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Xalapa de Enríquez, Mexico

Gutierrez-Granados G.,Institute Ecologa | Dirzo R.,Stanford University
Journal of Tropical Ecology | Year: 2010

The ecological effects of logging in the tropics have been analysed largely in terms of its impacts on species diversity and abundance. However, information is very limited regarding the impact of logging on ecological processes such as species interactions. Here we hypothesize that timber extraction per se, that is, in the absence of hunting, affects the abundance of the frugivorous spider monkey, Ateles geoffroyi, and that this has indirect effects on the recruitment of a predominant tree species, Manilkara zapota, and the diversity of the understorey plant community. We compared logged and unlogged sites, using a paired design. In each management condition we conducted line transects and interviews to evaluate spider monkey abundance and game preferences, respectively. Impact on plant recruitment and understorey diversity were evaluated using 2 2-m plots (N = 320) established under 40 M. zapota tree crowns. No spider monkeys were recorded in logged sites whereas they were abundant (15 8 individuals per man-km) in unlogged sites. Interviews showed that spider monkeys are not hunted by local inhabitants. Logging was correlated with a reduction of the number of M. zapota fruits used by A. geoffroyi; an increase in the number of sites dominated by M. zapota; and a reduction in understorey plant diversity. Our results suggest that the absence of A. geoffroyi in logged sites can indirectly impact plant recruitment and diversity via the disruption of plant-frugivore interactions. Further work is needed to assess if these effects persist over the long term, to define if logging operations affect the overall diversity of tropical forests. Copyright © 2009 Cambridge University Press. Source

Bonilla-Sanchez Y.M.,Institute Ecologia AC | Serio-Silva J.C.,Institute Ecologa | Pozo-Montuy G.,Institute Ecologia AC | Bynum N.,CNRS Center for Marine Biodiversity, Exploitation and Conservation
ORYX | Year: 2010

In the Mexican state of Chiapas the rainforest has been cleared, to make way for crops and extensive cattle ranching, at an annual rate of 12.4% since 2002. The conservation status of the Endangered black howler monkey Alouatta pigra in these fragmented landscapes in north-eastern Chiapas has not previously been examined. We therefore surveyed A. pigra populations in the municipality of Playas de Catazaj during 2004-2006 to obtain population and habitat data for this species in 115 fragments of remnant vegetation. A geographical information system was used to determine the variables (fragment size, and distances to the nearest fragment, human settlement and water body) that could be used to generate an index of habitat potential for A. pigra. We estimated a population of 659 individuals and a mean troop size of 5.0 ± SE 2.3. The adult male : female ratio was 1 : 1.4, the adult female : juvenile ratio 1 : 0.6 and adult female : immature ratio 1 : 0.8. The index of habitat potential indicates that 12% of the fragments have a high conservation potential for A. pigra. This index is a valuable tool for evaluating the conservation status of this species and its habitat, and can be expanded to include additional variables, thus allowing for a more comprehensive assessment. Copyright © 2010 Fauna & Flora International. Source

Scheffknecht S.,University of Natural Resources and Life Sciences, Vienna | Winkler M.,University of Natural Resources and Life Sciences, Vienna | Hlber K.,VINCA Vienna Institute for Nature Conservation and Analyses | Rosas M.M.,Institute Ecologa | Hietz P.,University of Natural Resources and Life Sciences, Vienna
Journal of Tropical Ecology | Year: 2010

The distribution of epiphytes differs between branches within tree crowns as well as within habitats. Where the original forests have been lost, shade coffee plantations can be important refuges for epiphytes, but are not suitable for all species. To understand what affects habitat quality, we transplanted 1440 seedlings each of two orchids, one, Lycaste aromatica, restricted to forests, the other, Jacquiniella teretifolia, common on trees in coffee plantations and in forests. Seedling mortality and growth were compared between three forests, three young and three old coffee plantations to test for differences between habitats and to analyse which habitat features affect growth and mortality. In J. teretifolia there was no clear pattern of habitat effect on mortality (c. 0.08 mo 1), but the production of new shoots was higher in coffee plantations than in forests. In L. aromatica, growth rates as well as seedling mortality increased over time. During the last census growth rates in forests (1.8 mm mo 1) were significantly higher than in old (0.9 mm mo 1) and young (1.2 mm mo 1) coffee plantations, and seedling mortality was about four times higher in old (0.10 mo 1) and young (0.11 mo 1) coffee plantations than in forests (0.025 mo 1), which may explain the natural absence of L. aromatica from coffee plantations. Mortality in L. aromatica at individual sites was negatively correlated with bryophyte cover on branches (Pearson r = -0.75) and positively with lichen cover (r = 0.70) and canopy openness (r = 0.75). Branch cover with non-vascular epiphytes, whether directly responsible by improving the water supply to epiphytes or indicative of differences in microclimate, may be a useful indicator of suitable habitats for vascular epiphytes. Copyright © 2009 Cambridge University Press. Source

Hernandez M.E.,Institute Ecologia | Marin-Muniz J.L.,University of Veracruz | Moreno-Casasola P.,Institute Ecologa | Vazquez V.,Institute Ecologia
International Journal of Biodiversity Science, Ecosystems Services and Management | Year: 2015

Wetlands play an important role in carbon cycling. Perturbation of these ecosystems by human activities causes changes in the soil carbon storage and carbon gaseous emissions. These changes might have important repercussions for global warming. The aim of this study was to investigate whether the conversion of freshwater forested wetlands (FW) to flooded grasslands (FGL) has affected soil carbon cycling. Soil carbon pools and soil organic carbon (SOC) fractions (water-soluble carbon (WSC), hot-water-soluble carbon (HWSC), and HCl/HF soluble carbon (HCl/HF-SC)) were compared between FW and FGL. Additionally, the seasonal dynamic of methane (CH4) and carbon dioxide (CO2) fluxes were monitored in both ecosystems located in the coastal plain of Veracruz State Mexico. In FW, soil organic matter (SOM) concentrations were significantly (P ≤ 0.05) higher than FGL. Soil bulk density (BD) was slightly higher in FGL than FW but it was not significantly different (P ≥ 0.05). The average of WSC and HWSC in FW were not significantly (P ≤ 0.05) different. Total carbon pools (44 cm deep) were not significantly different (P = 0.735). During the dry season, CO2 fluxes (26.38 ± 4.45 g m-2 d-1) in FGL were significantly higher (P = 0.023) than in FW (14.36 ± 5.77 g m-2 d-1). During the rainy and windy seasons, both CH4 and CO2 fluxes were significantly higher (P = 0.000 and P = 0.001) in FGL compared with FW. It was concluded that converting FW to FGL causes loss of SOC and increases carbon gaseous fluxes. © 2014 Taylor & Francis. Source

Agency: Cordis | Branch: FP7 | Program: CP-IP-SICA | Phase: ENV.2011.2.1.4-1 | Award Amount: 9.01M | Year: 2011

To realise the full potential of tropical forests in climate change mitigation (CCM) & the provision of other ecosystem services in the face of ongoing global change we must improve our understanding of the relationships between biodiversity (BD) and the socio-ecological processes through which we respond & adapt to change. ROBIN will provide information for policy & resource use options under scenarios of socio-economic & climate change to: quantify interactions between terrestrial BD, land use & CCM potential in tropical Latin America; develop scenarios for CCM options by evaluating their effectiveness, unintended effects on other ecosystem services (e.g. disease mitigation) and their socio-ecological consequences. We will achieve this by combining new techniques (including remote sensing) for BD assessments in complex multi-functional landscapes, data-based analyses, integrated modelling & participatory-driven approaches at local & regional scales. Case studies along a gradient of sites in Mesoamerica and Amazonia will be used to develop understanding of the relationships between BD & CCM options & feed policy development. These studies will improve understanding of the options favourable to stakeholders & barriers & drivers affecting adoption of resource management strategies. Key deliverables will be: improved understanding of the role of BD in climate change; participatory-driven strategies & tools for CCM; assessments of the risks & uncertainties associated with CCM options. The main impact of the work will be improved outcomes from CCM & BD protection measures by providing natural resource managers in Latin America with guidance on how BD & ecosystems can be used in CCM without creating new problems. We will provide improved indicators for BD relevant to the Convention on Biological Diversity & the design & implementation of REDD\/\\ schemes, to ensure increased storage of carbon in forests & multi-functional landscapes & decreased rates of BD loss.

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