Learning from 20 Years of Payments for Ecosystem Services in Costa Rica

Costa Rica's Payments for Ecosystems Services (PES) programme has become something of an icon in the world of conservation. Its innovative blend of economic and regulatory instruments - and its hitches and successes - provide a valuable source of inspiration for other countries that are looking for effective ways to conserve and regenerate ecosystems. Since 1997, nearly one million hectares of forest in Costa Rica have been part of the PES programme at one time or another, and forest cover has now returned to over 50 per cent of the country's land area, from a low of just 20 per cent in the 1980s. What lessons can be learnt from the 20 years since it was founded? Also published in Spanish, this paper is for local practitioners, international researchers and donors who are interested in the Costa Rican experience

Effects of a large wildfire on vegetation structure in a variable fire mosaic

Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying "invisible mosaic" of past fire frequencies, severities, and fire return intervals. However, establishing and maintaining variable mosaics in contemporary landscapes is subject to many challenges, one of which is deciding how the fire mosaic should be managed following the occurrence of large, unplanned wildfires. A key consideration for this decision is the extent to which the effects of previous fire history on vegetation and habitats persist after major wildfires, but this topic has rarely been investigated empirically. In this study, we tested to what extent a large wildfire interacted with previous fire history to affect the structure of forest, woodland, and heath vegetation in Booderee National Park in southeastern Australia. In 2003, a summer wildfire burned 49.5% of the park, increasing the extent of recently burned vegetation (<10 yr post-fire) to more than 72% of the park area. We tracked the recovery of vegetation structure for nine years following the wildfire and found that the strength and persistence of fire effects differed substantially between vegetation types. Vegetation structure was modified by wildfire in forest, woodland, and heath vegetation, but among-site variability in vegetation structure was reduced only by severe fire in woodland vegetation. There also were persistent legacy effects of the previous fire regime on some attributes of vegetation structure including forest ground and understorey cover, and woodland midstorey and overstorey cover. For example, woodland midstorey cover was greater on sites with higher fire frequency, irrespective of the severity of the 2003 wildfire. Our results show that even after a large, severe wildfire, underlying fire histories can contribute substantially to variation in vegetation structure. This highlights the importance of ensuring that efforts to reinstate variation in vegetation fire age after large wildfires do not inadvertently reduce variation in vegetation structure generated by the underlying invisible mosaic. © 2017 by the Ecological Society of America

Effects of a large wildfire on vegetation structure in a variable fire mosaic

Management guidelines for many fire-prone ecosystems highlight the importance of maintaining a variable mosaic of fire histories for biodiversity conservation. Managers are encouraged to aim for fire mosaics that are temporally and spatially dynamic, include all successional states of vegetation, and also include variation in the underlying "invisible mosaic" of past fire frequencies, severities, and fire return intervals. However, establishing and maintaining variable mosaics in contemporary landscapes is subject to many challenges, one of which is deciding how the fire mosaic should be managed following the occurrence of large, unplanned wildfires. A key consideration for this decision is the extent to which the effects of previous fire history on vegetation and habitats persist after major wildfires, but this topic has rarely been investigated empirically. In this study, we tested to what extent a large wildfire interacted with previous fire history to affect the structure of forest, woodland, and heath vegetation in Booderee National Park in southeastern Australia. In 2003, a summer wildfire burned 49.5% of the park, increasing the extent of recently burned vegetation (<10 yr post-fire) to more than 72% of the park area. We tracked the recovery of vegetation structure for nine years following the wildfire and found that the strength and persistence of fire effects differed substantially between vegetation types. Vegetation structure was modified by wildfire in forest, woodland, and heath vegetation, but among-site variability in vegetation structure was reduced only by severe fire in woodland vegetation. There also were persistent legacy effects of the previous fire regime on some attributes of vegetation structure including forest ground and understorey cover, and woodland midstorey and overstorey cover. For example, woodland midstorey cover was greater on sites with higher fire frequency, irrespective of the severity of the 2003 wildfire. Our results show that even after a large, severe wildfire, underlying fire histories can contribute substantially to variation in vegetation structure. This highlights the importance of ensuring that efforts to reinstate variation in vegetation fire age after large wildfires do not inadvertently reduce variation in vegetation structure generated by the underlying invisible mosaic.This research was financially supported by the Aus-tralian Research Council, the Long Term Ecological ResearchNetwork and the National Environmental Science Program. P.S. Barton was supported by an ARC DECRA Fellowship. D. B.Lindenmayer was supported by an ARC Laureate Fellowship

Analytic approach to the evolutionary effects of genetic exchange

We present an approximate analytic study of our previously introduced model of evolution including the effects of genetic exchange. This model is motivated by the process of bacterial transformation. We solve for the velocity, the rate of increase of fitness, as a function of the fixed population size, $N$. We find the velocity increases with $\ln N$, eventually saturated at an $N$ which depends on the strength of the recombination process. The analytical treatment is seen to agree well with direct numerical simulations of our model equations

Constraining forest certificate's market to improve cost-effectiveness of biodiversity conservation in Sao Paulo state, Brazil

The recently launched Brazilian "forest certificates" market is expected to reduce environmental compliance costs for landowners through an offset mechanism, after a long history of conservation laws based in command-and-control and strict rules. In this paper we assessed potential costs and evaluated the cost-effectiveness of the instrument when introducing to this market constraints that aim to address conservation objectives more specifically. Using the conservation planning software Marxan with Zones we simulated different scopes for the "forest certificates" market, and compared their cost-effectiveness with that of existing command-and-control (C&C), i.e. compliance to the Legal Reserve on own property, in the state of Sao Paulo. The simulations showed a clear potential of the constrained "forest certificates" market to improve conservation effectiveness and increase cost-effectiveness on allocation of Legal Reserves. Although the inclusion of an additional constraint of targeting the BIOTA Conservation Priority Areas doubled the cost (+95%) compared with a "free trade" scenario constrained only by biome, this option was still 50% less costly than the Baseline scenario of compliance with Legal Reserve at the property.The recently launched Brazilian "forest certificates" market is expected to reduce environmental compliance costs for landowners through an offset mechanism, after a long history of conservation laws based in command-and-control and strict rules. In this1110118sem informaçãosem informaçã

Market mechanisms and efficiency in urban dairy products markets in Ghana and Tanzania

This research report presents an analysis of the problems encountered in the milk markets in Ghana and Tanzania. It is based on a study carried out during 1999 and 2000 to identify and quantify the public health risks and economic performance in dairy product markets in these two countries. The study was led by the International Livestock Research Institute (ILRI). Scientists from the University and Technology (Kumasi, Ghana), the Animal Research Institute (Accra, Ghana), Sokoine University of Agriculture (Morogoro, Tanzania) and the Natural Resources Institute (UK) collaborated in implementing the study. Funding was obtained from the UK Department for International Development-Livestock Production Programme (DFID-LPP). This report is divided into an executive summary and a main section. The summary highlights the methodology used and the main outcomes of the research. Chapter 2 addresses market mechanisms and efficiency and contains the results of the economic and structural analysis. The key findings and achievements of the study. The main report gives a detailed account of the markets. Chapter 3 deals with the milk-borne public health risks, and focuses on the results of laboratory testing of milk and dairy product samples; this chapter also uses some of the economic results in the analysis. Processing of traditional dairy products is the topic addressed in Chapter 4, with a focus on the traditional fresh cheese, wagashi, in Ghana. Chapter 5 presents the impacts of the training activities conducted during the study while Chapter 6 indicates ways in which the project contributed to meeting the research goal. The project team hopes that the technologies and strategies developed in this study will inform development in other similar production and market systems

Lattice Green's function approach to the solution of the spectrum of an array of quantum dots and its linear conductance

In this paper we derive general relations for the band-structure of an array of quantum dots and compute its transport properties when connected to two perfect leads. The exact lattice Green's functions for the perfect array and with an attached adatom are derived. The expressions for the linear conductance for the perfect array as well as for the array with a defect are presented. The calculations are illustrated for a dot made of three atoms. The results derived here are also the starting point to include the effect of electron-electron and electron-phonon interactions on the transport properties of quantum dot arrays. Different derivations of the exact lattice Green's functions are discussed

Heterotic String Field Theory

We construct the Neveu-Schwarz sector of heterotic string field theory using the large Hilbert space of the superghosts and the multi-string products of bosonic closed string field theory. No picture-changing operators are required as in Wess-Zumino-Witten-like open superstring field theory. The action exhibits a novel kind of nonpolynomiality: in addition to terms necessary to cover missing regions of moduli spaces, new terms arise from the boundary of the missing regions and its subspaces. We determine the action up to quintic order and a subset of terms to all orders.Comment: 15 pages, no figures, LaTeX2e; v2: minor cosmetic change