Biodiversity of a Fragmented Landscape in the Southern Judean Lowland
Investigators (most current known information)
The ongoing fragmentation process at the semiarid area of the Southern Judean Lowland (SJL) requires a combined investigation of basic ecological mechanisms with a biodiversity management plan. Our current ecological knowledge, based on metapopulation dynamics and landscape ecology, suggests that any study of the SJL's heterogeneous landscape should take into account the spatial structure of the patchy environment and the way organisms respond to this patchiness. Among others, this includes understanding of how different processes affect species distribution and diversity at different scales – within patch, between patch (landscape scale), and the combination of them.
In our research proposal, we suggested studying how the fragmented landscape of SJL affects species distribution and diversity of two common beetle families – Tenebrionidae, detrivores; Carabidae, predators – based on the rationale that beetles are playing important roles in ecosystem functioning. In particular, we proposed:
- To characterize and identify beetle species-diversity patterns in the heterogeneous, fragmented landscape of SJL;
- To study the processes affecting beetle-community structure and species diversity at the patch and landscape scales in light of the natural and human-induced heterogeneity of the landscape.
We selected 25 natural habitat patches surrounded by an agricultural field matrix. These patches were classified into four size groups: 10 extra small (up to 1,000 m2), 7 small (1,000 - 5,000 m2), 7 medium (5,000 - 20,000 m2) and 1 large (40,000 m2). The selected patches represented the plant composition, soil type and rock formation of the area, but varied in their patch spatial attributes (e.g. shape) and location in the matrix (e.g. degree of isolation and contrast with surrounding habitats).
We combined advanced spatial-analysis technology with a field survey. The selected patches were characterized according to spatial attributes (size, shape, location in matrix, distance from other patches and type of disturbed habitat surroundings), geological variables (rock and soil), and biological variables (percentage vegetation cover, diversity, and composition).
Articles in Journals
Science Editor's Choice. 2007. "Ecology/Evolution: The Whole Is the Sum of the Parts." Science Vol. 317, No. 5841, Issue of 24 August 2007.
Yaacobi, G., Ziv, Y., and M.L. Rosenzweig. 2007. "Habitat fragmentation may not matter to species diversity." Proceedings of the Royal B Society. Vol. 274 (2409-2412) doi.10.1098/repb.2007.0674.
Topel, Elad. 2006. Green islands in arid environments: the effects of artificially productive patches on beetle assemblages in hyper regions . M.Sc. Thesis. Beer Sheva. Israel Ben-Gurion University of the Negev. 54 pp.
Yaacobi, Gal. 2005. The effect of landscape patchiness and heterogeneity on beetle species diversity in the southern judea lowland. M.Sc. Thesis. Beer Sheva, Israel. Ben-Gurion University of the Negev. 56 pp.