【摘要】 柏木(Cupressus funebris)是三峡库区喀斯特地貌区的主要乡土树种,为了解柏木人工林不同混交种植模式对土壤转化酶活性和碳氮含量的影响,筛选最优的柏木栾树混交种植模式,实现柏木人工林的可持续发展。本研究基于随机区组设计,以柏木纯林为对照,研究三峡库区栾树(Koelreuteria paniculata)和柏木(栾柏)带状混交、栾柏块状混交和栾柏株间混交3种混交种植模式对不同土层厚度下(0～20、20～40、40～60 cm)土壤转化酶活性和不同形态碳氮含量的影响。研究结果表明,3种混交种植模式下不同土层厚度土壤的转化酶活性均不同程度上高于柏木纯林,40～60 cm土层中带状混交种植模式的转化酶活性比柏木纯林显著提高了48.07%;栾柏带状混交、栾柏块状混交和栾柏株间混交种植模式不同土壤厚度中的总有机碳、易氧化有机碳和微生物量碳含量都显著高于柏木纯林,且均以栾柏带状混交种植模式增长量最大;栾柏带状混交种植模式的土壤活性有机碳含量也显著高于柏木纯林和栾柏块状、栾柏株间混交种植模式,栾柏带状混交种植模式不同土层厚度下的全氮、碱解氮、微生物量氮和水溶性有机氮含量与柏木纯林相比显著提高了34.07%～282.76%;栾柏块状混交和栾柏株间混交种植模式的土壤部分氮含量在不同土层中也较柏木纯林有显著的提高;带状混交种植模式在不同土层厚度中土壤转化酶活性和碳氮含量的衰减速率最低。栾柏混交种植模式的营造,特别是栾柏带状混交种植模式中土壤转化酶活性的显著增加,不同程度地提高了土壤中的碳氮含量,对于改善林地质量、促进林木生长十分有利。更多还原

【Abstract】 Cupressus funebris is the main native tree species in the karst area of the Three Gorges Reservoir area. In order to understand the effects of different mixed planting models of Cupressus funebris plantation on soil invertase activity,carbon and nitrogen content,screened the best mixed planting model of Cupressus funebris and Koelreuteria paniculate,and achieved sustainable development of plantation of Cupressus funebris. Based on the random block design,effects of three mixed planting models of Cupressus funebris and Koelreuteria paniculate strip mixed,block mixed and interspecific mixed on soil invertase activity,carbon and nitrogen content under different soil layers( 0-20 cm,20-40 cm and 40-60 cm) in the Three Gorges Reservoir area were studied. The results showed that,the activity of soil invertase in three mixed planting models under different soil layer thickness was higher than that in pure forest of Cupressus funebris,and under 40-60 cm soil layer thickness,the activity of soil invertase in mixed strip planting model was significantly increased by 48. 07 % compared with Cupressus funebris pure forest. The content of total organic carbon,oxidizable organic carbon and microbial biomass carbon in different soil thickness in three mixed planting models of Cupressus funebris and Koelreuteria paniculata strip mixed,block mixed and interspecific mixed was significantly higher than those in pure forest of Cupressus funebris,and the growth of mixed strip planting model was the largest. The soil labile organic carbon content of Cupressus funebris and Koelreuteria paniculata strip mixed planting model was also significantly higher than that of the pure forest of Cupressus funebris and the block and interspecific mixed planting model. The content of total nitrogen,alkali hydrolyzable nitrogen,microbial biomass nitrogen and water-soluble organic nitrogen of strip mixed planting model in different soil layer thickness was significantly increased by 34. 07%-282. 76% than that of the pure forest of Cupressus funebris. The content of nitrogen of strip and interspecific mixed planting model in different soil layers was significantly higher compared with pure forest of Cupressus funebris. The decline rate of soil invertase,carbon and nitrogen content of strip mixed planting model was the lowest in different soil thickness. The construction of mixed planting model of Cupressus funebris and Koelreuteria paniculata,especially the significant increase of soil invertase activity in strip mixed planting model of Cupressus funebris and Koelreuteria paniculata,can improve the soil carbon and nitrogen content,which is very beneficial to improve the quality of forest land and promote the growth of plants.更多还原