影响沙地樟子松天然更新的主要生态气候因子的定量分析

QUANTITATIVE ANALYSIS ON PRINCIPLE ECO\|CLIMATIC FACTORS OF LIMITING NATURAL REFORESTATION OF \%PINUS SYLVESTRIS\% VAR. \% MONGOLICA\% ON SANDY LAND

利用呼伦贝尔草原 2个组 8个站点的 33个变量进行了逐步判别分析。结果表明 ,影响沙地樟子松天然更新的生态气候因子主要是极端最低气温、极端最高地温、1月蒸发量和多年平均积雪日数等 4个 ,它们主要是通过对种子萌发和幼苗的生长发育施加限制作用。因此 ,在造林生产实践中应选择适宜的立地克服其消极影响 ,必要时应采取人工措施促使其天然更新 ,保障其持续稳定发展。

Stepwise discriminate analysis (SDA) was conducted using 33 variables from 8 meterological stations which are divided into 2 groups in this paper. Results show that principal limiting factors on natural forestation of \%P.sylvestris\% var. \%mongolica\% on sandy land include extremely lowest air temperature, extremely highest surface temperature, evaporation quantity in January and average days of accumulating snow for many years, which strongly influence the seed germination and the growth and development of shoots. Therefore, it is neccessary to choose suitable habitats or niches to overcome those adverse factors as mentioned above in aforestation pratice, and take effective artificial measures to promote its natural reforestation so as to guarantee their stable and sustainable development.