大别山上舍小流域不同林分土壤侵蚀特征研究

发布时间：2018-03-27 17:33

本文选题：大别山区　切入点：土壤抗蚀性　出处：《南京林业大学》2015年硕士论文

【摘要】：本试验通过对大别山马尾松林、杉木林和桑园土壤分析,可以系统性地掌握大别山典型土壤的理化性质,对马尾松林和桑园土壤的抗侵蚀能力进行了评定,并且通过扰动土人工模拟降雨,研究了植物篱带和植被覆盖度对大别山土壤坡面的土壤侵蚀影响。得出主要结论为:(1)土壤有机C、N空间变异显著大别山马尾松林和杉木林土壤有机C、N和随着土层深度的增加而减小,而桑园由于人为耕作和施肥导致土壤有机C和N含量较均匀;浅层土壤有机C含量:马尾松林杉木林桑园,桑园土壤N含量显著高于马尾松土壤和杉木林土壤;土壤有机C的含量变化与2mm土壤团聚体含量变化有相似趋势。(2)土壤团聚体变异多样化大别山马尾松林和杉木林土壤2mm团聚体含量由表层到深层递减,马尾松土壤表层团聚体最高达71.80%,大团聚体总量越高抗侵蚀能力越强,证明了下层土壤抗侵蚀性比上层土壤的抗蚀性弱;马尾松集水区粘粒1.87%和砂粒48.13%组成略大于马尾松各层次土壤;杉木林集水区的土壤颗粒是由土壤的浅层以下冲刷而下。(3)根系主导土壤抗侵蚀性大别山典型土壤利用类型马尾松林和桑园,土壤抗蚀性强弱表现为马尾松林桑园;表层(0—10 cm)范围内,根长的排列顺序为:桑园地马尾松,各样地土壤抗蚀性在垂直层面上的变化呈较明显的规律性,即随着土层深度的增加,抗蚀性呈减小趋势;两种土地利用类型根系主要分布在0—30 cm层次内,而且在1 mm的根系长度由表层向深层递减,土壤平均孔径随着深度的增加而减小,而土壤比表面积随着深度的增加而增大。(4)土壤孔径特征可以作为流失土壤来源参考属性大别山马尾松对0—40 cm次层土壤结构影响显著,各层次孔径分布呈分层现象,而桑园各层次土壤孔径分布差异不大。土壤孔径越大,土壤抗蚀性越强,土壤比表面积越大土壤抗蚀性越小;桑园土壤抗蚀性与土壤土壤根系质量在0.01水平上显著相关,马尾松土壤平均孔径与土壤根系质量在0.05水平上显著相关。降雨时马尾松林地坡面壤中流在下坡蓄满流出地表带处颗粒,导致马尾松径流场土壤和10—20 cm层次土壤大孔径分布完全吻合,而桑园人为翻种频繁,导致土壤层次性质相似,降雨时表层土壤颗粒流失严重。(5)植物篱拦沙截流效应显著模拟降雨研究发现,土壤有机碳流失量随着降雨强度的增加而增加,影响土壤有机碳流失三种因素强弱关系:降雨强度土壤植被覆盖度土地坡度;在5°80mm/h下,1.5m和3m植物篱覆盖土壤在降雨初期不会产生径流;3m植物篱减流率6.89%—10.05%;减沙率4.30%—9.38%;1.5m植物篱减流率24.55%—70.67%,减沙率25.96%—58.63%;1m植物篱覆盖径减流率48.38%—78.67%,减沙率42.37%—73.02%;由于植物篱地表覆盖和地下根系的拦流截沙,径流泥沙砂粒所占比例裸地1m植物篱1.5m植物篱3m植物篱,粘粒比例则相反3m植物篱1.5m植物篱1m植物篱裸地。
[Abstract]:Through the soil analysis of Pinus massoniana forest, Chinese fir forest and mulberry garden in Dabie Mountain, the physical and chemical properties of typical soil in Dabie Mountain were systematically grasped, and the soil erosion resistance of Pinus massoniana forest and mulberry orchard was evaluated. And artificial simulation of rainfall through disturbed soil, The effects of hedgerow and vegetation coverage on soil erosion in Dabie Mountain were studied. The main conclusions were as follows: 1) the spatial variation of soil organic C ~ (1) N in Pinus massoniana forest and Chinese fir forest in Dabie Mountain was significant, and with the depth of soil layer. The degree increases and decreases, The soil organic C and N contents in mulberry garden were uniform due to manmade tillage and fertilization, and the organic C content in shallow soil was significantly higher than that in Pinus massoniana forest and Chinese fir forest, and the N content in mulberry garden was significantly higher than that in Pinus massoniana and Chinese fir forest soil. The variation of soil organic C content was similar to that of 2mm soil aggregate content. (2) the variation of soil aggregates varied from surface layer to deep layer in Pinus massoniana forest and Chinese fir forest in Dabie Mountain. The surface aggregate of Pinus massoniana soil reached 71.80, and the higher the aggregate amount was, the stronger the erosion resistance of the lower soil was, which proved that the erosion resistance of the lower soil was weaker than that of the upper soil. The composition of clay and sand in Pinus massoniana catchment was 1.87% and 48.13% respectively. The soil particles in the catchment area of Chinese fir forest were washed down from the shallow layer of soil. The root system dominated the typical soil use types of Masson pine forest and mulberry orchard in Dabie Mountain, and the soil erosion resistance was shown as the mulberry garden of Masson pine forest. In the range of 0-10 cm), the order of root length was as follows: Pinus massoniana in mulberry garden, soil erosion resistance of various plots changed more regularly on vertical level, that is, with the increase of soil depth, the corrosion resistance decreased; The root system of the two land use types mainly distributed in 0-30 cm level, and the root length of 1 mm decreased from the surface layer to the deep layer, and the average pore diameter of the soil decreased with the increase of soil depth. The soil specific surface area increases with the increase of soil depth. 4) the soil pore size characteristics can be used as a reference attribute for soil loss. Pinus massoniana has a significant effect on the soil structure of 0-40 cm layer, and the pore size distribution of each layer is stratified. The larger the soil pore size, the stronger the soil erosion resistance, the smaller the soil specific surface area, the lower the soil corrosion resistance, and the higher the soil root quality, the more significant the soil erosion resistance of mulberry orchard is at 0.01 level, and the higher the soil specific surface area is, the smaller the soil specific surface area is. The average pore size of Pinus massoniana soil was significantly correlated with soil root quality at 0.05 level. The results showed that the large pore size distribution of Pinus massoniana runoff field was consistent with that of soil at 10 ~ (-20 cm) cm level, while the mulberry garden was planted frequently, which resulted in similar soil properties. The results showed that the soil organic carbon loss increased with the increase of rainfall intensity. There are three factors influencing soil organic carbon loss: rainfall intensity, soil vegetation cover degree, land slope; At the beginning of rainfall, the runoff reduction rate of 3 m hedgerow will not be 6.89-10.05; the sediment reduction rate of 4.30- 9.38m hedgerow is 24.55-70.67; the sediment reduction rate is 25.96- 58.63m hedgerow coverage diameter; the sediment reduction rate is 48.38-78.67m; the sediment reduction rate is 42.37-73.02.The sediment reduction rate is 42.37-73.02.The sediment reduction rate is 42.37-73.02.The sediment reduction rate is 24.55-70.67, and the sediment reduction rate is 25.96- 58.63m hedgerow covering diameter 48.38-78.67.The sediment reduction rate is 42.37-73.02. And the flow and interception of the underground roots, The proportion of sand and sand in runoff was 1.5 m hedgerow 3m in bare land, whereas the ratio of clay grain was opposite to that of 1m hedgerow in 3 m hedgerow on bare land.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714.7

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