The Research Of Ecological Adaptability Of6Acacia Species In The Coastal Casuarina Equisetifolia Regeneration Forestland

The investigation, comparison and analysis of the ecological adaptability and physiological mechanism of the growth adaptability, forest productivity, stand structure characteristics, root distribution and resistance among six kinds of8-years acacias in the Casuarina equisetifolia regeneration woodland of Chang le state-owned protection forest in Fujian, which is showed that:1. The performance of growth adaptability:The adaptability of Acacia cunninghamii plants, Acacia concinnatai plants, Acacia aulacocarpa plants and Acacia crassicarpa plants perform well, while Acacia crassicarpa is better than the others; The average tree height, DBH and volume of8-years acacias are9.53m,10.48cm and0.0476m3respectively, which is higher than even-aged Casuarina equisetifolia by4.15%、40.11%、126.67%. The growth of Acacia cunninghamii plants, Acacia concinnatai plants, Acacia aulacocarpa plants, comparatively speaking, is better. The average tree height and DBH of8-years acacias is from6.5to7.0m and from6.3to6.6m respectively. In addition, the ability of cold resistance, wind resistance and pest-resistant performs well, and preserving rate of those stands is also highter.2. The biomass and structure of those stands:The total biomass of those stands among Acacia cunninghamii plants, Acacia aulacocarpa plants and Acacia crassicarpa plants is higher than Casuarina equisetifolia by9.10%、1.20%、35.33%, thereinto, the highest total biomass of those stands is Acacia crassicarpa plants, which can reach to90.65t·hm-2; the upper and underground structure of Acacia cunninghamii plants, Acacia aulacocarpa plants and Acacia crassicarpa plants perform well, which also have large Canopy space and Widespread underground root system.3. The ability of stands’ water conservation:Compare with Casuarina equisetifolia the ability of water conservation among Acacia cunninghamii plants, Acacia aulacocarpa plants and Acacia crassicarpa plants is better; The water-holding capacity of Acacia crassicarpa plants is42.88t·hm-2, which have a highest water-holding capacity of the Aerial parts in those six kinds of Acacia plants. The water-holding capacity of the soil layer of Acacia cunninghamii plants’ roots is largest than other kinds of Acacia plants, which can reach to1795.02t·hm-2. Besides, the water-holding capacity of Acacia cunninghamii plants is1824.04t-hm-2and is higher than the others, which is followed by Acacia crassicarpa plants and Acacia aulacocarpa plants with the water-holding capacity of1770.75t-hm-2and1759.60t-hm-2respectively.4. The responses to resistance physiology:Comprehensive comparison of physiological indicators, the cold-resistance ability of Acacia cunninghamii plants, Acacia concinnatai plants and Acacia aulacocarpa plants perform well. Acacia cunninghamii plants, Acacia aulacocarpa plants and Acacia crassicarpa plants perform well in drought resistance, which is well fitted with the results of field measurements.Application of principal composition cluster analysis to six kinds of Acacia plants, Acacia cunninghamii plants, Acacia aulacocarpa plants and Acacia crassicarpa plants with adaptable ability are sifted, the growth adaptability, forest productivity, stand structure characteristics and root distribution and resistance of those kinds of Acacia plants perform well, which is also with a well water-holding capacity; those kinds of Acacia plants could be use for updated species of coastal Casuarina equisetifolia shelterbelt, which have a bright future.