湘西北小流域植被恢复区土壤酶活性及养分相关性

摘要

研究了湘西北女儿寨小流域马尾松天然林、杉木人工林、杜仲人工林、油桐人工林、润楠次生林、毛竹杉木混交林及荒草灌丛7种典型植被恢复模式下的土壤酶活性、综合指数及土壤酶活性与土壤养分的通径相关关系.结果表明:不同植被恢复模式土壤脲酶、蔗糖酶、脱氢酶、过氧化氢酶、多酚氧化酶、蛋白酶、磷酸酶活性的变化范围分别为0.15～0.59 mg·g-1、0.36～3.76 mg·g-1、4.02～11.76 mg·g-1、0.03～O.06 mL·g-1,0.50～1.26 mg·g-1、0.09～0.50 mg·g-1和15.67～35.50mg·g-1,且土壤酶活性均表现为00.1);水解氮对土壤脲酶,水解氮、全氮对土壤蔗糖酶,pH值对土壤脱氢酶,以及有机质对土壤过氧化氢酶的直接通径系数、决定系数及对R2的贡献较大,存在较显著地影响.%A survey was conducted to study soil enzyme activities, synthetical index and their path analysis with soil nutrient properties for seven typical vegetation restoration patterns, which was comprised of P. massoniana natural forest ( Ⅰ ),Cunninghamia lanceolata plantation ( Ⅱ ), Eucommia ulmoides plantation ( Ⅲ ), Vernicia fordii plantation ( Ⅳ ), Machilus pingii secondary forest ( Ⅴ ), Phyllostachys edulis-C. lanceolata mixed forest ( Ⅵ ), wasteland-shrub ( Ⅶ ). Results showed that the activities of urease, sucrase, dehydrogenase, catalase, polyphenol oxidase, proteinase and phosphatase ranged from 0.15-0.59 mg · g-1, 0.36-3.76 mg· g-1, 4.02-11.76 mg · g-1, 0.03-0.06 mL · g-1, 0.50-1.26 mg·g-1, 0.09-0.50 mg · g-1 and 15.67-35.50 mg·g-1 for different vegetation patterns. Moreover, activities of these enzymes in the 0-20 cm soil layer were higher than those in the 20-40 cm soil layer. The synthetical index of soil enzyme activities of C. lanceolata plantation was the highest (8. 341 7), followed by wasteland-shrub (6.445 4) and C. lanceolata plantation (6.339 3 ). Soil nutrient properties could explain 80.42 percent, 79.56 percent, 80.69 percent and 84.26 percent of variance of the enzyme activities of urease, sucrase, dehydrogenase and catalase, with residual path coefficients of 0.442 5, 0.452 1,0.439 4 and 0. 396 7, respectively. However, there were unobvious linear relations between polyphenol oxidase, proteinase, phosphatase and soil nutrient properties (p＞0. 1 ). The direct effects of hydrolyzable nitrogen on urease activity and hydrolyzable nitrogen, total nitrogen on sucrase activity, pH on dehydrogenase activity, and organic matter on catalase activity all exhibited higher path coefficient, coefficient of determination, and contribution to R-square.