In 2003, MSc student Juan Carlos Ruiz Guajardo from the University of East Anglia, UK, carried out research within the Rio Bravo Conservation and Management Area. Funded by Jaguar Cars, and supported by the World Land Trust and Programme for Belize, Juan, who is originally from Mexico, looked at the “Effects of Selective Logging on the Relative Abundance and Distribution of Vertebrate Species in the Rio Bravo”. Read the abstract of this project below.
Effects of selective logging on the relative abundance and distribution of some vertebrate species in the Rio Bravo Conservation and Management Area in Belize, Central America.
Juan Carlos Ruiz Guajardo, University of East Anglia, UK 2003
Selective extraction of valuable trees in tropical forests is a widespread and profitable human activity. It has direct and profound effects on the forest structure and habitat composition, and as a consequence, it significantly impacts the abundance and distribution of tropical wildlife associated to them. The majority of the studies of the effect of logging on wildlife have been concentrated on primates and birds and mainly on African or Asian tropical forests, while very few have studied this on Neotropical forests.
The effect of selective logging on the forest structure and its implications on the abundance and distribution of important vertebrate species, was studied in the Rio Bravo Conservation and Management Area in northern Belize. On the basis of 30 (0.25 ha) vegetation plots and 6 (5 km) line transects for wildlife census, significant differences were found on the forest structure and the vertebrate composition between the logged and unlogged areas. Logged plots had bigger forest disturbance indicated by lower heterogeneity, less number of tree species, bigger canopy gaps and smaller tree basal areas. The response of the vertebrate community to logging disturbance also showed significant differences between logging regimes. On average, in terms of species assemblages and abundance, the overall dissimilarity between sites was bigger than 60%. From the 18 vertebrate species included on the analysis, 11 showed significantly lower abundance on logged sections. With the exception of carnivores, all guilds or groups with similar dietary habits appeared to be affected by logging. Species like Ateles geoffroyi (Spider Monkeys) and Nasua nasua (Coatis) were completely extirpated from logged sections and Meleagris ocellata (Ocellated Turkey) was ten times less abundant in logged sections than unlogged. The study is a pioneer in using a pairwise comparison to show that on absence of hunting pressure, logging is clearly affecting the abundance and distribution of Neotropical wildlife.
This MSc research project was funded by Jaguar Cars, and supported by the World Land Trust and Programme for Belize.