降水和遮荫对侧柏林地种子萌发的影响

植物从种子萌发到独立自营体系建立过程中的水热平衡是适应环境的重要机制。为了解决侧柏林地内更新欠佳、籽苗分布不均等问题,开展了气象大数据的统计分析和侧柏(Platycladus orientalis)种子萌发、籽苗萌生数量的调查。结合室内种子的发芽试验,研究了侧柏种子萌发与降水时空分布、母树及一些伴生树种的关系。结果表明,土壤水分是种子萌发和幼苗出土的限制因素。降水量作为土壤水分的主要来源,对种子的萌发和幼苗生长的影响达到显著水平。夏季干旱等水热失衡的诱发因素常抑制种子的萌发出土,母树树体下和适度遮荫环境有利于侧柏种子的萌发和幼苗生长。

Effects of Precipitation and Shade on Seed Germination of Platycladus orientalis

The balance of water and heat is an important mechanism for plant acclimatization during the process of seed germination to independent self-supporting establishment. In order to solve the problems of poor update and uneven seedling distribution in the forest land of Platycladus orientalis , statistical analysis of meteorological big data and investigation on seed germination and seedling initiation of P. orientalis were carried out. Simultaneously, the relationship between seed germination and precipitation distribution, parent tree and some associated tree species was also investigated based on the indoor seed germination experiments. The results showed that soil moisture was the limiting factor for seed germination and seedling emergence. And the precipitation, as the main source of soil water, had a significant effect on seed germination and seedling growth. Drought in summer and other factors inducing the imbalance of water and heat often inhibited the germination and unearthed of P. orientalis seeds, while the seed germination and seedling growth of P. orientalis were promoted by shading under parent trees and moderate shade environment.