Impact of Grazing on Soil Seed Bank Replenishment under the Mediterranean Climate of Northern Syria

Abstract

Rangelands represent 70% of the semi-arid and arid Mediterranean land mass. It is a habitat for millions of people whose livelihood depends on animal husbandry. The revolutionary developments in the animal husbandry and veterinary medicines resulted in exponential increases in livestock and human populations living on and from dry lands. To respond to population growth, expansion on urbanization, transportation and road networks, land reform and rural development policies forced nomads to adopt sedentary lifestyles. The demographic changes coupled with national and international border crossing restrictions escalated opportunistic cultivation, and excessive exploitation of the scarce and slowly renewable vegetation cover of rangelands. In an attempt to stop and reverse the degradation process, large-scale re- vegetation programs based on transplanting and reseeding with perennial shrubs, resting and grazing management systems were devised and implemented. This study aimed to evaluate the impacts of the rehabilitation programs on the above-ground vegetation cover and soil seed bank replenishment in the Syrian rangelands. The underlying assumption of the rehabilitation program is that with a well-established perennial plant cover and proper grazing management, top soil is stabilized, soil moisture, nutrients and seed bank are replenished and organic matter is accumulated resulting in greater abundance, species richness and diversity of annuals. To test the above hypothesis, field and controlled environment based studies were carried out with quantitative data collection and processing on plant species abundance, richness and diversity of above-ground vegetation and soil seed bank for fully protected rotationally and continuously grazed areas of 10 rangeland sites in northern Syria for two consecutive seasons based on Hayashi, I. & Numata, M. (1964).