Profile
International Journal of Earth & Environmental Sciences Volume 1 (2016), Article ID 1:IJEES-124, 8 pages
https://doi.org/10.15344/2456-351X/2016/124
Research Article
Sustainability of Hillslopes in Semiarid Rangelands: Effects of Rock Fragments

Pariente Sarah

Laboratory of Geomorphology and Soil, Department of Geography and Environment, Bar Ilan University, Ramat-Gan, Israel
Prof. Pariente Sarah, Laboratory of Geomorphology and Soil, Department of Geography and Environment, Bar Ilan University, Ramat-Gan, Israel; E-mail: sarah.pariente@biu.ac.il
25 May 2016; 16 December 2016; 19 December 2016
Sarah P (2016) Sustainability of Hillslopes in Semiarid Rangelands: Effects of Rock Fragments. Int J Earth Environ Sci 1: 124. doi: https://doi.org/10.15344/2456-351X/2016/124

Abstract

Rock fragments (RFs) affect micro-environmental conditions in underlying and surrounding soil, and thereby stimulate abiotic and biotic processes that interact with the surrounding environment. Microenvironmental conditions are of great importance in arid and semiarid landscapes, where surfaces feature high percentages of RFs.

On south-facing hillslopes in the northern Negev region of Israel, soil was sampled from beneath small, medium, and large RFs – i.e., 4-6, 8-10, and 13-16 cm, respectively – that lay on the surface or were partially embedded in the soil. Control samples were taken from nearby bare soil.

Rock fragment characteristics affected various soil properties with differing intensities. Under large and medium RFs soil moisture contents were higher than under the small ones; and embedded RFs promoted higher moisture contents than those lying on top of the soil (designated as "on top"). Rock fragment position had the most significant effect on soil organic matter content, which was higher under on-top fragments than under embedded ones. The amplitude of soil temperature variation in all microenvironments followed that of air temperature. Soil temperature gradients underneath RFs of the various sizes, and most notably of those on top, and the differences among microenvironments depended on atmospheric conditions.

The RFs can be seen as fertile micro-islands, i.e., they concentrate natural resources and release them to the environment, thereby forming potential habitats for various fauna and flora. Soil quality is improved under RFs, which thereby compensate for the impaired quality of the exposed soil. The present paper presents a conceptual model of the contribution of RFs to hillslope sustainability in rangelands.