间伐对塔里木沙漠公路防护林乔木状沙拐枣生长与土壤水盐分布的影响!

Effects of thinning on Calligonum arborescens growth and soil water-salt distribution in Tarim Desert Highway shelterbelt,Xinjiang of Northwest China

在塔里木沙漠公路防护林示范段对老化衰败的乔木状沙拐枣林进行间伐试验,并对间伐后沙拐枣的生长与土壤水盐分布进行连续监测.结果表明:间伐对乔木状沙拐枣的物候期不会产生影响;间伐后保留株的当年株高、冠幅、地径和新枝长等的生长量均大于对照,其增幅的大小依次为株行距2m×1m>株行距1m×1m>对照,且差异显著;间伐当年株行距2m×1m和1m×1m同化枝的表面积分别为每株5.97和5.22m2,均显著高于对照的每株3.1m2;株行距2m×1m、1m×1m与对照在0～160cm土层含水量的差异达到极显著水平,且随间伐强度的增大土层含水量明显增加;土壤含盐量的大小依次为对照>株行距1m×1m>株行距2m×1m,差异显著;间伐后保留株的密度以株行距2m×1m的效果为佳.

In order to understand the effects of thinning on the growth of Calligonum arborescens and the soil water-salt distribution in Tarim Desert Highway shelterbelt,a thinning experiment was conducted on an aged and declined C.arborescens woodland in a demonstration section of the shelterbelt,with the growth of C.arborescens and the soil water-salt distribution monitored.Thinning had no effects on the phenophase of C.arborescens,but after thinning,the growth of the current year plant height,crown width,ground diameter,and new branch length of reserved trees was larger than that of the control,and the increment was in the order of planting space 2 m×1 m 〉 1 m×1 m 〉 the control,with significant differences among the treatments.The assimilation branch surface area in treatments 2 m×1 m and 1 m×1 m were 5.97 m2 and 5.22 m2 per plant,respectively,being significantly larger than the control（3.1 m2 per plant）.The soil moisture content in 0-160 cm layer was significantly higher in treatments 2 m×1 m and 1 m×1 m than in the control,and increased obviously with thinning intensity.The soil salt content was in the order of control 〉 planting space 1 m×1 m 〉 2 m×1 m,and the differences among the treatments were significant.It was suggested that the best reserved plant density after thinning was planting space 2 m×1 m.