Quantitative description of woody plant communities: Part I. An approach.

Abstract

Various descriptive units for woody plant communities are proposed. These are the evapotranspiration tree equivalent (ETTE), browse tree equivalent (BTE) and canopied subhabitat index (CSI), which describe the status of woody community in terms of potential moisture use, value of the trees as food for browsers and subhabitat suitability for grass-tree associations, respectively. A quantitative description index (QDI) for woody plant communities, containing descriptive unit-values, is proposed. The calculation of the various unit-values, excluding the CSI, rest upon the relationship between spatial volume of a tree crown and its true leaf volume and true leaf dry matter, taking into account difference in leaf densities. These relationships, and the factors that influence the estimation of leaf densities, are discussed. Regression equations were developed from harvested Acacia karroo trees. Their applicability to other woody species was confirmed as predicted values differ non-significantly from true values of two other species.Language: English

Keywords: acacia karroo; Available browse; botany; browse; Browse Tree Equivalent; browsers; BTE; Canopied Subhabitat Index; Competition for moisture; CSI; dry matter; eastern cape; ETTE; evapotranspiration; Evapotranspiration Tree Equivalent; false thornveld; Grass-tree associations; leaves; plant communities; Predictions; south africa; Spatial tree volume; subhabitat; woody species