日照因子与汉中飞播油松成苗效果关联分析

Correlation Analysis on Sunshine Hours and Effective Grown-up Seedling of Pinus tabulaeformis by Aerial Seeding in Hanzhong

日照因子是1种主要的气候资源,决定着林地水热资源的存在状态和分配规律,进而影响飞播造林成苗效果。为此,在研究汉中降水量和温度与飞播油松成苗效果关系的基础上,利用1997年汉中飞播油松成苗期有苗样方频度和成苗量调查数据,结合当地1997-2004年日照指标,采用相关分析法和逐步回归模型分析法研究了成苗效果与日照因子的关系,并通过与温度和降水量研究结果对比分析,探讨了日照、温度和降水量匹配协调作用对成苗效果的影响。结果表明:成苗效果与年日照时数和年降水量呈极显著正相关,与年均温正相关显著。日照、温度和降水与成苗效果相关性季节变化明显,日照和温度与成苗效果相关具有同向性,与降水多反向。冬季,成苗效果与12月和2月日照和均温正相关,与1月日照和均温负相关,而与各月降水量负相关极显著。春季,与3月和5月日照和均温呈显著或极显著负相关,与4月正相关极显著,而与各月降水均呈极显著正相关。夏季,与6月日照、均温和降水均呈负相关,其中,与均温和降水显著;与7月日照和均温负相关极显著,与降水呈极显著正相关;与8月日照、均温和降水正相关显著或者极显著。秋季,成苗效果与日照和均温正相关,与降水量负相关,但各月相关度有差异。剔除时间因子,6、8、9月和12月日照与对照成苗效果关系密切,4、5、11、12、9月和2月日照与RPA成苗效果相关性强。4月和11月均温对照成苗效果和RPA成苗量作用较大,4月均温和年极端最高温度与RPA有苗样方频度关系紧密。5月和2月降水与对照成苗效果和RPA成苗量相关性强,7、9月和12月降水对RPA有苗样方频度作用较大。引进时间因子,成苗效果与月均温模型关系不变;5月日照和降水成为影响成苗效果的关键因子。

As a major climatic resource,sunlight decides existential state and distribution of the forest waterheat resource,and further influences the effective grown-up seedling of afforestation by aerial seeding.Previously,based on the data of the aerial seeding of Pinus tabulaeformis in Hanzhong in 1997,we reported the relationships between the effective grown-up seedling and precipitation,as well as temperature.In this paper,we analyzed the relationship between he effective grown-up seedlings and sunshine factors.The results showed that the effective grown-up seedlings were very significantly and positively correlated to theannual sunshine hours and the annual precipitation,and significantly and positively correlated to annual average temperature.Correlations between the effective grown-up seedling and the sunshine,the temperature and the rainfall exhibited obvious seasonal variations.The sunshine and the temperature that were correlated with the effective grown-up seedling presented the same correlation trends,and reversed to precipitation.In winter,the effective grown-up seedling was positively correlated to the sunshine and the temperature of December and February,negatively correlated to the sunshine and temperature of January,and most significantly and negatively correlated to the monthly precipitation in a year.In spring,the effective grown-up seedling was significantly or very significantly and negatively correlated to the sunshine and the temperature of March and May,significantly and positively correlated to the sunshine and temperature of April,and most significantly and positively correlated to the monthly precipitation.In summer,the effective grown-up seedling was negatively correlated to the sunshine,temperature and precipitation of June,in which the correlations to temperature and the precipitation were significant,most significantly correlated to the sunshine and temperature in July,most significantly and negatively correlated to the precipitation,of July,and significantly（or most significantly）and positively correlated to the sunshine,temperature and precipitation of August.In autumn,the effective grown-up seedling was positively correlated to the sunshine and temperature,negatively correlated to the precipitation with different levels in each month.Without considering the impact of time,close correlations were found between the effective grown-up seedling and sunshine of June,August,September,and December sunshine in control area,while the sunshine of April,May,November,December,September,and February was strong associated with the effective grown-up seedling by using RPA.The mean temperature of April and November had a stronger influence on the effective grownup seedling in control area and the quantity of available seedling in RPA application area,the mean temperature of April and the annual extreme maximum temperature were closely correlated to the frequentness of the sampling plots with available seedling in RPA.The May and February precipitations were strongly correlated to the effective grown-up seedling in control area and the quantity of available seedling in RPA area,the July,September and December rainfalls had a stronger role for the quantity of available seedling in RPA area.Considering time factor,the model relationship between the effective grown-up seedling and the monthly mean temperature unchanged.The May sunshine and precipitation were key factors affecting the effective grown-up seedling.