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Beeko C.,Forestry Commission of Ghana | Arts B.,Wageningen University
International Forestry Review | Year: 2010

The European Union's FLEGT initiative aims at eliminating illegal timber from its market. An important instrument to achieve this is the Voluntary Partnership Agreement (VPA) to install, amongst others, wood tracking systems in timber exporting countries. Ghana was the first to conclude VPA negotiations with the EU. Using the Policy Arrangement Approach (PAA), this paper presents a critical policy analysis of the consensus building and negotiation process and outcome (so far). It shows that the national forest discourse of Ghana has been reshaped by the VPA process, that the traditional forest sector has been opened up, that new forest rules have been designed and that power relations have changed in favour of so-called fringe actors. Theses developments seem in line with the wider shift from government to governance in politics. Yet the question is whether these observable changes will be sustained in the implementation phase of the VPA. Source

Burton A.C.,University of California at Berkeley | Sam M.K.,Forestry Commission of Ghana | Kpelle D.G.,Forestry Commission of Ghana | Balangtaa C.,Forestry Commission of Ghana | And 2 more authors.
Biological Conservation | Year: 2011

Carnivore extinctions frequently have cascading impacts through an ecosystem, so effective management of ecological communities requires an understanding of carnivore vulnerability. This has been hindered by the elusive nature of many carnivores, as well as a disproportionate focus on large-bodied species and particular geographic regions. We use multiple survey methods and a hierarchical multi-species occupancy model accounting for imperfect detection to assess extinction risk across the entire carnivore community in Ghana's Mole National Park, a poorly studied West African savanna ecosystem. Only 9 of 16 historically occurring carnivore species were detected in a camera-trap survey covering 253 stations deployed for 5469 trap days between October 2006 and January 2009, and our occupancy model indicated low overall likelihoods of false absence despite low per-survey probabilities of detection. Concurrent sign, call-in, and village surveys, as well as long-term law enforcement patrol records, provided more equivocal evidence of carnivore occurrence but supported the conclusion that many carnivores have declined and are likely functionally or fully extirpated from the park, including the top predator, lion (Panthera leo). Contrary to expectation, variation in carnivore persistence was not explained by ecological or life-history traits such as body size, home range size or fecundity, thus raising questions about the predictability of carnivore community disassembly. Our results imply an urgent need for new initiatives to better protect and restore West Africa's embattled carnivore populations, and they highlight a broader need for more empirical study of the response of entire carnivore communities to anthropogenic impact. © 2011 Elsevier Ltd. Source

Feldpausch T.R.,University of Leeds | Banin L.,University of Leeds | Phillips O.L.,University of Leeds | Baker T.R.,University of Leeds | And 59 more authors.
Biogeosciences | Year: 2011

Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were:

1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap).

2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A).

3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass.

Annual precipitation coefficient of variation (PV), dry season length (SD), and mean annual air temperature (TA) emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in H:D relationships not accounted for by this model could be attributed to variations in soil physical conditions. Other things being equal, trees tend to be more slender in the absence of soil physical constraints, especially at smaller D. Pantropical and continental-level models provided less robust estimates of H, especially when the roles of climate and stand structure in modulating H:D allometry were not simultaneously taken into account. © 2011 Author(s). Source

Banin L.,University of Leeds | Banin L.,University of Ulster | Feldpausch T.R.,University of Leeds | Phillips O.L.,University of Leeds | And 31 more authors.
Global Ecology and Biogeography | Year: 2012

Aim: To test the extent to which the vertical structure of tropical forests is determined by environment, forest structure or biogeographical history. Location: Pan-tropical. Methods: Using height and diameter data from 20,497 trees in 112 non-contiguous plots, asymptotic maximum height (H AM) and height-diameter relationships were computed with nonlinear mixed effects (NLME) models to: (1) test for environmental and structural causes of differences among plots, and (2) test if there were continental differences once environment and structure were accounted for; persistence of differences may imply the importance of biogeography for vertical forest structure. NLME analyses for floristic subsets of data (only/excluding Fabaceae and only/excluding Dipterocarpaceae individuals) were used to examine whether family-level patterns revealed biogeographical explanations of cross-continental differences. Results: H AM and allometry were significantly different amongst continents. H AM was greatest in Asian forests (58.3 ± 7.5m, 95% CI), followed by forests in Africa (45.1 ± 2.6m), America (35.8 ± 6.0m) and Australia (35.0 ± 7.4m), and height-diameter relationships varied similarly; for a given diameter, stems were tallest in Asia, followed by Africa, America and Australia. Precipitation seasonality, basal area, stem density, solar radiation and wood density each explained some variation in allometry and H AM yet continental differences persisted even after these were accounted for. Analyses using floristic subsets showed that significant continental differences in H AM and allometry persisted in all cases. Main conclusions: Tree allometry and maximum height are altered by environmental conditions, forest structure and wood density. Yet, even after accounting for these, tropical forest architecture varies significantly from continent to continent. The greater stature of tropical forests in Asia is not directly determined by the dominance of the family Dipterocarpaceae, as on average non-dipterocarps are equally tall. We hypothesise that dominant large-statured families create conditions in which only tall species can compete, thus perpetuating a forest dominated by tall individuals from diverse families. © 2012 Blackwell Publishing Ltd. Source

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