Study On The Growth Of Scotch Pine Plantations And The Variation Of Soil Nutrients In Saihanba Aera

Scotch Pine(Pinus sylvestris var. mongolica)is one of the constructive species and is very precious in Chinese cold temperate coniferous forest,witha wide distribution in Saihanba area.But the growth of the Scotch pine forests in the region have not been systematically studied, which to some extent affected the sustainable management of Scotch pine plantations in Saihanba region.In order to understand the growth of Scotch pineplantationsin Saihanba regionand provide a scientific basis for the forest management in the region,someplots were set up and investigatedaccording todifferent site conditions, different ages and different stand density in the Dahuanqi forest farm, Qiancengban forest farm,Beimandian forest farm and Sandaohekou forest farm. The main results were as follows:(1)In the spatial variation of soil nutrients, the soil nutrients on the whole in the upper part of dam were better than that in the lower part of dam.The soil nutrients on the whole in the esat of upper dam were obviously better than that in the west. Each index’s content of soil nutrients was gradually decreased with soil depth increased in the whole Saihanba area. The relationship between N,P,K content andorganic matter in soil,total nitrogen, alkaline hydrolysis nitrogen, total phosphorus, the rapid available phosphorus, total potassium andthe rapid available potassium increased with the increase of organic matter. The correlation between other N,P,K content in addition to the rapid available phosphoruswith organic matterwere extremely significant.The correlation between soil nutrients and tree height growth were insignificant.(2) The optimal model of DBH total increment was the log linear model, namely y=A+B·ln(a+C). The DBH number of average growth reaches its maximum age of sample trees and dominant trees was 9-17 years and it was late with the worse of site condition. The optimal model of height total increment was Richards model, namely y=A ·(1-Exp(-C · a))B. The model of year after year growth was z=A·B·C·(1-Exp(-C·a))B-1·Exp(-C·a). The height number of average growth reaches its maximum age of sample trees and dominant trees was 15-39 years and it was late with the worse of site condition. The optimal model of volume total increment was Richards model, the same as height, namely y=A·(1-Exp(-C·a))B. The model of year after year growth was z=A·B·C·(1-Exp(-C·a))B-1·Exp(-C·a).The volume number of average growth reaches its maximum age of sample trees was 45-60 years and it was late with the worse of site condition. Due to the limitation of age of the Scotch pine, the volume of dominant trees had not yet reached the number of mature age.(3) The optimal models between each organ and the whole plant biomass with DBH were W干=0.0268D2.6436,W枝=0.0612D1.8627,W叶=0.1124D1.5429,W果=0.0003D2.6893,W整=0.093D2.3429. The range of biomassof Scotch pinein Saihanba areawas39.09-122.91 t/hm2.Scotch pine biomass allocation proportion has certain law, as the stem > branch > leaf > fruit. The stem proportion increased with the increase of age. The branch proportion and the leaf proportion decreased with the increase of age. But the proportion of each organ tended tobe stable until a certain age. The correlation between the proportion of each organ biomass and DBH was insignificant.