Trends in Livestock Numbers and Spectral Properties of the Pasture Surface: Case Study of the Middle Gobi Aimag of Mongolia

Abstract

The paper analyzes linear correlations between MODIS parameters, i.e., the albedo, surface temperature, NDVI, and evapotranspiration, and with annual livestock numbers on Mongolian pastures for June–August throughout 2000–2015. The degree of association between the annual livestock density and average spectral properties of pastures were determined at the level of the whole country, region (aimag), and district (sum). Linear trends were assessed in the annual livestock density and spectral properties of the pasture surface within the boundaries of the specified administrative units of Mongolia. The total density and density with consideration for a structure of the livestock population within the stated territories are weakly related to the average spectral parameters of the pasture surfaces for the territories. The exception is Gurvansaikhan district, in which the relationships are significant; an increase in livestock density increases the albedo, decreases NDVI, and eventually reduces the forage reserve. The R2 coefficients of determination reveal insignificant linear trends in albedo, NDVI, and evapotranspiration as opposed to a significant positive trend in livestock density. A cooling trend and decreased precipitation was evident in 2000–2015. In the years of a sharp drop in livestock density (2000 and 2010), the spectral characteristics of pastures exhibit insignificant departures from the trend line, i.e. their sensitivity to a sharp drop in livestock numbers is minimal in the present situation.