Throughout the world, the land tropical forests stand on is being converted to agriculture, urbanization, and other human land uses. The loss and fragmentation of habitat is considered the most significant threat to global biodiversity (Sala et al., 2000); thus, we need to understand its effects in the tropics, where biodiversity is the highest (Reaka-Kudla et al. 1997) and land conversion the greatest (Lepers et al. 2003).
Despite the importance of the tropics the area is understudied, constituting only 13% of fragmentation research (McGarigal and Cushman, 2002). Thus, we still have limited understanding of relative effects of habitat loss and fragmentation and the impacts of different types of land cover and land uses on species patterns and processes in tropical ecosystems.
SMBC research will address this knowledge gap and provide essential guidance on how best to manage forest fragments that now serve as refuges for many endemic tropical birds in the Caribbean.
The Caribbean's Greater Antilles are an ideal location to examine fragmentation issues because rates of deforestation are among the highest in the world (Lepers et al., 2003), and this region remains one of the top 4 biodiversity hotspots in the world (Myers et al., 2000). Unfortunately, the Caribbean is also predicted to lose most of its endemic species under current deforestation rates (Brooks et al. 2002).
Within the Caribbean, the island of Jamaica has suffered extreme forest loss. Today, less than 30% of Jamaica's natural forests remain (FAO 2001). Despite such extensive loss, remnant forests are essential to the economic life of the island, and serve to protect water supplies, soils, and biodiversity (NRCA, 1995).
Jamaica has the highest number of endemic species of all Caribbean islands, with 100 endemic ferns, 27 endemic reptiles, and 28 endemic birds (Koenig 2000). Despite the ecological importance of Jamaica's forests, the effects of deforestation have received little attention from the scientific community.
In fact, ecological and demographic information is lacking for the vast majority of species in Jamaica from which to base effective conservation management strategies (NEPA 2003). Jamaica's unique biodiversity combined with its legacy of extensive forest fragmentation, and the lack of research on this interaction, were the basis for targeting this country for SMBC research.
This Jamaican tody, an endemic species found only in Jamaica, has been caught in a mist net. It will be quickly removed, measured, and banded with a unique identifier (colored ankle bracelets) so its future movements can be followed.
SMBC researchers are examining how intervening land cover surrounding forest fragments (i.e., matrix) affect bird distributions, abundances, and population persistence in Jamaica.
We work in landscapes that vary in resource availability and structural connectivity for birds—within forests fragmented by agricultural pastureland, bauxite mining, and residential development and continuous forest.
Aerial view of landscapes under investigation in Jamaica fragmented by agriculture (upper left), suburban development (upper right), and bauxite mining (lower left). Forest cover appears in dark green surrounded by pasture, treelined fencerows, and paddock trees in agricultural landscapes; by houses, roads, ornamental lawns and gardens, and roadside vegetation in peri-urban landscapes; and exposed bauxitic (terra rossas) soil (as shown in red) and early growth of ferns and Acacia stands in bauxite mining landscapes.
Through population surveys and experimental translocations of resident and migratory birds, we are testing whether the matrix within fragmented landscapes affects bird diversity and abundance patterns; and if so, whether differences are predominately driven by varying resources or differential connectivity at the landscape-scale.
Understanding the mechanism(s) behind species response to fragmented systems, in relation to life history traits, will help to improve the potential to support native biodiversity amidst land cover change in the tropics.
Citation: Withey, J., and C. Kennedy. 2012. Does the Matrix Matter? Testing the Influence of Matrix Type on Bird Responses to Forest Fragmentation. National Center for Case Study Teaching in Science, University at Buffalo, State University of New York.
Description: based on SMBC's research on Neotropical birds in Jamaica, a case study and teaching materials have been developed on principles of landscape ecology, experimental design, and data interpretation to examine alternative explanations for how birds respond to forest fragmentation and landscape matrix. As written, the case can be used in ecology courses with a unit on landscape ecology, or upper-division conservation or landscape ecology courses. Teaching materials (case study, teaching notes, & answer key) can be accessed at: http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=649&id=649.