SPECIFIC LEAF AREA AND LEAF AREA INDEX OF CONIFER PLANTATIONS IN QIANYANZHOU STATION OF SUBTROPICAL CHINA

Abstract

Aims Our objective was to determine foliage biomass and leaf area index (LAI) of four types of conifer plantations in Qianyanzhou Experimental Station in subtropical China. Methods We developed allometric equations between foliage biomass and stem diameter at breast height (DBH) and obtained specific leaf area (SLA) from data on leaf length, width and weight for different ages and types of leaves from three dominant species: slash pine (Pinus elliotii), masson pine (P. massoniana) and Chinese fir (Cunninghamia lanceolata). Important findings Allometric equations for foliage biomass of slash pine, masson pine and Chinese fir were W=12.074 1D 2.151 5 , W=6.972 7D 2.197 3 and W=5.261 9D 2.302 7 , respectively. Foliage biomass of slash pine plantation (0.822 kg·m -2 ) was the highest among all stands, followed by mixed coniferous plantation (0.679 kg·m -2 ), Chinese fir plantation (0.572 kg·m -2 ) and masson pine plantation (0.528 kg·m -2 ). For each species, SLA of new leaves was larger than old ones, and that of three-needle leaves was larger than two-needle ones. Mean specific hemisurface area of masson pine (8.62 m2·kg -1 ) was the largest, followed by Chinese fir (7.91 m2·kg -1 ) and slash pine (6.04 m2·kg -1 ). Regression equations between stem DBH (D) and mean hemisurface area (LA) for slash pine, masson pine and Chinese fir were LA=0.073 D 2.151 5 , LA=0.060D 2.197 3 and LA=0.042D 2.302 7 , respectively. LAI was 5.03 for slash pine plantation, 4.31 for both masson pine plantation and Chinese fir plantation, and 4.77 for mixed coniferous plantation, all larger than that measured with CI-110 plant canopy digital imager.