摘要
鲜黄小檗是我国祁连山区长期适应高寒气候条件而发展起来的主要的亚高山灌丛类型之一,通过野外观测,对祁连山西水林区鲜黄小檗灌丛在39次降雨事件中冠下穿透雨的分区性、径向分布特征及影响因素进行了分析,结果表明：鲜黄小檗灌丛单株的平均穿透雨率为40.44%;冠层中心区和辐散区的穿透雨量与次降雨量之间均为线性关系,当降雨量小于0.7 mm时,冠层中心区没有穿透雨产生;冠层辐散区穿透雨率随降雨量的增大出现先增大后趋于稳定的幂函数关系,受冠层结构影响,冠层辐散区穿透雨具有明显的空间异质性,沿径向由距灌丛基部10 cm处的16.19%单调递增至90 cm处的69.92%,30-70 cm为主要递增区,穿透雨率径向空间变异系数随降雨量的增大而降低;此外,鲜黄小檗灌丛的穿透雨率随物候期发生变化,叶量稳定期比展叶期的穿透雨率低11.82%。研究结果可为祁连山鲜黄小檗灌丛生态水文功能的定量评价和基于生态过程的灌丛水文模型的参数化提供数据支撑。
Berberis diaphana is one of the main subalpine shrubs in Qilian Mountains,Northwest China which has adapted the high-cold climate and evolved in a long period. In mountain habitat condition,the shrub density expresses a large difference between different slope positions and different altitudes,then,the allocation characteristics of rainfall in forest stand have no universality for other forestlands. While research the allocation characteristics of rainfall on individual shrub scale has a positive significance for quantitatively recognize and accurately evaluate the eco-hydrologic processes of this type shrub. In this paper,the individual Berberis diaphana shrub was made as the observed object,the area partition,radial distribution characteristic of throughfall under the canopy as well as its influence factors were measured and analyzed under four single representative Berberis diaphana shrubs. The results show as follows：（1）there were 39 meaningful rainfall events occurred in the research period,of which the mean throughfall rate of Berberis diaphana shrubs was 40.44%,therein,the throughfall rate was 19.98% and 50.57% in canopy center area and canopy radial area,respectively;（2）there were linear relationships between throughfall and rainfall both in canopy center area and canopy radial area： the throughfall increased with the increasing rainfall,but the increase rate in canopy central area was far smaller than that in canopy radial area;when the rainfall was no more than 0.7 mm,there was no throughfall appeared under the canopy central area;（3）along with the increase of rainfall,throughfall rates in canopy radial area firstly increased and then tended to stable,a power function relationship was expressed between them;while in the canopy central area,the throughfall rates expressed discrete distribution;（4）in canopy radial area,the throughfall rates had obvious spatial heterogeneity which increased from 16.19% at distance 10 cm to 69.92% at distance 90 cm,the main increase region was 30- 70 cm;the spatial variable coefficients along the radial direction of throughfall rate increased with the increasing rainfall;（5）amount of branch and leaf influenced the throughfall rate,the throughfall rate in stable phase of leaf amount was 11.82% lower than that in leaf extension stage,and the influence of leaf amount was more obvious in smaller rainfall events.
出处
《干旱区地理》
CSCD
北大核心
2016年第4期793-799,共7页
Arid Land Geography
基金
国家自然科学基金项目(91125012
31460221)资助
关键词
祁连山
鲜黄小檗灌丛
穿透雨
分布特征
Qilian Mountains
Berberis diaphana shrub
throughfall
distribution characteristics
