Using Economic and Regulatory Incentives to Restore Endangered Species: Lessons Learned from Three New Programs

Abstract:  We studied three new incentive-based programs for restoring endangered species on private lands in the United States: safe harbor, Environmental Defense's Landowner Conservation Assistance Program, and conservation banking. For each program, we gathered data on the number of participating landowners, the number of species targeted for assistance, and the cumulative acreage of enrolled land. Measured in this way, both safe harbor and the Landowner Conservation Assistance Program have been remarkably successful. Landowners are drawn to three aspects of these programs: (1) the removal of regulatory burdens associated with attracting endangered species to their property; (2) technical guidance on how to restore habitats for endangered species; and (3) cost-share assistance for habitat restoration. Technical guidance appears to be more important than either regulatory relief or financial assistance in securing the cooperation of some landowners. Assessing the success or failure of conservation banking proved more difficult, given the relatively small number of banks created to date and the lack of any centralized database on them. However, nearly half of the 47 endangered-species conservation banks we surveyed have sold credits, indicating some success in either acquiring or restoring essential habitats.     

Establishment Success across Convergent Mediterranean Ecosystems: an Analysis of Bird Introductions

Abstract:  Concern over the impact of invaders on biodiversity and on the functioning of ecosystems has generated a rising tide of comparative analyses aiming to unveil the factors that shape the success of introduced species across different regions. One limitation of these studies is that they often compare geographically rather than ecologically defined regions. We propose an approach that can help address this limitation: comparison of invasions across convergent ecosystems that share similar climates. We compared avian invasions in five convergent mediterranean climate systems around the globe. Based on a database of 180 introductions representing 121 avian species, we found that the proportion of bird species successfully established was high in all mediterranean systems (more than 40% for all five regions). Species differed in their likelihood to become established, although success was not higher for those originating from mediterranean systems than for those from nonmediterranean regions. Controlling for this taxonomic effect with generalized linear mixed models, species introduced into mediterranean islands did not show higher establishment success than those introduced to the mainland. Susceptibility to avian invaders, however, differed substantially among the different mediterranean regions. The probability that a species will become established was highest in the Mediterranean Basin and lowest in mediterranean Australia and the South African Cape. Our results suggest that many of the birds recently introduced into mediterranean systems, and especially into the Mediterranean Basin, have a high potential to establish self-sustaining populations. This finding has important implications for conservation in these biologically diverse hotspots.     

工业聚合氯化铝的形态分布及混凝效果

对铝浓度为2.50mol·l-1的聚合氯化铝.采用Al-Ferron络合比色法和烧杯混凝实验对样品的形态分布和混凝性能进行了研究.结果表明:三个工业系列样品中Al的形态分布规律基本一致,Ala随盐基度的升高而逐渐降低;Alc随盐基度的升高而升高;Alb则先随盐基度的升高而升高,达到最大值后,再随盐基度的升高而降低.同一系列样品在相同加药条件下,盐基度愈高,混凝效果愈好,Alb含量愈高,混凝效果并不一定愈好.因此,提高Alb不一定能提高混凝效果,工业产品的质量控制以及追求目标应当是尽量提高盐基度,而不是Alb的含量.     

Finding all optimal solutions to the reserve site selection problem: formulation and computational analysis

The problem of selecting nature reserves has received increased attention in the literature during the past decade, and a variety of approaches have been promoted for selecting those sites to include in a reserve network. One set of techniques employs heuristic algorithms and thus provides possibly sub-optimal solutions. Another set of models and accompanying algorithms uses an integer programming formulation of the problem, resulting in an optimization problem known as the Maximal Covering Problem, or MCP. Solution of the MCP provides an optimal solution to the reserve site selection problem, and while various algorithms can be employed for solving the MCP they all suffer from the disadvantage of providing a single optimal solution dictating the selection of areas for conservation. In order to provide complete information to decision makers, the determination of all alternate optimal solutions is necessary. This paper explores two procedures for finding all such solutions. We describe the formulation and motivation of each method. A computational analysis on a data set describing native terrestrial vertebrates in the state of Oregon illustrates the effectiveness of each approach.     

衡阳市蔬菜品种及产业发展研究报告

为了及时掌握衡阳市蔬菜产业发展动态,有效的指导衡阳市蔬菜生产,笔者对2006年衡阳市蔬菜品种及产业发展情况进行了调查,主要是摸清蔬菜品种,找出存在的主要问题,提出了下一步蔬菜品种及产业发展措施,把衡阳市蔬菜生产推向一个新的发展水平．表10,参7．     

高寒小嵩草草甸种子库和种子雨动态分析

对小嵩草草甸种子库的大小和物种组成及与种子雨、地上植被的关系进行了初步研究 .结果表明 ,返青期和枯黄期小嵩草草甸种子库单位体积 (1.0m× 1.0m× 0 .1m)分别有种子nf=10 5 5 0粒和nk=13 815粒 ,分别由 2 2种和 2 4种植物组成 ,分属 9个科 .其中 ,莎草科、豆科和龙胆科占优势 ,禾本科所占比例较小 .每平方米种子雨nr=8436 .4粒 ,由2 5种植物组成 ,分属 10个科 ,莎草科和禾本科所占比例较大 .种子库和种子雨在物种组成上有一定的相似性 (r =0 .76 0 0 ,P <0 .0 1) ,二者共有 19个种 ,分别占种子库和种子雨物种总数的 82 .6 1%和 90 .48% .地上植被与种子库的相似性较小 ,地上植被中有 43.2 4%和 5 1.35 %的植物分别在返青期和枯黄期种子库中出现 ,6 0 %的植物出现于种子雨中 .在物种分布和优势度上 ,地上植被与种子雨间一致性较高 ,但它们与种子库间有一定的分歧 .从地上植被到返青期时的种子库 ,物种多样性降低了 1.6 1% ,从而说明种子库不仅是地上植被补充更新的源泉之一 ,而且是维持植物物种多样性的一种机制 .图 3参 13     

Conservation Strategies for Endemic Fish Species Threatened by the Three Gorges Dam

Abstract:   The largest damming project to date, the Three Gorges Dam has been built along the Yangtze River (China), the most species-rich river in the Palearctic region. Among 162 species of fish inhabiting the main channel of the upper Yangtze, 44 are endemic and are therefore under serious threat of global extinction from the dam. Accordingly, it is urgently necessary to develop strategies to minimize the impacts of the drastic environmental changes associated with the dam. We sought to identify potential reserves for the endemic species among the 17 tributaries in the upper Yangtze, based on presence/absence data for the 44 endemic species. Potential reserves for the endemic species were identified by characterizing the distribution patterns of endemic species with an adaptive learning algorithm called a "self-organizing map" (SOM). Using this method, we also predicted occurrence probabilities of species in potential reserves based on the distribution patterns of communities. Considering both SOM model results and actual knowledge of the biology of the considered species, our results suggested that 24 species may survive in the tributaries, 14 have an uncertain future, and 6 have a high probability of becoming extinct after dam filling.     

Protected Areas and Prospects for Endangered Species Conservation in Canada

Abstract:  Reserve networks figure prominently in conservation strategies that aim to reduce extinction rates. We tested the effectiveness of the current reserve network at protecting species at risk in Canada, where relatively extensive wilderness areas remain. We compared numbers of terrestrial species at risk included in existing reserves to randomly generated networks with the same total area and number of reserves. Existing reserve networks rarely performed better than randomly selected areas and several included fewer endangered species than expected by chance, particularly in the most biologically imperiled regions. The extent of protected area and density of species at risk were unrelated at either broad (countrywide) or finer spatial scales (50 × 50 km grids), although there was a tendency for the most threatened regions of the country to have few or no protected areas (1.5% of areas with >30 endangered species were in reserves). Although reserves will play a useful role in conserving endangered species that occur within them, reducing extinction rates in a region with much of the world's remaining wilderness will require integrating conservation strategies with agricultural and urban land-use plans outside formally protected areas.