ETD RECORD
Effects of deforestation and riparian buffers on lotic communities in southeastern Costa Rica :implications for biodiversity conservation in tropical streams
Citation
Lorion, Christopher M.. (2007). Effects of deforestation and riparian buffers on lotic communities in southeastern Costa Rica :implications for biodiversity conservation in tropical streams. Theses and Dissertations Collection, University of Idaho Library Digital Collections. https://www.lib.uidaho.edu/digital/etd/items/etd_219.html
- Title:
- Effects of deforestation and riparian buffers on lotic communities in southeastern Costa Rica :implications for biodiversity conservation in tropical streams
- Author:
- Lorion, Christopher M.
- Date:
- 2007
- Keywords:
- Freshwater ecology--Effect of human beings on--Costa Rica--Limón (Province) Deforestation--Costa Rica--Limón (Province) Freshwater biodiversity conservation--Costa Rica--Limón (Province)
- Program:
- Natural Resources
- Abstract:
- Freshwater biodiversity in the tropics is threatened by a variety of anthropogenic factors, and land cover change may have the most widespread and pervasive impacts. Costa Rica has experienced extensive deforestation, and there is a great need to understand how land cover change has affected stream ecosystems and investigate strategies for mitigating these impacts. Understanding the distribution of freshwater biodiversity in relatively pristine systems is also critical for effective conservation planning.;To examine the effects of deforestation on stream communities in southeastern Costa Rica and test the hypothesis that riparian forest buffers can reduce these effects, comparisons were made between forested stream reaches and stream reaches adjacent to pasture with and without a riparian forest buffer. Based on these comparisons, deforestation appeared to significantly alter the diversity and taxonomic composition of fish and benthic macroinvertebrate assemblages in the study streams, as well as stream temperatures and allochthonous inputs. Reaches with a riparian forest buffer, however, generally maintained aquatic assemblages and stream ecosystem conditions more similar to those observed in forested reaches. Overall, these results provide support for existing Costa Rican regulations mandating riparian forest protection, and suggest that appropriate riparian management could significantly reduce the impacts of deforestation on tropical stream biota.;To investigate landscape-scale patterns in fish diversity, stream fishes were sampled along an altitudinal gradient of nearly 500 m in the Sixaola River basin. Fish diversity decreased steeply with increasing elevation, and the main gradient in assemblage structure was strongly correlated with several stream habitat variables. Diadromous fishes were common throughout the altitudinal gradient and dominated the highest elevation sites, highlighting the importance of longitudinal connectivity in Mesoamerican river systems.;Systematic conservation planning that focuses on terrestrial and aquatic ecosystems, as well as biophysical linkages between these realms, could potentially identify more efficient and effective reserve networks. A critical evaluation of existing planning methods illustrates how incorporating linkages among ecosystems increases planning complexity. Several of the methods reviewed would be applicable to an example planning domain in Costa Rica and Panama, but new tools will be needed to realize the full potential of a comprehensive planning approach.
- Description:
- Thesis (Ph. D., Natural Resources)--University of Idaho and Centro Agronómico Tropical de Investigación y Enseñanza, December 2007.
- Major Professor:
- Brian Kennedy and Celia Harvey.
- Defense Date:
- December 2007.
- Type:
- Text
- Format Original:
- xiii, 132 leaves :ill., maps ;29 cm.
- Format:
- record
Rights
- Rights:
- In Copyright - Educational Use Permitted. For more information, please contact University of Idaho Library Special Collections and Archives Department at libspec@uidaho.edu.
- Standardized Rights:
- http://rightsstatements.org/vocab/InC-EDU/1.0/