砒砂岩地区3种主要树种边材液流动态特征

为深入了解砒砂岩地区主要树种的水分利用特征,以内蒙古圪秋沟小流域砒砂岩区水土保持科技示范区为研究区域,运用茎热平衡法(SHB)对沙棘、柠条、油松3种主要树种蒸腾耗水进行研究,监测3种树种的边材液流日变化及不同天气条件下的液流速率。结果表明:(1)在生长期内,3种树种的液流速率均呈单峰曲线,其到达峰值时间大体相同。(2)在晴天时,沙棘的平均液流速率最高,可达到0.117 72cm/s,而油松与柠条的液流速率相近,3种树种的日平均流速分别为0.029 01,0.018 15,0.022 03cm/s。(3)在不同天气条件下,3种树种的边材液流速率变化规律均为晴天阴天雨天,各树种达到峰值的时间也有所差异,其规律亦为晴天阴天雨天。研究结果旨在为砒砂岩地区植物水分供求关系提供数据支撑,为该地区生态恢复与环境治理提供理论依据。

Dynamic Variation of Sapwood Flow of Three Main Tree Species in a Soft Sand-rock Area

To understand the water use character of main tree species in soft sand-rock area,three main tree species (Caragana korshinskii Kom 、Hippophae rhamnoides Linn.Pinus tabuliformis) in Geqiugou,Ordos,Inner Mongolia was examined using stem heart balance method to explore sap flow of these three tree species under different weather conditions and the daily change.The results showed:(1) The sap flow rates of the three tree species showed a unimodal curve,and nearly reached the peak at the same time during growing.(2) In the sunny day,the sapflow rate of Hippophae rhamnoides Linn was the highest,about 0.117 72 cm/s,the sap flow rate of Caragana korshinskii Kom and Pinus tabuliformis were similar;the daily average rates of the three species were 0.029 01 cm/s,0.018 15 cm/s,and 0.022 03 cm/s,respectively.(3) In different weather conditions,the sapflow rates of the three species showed sunny day＞cloudy day＞rainy day,and the time when they reached the peak showed sunny day＞cloudy day＞rainy day.The results of the study are to provide theoretical basis for studying the water supply-demand relationship of plants in soft sandrock area and environmental management.