations: (1) reduce selection in captivity as much as possible to reduce fitness load (keep them similar), or (2) breed a separate population to reduce captive‐wild interactions as much as possible (make them different). We quantitatively evaluate these 2 strategies with a coupled demographic–genetic model based on Pacific salmon hatcheries that incorporates a variety of relevant processes and dynamics: selection in the hatchery relative to the wild, assortative mating based on the trait under selection, and different life cycle arrangements in terms of hatchery release, density dependence, natural selection, and reproduction. Model results indicate that, if natural selection only occurs between reproduction and captive release, the similar strategy performs better. However, if natural selection occurs between captive release and reproduction, the different and similar strategies present viable alternatives to reducing unintended fitness consequences because of the greater opportunity to purge maladaptive individuals. In this case, the appropriate approach depends on the feasibility of each strategy and the demographic goal (e.g., increasing natural abundance, or ensuring that a high proportion of natural spawners are naturally produced). In addition, the fitness effects of hatchery release are much greater if hatchery release occurs before (vs. after) density‐dependent interactions. Given the logistical challenges to achieving both the similar and different strategies, evaluation of not just the preferred strategy but also the consequences of failing to achieve the desired target is critical. Evaluación de Estrategias Alternativas para Minimizar las Consecuencias No Inesperadas en la Adecuación de Individuos Criados en Cautiverio sobre Poblaciones Silvestres     

Measuring and Monitoring Illegal Use of Natural Resources

Abstract: Illegal use of natural resources is a threat to biodiversity globally, but research on illegal activities has methodological challenges. We examined 100 studies that empirically identify targeted resources, techniques used to procure resources illegally, locations of illegal activities, characteristics of typical violators, incentives driving illegal use of resources, magnitude of the problem of illegal use (e.g., quantities used), or frequency of illegal activity. We based our evaluation of the methods used in these studies on their ability to provide these empirical data, relative labor demands, training and technology requirements, and levels of uncontrollable bias. We evaluated eight different methods: law‐enforcement records, indirect observation, self‐reporting, direct observation, direct questioning, randomized response technique (a survey method designed to improve accuracy of responses to sensitive questions), forensics, and modeling. Different situations favored different methods, each with distinct advantages and limitations. Six context‐specific factors—location of resource use (in situ vs. ex situ), budget, technology and training capacity, ease of detection of illegal activity, scope of illegal activity (limited vs. widespread), and researchers’ willingness to accept bias in results—help narrow the choice of methods. Several methodological concerns applied to any study of illegal resource use: regular monitoring can detect trends; modeling can incorporate sampling error and data uncertainties; researchers must manage levels of bias that vary between methods; triangulation of results from multiple methods can improve accuracy. No method is a panacea, but a combination of techniques can help address the lack of data on illegal activity. Researchers empirically compared results from different methods in only four studies, and no one has compared more than two methods simultaneously. Conservation would benefit from more research focused on: methods comparisons that include cost effectiveness, time efficiency, and statistical rigor; unique applications of the eight techniques currently in use; and testing of new methods.     

Infill McMansions: Style and the psychophysics of size

The number and size of infill oversized houses, or McMansions, has increased in the U.S. and the world. To maintain desirable neighborhood appearances, communities should know what constitutes “too big.” This paper reports six studies that used color simulations of blocks of houses to examine compatibility and visual appeal in relation to attributes of the infill house and its context. Following psychophysical findings, the relative size of the infill house should have larger effects on response than its actual size. The studies confirmed that the infill ratio had more weight than size for perceived compatibility. Compatibility did not always translate into visual appeal. For visual appeal, infill style had larger effects than did size or size ratio, height had larger effects than width, and, for larger sizes and ratios, infill ratio had larger effects than actual size. To maintain visual quality in relation to infill houses, communities should first seek an architecturally compatible style, and then try to control its relative size (the infill façade area). Tests of responses to real infill houses can show how well these findings generalize.     

环境标准实际执行中的存在问题

从规范环境管理和环境执法出发，结合其实际执行过程使用环境标准存在的问题作了简单归纳，并提出初步建议。     

绿色产业与绿色产业法

环境保护产业化是环保工作发展的主要趋势之一。在理论研究和实际工作中。环保产业、环境产业、绿色产业等概念的研究与应用日趋增多。就环境法学而言，界定一个适应环保产业发展的相关概念，并研究其相关法制的构建与发展是十分必要的。绿色产业与绿色产业法研究正是这一思路的具体落实。