Sustainability of Hillslopes in Semiarid Rangelands: Effects of Rock Fragments

Pariente Sarah

doi: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

Highlights

IntroductionRock fragments (RFs) vary in size, shape, position, porosity and color [1-6] and bulk density [7], and there are variations in microenvironmental conditions, such as moisture content and temperature, in the underlying soil
Rock fragment effect on the environmentRock fragments (RFs) vary in size, shape, position, porosity and color [1-6] and bulk density [7], and there are variations in microenvironmental conditions, such as moisture content and temperature, in the underlying soil
The present paper presents a conceptual model of the contribution of RFs to hillslope sustainability in rangelands

Summary

Introduction

Rock fragments (RFs) vary in size, shape, position, porosity and color [1-6] and bulk density [7], and there are variations in microenvironmental conditions, such as moisture content and temperature, in the underlying soil. These conditions, which influence abiotic and biotic processes that interact with the surrounding environment, are of great importance in semiarid and arid regions [8-11], whose landscapes are characterized by high percentages of RFs [12]. When raindrops hit the bare soil surface directly they cause crusting of the topsoil and generation of overland flow [21]

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Conclusion