The consequences of habitat fragmentation are widely discussed in the conservation literature, usually with an emphasis on metapopulation dynamics and landscape ecology. Spatial aspects of fragmentation typically receive the greatest attention; in particular, how the size and shape of habitat patches and the distance between patches affect resident species. Relatively little notice has been given to the most obvious and direct effect of fragmentation: the physical changes that accompany the division of continuous habitat into fragments. In terrestrial systems, physical change is first expressed in the increase of perimeter to area ratio for each habitat patch. This change initiates a sequence of related physical changes that can profoundly influence resident flora and fauna. A comparable sequence of events follows fragmentation in aquatic systems. Field research is just beginning to provide links between patterns of fragmentation and the mechanisms that may lead to biotic changes. My aim in this chapter is to highlight the non-spatial effects of fragmentation. I limit my discussion to two types of ecosystems: forests and rivers. The first section considers the direct abiotic impacts of fragmentation on remnant habitat patches, often referred to as “edge effects” in the literature, and illustrates how these physical factors affect various organisms. In the second section I address the indirect effects of fragmentation, the biotic effects we can expect as a secondary consequence of the direct effects of fragmentation. I center many of my examples on recent research in an attempt to keep pace with the burgeoning conservation literature.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
- Physical Effects of Habitat Fragmentation
Lauri K. Freidenburg
- Springer US
- Chapter 4