Abstract:

Successive cultivation of pure coniferous plantations has many defects. Planting mixed coniferous broad-leaved forests. is one of the most available methods to dispel these defects. Thus in 1982, we introduced a dozen of broad-leaved tree species, and established 35 hm². coniferous broad-leaved forests at Lu' an, Anhui Province, in order to select the appropriate mixture combinations, mixture pattern and proportion. This report deals with a part of the research of project. The results, from experimental study done in the past several years, showed that the mixed stand of Pinus massoniana and Liquidambar formosana with rational proportion and mixture pattern had significant economical and ecological benefits. The mixtures were suitable for maintaining soil ferdlity and site producdvity in long-term, promoting its growth and establishing a stable, man-made forest ecosystem. The growing stock in 12-year-old mixed stands was from 47.823 m³/hm² to 62.201m³/hm², 13.9%-72.5% higher than that of the pure stand of masson pine. The content of organic matter in the soil increased by 52.3%, total N increased by 24.1%, quickacting N, P, K increased by 13.7%. 25.2% and 26.8% respectively. The microclimatic condition was improved apparently. Meanwhile, the mixtures increased accumulation of chlorophyl in the leaves of masson pine. The daily average rate of net photosynthesis of masson pine in the mixed stand was 7.72 mgCO₂·Dm^-2·h^-1, 20.8% higher than that of the control.

Key words: Pinus massoniana, Liquidambar formosoana, Coniferous broad-leaved mixture, Productivity, Soil fertility, Physiological characteristics