Comparison of Rangeland Inventory Techniques in Semi-arid Areas as Related to Rangeland Management

Abstract

This research was conducted during years 2009-2011, in Kadugli locality, South Kordofan State, Sudan. The study aimed to make comparison between two measurement techniques in semi-arid rangeland inventory, and investigate the reliable and appropriate techniques to use in rangeland inventory programs. Two inventory techniques were used in the study to examine the reliable and appropriate one in semi-arid rangeland inventory program; ground inventory and remote sensing technology. Study area selected after primary field survey of the study area. Stratified sampling design was used in the ground data collection, using Global Positioning System (GPS), dividing the study area into four sites based on their soil types; namely sandy soil, clay soil, rocky soil and Gardoud soil range sites, the area of any site was 1 km2. Five transects were established of 100 m length, in each sites systematically. Parker loop method was used along transects with interval 1 m between hits to determine plant composition and cover estimation. Other method used in ground inventory was quadrate of 1 m2 size, distributed systematically, along transects with interval 25 m between each other, to determine plant density, frequency, biomass, rangeland productivity and carrying capacity. The study used Multi-temporal Landsat TM5satellite, for three years (2009, 2010 and 2011). Image classification was carried out to produce the land cover map of the study area, and then used NDVI map. The data obtained from the inventory technique was analyzed and computed using SAS statistical packages and EXCEL spread sheet, to determine the averages and significant differences among the range sites and inventory techniques. III The results obtained from ground survey found that the rocky and clay soil range sites were the best rangelands concerning plant cover, biomass production and carrying capacity, also Schoenefoldia gracilis (Danab Elnaga), was found good distribution and more abundance in all types of rangelands in the study area. The land cover obtained from RS data explained the incensement of grassland from 5015 ha in 2009 to 9378 ha in 2010, but it had on significant differences in 2011. Study found that the RS technique was reliable and appropriate compared with the ground survey, and also explained the direct correlation among plant productivity and NDVI values r=0.64. The study concluded that the ground inventory provides more detailed information about the vegetation attributes, but it needs intensive labor and time. The remote sensing data gave more reliable results and appropriate relevant to the ground measurements. These results make the remote sensing technique practical in collecting data from the wide area like the vast area in semi arid rangeland. Based on results obtained from this research the study recommended to use the combination of remote sensing data and ground inventory methods in measurement and monitoring rangeland resources in semi arid area and the use of the species Schoenefoldia gracilis for reseeding the deteriorated grassland.