The seasonal dynamics of nutrient contents in Manchuria ash-dahurian larch mixed stand

Abstract

The yield increasing mechanism of the manchurian ash (Fraxinus mandchurica) and dahurian larch(Larix gmelini) mixed stand was studied on nutrition status of soil and leaves. The results showed that nutrient contents of leaves and contents of the available nutrients of soil in the mixed and pure stands varied with seasons of the year. The available phosphorus contents of the soil in the larch belt were much higher than those in the manchurian ash belt during growing season, with the highest value of 3.5 mg/100g, 2–3 times of the latter. The nitrogen contents of leaves of the manchurian ash trees nearest from dahurian larch belt were 12.7%–80.8% higher than those of its pure stand, and phosphorus 13.4%–140.8%. The different uptake rhythm of the nutrients modified the interspecific competition. The general conclusion is that the high contents of available phosphorus of the soil in dahurian larch belt improved the growing condition of nearby manchurian ash trees.