Sexual selection,male morphology,and the efficacy of courtship signalling in two wolf spiders (Araneae: Lycosidae)

Males of the brush-legged wolf spider, Schizocosa ocreata (Araneae: Lycosidae), possess a conspicuous male secondary sexual character: dark pigmentation and tufts of bristles on the tibiae of their forelegs. We tested several hypotheses relating to the role of this conspicuous trait in sexual selection. Triad mating experiments suggest that the tufts do not play an obvious role in the operation of sexual selection by either male competition or female choice, as there were no significant differences in the mating success of intact and experimentally shaved males. However, females mated more often with males that initiated courtship first, suggesting that capture of a female’s attention by male signalling may play a critical role. In behavioral experiments that paired a single male with a female in arenas that allowed both visual and vibratory signal transmission during courtship, female receptivity did not vary significantly with the presence or absence of tufts. However, experiments that isolated the visual component of communication (by eliminating vibratory communication) revealed a significant effect of the presence of tufts: females showed receptivity less often to males with tufts removed. Female response to visual signals was much greater in S. ocreata than in its sibling congener, Schizocosa rovneri, which lacks male tufts. We hypothesize that the tufts serve to increase the efficacy of visual displays of S. ocreata, as vibratory communication is constrained by the complex leaf litter habitat of some populations. Such environmental constraints may make visual signalling over distance a critical factor for effective courtship communication, which may in turn strongly influence male fitness. Received: 30 September 1994/Accepted after revision: 4 August 1995     

Temporal patterning of within-song type and between-song type variation in song repertoires

In many songbird species, males sing a repertoire of distinct song types. Song sparrows typically are described as having repertoires of about a dozen song types, but these song types are themselves quite variable and some songs are produced that appear intermediate between two types. In this study we quantify the similarity between successive songs produced by song sparrows in order to determine if differences between song types are emphasized or deemphasized in bouts of continuous singing. In spite of the high degree of variation within song types and similarity between song types observed in this species, we show that transitions from one song type to the next are distinct as compared to transitions within sequences of the same type (Figs. 4 and 5). Variation does not accumulate across sequences of the same song type, and the average variation observed within a continuous sequence of the same song type is significantly less than is predicted from the total variation recorded for that type across many different bouts (Fig. 6). These results support the view that song sparrows include two levels of variation in their singing: differences between song types as is commonly observed in species with song repertoires, and an independent level of variation observed for songs of the same type.     

工程与环境相结合,定量化筛选评价因子

在总结环境影响评价因子筛选方法的基础上,提出了"工程与环境相结合 ,定量化进行评价因子筛选"的新方法.同时,结合实践工作体会,提出了对较复杂项目, 在报告书阶段进行"环境影响因子再识别和评价因子再筛选"的思路.     

危险废弃物安全填埋场的选址及安全措施

在工业生产过程中，会产生大量的固体废弃物，而其中危险废弃物占有一定比例，如果对这类废弃物不适当或随意处置，则对自然环境和人体健康将产生有害影响．文中就危险废物安全填埋场的作用、选址要求、选址工作程序、建设标准、营运管理体制，以及污泥稳定化固化预处理方案等问题进行了研究和探讨。     

从生态文明视角谈文化产业园区发展路径创新

概述了我国文化产业在发展过程中出现的诸如文化国际贸易污染转移、资源成本透支以及生态结构不合理等问题,根据生态和文化天生具有亲近性和共同特征,建议通过树立“生态消费”观念、进行结构调整等对策实现文化产业与生态文明的有机结合.     

可渗透反应墙技术中反应介质的研究进展

以PRBs技术中最为关键的填充反应介质为研究对象，介绍了常用的五种反应介质（零价铁、活性炭、无机矿物、黏土、和以固体废弃物为前体材料的反应介质）的研究现状，阐述了影响反应介质选择的主要因素，同时介绍了PRBs技术在实际工程应用中的典型案例，并对PRBs技术的现存问题和未来发展进行了总结和展望，以期为研发长期高效和环境友好型的PRBs反应介质提供有益的支持.     

Sex linkage among genes controlling sexually selected traits

Using literature data on reciprocal crosses I estimated the influence of sex-chromosomal genes on morphological and behavioral traits. To determine a special role of the sex chromosomes for sexually selected traits, I compared the estimated influence of X-chromosomal genes on sexually selected traits with their estimated influence on traits not under sexual selection. About one-third of the phenotypic variation in sexually selected traits is caused by X-chromosomal genes. There was, in contrast, no significant influence of X-chromosomal genes on traits that were classified as not sexually selected. Sexually selected traits thus seem to be influenced significantly more by X-chromosomal genes than traits not under sexual selection. Though this differential influence of X-chromosomal genes cannot readily be explained with current theoretical knowledge, it may shed some light on X-linked hybrid sterility and on the discussion between arbitrary and good-gene models for the evolution of female choice. Received: 30 January 1998 / Accepted after revision: 20 June 1998     

Area-Based Refinement for Selection of Reserve Sites with the Benefit-Function Approach

Abstract:  Optimization of resource use is necessary for efficient conservation planning. Many reserve-selection algorithms aim to identify representative but inexpensive networks, which may lead to selecting small sites due to their lower costs and collectively higher species richness. Nevertheless, larger sites would be preferable regarding species' long-term persistence. An area-based refinement can be used to overcome this problem. We used a reserve-planning framework in which continuous benefit functions valued representation (numbers of populations), and differential species weights were based on a species' local rarity and threatened status. We introduced a refinement based on the species-area relationship that provides relatively higher values for larger sites. We applied the proposed method to rich fen vegetation in southern Finland. The species-area refinement resulted in a network of significantly larger sites with minor trade-offs with representation (numbers of populations). Giving endangered species higher weights ensured that the trade-off occurred mostly between site size and representation of low-priority species. We recommend using a species-area refinement for practical, maximum-coverage conservation planning.     

南水北调中线水源区（南阳市）生态环境敏感性与生态功能重要性研究

河南省南阳市既是南水北调中线工程重要的水源地，也是工程渠首所在地，其生态地位非常重要。在分析影响区域生态环境敏感性和生态系统功能重要性的主要指标基础上，采用定性分析和定量评价方法相结合，进行了水源区生态环境敏感性和生态功能重要性研究。结果表明：研究区属土壤侵蚀中度敏感区；区域的南部丹江口水库库体周围和丹江支流水体周围是重要的水源涵养区，北部山区是重要的生物多样性保护区，库区周围的低山丘陵区是重要的土壤保持区。提出了在生物多样性功能区，禁止滥砍滥伐林木和人为捕猎野生动物；在丹江口水库水源涵养区，要栽植水源涵养林，发展生态农业，控制工业、生活和面源污染；在丹江口库区及周围的浅山丘陵区（土壤保持区），要控制区内植被破坏，退耕还林、还草。     

鲁中南岩溶塌陷区岩溶水污染途径研究

在鲁中南岩溶发育区,由于过量开采岩溶地下水,岩溶塌陷频繁发生,岩溶地下水也受到不同程度的污染。在岩溶塌陷区,岩溶地下水污染与岩溶塌陷有着密切联系。岩溶塌陷的条件、规模、频度、塌陷的时空阶段性等都直接影响岩溶地下水的污染程度。根据岩溶水的补给途径,岩溶水污染途径主要有四种:面状垂直渗透污染、带状侧向渗漏污染、点状塌陷坑灌入污染和超采岩溶水激发越流污染,不同的污染途径其污染源也不相同。要防止岩溶水污染,必须从根本上解决岩溶塌陷问题,切断污染途径,加强岩溶塌陷的防治和监测,从而保证岩溶水资源可持续发展。