【作者】 包贺喜吐；

【导师】 红雨； 孙铁军；

【作者基本信息】 内蒙古师范大学 ， 植物学， 2010， 硕士

【摘要】 荒山荒坡地植被覆盖度低,保水固土性差,易使水土流失,是北京生态圈建设的重要组成部分,也是山区生态建设的重点和难点。因而如合理、有效地利用土壤水资源就成为保证植被生理需水、改善生态环境关键。针对当前该区植被恢复重建中存在的科学问题,以植被建设的关键性限制因素土壤水分为出发点,通过自然降雨条件下,选择15°和25°坡地设置草地雀麦种植试验小区,并以裸露地为对照,观察草地雀麦生物学特性及坡地降雨入渗、产流及土壤水分的动态变化规律,研究草地雀麦种植对坡地土壤水分动态变化的影响,取得的主要结论如下:1.北京地区在15°坡地草地雀麦种植4年后,地上生物量可达4967.3 kg/hm2 ,0～30 cm地下生物量为3941.4kg/hm2,且0～10cm土层地下生物量是草地地下水土保持功能发挥的主要组成部分。坡度对草地雀麦地上生物量有显著影响,而坡度对草地雀麦地下生物量无显著影响;草地雀麦刈割处理对地上、地下生物量的生长有一定的促进作用。2.草地雀麦种植可显著提高土壤入渗速率,水土流失防治效果明显,其保水能力达94.2%。坡度对地表年径流深度影响不显著;刈割会降低草地的土壤入渗速率,从而加大草地雀麦坡地地表径流,但对年径流深度影响不大;草地雀麦不同行距种植对植被高度无显著影响,对盖度影响显著,进而显著影响年径流深度;密度越大,水土流失防治效果越明显。3.北京地区15°坡地土壤水分动态变化较为明显的时期主要分布在3～9月份,期间又可以分为雨季前期(3月～6月)土壤含水量持续下降和雨季(7月～9月)土壤含水量逐步上升阶段。其中,雨季前期土壤含水量较低,草地雀麦种植可以减缓坡地0～60cm深度土壤含水量下降,并以0～20cm土层作用最大,维持土壤含水量在13.3%～14.6%之间;雨季降雨明显增加时,草地雀麦可以促进坡地土壤水分吸收达到相对较高的状态,并在土壤含水量高于16%以上后,加速0～60cm土层,尤其是0～20cm土层土壤水分散失,维持土壤含水量在13.4%以下。坡度的变化、刈割处理对草地雀麦土壤水分动态变化规律影响不明显;而草地雀麦行距的变化对土壤水分的动态变化影响较大,合理的密度种植对坡地土壤水分的动态变化的影响作用最大,北京地区以30cm为行距种植草地雀麦对坡地水土保持效果最为明显。4.在饱和持水量条件下,不同密度草地与裸地土柱蒸散量随着时间的延续呈现出先增加后减小的趋势,其中,裸地土柱蒸散量最少;草地雀麦土柱蒸散量随种植密度的增加而增大。在饱和持水量的条件下,草地雀麦具有加速土壤水分散失的作用。更多还原

【Abstract】 Slope in barren hills has a low rate of vegetation coverage, poor soil and water conservation and easy to erosion, and it is an important part in ecosystem construction of Beijing,and also an important component of mountain area ecosystem construction. Therefore how to use of soil water reasonable and effectively becomes the key to insuring water vegetation needs and the improving the ecological environment. In light of existing vegetation rehabilitation in this area of scientific issues, which has taken soil water the key limiting factor in vegetation which has as into the starting point of through natural rainfall conditions, Choose 15°and 25°slope to set Bromus riparius test plot, and take bare places as comparison, observe the biological characteristics of brome and slope rainfall infiltration, runoff and soil moisture dynamic variation, research Bromus riparius on hill slope soil moisture changes, the main conclusions are as follows:1. Planting Bromus riparius for 4 years in 15°slope in Beijing the amount of aboveground biomass can up to 4967.3 kg/hm2,while 0 ~30 cm below-ground biomass was 3941.4kg/hm2, and underground biomass of 0 ~ 10cm is major part of underground water and soil conservation. Slopes has significant effect on the up-ground and has nothing with on the underground biomass ; Grass harvesting treatment on the ground and underground biomass have a certain role in promoting growth.2. Planting of Bromus riparius can significantly increase soil infiltration rate, and to prevent from soil erosion, and its water-retention capacity was 94.2%. Slope on earth surface runoff has no significant effect with it; Grass cutting will reduce the soil infiltration rate, thereby to increase the Bromus riparius slope surface runoff, but has little effect on annual runoff depth; Bromus riparius different plant spacing on plant height no significant effect on the cover, but significantly affect the depth of annual runoff. The higher density, the more obvious soil erosion control effect was.3. The period of soil dynamic moisture 15°slope in Beijing, are more obviously between March to September, in which, it can be divided into the early rainy season (March ~ June) soil moisture continued to decline and rainy season (July to September) the soil moisture content increased gradually phase, which pre-rainy season, low soil moisture and Bromus riparius can slow down the slope of 0 ~ 60cm depth soil water content decreasing , and play the role of the largest to the 0 ~ 20cm soil layer to maintain soil water content between 13.3% ~ 14.6%; rainfall significant increase during the rainy season, Bromus riparius hill slope can contribute to achieve a relatively high status of soil water absorption, and after 16% of soil water content, the acceleration of 0 ~ 60cm soil layer, in particular with 0 ~ 20cm layer of soil water loss, can maintain soil water content under 13.4%; gradient changes and cutting treatments on Bromus riparius dynamic changes of soil moisture had no obvious effect; Bromus riparius spacing change has some effect on soil Dynamic changes of water, reasonable density of planting the slope of the dynamic changes of soil moisture plays an important part and the slope to 30cm for the spacing on the slope planted Bromus riparius best soil and water conservation in Beijing.4. Under the conditions of saturated water, evapotranspiration increase and then decrease for grassland and bare land with different density as the extension of time, in which, evapotranspiration of bare soil column is the least, evapotranspiration of brome increase with grass planting density. When the soil moisture is saturated, Bromus riparius can accelerate the loss of soil moisture .更多还原