摘要
兴安落叶松在大兴安岭分布广泛,土壤水分变化与其生长、发育关系密切,二者相互影响。通过测定兴安落叶松林不同深度土壤水势,研究兴安落叶松林生长季土壤水势的月、日变化特征。结果表明,土壤水势均值随深度增加而减小。20、80cm土壤水势变化程度大,40、60cm变化较为平缓。60cm土壤水势值较能反应林下土壤水势的大小。各深度土壤水势均采用三次函数拟合较好。生长季土壤水势在20cm呈整体下降趋势,40、60、80cm呈较快上升后平缓下降趋势。5、6月为土壤聚水期,水势上升迅速,土壤水势随深度增加而下降。7、8、9、10月为土壤失水期,水势下降平缓,土壤水势随深度增加而上升。土壤水势变化响应降水量、土壤温度的变化。土壤水势日变化特征:除5月20cm土壤水饱和外,各月20、40、60cm日变化特征一致,80cm在7、10月与其它深度特征不同。一天中,土壤水势极值常出现在7点左右与9点左右。
Larch(Larix gmelini Rupr.)are widely distributed in the Greater Khingan Mountains.Its growth and development are closely related to soil water.By the determination of soil water potential of different depths,I studied the monthly variations and diurnal variations of soil water potential in larch forest.The results of the experiment indicate that the mean value of soil water potential decreased with the increase of depth.The soil water potential of the depth of 20cm and 80cm changes in a large extent,the depth of 40cm and 60cm changes more gently.The 60cm soil water potential values can reflect the soil water potential values in the forest.The soil water potential values are fitted with cubic functions.During the growing season,the soil water potential of the depth of 20cm has downward trend all the time,others show a rapid rise is followed by a gentle downward trend.It is the soil water accumulation period from May to June.In this period,the soil water potential increased with time and decreased with the increase of depths.It is the soil water consumption period from July to October.In this period,the soil water potential decreased with time and increased with the increase of depth.The precipitation and the soil temperature affect the soil water potential.Daily change characteristics of soil water potential of depths from 20cm to 80cm are identical except for the depth of 20cm in May.In July and October,features of the depth of 80cm are different from others.Extreme values of the soil water potential are usually appearing about 7 o'clock and 9 o'clock in a day.
作者
田原
张秋良
巴特
匡艳华
Yuan Tian;Qiuliang Zhang;Te Ba;Yanhua Kuang(Inner Mongolia Agricultural University,Hohhot,Inner Mongolia,010020,China;Forestry Bureau of Linxi County,Chifeng,Inner Mongolia,025250,China)
基金
国家自然科学重大项目子课题(31290221)
内蒙古自治区博士基金(2014BS0318)
内蒙古自治区高等学校科学技术研究项目(NJZY13080)
关键词
大兴安岭
兴安落叶松
土壤水势
月变化
日变化
The Greater Khingan Mountains
Larix gmelini Rupr.
Soil Water Potential
Monthly Variation
Daily Variation
