【作者】 龚伟；

【导师】 胡庭兴； 宫渊波；

【作者基本信息】 四川农业大学 ， 森林培育， 2006， 博士

【摘要】 本文从林地枯落物层水文生态功能、土壤水源涵养功能、土壤肥力特征、土壤碳库变化、土壤分形特征以及枯落物对土壤肥力的影响等方面，系统地研究了川南林区天然常绿阔叶林及其人工更新成檫木林、柳杉林和水杉林后土壤生态特性的变化，其结果如下： ①天然常绿阔叶林及其人工更新成檫木林、柳杉林和水杉林后林下枯落物层蓄积量，天然常绿阔叶林(25.68t／hm~2)＞水杉林(18.14t／hm~2)＞檫木林(9.95t／hm~2)＞柳杉林(1.13t／hm~2)。天然常绿阔叶林枯落物层自然含水量分别是檫木林、柳杉林和水杉林的3.18、41.33和1.53倍。在整个持水过程中，前2h内各林分枯落物层持水作用较强。林下枯落物层持水量与浸泡时间之间的关系式为Q=a ln t+b，吸水速率与浸水时间之间的关系式为V=k t~n。枯落物层最大持水量、最大拦蓄量和有效拦蓄量均为天然常绿阔叶林＞水杉林＞檫木林＞柳杉林。 ②天然常绿阔叶林人工更新后土壤容重增加和孔隙度降低导致林地土壤持水量、排水能力和渗透性降低；3种人工林中，土壤持水量、排水能力和渗透性檫木林较好，水杉林次之，柳杉林最差；相关性分析发现，土壤有机质、容重、孔隙度、持水量、排水能力和渗透性之间的相关系数均达到显著水平。 ③天然常绿阔叶林人工更新后各季节土壤自然含水率以及有机质、全氮、碱解氮、铵态氮、硝态氮、全磷、速效磷、全钾、速效钾、有效硫含量均降低，且3种人工林中，檫木林＞水杉林＞柳杉林；各林分土壤自然含水率和养分含量均为秋季＞春季＞冬季＞夏季，而土壤碳／氮比的变化恰好相反，夏季＞冬季＞春季＞秋季。土壤养分含量与土壤物理性质之间存在显著相关性。 ④天然常绿阔叶林人工更新后各季节土壤微生物量碳、微生物量氮含量以及微生物总数、细菌、真菌、放线菌数量均降低，且3种人工林中，檫木林＞水杉林＞柳杉林；各林分土壤微生物生物量和微生物数量均为秋季＞春季＞冬季＞夏季。土壤微生物生物量、微生物数量与土壤物理性质、养分含量之间存在显著相关性。 ⑤天然常绿阔叶林人工更新后各季节土壤蔗糖酶、尿酶、磷酸酶和过氧化氢酶活性均降低，且3种人工林中，檫木林＞水杉林＞柳杉林；各林分土壤酶活性均为秋季＞春季＞冬季＞夏季。土壤酶活性与土壤物理性质、养分含量、微生物生物量、微更多还原

【Abstract】 This paper systematically studied on the change of soil ecological characteristics which include eco-hydrological benefits of forest litter layer, soil’s water conservation, soil fertility feature, change of soil carbon pool, soil fractal feature, and effects of litter on soil fertility under natural evergreen broadleaved forest and three artificial plantations, Sassafras tzumu, Cryptomeria fortunei and Metasequoia glyptostroboides forests, which formed by artificial regeneration of natural evergreen broadleaved forest in southern sichuan province. The results as follows:CD The amount of litter layer was natural evergreen broadleaved forest(25.68 t/hm~2) >Metasequoia glyptostroboides plantation(18.14 t/hm~2)>Sassafras tzumu plantation(9.95 t/hm~2)> Cryptomeria fortunei plantation(1.13 t/hm~2). The natural water content of whole litter layer in natural evergreen broadleaved forest was 3.18, 41.33, 1.53 times of that in Sassafras tzumu, Cryptomeria fortunei and Metasequoia glyptostroboides plantations, respectively. During the process of water holding of litter layer, the water holding capacity and absorption speed of the first 2 h were superior to the rest of time. The equation between the water holding capacity of the litter layer and the immerse time was Q = a ln t + b, the equation between the water absorption speed of the litter layer and the immerse time was V = k f. The maximum water holding capacity, the maximum interception and the modified interception of litter layer were natural evergreen broadleaved forest > Metasequoia glyptostroboides plantation > Sassafras tzumu plantation > Cryptomeria fortunei plantation.② The bulk density increase and porosity decrease are the main factors which resulted in the decrease of soil water storage and drainage capacity and infiltration after natural evergreen broadleaved forest artificial regeneration; Among the three artificial plantations, Sassafras tzumu plantation soil had higher water storage and drainage capacity and better infiltration, followed by soils with Metasequoia glyptostroboides plantation and Cryptomeria fortunei plantation; Correlation analysis indicated that the correlation coefficient between the soil organic matter, bulk density, porosity, water storage and drainage capacity and infiltration reached significant level.更多还原