华北土石山区基于水分承载力的植被结构配置分析

对华北土石山区潮关西沟坡度、土壤厚度、海拔、坡向等立地因子进行立地类型划分，将其森林区域划分为72个立地类型，包括中山阴坡陡坡薄层土立地类型、中山阴坡陡坡中层土立地类型、中山阴坡陡坡厚层土立地类型等。结果表明:1）山杏、臭椿、油松的可承载量相对比山杨、侧柏和栓皮栎大；2）潮关西沟地区大多数中等退化区的样地水分供应较为充足，能满足主要乔木树种在5月份的需水量；3)4种立地条件下的样地涵养水源效益的排序，不同立地条件下样地D4的可能截流量最高；4）在垂直结构配置上，以混交林C4、D4、C5、臭椿林A2的自然演替为基础进行人工配置较优；5）在水平结构配置上，低山阴坡陡坡中层土下坡位配置以油松为主；低山阳坡平坡薄土层下坡位人工增加山杏种植；低山阴坡陡坡厚层土中坡位应因地制宜，在土壤含水量较多的样地内适当增大白蜡的栽植比例，在土壤含水量较少的地区以椴树为主要树种，根据立地条件和林分类型配置最优样地的林分结构。

A Study on the Technology of Vegetation Horizontal and Vertical Structure Configuration in Secondary Degeneration Area Based on the Natural Succession Rule

According to the slope,the thickness of soil,altitude,the direction of slope and others site factors in Chaoguan Xigou,a typical rocky mountain area in northern China,72 site types were divided,such as thin,moderate,and thick soil layers in steep slope of middle mountain.The results indicated that:1) Armeniaca sibirica,Ailanthus altissima,and Pinus tabulaeformis showed higher tree carrying capacity than Pobulus davidiana,Platycladus orientalis,and Quercus variabilis.2) Relatively adequate water supply was found in most areas with moderate degradation,which could meet the water demand of the main tree species in May.3) The comparison of water conservation benefits under 4 site conditions indicated that plot D4 exhibited the highest water intercepting capacity.4) In the vertical configurations,manual optimal configurations based on natural succession were found in plots C4,D4,C5 and plot A2 (Ailanthus altissima).5) In the horizontal configurations in low mountainous area,P.tabulaeformis was suitable for steep and low shady slope with moderate soil layer,A.sibirica for sunny zero slope with thin soil layer.In shady and steep slope with thick soil layer,Fraxinus chinensis were suitable for the soils with high moisture,while Tilia platyphylla for low moisture.The stand structure optimization should be conducted in accordance with site conditions and stand types.