陕北黄土丘陵区河北杨和油松幼树径向生长特征归因分析OA

This study aimed to examine the radial growth characteristics of typical tree species used for veg-etation restoration in the loess hilly region of northern Shaanxi and to investigate their responses to envi-ronmental factors.P.tabuliformis and P.hopeiensis in plantation forest sample plots were selected in Wu-qi County,Shaanxi Province,and the stem perimeter was observed using a trunk radial change recorder and meteorological data were recorded simultaneously from April to October 2018,using the Compertz model,Mann-Kendall model,and double cumulative curve for fitting and attribution analysis.1)The stem perime-ter growth season of Pinus tabuliformis and Populus hopeiensis in northern Shaanxi Loess Hills started at the end of May,and the M-K mutation point was at the end of June and the beginning of July,and the growth slowed down in mid-July,and basically stopped after August.The growth mode of stem circumfer-ence was close to"S"type.2)Stem girth growth in this study area responded most significantly to daily minimum temperature,followed by more pronounced effects of solar radiation and air water vapor pressure deficit,and a short term surge in precipitation had a large effect on radial growth in the July rainy season,with little correlation from the entire growing season.Under the condition of more adequate moisture,the daily minimum temperature is the key meteorological factor affecting the growth of stem girth of Pinus tabuliformis and Populus hopeiensis during the growing season.Warm and suitable daily low temperature at the beginning of the growing season is the guarantee of normal growth of major native and afforestation species in the Loess Hills area of northern Shaanxi.