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11.
Of the twelve species ofChamaedorea palm recorded for Belize, three are of international economic value because their cut leaves (xaté) are traded in the floricultural industry. Traditionally, Belize has not harvested xaté, the industry being based in Mexico and Guatemala. However, a decline in wild xaté stocks in these countries means Guatemalan leaf harvesters now illegally harvest xaté in Belize. To assess the local abundance of the BelizeanChamaedorea resource, its economic value, and the extent to which it has been illegally harvested, 209 plots measuring 20 meters (m) by 20 m were established in the Greater Maya Mountains (GMM) in western Belize, which includes the Chiquibul Forest Reserve (CFR). We estimate that 37.8 million leaves with a value of U.S. 0.3 million to xateros have been extracted from the CFR. The standing export value is calculated as U.S.0.3 million to xateros have been extracted from the CFR. The standing export value is calculated as U.S. 1.8 million for the CFR and U.S. $5 million for the GMM.  相似文献   
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We explore the issues relevant to those types of ecosystems containing new combinations of species that arise through human action, environmental change, and the impacts of the deliberate and inadvertent introduction of species from other regions. Novel ecosystems (also termed 'emerging ecosystems') result when species occur in combinations and relative abundances that have not occurred previously within a given biome. Key characteristics are novelty, in the form of new species combinations and the potential for changes in ecosystem functioning, and human agency, in that these ecosystems are the result of deliberate or inadvertent human action. As more of the Earth becomes transformed by human actions, novel ecosystems increase in importance, but are relatively little studied. Either the degradation or invasion of native or 'wild' ecosystems or the abandonment of intensively managed systems can result in the formation of these novel systems. Important considerations are whether these new systems are persistent and what values they may have. It is likely that it may be very difficult or costly to return such systems to their previous state, and hence consideration needs to be given to developing appropriate management goals and approaches.  相似文献   
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Threatened species, red listing and an increase in protected areas have been, and currently remain, key foci for nature conservation. Yet as it becomes more evident we are living in the Anthropocene biosphere the relevance and value of those activities declines. The “new conservation”, controversially argued for by some since 2011, has different foci and strategies, yet they are perhaps too anthropic. A nature conservation for the Anthropocene biosphere must be built on an understanding of biocultural diversity, take account of the conservation potential of novel ecosystems, de-emphasise the role of protected areas while examining the role of novel ex situ approaches to biodiversity conservation and review effort and expenditure on Red Listing of threatened species as conservation actions. The 2016 IUCN World Conservation Congress offers potential to provide global leadership towards a new nature conservation for the Anthropocene biosphere.  相似文献   
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WNT/beta-catenin signaling has an established role in nephron formation during kidney development. Yet, the role of beta-catenin during ureteric morphogenesis in vivo is undefined. We generated a murine genetic model of beta-catenin deficiency targeted to the ureteric bud cell lineage. Newborn mutant mice demonstrated bilateral renal aplasia or renal dysplasia. Analysis of the embryologic events leading to this phenotype revealed that abnormal ureteric branching at E12.5 precedes histologic abnormalities at E13.5. Microarray analysis of E12.5 kidney tissue identified decreased Emx2 and Lim1 expression among a small subset of renal patterning genes disrupted at the stage of abnormal branching. These alterations are followed by decreased expression of genes downstream of Emx2, including Lim1, Pax2, and the ureteric tip markers, c-ret and Wnt 11. Together, these data demonstrate that beta-catenin performs essential functions during renal branching morphogenesis via control of a hierarchy of genes that control ureteric branching.  相似文献   
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The Lesser White‐fronted Goose (Anser erythropus), smallest of the “gray” geese, is listed as Vulnerable on the IUCN Red List and protected in all range states. There are three populations, with the least studied being the Eastern population, shared between Russia and China. The extreme remoteness of breeding enclaves makes them largely inaccessible to researchers. As a substitute for visitation, remotely tracking birds from wintering grounds allows exploration of their summer range. Over a period of three years, and using highly accurate GPS tracking devices, eleven individuals of A. erythropus were tracked from the key wintering site of China, to summering, and staging sites in northeastern Russia. Data obtained from that tracking, bolstered by ground survey and literature records, were used to model the summer distribution of A. erythropus. Although earlier literature describes a patchy summer range, the model suggests a contiguous summer habitat range is possible, although observations to date cannot confirm A. erythropus is present throughout the modeled range. The most suitable habitats are located along the coasts of the Laptev Sea, primarily the Lena Delta, in the Yana‐Kolyma Lowland, and smaller lowlands of Chukotka with narrow riparian extensions upstream along major rivers such as the Lena, Indigirka, and Kolyma. The probability of A. erythropus presence is related to areas with altitude less than 500 m with abundant wetlands, especially riparian habitat, and a climate with precipitation of the warmest quarter around 55 mm and mean temperature around 14°C during June‐August. Human disturbance also affects site suitability, with a gradual decrease in species presence starting around 160 km from human settlements. Remote tracking of animal species can bridge the knowledge gap required for robust estimation of species distribution patterns in remote areas. Better knowledge of species'' distribution is important in understanding the large‐scale ecological consequences of rapid global change and establishing conservation management strategies.  相似文献   
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Wetlands have declined in area and quality at an accelerating pace in the last 50 years. Yet, the last 50 years is when international attention has been focussed on wetlands through the Ramsar Convention. An analysis of how the convention has evolved over the past 50 years suggests it has been drifting away from its original mandate in a maladaptive manner, and this drift is a problem for achieving its original objectives. A review of the strategic plans of the convention revealed two key conditions for institutional drifting and the associated lack of success. The first condition lies in its unique situation as a non-UN convention, which reduces the convention’s visibility and interactivity with other biodiversity-related conventions, agencies, or programmes. The second condition is an increasing number of conventions dealing with biodiversity issues, all forcing the Ramsar Convention to seek different roles in an increasingly competitive institutional landscape. A more effective future for the convention arguably lies in reasserting its original mandate, but with cognisance of the changed environmental pressures of the twenty-first century. While this would narrow its increasingly broad focus, such a reorientation will allow wetlands and waterfowl to start a track to recovery, backed by active and focused Contracting Parties in a renewed international convention on wetland conservation, management, and sustainable use.

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The Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) held its 5th plenary session in Bonn during March 2017. After last year’s pollinator assessment, the biodiversity assessments currently being undertaken are shortly to be available for peer review. The scientific community can play an important role in both conducting assessments and in the peer-review process. Independent scientists can contribute to ensure that these assessments are comprehensive with respect to the current state and future trends of biodiversity and the ecosystem services. We outline possibilities for deeper involvement of the scientific community in the IPBES process and draw attention to upcoming reviews in 2017.  相似文献   
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