摘要
塔里木沙漠公路防护林生长于极端干旱的塔克拉玛干沙漠中,防护林植物的蒸腾耗水和灌溉管理是防护林可持续的核心问题。利用植物茎流计连续测定了塔里木沙漠公路塔中段防护林植物梭梭的茎干液流、蒸腾耗水量。结果表明:梭梭茎干液流具有明显昼夜节律性,液流的高峰值出现在白天10:00~15:00,最小值出现在0:00~03:00,夜间也保持较小的液流;茎干液流受环境因子影响而波动,太阳辐射、气温和风速与茎干液流有较明显的正相关关系,相对湿度和茎干液流呈负相关关系;滴灌条件下,防护林带内土壤含水量充足且在各个月份变化不大,土壤含水量对茎干液流影响不大;依据清晨和午后水势变化,梭梭体内水分在夜间得到了较好的恢复;在一个生长季内,3株直径为2.0、2.8、3.4cm的梭梭总的耗水量分别为295、436、616kg,日平均耗水量分别为1.48、2.18、3.08kg;现行灌溉模式提供了充足的水分供应,梭梭的水分状况良好;在充足水分条件下,梭梭有较大的蒸腾耗水量,干旱的环境条件和较为充足的水分供应是梭梭耗水量大的主要原因;依据梭梭的水分状况,当前水分管理为防护林提供了较充足的水分。
Abstract: The Tarim desert highway protection forest grows in the hyperarid Taklimakan Desert. Therefore, irrigation and water use are crucial for a sustainable management of this protection forest. In a protected part of the forest near the Tarim Desert highway, stem sap flow and water use of Haloxylon ammodendron were measured using the heat-balance technique. The stem sap flow exhibited a distinct diurnal course with maximum values between 10:00 to 15:00, and minimum values between 00:00 to 03:00. Generally, sap flow was lower at night than during the day. The sap flow was influenced by environmental factors:it was positively correlated with solar radiation, air temperature and wind speed, and negatively correlated with the relative humidity. Under the present irrigation scheme, the soil moisture remained almost constant, and was not correlated with sap flow. In Haloxylon ammodendron, the values of predawn and midday water potential provided no indications of drought stress. The average daily water use of three individuals of Haloxylon ammodendron with a diameter of 2.0 cm,2.8 cm and 3.4 cm were 1.48 kg,2.18 kg and 3.08 kg,respectively,amounting to an annual water consumption of 295 kg ,436 kg and 616kg. The good water status of Haloxylon ammodendron indicated that the water supply to the protection forest by the present water management is sufficient. When sufficiently irrigated, Haloxylon ammodendron used a relatively large amount of water, what was also caused by the extremely arid environment.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第8期3713-3720,共8页
Acta Ecologica Sinica
基金
中国科学院知识创新工程重要方向资助项目(KZCX3-SW-342-02)
国家科技部西部开发科技行动重大资助项目(2004BA901A21-1)~~
关键词
塔克拉玛干沙漠
梭梭
蒸腾
耗水量
茎干液流
气象因子
Taklimakan desert
Haloxylon ammodendron
transpiration, water consumption
stern sap flow
meteorological factors