Species Diversity and Ecological Function
Principal Investigator: Trond H. Larsen, Princeton University
Species loss may cause functional shifts that disrupt ecological
processes. Several studies have examined the relationship between diversity
and ecological function, although most have measured plant diversity and
primary production in grassland ecosystems. Artificially assembled communities
are poor at helping us understand real communities where species are not
lost randomly. Few studies have examined species diversity and ecosystem
functioning in tropical forests where most of the earth’s biodiversity
is concentrated. Arthropods represent the majority of this diversity,
occupying many functional niches and microhabitats.
Dung beetles comprise a keystone guild in the tropics by acting as secondary seed dispersers for monkey-dispersed seeds. By burying dung and the seeds it contains, beetles protect seeds that otherwise suffer from intense rodent predation, and thereby greatly increase seed survival. Beetle-mediated dung burial further contributes to ecosystem functioning through nutrient cycling and soil conditioning, increasing the availability of nitrogen and phosphorus to plants. Dung burial also helps control helminth parasite and pest fly populations. Larger-bodied beetle species bury more dung and contribute the bulk of ecological function. The selective extinction of many larger-bodied species of dung beetles in response to fragmentation, hunting of mammals, and other anthropogenic impacts can rapidly result in the disruption of this ecological function. I am examining the nature of this relationship, with particular focus on the contribution of large extinction-prone dung beetle species to seedling recruitment across different habitat types and disturbance regimes.
Contact:
TROND
HALVOR LARSEN
Dept. of Ecology and Evolutionary Biology
Princeton University
Princeton, NJ 08544
tlarsen@princeton.edu
Phone (609) 258-7925, Fax (609) 258-7892
http://www.princeton.edu/~tlarsen/