A Small‐Scale Land‐Sparing Approach to Conserving Biological Diversity in Tropical Agricultural Landscapes

Two contrasting strategies have been proposed for conserving biological diversity while meeting the increasing demand for agricultural products: land sparing and land sharing production systems. Land sparing involves increasing yield to reduce the amount of land needed for agriculture, whereas land‐sharing agricultural practices incorporate elements of native ecosystems into the production system itself. Although the conservation value of these systems has been extensively debated, empirical studies are lacking. We compared bird communities in shade coffee, a widely practiced land‐sharing system in which shade trees are maintained within the coffee plantation, with bird communities in a novel, small‐scale, land‐sparing coffee‐production system (integrated open canopy or IOC coffee) in which farmers obtain higher yields under little or no shade while conserving an area of forest equal to the area under cultivation. Species richness and diversity of forest‐dependent birds were higher in the IOC coffee farms than in the shade coffee farms, and community composition was more similar between IOC coffee and primary forest than between shade coffee and primary forest. Our study represents the first empirical comparison of well‐defined land sparing and land sharing production systems. Because IOC coffee farms can be established by allowing forest to regenerate on degraded land, widespread adoption of this system could lead to substantial increases in forest cover and carbon sequestration without compromising agricultural yield or threatening the livelihoods of traditional small farmers. However, we studied small farms (<5 ha); thus, our results may not generalize to large‐scale land‐sharing systems. Furthermore, rather than concluding that land sparing is generally superior to land sharing, we suggest that the optimal approach depends on the crop, local climate, and existing land‐use patterns. Un Método para Reservar Tierras a Pequeña Escala para Conservar la Biodiversidad en Paisajes Agrícolas Tropicales     

Testing Decision Rules for Categorizing Species’ Extinction Risk to Help Develop Quantitative Listing Criteria for the U.S. Endangered Species Act

Lack of guidance for interpreting the definitions of endangered and threatened in the U.S. Endangered Species Act (ESA) has resulted in case‐by‐case decision making leaving the process vulnerable to being considered arbitrary or capricious. Adopting quantitative decision rules would remedy this but requires the agency to specify the relative urgency concerning extinction events over time, cutoff risk values corresponding to different levels of protection, and the importance given to different types of listing errors. We tested the performance of 3 sets of decision rules that use alternative functions for weighting the relative urgency of future extinction events: a threshold rule set, which uses a decision rule of x% probability of extinction over y years; a concave rule set, where the relative importance of future extinction events declines exponentially over time; and a shoulder rule set that uses a sigmoid shape function, where relative importance declines slowly at first and then more rapidly. We obtained decision cutoffs by interviewing several biologists and then emulated the listing process with simulations that covered a range of extinction risks typical of ESA listing decisions. We evaluated performance of the decision rules under different data quantities and qualities on the basis of the relative importance of misclassification errors. Although there was little difference between the performance of alternative decision rules for correct listings, the distribution of misclassifications differed depending on the function used. Misclassifications for the threshold and concave listing criteria resulted in more overprotection errors, particularly as uncertainty increased, whereas errors for the shoulder listing criteria were more symmetrical. We developed and tested the framework for quantitative decision rules for listing species under the U.S. ESA. If policy values can be agreed on, use of this framework would improve the implementation of the ESA by increasing transparency and consistency. Evaluando Reglas de Decisión para Categorizar el Riesgo de Extinción de Especies con el Fin de Desarrollar de Criterios Cuantitativos de Alistamiento en el Acta de Especies en Peligro de los EE. UU.     

The Capacity of Australia's Protected‐Area System to Represent Threatened Species

Abstract: The acquisition or designation of new protected areas is usually based on criteria for representation of different ecosystems or land‐cover classes, and it is unclear how well‐threatened species are conserved within protected‐area networks. Here, we assessed how Australia's terrestrial protected‐area system (89 million ha, 11.6% of the continent) overlaps with the geographic distributions of threatened species and compared this overlap against a model that randomly placed protected areas across the continent and a spatially efficient model that placed protected areas across the continent to maximize threatened species’ representation within the protected‐area estate. We defined the minimum area needed to conserve each species on the basis of the species’ range size. We found that although the current configuration of protected areas met targets for representation of a given percentage of species’ ranges better than a random selection of areas, 166 (12.6%) threatened species occurred entirely outside protected areas and target levels of protection were met for only 259 (19.6%) species. Critically endangered species were among those with the least protection; 12 (21.1%) species occurred entirely outside protected areas. Reptiles and plants were the most poorly represented taxonomic groups, and amphibians the best represented. Spatial prioritization analyses revealed that an efficient protected‐area system of the same size as the current protected‐area system (11.6% of the area of Australia) could meet representation targets for 1272 (93.3%) threatened species. Moreover, the results of these prioritization analyses showed that by protecting 17.8% of Australia, all threatened species could reach target levels of representation, assuming all current protected areas are retained. Although this amount of area theoretically could be protected, existing land uses and the finite resources available for conservation mean land acquisition may not be possible or even effective for the recovery of threatened species. The optimal use of resources must balance acquisition of new protected areas, where processes that threaten native species are mitigated by the change in ownership or on‐ground management jurisdiction, and management of threatened species inside and outside the existing protected‐area system.     

THE ECONOMICS OF CO-OPERATION IN SHARED WATER RESOURCES DEVELOPMENT

This article assesses the various methodologies that have been used to devise equitable approaches in the joint utilization of water resources shared by two or more countries. Noting that no single technique is applicable in all or even most situations, the article first presents a review of the approaches taken in three cases, the basins of the Uruguay, the Senegal and the Yaguaron rivers. Next, the issues raised in these cases are examined, and the three major steps in the sharing of benefits and costs in projects for the development of shared water resources are discussed. The article concludes with a number of observations concerning the present and probable future status of shared water resource negotiations. Cet article évalue les différentes méthodes que l'on emploie pour définir les manières équitables d'utiliser conjointement les ressources en eau communes à deux ou plusieurs pays. Tout en soulignant qu'il n'existe pas de technique qui puisse s'appliquer à toutes ou presque toutes les situations, l'article dans un premier temps passe en revue les méthodes utilisées dans trois cas: les bassins des fleuves Uruguay, Sénégal et Yaguaron. L'article examine ensuite les questions soulevées dans ces cas et discute des trois mesures importantes adoptées dans le partage des coûts et bénéfices dans le cas de projects conçus pour la mise en valeur des ressources en eau communes. L'article conclut par un certain nombre d'observations sur l'état actuel et l'avenir probable des négociations en matière de ressources en eau communes. Este artículo evalúa varias metodologias usadas para establecer formas de la utilización conjunta y equitativa de recursos hídricos compartidos por dos o más países. El artículo señala que no hay una técnica única aplicable a la mayoría de los casos y revisa los procedimientos seguidos en tres casos: las cuencas de los ríos Uruguay, Senegal y Yaguaron. Luego se examinan los asuntos saltantes en los tres casos y se discuten los tres pasos a seguirse en la participación de beneficios y costos de los proyectos de desarrollo de recursos hídricos compartidos. El artículo concluye con algunas observaciones concernientes a las negociaciones presentes y futuras sobre uso de recursos hídricos compartidos.     

Non-metallic Minerals and the Developing Countries: Patterns, Constraints, Initiatives

This paper reviews the role of non-metallic minerals in the economy and examines the relationship between demand patterns and the process of industrialization. As developing countries industrialize, large volumes of construction minerals (sand, gravel, crushed stone, etc.) will be required while with most other industrial minerals increasing quantities will be consumed only in the more advanced stages of economic development. In many developing countries the assurance of an adequate supply of these minerals from indigenous resources will necessitate initiatives aimed at removing constraints and barriers to mining sector development.     

Captive Breeding, Reintroduction, and the Conservation of Amphibians

Abstract: The global amphibian crisis has resulted in renewed interest in captive breeding as a conservation tool for amphibians. Although captive breeding and reintroduction are controversial management actions, amphibians possess a number of attributes that make them potentially good models for such programs. We reviewed the extent and effectiveness of captive breeding and reintroduction programs for amphibians through an analysis of data from the Global Amphibian Assessment and other sources. Most captive breeding and reintroduction programs for amphibians have focused on threatened species from industrialized countries with relatively low amphibian diversity. Out of 110 species in such programs, 52 were in programs with no plans for reintroduction that had conservation research or conservation education as their main purpose. A further 39 species were in programs that entailed captive breeding and reintroduction or combined captive breeding with relocations of wild animals. Nineteen species were in programs with relocations of wild animals only. Eighteen out of 58 reintroduced species have subsequently bred successfully in the wild, and 13 of these species have established self‐sustaining populations. As with threatened amphibians generally, amphibians in captive breeding or reintroduction programs face multiple threats, with habitat loss being the most important. Nevertheless, only 18 out of 58 reintroduced species faced threats that are all potentially reversible. When selecting species for captive programs, dilemmas may emerge between choosing species that have a good chance of surviving after reintroduction because their threats are reversible and those that are doomed to extinction in the wild as a result of irreversible threats. Captive breeding and reintroduction programs for amphibians require long‐term commitments to ensure success, and different management strategies may be needed for species earmarked for reintroduction and species used for conservation research and education.     

Financial Considerations of Reserve Design in Countries with High Primate Diversity

Abstract. Many developing countries with high primate diversity are still forming wildlife reserves. However, financial resources for conservation in these countries are often limited. In this paper we show that the biology of reserve design in terms of island biogeography and minimum viable populations can be compatible with measures that minimize maintenance costs, namely perimeter surveillance. Large protected areas have substantially less perimeter to patrol than many small reserves of the same total area. Likewise, circular reserves have less perimeter than square or rectangular ones. Generally, countries with high primate diversity are using desirable strategies in design of nature reserves in terms of both finances and conservation; they have relatively large reserves and large amounts of area protected in relation to country size. However, some key primate-containing countries, such as Madagascar, Indonesia, and southeastern Brazil, require many small reserves to insure preservation of endemic taxa.     

Environmental Policy Implementation in Rural China: A Case Study of Yuhang, Zhejiang

The rapid growth of rural enterprises has transformed the Chinese countryside. Although rural industrialisation has resulted in increased financial well-being, it has also contributed to decreased environmental quality. While China has strong environmental protection laws, this paper will demonstrate that they are not being effectively implemented in a rural region in Zhejiang Province. This is due to a number of social, political, and economic barriers that prevent agencies from effectively enforcing environmental policies and regulatory mechanisms. This paper investigates the implementation of China's environmental policies through a case study in Yuhang County, Zhejiang Province. It demonstrates that the implementation of environmental impact assessment, discharge fees, and limited time treatment is limited by inadequate technology, low finances, limited human resources, poor public environmental awareness, faulty data, inferior agency reports, organizational conflict, relations based on guanxi, and low discharge fee prices.