Diversity indices based on angle count sampling and their interrelationships when used in forest inventories

Abstract

Sampling procedures within stands for species and diversity indices have been widely discussed. However, little attention has been paid to the assessment of such indices within the framework of forest inventories on the management district level. This study deals with such an inventory comprising 245 angle counts in a 750-ha forest management district at the northern fringe of the Austrian Alps. To calculate spatially explicit indices, the nearest neighbours of the angle count in-trees have to be assessed. The distributions of the indices, their correlations and their ability to discriminate between different stand classes are discussed. It is concluded that these indices are meaningful, because they describe the species composition and the structure of the forest district in the expected way and differ significantly and meaningfully among stand classes which have been classified for silvicultural purposes.