Time filter

Source Type

van Etten J.,Tropical Agriculture Research and Higher Education Center
Journal of Statistical Software | Year: 2017

The R package gdistance provides classes and functions to calculate various distance measures and routes in heterogeneous geographic spaces represented as grids. Least-cost distances as well as more complex distances based on (constrained) random walks can be calculated. Also the corresponding routes or probabilities of passing each cell can be determined. The package implements classes to store the data about the probability or cost of transitioning from one cell to another on a grid in a memory-efficient sparse format. These classes make it possible to manipulate the values of cell-to-cell movement directly, which offers flexibility and the possibility to use asymmetric values. The novel distances implemented in the package are used in geographical genetics (applying circuit theory), but also have applications in other fields of geospatial analysis. © 2017, American Statistical Association. All rights reserved.

Agency: European Commission | Branch: FP7 | Program: BSG-CSO | Phase: ENV.2011.4.2.3-1 | Award Amount: 2.41M | Year: 2012

International debates on climate change highlight the need to foster adaptation planning in Latin America where significant impacts are expected. However, little progress has been made due to the difficulty of managing environmental dynamics characterized by deep uncertainties and potential tensions at various scales. EcoAdapt is built on the outcomes of two rounds on regional consultation with Latin American civil society organizations (CSO) and scientists. It aims at increasing the capacity of local communities, CSOs, policy-makers and scientists to engage in inter-disciplinary action-research to increase their collective capacity to adapt to climate change. The EcoAdapt CSOs stated that watershed services were the most critical with respect to possible tensions and social conflicts that may arise due to climate change. The EcoAdapt team considers that 1) adaptation to climate change is not something that can be done in isolation, and 2) ecosystem-based management is a robust basis for successful adaptation to climate change in Latin America. Therefore in the project concept, watershed ecosystem services (WES) are mainstreamed in an overall adaptation strategy by a variety of players involved in science-policy-civil society networks across-scales. EcoAdapt will be implemented in model forest landscapes in Argentina, Bolivia, and Chile. Knowledge sharing forms the backbone of the project and provides scientists and policy-makers with an in-depth insight into local knowledge and issues, which will frame the research to be done. Based on this common understanding EcoAdapt will assist communities in developing their WES-based adaptation strategy. This will be achieved by combining exploratory scenario analysis, participatory backcasting, and social validation via hybrid forums. EcoAdapt will implement part of the strategy in pilot communities and build on existing networks for dissemination to other communities of Latin America and Europe.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: ENV.2009. | Award Amount: 4.33M | Year: 2010

POLICYMIX aims to contribute to achieving the EUs goals of reversing trends in biodiversity loss beyond 2010 through the use of cost-effective and incentive-compatible economic instruments. POLICYMIX focuses on the role of economic instruments in a mix of operational conservation policy instruments. To this end, POLICYMIX will develop an integrated evaluation framework that considers multiple policy assessment criteria biodiversity and ecosystem service provision indicators; valuation of their economic benefit and policy implementation costs; social and distributional impacts; and legal and institutional constraints at different levels of government. This multi-level approach is of paramount importance for effective biodiversity conservation policy given the overlap between ecological systems and systems of governance in practice. In particular, we evaluate the cost-effectiveness and benefits of a range of economic instruments vis--vis direct regulation through command-and-control in a variety of European and Latin American case studies. The suite of selected POLICYMIX case studies aims to provide complementary examples of innovative economic instruments such as Payments for Ecosystem Services (PES) and ecological fiscal transfers, and assess the possibilities for transfer of policy success stories, providing concrete learning possibilities for policy-makers. POLICYMIX actively uses advisory boards including land-users, local managers and national policy-makers, who collaborate with our researchers in the feasibility assessments of economic instruments. Based on this science-policy dialogue, POLICYMIX will develop a stepwise framework for carrying out policy assessment using available data, multi-criteria spatial targeting tools and tiered policy selection matrices. The POLICYMIX approach to policy design at multiple government levels is highly complementary with on-going EU ecological research on multi-scale conservation prioritization.

Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: KBBE-2009-3-4-01 | Award Amount: 1.34M | Year: 2010

The objective of the Global-Bio-Pact project is the development and harmonisation of global sustainability certification systems for biomass production, conversion systems and trade in order to prevent negative socio-economic impacts. A functioning and sustainable certification scheme requires reliable data and profound research in order to evaluate impacts of biomass production. Currently, the sustainability debate is faced by the lack of data on socio-economic impacts. Furthermore, mainly impacts of biofuels are investigated and impacts of bioproducts are neglected. Thus, a harmonised certification scheme for biofuels and bioproducts is required. In order to harmonise sustainability certification globally, the Global-Bio-Pact proposal includes partners from Europe, Latin America, Africa, Asia and USA. Emphasis of the Global-Bio-Pact proposal will be placed on a detailed assessment of the socio-economic impacts of raw material production and a variety of biomass conversion chains. The impact of biomass production on global and local food security and the links between environmental and socio-economic impacts will be analysed. The Global-Bio-Pact project will investigate the interrelationship of global sustainability certification systems with international trade of biomass and bioproducts. Furthermore, Global-Bio-Pact will assess public perception of biomass production for industrial uses. This will be completed by the development and test audit of a set of socio-economic sustainability criteria and indicators for inclusion into a future effective certification scheme. Thereby, opportunities and limitations of social issues in biomass/bioproducts certification schemes will be investigated. Finally, the project will elaborate recommendations on how to best integrate socio-economic sustainability criteria in European legislation and policies on biomass and bioproducts. Results of the Global-Bio-Pact project will contribute to the EU energy policy and to the MDG.

Bouroncle C.,Tropical Agriculture Research and Higher Education Center | Finegan B.,Tropical Agriculture Research and Higher Education Center
Biotropica | Year: 2011

Edge effects along tropical forest-pasture margins are thought to cause a shift toward early successional characteristics of the understory forest vegetation. We tested this idea by sampling vegetation at five forest sites in northeast Costa Rica each of which had edges that were established over 20yr earlier. Four of these sites had been selectively logged. We sampled woody plants >0.2 and ≤1.3m height in 54m 2 within 0.2ha plots at edges (N=14), and at 150m (N=11) and 300m from edges (N=9). Composition and diversity did not vary with edge distance. Abundance of tree regeneration, mainly of canopy and emergent species, increased at edges. Abundance of lianas and slow-growing tree species did not differ significantly across the sampling locations. Weighted mean wood density varied little, with a reduction at edges for canopy species. Palms were less abundant at edges, but not less species rich. At edges, these plant assemblages maintain many of the characteristics of forest interior vegetation, though the changes observed may indicate ongoing functional change. Degradation of forest-pasture edges is not a universal feature of tropical forest fragmentation, and forests with high rates of natural turnover might have a high capacity to maintain themselves within forest edges alongside pasture. © 2011 The Author(s). Journal compilation © 2011 by The Association for Tropical Biology and Conservation.

Robalino J.,Tropical Agriculture Research and Higher Education Center | Pfaff A.,Duke University
Land Economics | Year: 2013

We offer a nationwide analysis of the initial years of Costa Rica's PSA program, which pioneered environmental-services payments and inspired similar initiatives. Our estimates of this program's impact on deforestation, between 1997 and 2000, range from zero to one-fifth of 1% per year (i.e., deforestation is avoided on, at most, 2 out of every 1,000 enrolled hectares). The main explanation for such a low impact is an already low national deforestation rate. We also consider the effect of enrollment. Predicted deforestation on enrolled versus nonenrolled hectares, and matching analyses suggest an enrollment bias toward lower clearing threat. Enrolling land facing higher threat could raise payments' impact on deforestation. © 2013 by the Board of Regents of the University of Wisconsin System.

Somarriba E.,Tropical Agriculture Research and Higher Education Center
Agroforestry Systems | Year: 2012

Acacia pennatula trees are the most conspicuous woody species in the pasturelands of the Nature Reserve Mesas de Moropotente, Estelí, Nicaragua. Cattle ranchers keep A. pennatula because it produces fence posts, forage (pods) and firewood. A population projection matrix model was developed to: (1) estimate the sustainable harvest (H) of fence posts at different tree population densities, (2) explore the range of recruitment (R), and survival and growth of both saplings and small poles compatible with current population density, and (3) determine how much carbon is stored in the soil-pasture-tree system. Acacia pennatula trees take 40 years to reach H size (D 30 ≥ 30 cm). Estimated sustainable H from current tree population density is 1.8l7 trees ha -1 year -1, yielding 2.8 large and 11.2 regular size fence posts ha -1 year -1. This annual output easily satisfies the needs of a typical 100 ha cattle ranch in the study area. Current population density is congruent with very low R (>100 saplings ha -1 year -1), very low survival rates (>0.30%) and/or retarded D 30 growth of saplings and small poles. Total carbon in tree biomass was only 37 Mg ha -1. Cattle ranchers have learned to harness the invasive nature of the species to obtain valuable tree products for farm use or sale. © 2011 Springer Science+Business Media B.V.

Pfaff A.,Duke University | Robalino J.,Tropical Agriculture Research and Higher Education Center
Oxford Review of Economic Policy | Year: 2012

Policies must balance forest conservation's local costs with its benefits-local to global-in terms of biodiversity, the mitigation of climate change, and other eco-services such as water quality. The trade-offs with development vary across forest locations. We argue that considering location in three ways helps to predict policy impact and improve policy choice: (i) policy impacts vary by location because baseline deforestation varies with characteristics (market distances, slopes, soils, etc.) of locations in a landscape; (ii) different mixes of political-economic pressures drive the location of different policies; and (iii) policies can trigger 'second-order' or 'spillover' effects likely to differ by location. We provide empirical evidence that suggests the importance of all three considerations, by reviewing high-quality evaluations of the impact of conservation and development on forest. Impacts of well-enforced conservation rise with private clearing pressure, supporting (i). Protection types (e.g. federal/state) differ in locations and thus in impacts, supporting (ii). Differences in development process explain different signs for spillovers, supporting (iii). © The Authors 2012. Published by Oxford University Press.

Somarriba E.,Tropical Agriculture Research and Higher Education Center | Beer J.,Tropical Agriculture Research and Higher Education Center
Agroforestry Systems | Year: 2011

Timber production and cocoa yields were studied (initial 10-11 years) in two experimental plantations: a Cocoa-Legume system (CL, Erythrinapoeppigiana, Gliricidiasepium or Ingaedulis), and a Cocoa-Timber system (CT, Cordia alliodora, Tabebuiarosea or Terminaliaivorensis, plus I. edulis for inter-site comparisons). These trials had two major goals: (1) to evaluate the use of mono-specific timber shade canopies as an alternative to traditional, mono-specific, legume service shade tree canopies; and (2) to determine the production potential of ten cocoa clonal bi-crosses under these shade tree species. Within each site, shade tree species did not influence dry cocoa bean yield nor pod counts (total number of pods produced, number of healthy pods harvested, pod losses due to monilia [Moniliophthora roreri], black pod [Phytophthora palmivora] or other causes-birds and squirrels in this study-, and total pod losses). Significant differences were found between cocoa bi-crosses for both cocoa bean yield and pod counts. Sites differed only in terms of total pod losses (43% in CL; 54% in CT) and their causal factors (mainly monilia in CL; both monilia, squirrels and birds in CT). At CT, all timber tree species grew rapidly, reaching 30-34 cm dbh, 17-25 m total tree height and 97-172 m3 ha-1 total stem volume (age 10 years). Timber species should be promoted for the shade component of cacao plantations given their potential production and the fact that their presence did not negatively affect cocoa yields. © 2010 Springer Science+Business Media B.V.

Agency: European Commission | Branch: FP7 | Program: CP-SICA | Phase: KBBE-2008-1-2-05 | Award Amount: 3.81M | Year: 2009

The increasing demand of livestock products, larger climate uncertainty and resource degradation, and the rampant poverty of farmers in the semi-arid tropics calls for modernized agroforestry systems (AFS) capable of providing multiple functions. The project will develop regionally specific, trait-based and field tested AFS capable of providing critical agro-ecosystem functions in semi-arid Africa and Central America. The primary objective is to provide farmers with a portfolio of regionally suitable tree and shrub species organized by their traits or attributes, in relation to the provisioning of multiple services, as perceived by the farmers and in terms of fundamental ecological functions. The project will make substantial contributions to AF and ecological science through its integration of theories and concepts from both fields, and will thereby provide a scientifically based model for the design of modernized AFS. The project will identify, and characterize the main factors influencing the adoption/non adoption of AF in selected target areas. It will improve the performance of AFS in dry and marginal areas with particular focus on how species can be assembled according to their traits to improve the multi-functionality of AFS and will identify the potential of new multipurpose tree species suitable for AF in dry and marginal areas by grouping these species according to their functional traits and their capacity to provide critical AFS services. The project will specifically enhance the synergies between the species traits and model how trait combinations contribute to the multi-functionality of AFS including soil, trees, crop/pasture and livestock. We will evaluate the short and medium environmental impacts of AF and its socio-economic implications through sophisticated interdisciplinary models and will produce policy recommendations aimed at promoting AFS and related husbandry practices best adapted to specific local needs, yet universal in scope.

Loading Tropical Agriculture Research and Higher Education Center collaborators
Loading Tropical Agriculture Research and Higher Education Center collaborators