生态因子对铁卜加地区牧草产量动态影响的分析

Effects of Climatic Factors on Herbage Yields in Tiebujia Region

根据7年的牧草月产量定位观测资料,运用相关普查法对影响牧草产量的气候因子进行了筛选。结果表明,春季∑2～4月降水量和3～5月日均气温对5～9各月牧草产量(干重)分别有显著的相关(P<0.05);而∑2～6月和∑2～8月日照只与8、9两月产量(干重)有显著的负相关。对牧草月产量之间进行相关分析发现,5月鲜草量与后期产量有极显著的正相关(P<0.01)。通过采用逐步回归法建立了牧草月产量的多元回归数学模型,其中,7、8两月牧草产量(干重)模拟率均在85%和90%以上。由各因子贡献率大小得出,5月鲜草量是铁卜加地区牧草产量的主要限制因子,春季∑2～4月降水量和3～5月日均气温是制约5月鲜草量的主要气候因子。

Based on data of herbage yields and climatic records for 1987～1993, the major climatic factors affecting herbage yields were selected throught observing the degree of correlation between them. It was shown that the monthly dry herbage yield for the period of May—September was significantly correlated, respectively, with the total amount of Precipitation for February—April and the average daily temperature for March—May (P<0.05). Significant negative correlation was found between the accumulated hours of sunshine for February—June or February—August and the dry yield for August—September. It was also observed that the correlation was highly significant between the fresh yield in May and that in later months. A regresssion model based on the above observations gave a forecast of dry herbage yield for July and August, with a degree of fit as 850% and 90%, respectively. It could be concluded that the fresh herbage yield in May was a major indicator of the total yield in the year in Tiebujia region, while the indiator itself was determined by the amount of precipitation for February—April and the average daily temperature for March—May.