|
|
|
|
December 2009 | Vol. 2 | Issue 4 | pages 374-468
Teegalapalli Karthik, Gopi G V and Prasanna K Samal Shifting cultivation is an agricultural system which involves a cultivation phase interspersed with a fallow phase that allows for forest regeneration. Recently, the practice has been identified as a global deforestation driver. In the following review, we have generalized findings of studies that have examined recovery of plants, birds and mammals following shifting cultivation. Research on vegetation recovery indicates that pioneer soft wood tree species recover relatively faster, however, mature forest tree species, particularly endemic species, recover several decades following suspension of cultivation. Most avifaunal studies report presence of several mature forest species in 25 year old successional sites and that at least 50% bird species were common between the two habitats. Results of mammal studies were likely to have been confounded by effects of hunting, a practice closely associated with shifting cultivation, and therefore future research on recovery of mammals must incorporate this factor. Based on findings of available studies, we conclude that community recovery can be expected to be accelerated when relatively large forest tracts adjoin a shifting cultivation landscape, in comparison with recovery in sites with shorter fallow cycles in the absence of contiguous forests, which act as sources for recolonization of fauna and vegetation. Biological correlates of extinction and persistence of primates in small forest fragments: a global analysis | pages 388-403 Matthew A. Gibbons and Alexander H. Harcourt In this study, the authors attempt to understand the biological basis of extinction risk in primates in small forest fragments. This was accomplished by asking which traits distinguished primate species that are at risk of extinction from those species that are more persistent in forest fragments. The traits investigated all related to various aspects of primate biology, including: the amount of habitat needed, reproductive rate, and types of specialization. They found no significant relationship between extinction risk and any of the biological parameters. The authors’ most likely explanation for this unexpected finding is that the forest fragments in which primates are currently studied are usually so small that all primate species in them are doomed in the long-term and therefore, no biological traits can distinguish at-risk species. The finding implies that conservation research and efforts should be directed at assessing the efficacy of forest fragments and small biological preserves in conserving primate species in the long-term. Rapid assessment of dispersal failure and seedling recruitment of large-seeded non- timber forest products trees in a tropical rainforest | pages 404-424 Clément Lermyte and Pierre-Michel Forget Tropical rainforests are increasingly threatened by human activities – especially by hunting, logging and large-scale deforestation. As an alternative to the unsustainable use of tropical forest, the sustainable harvesting of non-timber forest products (NTFPs), meeting the purposes of conservation and development strategies, has been widely promoted. There is thus an urgent need to evaluate the impact of such human activities on tree regeneration, if natural resources protection and conservation measures are to be implemented. A novel rapid assessment protocol is proposed in this paper, which has been used to sample and evaluate the impact of anthropic disturbances of seed dispersal and seedling recruitment of hard-tegument fruit species enclosing large seeds, such being the case for many plants yielding NTFPs. This sampling method was implemented in French Guiana for a large-seeded scatter-hoarded tree species, Carapa surinamensis (andiroba), at three different forest sites affected by a variety of anthropic pressures, e.g. hunting and logging. It was found that seed dispersal and seedling recruitment are affected in two sites subjected to major anthropic pressure from low-income populations, especially by hunting. Indices may thus be generated, that can be used to define an ecological “sustainable management” label (or eco-label) for the harvesting of forest products and for fauna management purposes. This will serve to promote all conservation and protection measures useful for the regeneration dynamics of commercial large-seeded hard-fruited species harvested for NTFPs. Tree responses to edge effects and canopy openness in a tropical montane forest fragment in southern Costa Rica | pages 425-436 Cayuela, L., Murcia, C., Hawk, A. A., Fernández-Vega, J. and Oviedo-Brenes, F. Tropical forests frequently experience the opening and closing of canopy gaps as part of their natural dynamics. When an edge is created, and the area outside the boundary is a disturbed or unnatural system, forests can be seriously affected even at some distance from the fragmented edge, since sunlight and wind penetrate to a much greater extent. This increases tree mortality and, consequently, canopy openness close to the edge. Thus, canopy openness can be both part of a natural gap-dynamics cycle and the direct manifestation of human edge effects. A new study, published in Tropical Conservation Science, investigates how tree communities respond to both distance to edges and canopy openness in a tropical montane forest at Las Cruces Biological Station, SW Costa Rica. Cayuela and colleagues found that proximity to the forest edge does not increase the rate of canopy openness. When looking closely at the separate effects of edges and natural canopy gaps, a small or even negligible effect of edges on tree structure, diversity and composition was found, whereas natural canopy gaps exerted a stronger influence on these variables. The study concluded that edge effects may be minimized -or even suppressed- in older fragments through the sealing of edges by a thick growth of thin stems and through lateral growth of tree crowns; whereas canopy gap formation remains an active force that can create micro-environmental conditions that have significant effects on plant communities. Rapid ecological assessment of bats in the ecological park of Montelibano, Cordoba, Colombia | pages 437-449 Elkin Y. Suárez-Villota, Javier Racero-Casarrubia, Giovany Guevara and Jesús Ballesteros Considering the rapid expansion of urban areas at the expense of native vegetation in the tropics and the resulting loss of biodiversity, one major conservation planning problem is to determine the location of conservation-oriented projects in urban and semi-urban environments. Elkin and coauthors argue that rapid ecological assessments are important in this process, especially when they use indicator animal groups such as bats. They applied this approach in a semi-urban environment in Cordoba, Colombia. Their results indicate that the creation of ecological parks, coupled to the conservation of forest remnants in expanding urban areas, is an important mechanism for conservation of bats and of those organisms supported by bat presence and activities. Sustainable utilization of mangroves using improved fish smoking systems: a management perspective from the Douala-Edea wildlife reserve, Cameroon | pages 450-468 Njisuh Z. Feka, George B. Chuyong and Gordon N. Ajonina Fuel wood extraction for commercial fish-smoking (FS) is the most pervasive threat to the sustainability of mangrove ecosystems in the Douala-Edea Wildlife Reserve (DEWR), Cameroon, and most West-Central African coastal states. This high rate of fuel wood exploitation is the result of enhanced wood consumption systems used for fish smoking in this region. In order to reduce this current trend of excessive wood consumption, we advocate for the introduction of the Eeyed/CWCS improved fish smoke system (ISS) in the coastal cities of Cameroon and beyond. The use of Traditional Smoke System (TSS) might be the principal cause of the current excessive exploitation of mangrove wood in most of the coastal fishing cities of the region. This is because this study reveals the relative fuel wood saving economy of the ISS over TSS under use in the region. If successfully introduced in the region, ISS will contribute to reducing fishing household’s mangrove wood consumption by 60% per year. This implies that, by accepting this system each of these households will contribute to conserving about 0.60% ha of mangrove per year, improve working conditions for women and children and alleviate poverty as additional money for wood purchase will be saved. Reader comments are generally moderated. If you find something inappropriate, please contact Tropical Conservation Science. The opinions expressed in reader comments are those of the author only, and do not necessarily reflect the opinions of other authors or Tropical Conservation Science. |
 |
Tropical Conservation Science is an open-access e-journal that publishes research relating to conservation of tropical forests and other tropical ecosystems.
Volume 2: Issue 4 Table of Contents Articles Estrada & Butler Karthik et al. Gibbons & Hartcourt Lermyte & Forget Cayuela et al. Suárez-Villota et al Feka et al All issues Mar 2008 Jun 2008 Sep 2008 Dec 2008 Mar 2009 Jun 2009 Sep 2009 Dec 2009 Mar 2010 Jun 2010 Sep 2010 Dec 2010 Mar 2011 Jun 2011 Sep 2011 Dec 2011 Mar 2012 Jun 2012 Sep 2012 Dec 2012 Mar 2013 Jun 2013 Aug 2013 Sep 2013 Nov 2013 Dec 2013 Mar 2014 Jun 2014 Sep 2014 Dec 2014 Mar 2015 Jun 2015 Sep 2015 Dec 2015 Mar 2016 Jun 2016 Most downloaded 2008 2009 2010 2011 2012 All time ADVERTISEMENT SEARCH  This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. |
_200.jpg)
|
About | Privacy Copyright mongabay.com 2008-2014 |
