| With fewer resources of our country and Superadded with poor management of forest resources and deterioration of the ecological environment,which resulting in the increasingly depleted of forest resources.Meanwhile,with the rapid development of China's socio-economic and the improvement of living standards of people,the demanding for timbers are sharply increased.Particularly implemented the natural forest protection project since 1998,contributing in the imbalance between the supply and demand which were more prominently.Acacia melanoxylon is a typically heliophilous specie,with a short growth circle,has the ability of cold resistance,drought-resistance,water logging resistance,poor soil resistance and its root nodule can improve and enhance the land capability with a great economic,social,and ecological benefit. It is convenient to cultivate large acreage plantation of Acacia melanoxylon for Fujian province large parts of which lie in the southern subtropical zone.Nevertheless,it has not been investigated the relationship between ecological factors and growth of Acacia melanoxylon,because it was introduced lately.Through study on effects of principal ecological factors on the growth of Acacia melanoxylon in this paper,which provide the reasonable theoretical basis for scientific introduction,the plant sites selection,the planting scale expansition,and has important significance to development the artificial forest of Acacia melanoxylon.The results were showed as follows:1.The study on effects of soil factors on height growth of Acacia melanoxylon shows that the positive correlation with very significant or significant between the content of organic matters, nitrogen,phosphorus,minimal water holding capacity,hydrolyzable nitrogen,rapidly available phosphorus and height growth of Acacia melanoxylon.The correlation sorting was that,organic matters＞hydrolysable nitrogen＞phosphorus＞nitrogen＞rapidly available phosphorus＞minimal water holding capacity.The negative correlation with very significant between the content of soil bulk density,pH value,potassium,rapidly available potassium and height growth of Acacia melanoxylon.The correlation sorting was that potassium＞rapidly available potassium＞soil bulk density＞pH value.Established the multiple regression equation of height of Acacia melanoxylon and respective soil factors,the regression equation reached the very significant level.2.The study on effects of soil factors on ground diameter growth of Acacia rnelanoxylon shows that the positive correlation with very significant between the content of nitrogen,organic matters,phosphorus,potassium,hydrolyzable nitrogen,rapidly available phosphorus,rapidly available potassium and ground diameter growth of Acacia melanoxylon.The correlation sorting was that nitrogen＞organic matters＞potassium＞hydrolysable nitrogen＞phosphorus＞rapidly available phosphorus＞rapidly available potassium.The negative correlation with very significant between the content of soil bulk density,pH value and ground diameter growth of Acacia melanoxylon.The correlation sorting was that soil bulk density＞pH value.Established the multiple regression equation of ground diameter of Acacia melanoxylon and respective soil factors, the regression equation reached the very significant level.3.The study on effects of topographical factors on height growth of Acacia melanoxylon shows that the important degree of influence of respective topographical factors was that,slope gradient＞slope direction＞slope position＞slope shape.Established the multiple regression equation of height of Acacia melanoxylon and respective topographical factors,the regression equation reached the very significant level.4.The study on effects of topographical factors on ground diameter growth of Acacia melanoxylon shows that the important degree of influence of respective topographical factors was that,slope direction＞slope position＞slope shape＞slope gradient.Established the multiple regression equation of ground diameter of Acacia melanoxylon and respective topographical factors,the regression equation reached the very significant level.5.The study on effects of climatic factors on height growth of Acacia melanoxylon shows that the positive correlation with very significant or significant between the monthly mean temperature, annual sunshine hours,monthly mean relative humidity and height growth of Acacia melanoxylon. The correlation sorting was that annual sunshine hours＞monthly mean temperature＞monthly mean relative humidity.The negative correlation with very significant between annual extreme maximum air temperature,monthly mean wind speed and height growth of Acacia melanoxylon. The correlation sorting was that annual extreme maximum air temperature＞monthly mean wind speed.Established the multiple regression equation of height of Acacia melanoxylon and respective climatic factors,the regression equation reached the very significant level.6.The study on effects of climatic factors on ground diameter growth of Acacia melanoxylon shows that the positive correlation with very significant between the monthly mean temperature, annual sunshine hours,monthly mean relative humidity and ground diameter growth of Acacia melanoxylon.The correlation sorting was that annual sunshine hours＞monthly mean temperature＞monthly mean relative humidity.The negative correlation with very significant between annual extreme maximum air temperature and ground diameter growth of Acacia melanoxylon.Established the multiple regression equation of ground diameter of Acacia melanoxylon and respective climatic factors,the regression equation reached the very significant level.7.The results showed that it should select the reasonable contents of afforestation land when cultivation the Acacia melanoxylon,soil bulk density ranged from 0.86 to 1.35 g·cm-3,pH value ranged from 4.6 to 4.9,content of organic matter ranged from 5.35 to 14.19 g·kg-1,content of nitrogen ranged from 0.38 to 1.16 g·kg-1,content of phosphorus ranged from 0.62 to 3.76 g·kg-1, content of potassium ranged from 14.69 to 42.13 g·kg-1,content of hydrolyzable nitrogen ranged from 0.2 to 0.76 mg·kg-1,content of rapidly available phosphorus ranged from 1.9 to 23.58 mg·kg-1,content of rapidly available potassium ranged from 59.47 to 98.27 mg·kg-1.It must select the terrain condition of afforestation land,that was sunny slope,slope gradient less than fifteen, downhill,straight slope shape.The favorable climate was monthly mean temperature ranged from 20.9 to 21.7℃,annual sunshine hours ranged from 1607.2 to 1821 h,monthly mean relative humidity ranged from 66.9%to 73.5%,rain capacity ranged from 1216.3 to 1297.9 mm when introduced.
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