Application Perspectives of the Leaf Area Index (LAI) Estimated by the Hemiview System in Forestry

摘要

Leaf area index (LAI) is widely used to describe the main characteristics of forest stands such as cover intensity at different forest levels from moss to tree as well as main stand dendrometric parameters. Hemispherical canopy photograph was used for analyzing quality and quantity of coniferous forest in Aukstaitija national park. Different sampling systems from single plots to aggregating them into stands allowed assessing significance of LAI detected by the HemiView system in forestry without special preparation. The obtained data revealed that the use of hemispheric photograph for LAI estimation in multi-aged and multi-layered mature and over mature pine and spruce stands was rather problematic. Only cover intensity of understory vegetation (grasses and mosses) was reflected best. In pure pine stands LAI also significantly reflected spatial changes in cover intensity of shrubs, grasses and mosses levels and in addition - spatial changes in main dendrometric stand parameters. Key findings - significant relationships between LAI detected in November and pine needle litterfall over September-October. It allowed detecting significance of LAI in mass balance of the main nutritional and contaminant components calculations. LAI increase by 1 m2 m?2 increased total litterfall amount by 1.7 t ha?1 in a pure mature pine forest. The obtained results indicated good perspectives of LAI detected by HemiView system in forestry even without special their preparation.