不同经营措施笋用麻竹人工林的地表径流研究

Study on runoff in Dendrocalamus latiflorus plantation used for shoot by the different management measures

通过测定南靖国有林场山地麻竹笋用林 3种经营措施的地表径流和泥沙含量 ,结果表明在一定降雨量范围之内 ,呈现出随着降雨量级别的上升 ,地表径流量先增长较慢 ,后增加较快的趋势 ;降雨量在 1 0 mm以下均不出现地表径流 ,60 mm以上的降雨占全年降雨量的 5 9.5 0 % ,产生的地表径流总量却占年地表径流量的 79.5 8%。从泥沙含量月动态来看 ,采用扩穴经营的林地泥沙含量最大的月份出现在 2 0 0 0年 8月 ,与地表径流出现的最大月份吻合 ,而经过全翻和带翻的林地的径流泥沙含量在 2 0 0 0年 6月达到最大。地表径流和泥沙含量都以实行全翻的竹林为最大 ,每年流失分别达 30 .37mm和 2 34.45 kg· hm- 2 ,其次是带翻 ,最小的是扩穴 ;并经方差分析显示全翻与扩穴之间的差异显著 ,带翻却不显著。地表径流及其泥沙含量均具有明显的季节性 ,雨季大于旱季 ;地表径流量与一次性降雨量呈显著的指数函数相关。通过对笋用麻竹人工林不同经营措施的对比研究 ,发现麻竹人工林具有较强的水源涵养能力和泥沙固着能力 ,适合在我国热带和南亚热带地区作为特殊用途的水土保持林。

Dendrocalamus latiflorus is an important bamboo of wide usage, fast growing and wide adaptability. Dendrocalamus latiflorus spread widely in Tropic and Subtropical areas, especially in the southeast of Fujian Province. Bamboo shoot of Dendrocalamus latiflorus not only tastes delicious but also has abundant nutrition. Its strong root has great ability to maintain water and soil resources effectively. Dendrocalamus latiflorus has high economic benefit, as well as social and ecological benefit. However, the knowledge about silviculture technique of Dendrocalamus latiflorus was still in the superficial stage because its biological and ecological properties have not been fully recognized. Furthermore, unreasonable management measures taken by the farmer leads to the serious soil losses in Dendrocalamus latiflorus plantation. Therefore, effective measures for water and soil conservation in management of Dendrocalamus latiflorus plantation should be taken. Experiment plots with were established in Xiaoshangcheng working unit of Nanjing Stated own Forest Farm, which include overall tending, strip tending and ditch tending. The soil and water losses of each plot were measured for one year.The results showed that the runoff increased gradually with the increase of rainfall. Furthermore, runoff increased slowly at the first stage, then did faster .Surface runoff happened when rainfall exceeded 10mm. The over 60mm rainfall accounted for 59 50 percent of the total annual rainfall, however it's surface runoff accounted for 79 58 percent of the total annual runoff. The monthly soil and water losses in the ditch tending treatment was the highest in August during whole year. The runoff in overall tending treatment and strip tending treatment was in June. Annual surface runoff and soil losses in the overall tending treatment were 30 37 mm and 234 45 kg·hm -2 ,respectively. There were in the sequence of the overall tending > the strip tending treatment > the ditch tending treatment. There was obvious difference between the ditch tending treatment and the overall tending treatment through equation analysis. There were obvious seasons dynamic change in runoff and soil losses ,in sequence of rainy season > drought season. The correlation between Surface runoff and rainfall could be modeled fairly by index. Dendrocalamus latiflorus plantation was suited for planting in the southern subtropical areas of China. For possessing the function of maintaining water and soil resources, tropical and Dendrocalamus latiflorus plantation also could be specially used for soil and water conservation.