The role of invisible biodiversity in pasture landscapes

Abstract

Prior to Frans Vera’s work, several workers in the UK were advocating that areas of temperate Europe were not covered with a continuous unbroken tree cover. Crawley and Green (in prep.) suggest a countryside of ‘glades with trees round them’. It is suggested that pests and diseases could create the glades in woodland or other vegetation and in some cases maintain them. Browsing / grazing animals would continue to maintain the open spaces until they themselves were affected by diseases and pests after events such as prolonged drought, leading to a sudden large drop in numbers allowing colonisation by trees and shrubs. The cycle of tree cover would then begin again — until the arrival of man. Man colonised the savannah and glades and expanded them for the final time … or perhaps until he too succumbs.