T.A. GLASSER
L. HADAR
Y. NAVON
A. PEREVOLOTSKY

Introduction of goats into a Mediterranean nature park leads to changes in woody vegetation cover as well as changes in landscape properties. As part of the “adaptive management” approach, this management action should be accompanied by a monitoring program to assess the impact of grazing on various landscape parameters, and the extent to which management objectives have been accomplished. This study provides insight into the effectiveness of combining the interpretation of aerial photos with ground surveys to monitor changes in woody cover and landscape structure caused by goat grazing. Measuring woody cover by both methods has led to similar results, although data analyzed from aerial photo classification were more accurate, when applied to the whole site level. Changes in landscape structure indices, such as patch size, patch density, or edge density can be more easily measured by aerial photo classification, but they supply a two-dimensional image and overlook the fact that goat browsing influences vegetation mainly beneath the canopy. More relevant parameters, such as vegetation height distribution, cover of the understorey layer, dimension of gaps, or shifts in community composition can be detected exclusively by detailed ground surveys. In order to evaluate the extent to which the landscape was visually altered by goat browsing, an index (BLD) was developed and applied to data obtained from ground and aerial photography. Changes in woody cover and landscape structure were measured on both a spatial and temporal basis. A combination of parameters and methods was proposed to obtain maximum efficiency of the monitoring program. The complexity of the landscape, together with the wide range of uses and functions, requires monitoring techniques to be directed towards the perspective of the human eye.