Geography, Environment, Sustainability (Jun 2015)
THE IMPACT OF ROCKY TOPOGRAPHY ON SHRUBLAND HERBACEOUS PRODUCTI VITY IN SEMI-ARID ENVIRONMENTS
Abstract
One of the consequences of soil erosion in arid and semi-arid environments is the emergence of rocky shrublands. While their existence is well documented, gaps exist in our understanding of processes affecting the soil fertility inside them and in their surrounded environment which is crucial for their successive sustainably management. Our aims were as follows: (i) assessing the impact of various parameters (geographical, chemical and physical) on the herbaceous cover in shrublands located in arid rocky areas; (ii) assessing the impact of the rocky topography on the fertility parameters at the inter-patches and surrounded matrix areas. Geographically, the site of study is located in private family farm at Chiran area, northern Negev, Israel. It has semi - arid climate (precipitation 200 mm year-1) with hilly rocky topography. Ecologically the area is sustainably grazed shrubland characterized by patch-matrix patterns.For analyzing the impact of the above mentioned parameters we chose 24 patches belonging to different geographic groups: “Inside the rock”, “Adjacent to rock”, “Parallel to rock” and “Slopped”). From each patch we took soil and herbaceous biomass samples from predefined locations based on the geographical patterns of each group. Four methodologies were implemented for analysis as follows: (i) comparisons between the actual values; (ii) ranking the differences between the patches” sub-plots; (iii) correlating the soil parameters with the herbaceous biomass using regression analysis; (iv) spatial analysis of the different parameters based on kriging. The results demonstrate that the most influential parameter in the plots inside the patch were the Soil Organic Matter and clay content. The soil moisture in this study did not affect the area fertility. The rocky topography, together with the patch spatial patterns had high impact on the values of the examined parameters, even when compared to the surrounding matrix. Altogether, the presented results indicate that the patch fertility is affected by combination of different soil parameters and the geographic topography of a given patch. Additionally, reciprocal effects between the patches and their surrounding environment are also important determinants of fertility. The techniques and methodologies demonstrated here could be applied to other landscapes as well.
Keywords
