IALC Peace Fellowship Report
Ben-Gurion University of the Negev, Israel
Causes and Predictions of Species Loss
Fragmented Semiarid Landscape
The International Arid Lands Consortium Peace Fellowship Program enabled
me to travel to the University of Arizona and work with Dr. Michael L. Rosenzweig.
We analyzed a large data set, collected in our semiarid biodiversity research
(supported by IALC) as a case study for answering a fundamental question
in ecology: How to predict species loss due to fragmentation processes.
The biodiversity research takes place in the Southern Judea Lowland in
Israel, a very fragmented semiarid environment. This area is characterized
by a mixture of different-sized natural habitat patches, located between
agricultural fields and human developments. Due to the climatic conditions
and location of this area, where three biogeographic zones overlap
(the Saharo-Arabian, Irano-Turranian and Mediterranean), it is exceptionally
important for conservation of both species diversity and genetic variability.
However, the area is at high risk owing to prospective developmental
plans and further fragmentation. Furthermore, we know very little how
ecological processes influence species diversity and community structure
in this area.
In order to predict the species loss in the research area, we applied new
quantitative methods and computer applications of species diversity estimators.
This new analysis revealed fascinating results, linking observed patterns
of species loss of different taxa to different mechanisms. Some groups such
as ground beetles showed sensitivity to reduction in habitat area without
any additive influences, while another group, perennial flowering plant
showed reduction in species number due to fragmentation processes.
We emphasize that, regardless of the effect of fragmentation, a reduction
in area immediately results in a reduction in species diversity. However,
conservation biologists should test for whether any reduction is indeed
a product of fragmentation or merely a result of the species-area curves.
Our experiment is especially important because it suggest/produces a founded/established
mechanism for the observed phenomenon of reduction in species number.
NOTE: A paper is in final preparation and an abstract has been published
in the proceedings of an Israel Zoological Society conference held on 1