巨尾桉萌芽林引入降香黄檀后的土壤化学性质变化

Changes of Chemical Property in the Soil of Secondary Eucalyptus Plantation after Introducing Dalbergia odorifera

通过桉树二代萌芽林补植降香黄檀后林地N,P养分、酶活性及酚类物质含量的关系,分析土壤化学性质的变化.结果表明:1)桉树纯林林间和根区土壤N含量与混交林均存在显著差异,尤其是纯林桉树根区比混交林的N含量高87.7%,而P含量差异不明显;2)桉树纯林林间土壤脲酶活性是混交林的2.2倍,酸性磷酸酶活性以混交林为高.在根区土中,磷酸酶活性与脲酶的变化趋势相同,即混交林桉树根区显著低于桉树纯林桉树根区、混交林降香黄檀根区;3)桉树纯林根区土壤总酚和复合酚含量均比混交林桉树和降香黄檀根区高,林间土水溶酚含量低于混交林.降香黄檀根区土壤的水溶酚含量极显著高于两个林分的桉树根区,差异幅度达到32.40%,43.86%;4)两个林分桉树根区土N/P无显著差异,但纯林林间土比混交林高238.8%;土壤N/P与P含量存在极显著关系,与酸性磷酸酶活性显著负相关,而与酚类含量关系不显著;水溶酚与复合酚为极显著负相关关系.

In order to understand the soil chemical environment change of the Eucalyptus mixed forest after Dalbergia odorifera was replanted,the soil nutrient,enzyme and phenolic content of Eucalyptus pure and mixed forests were detected and then were further compared and analyzed.The results showed that：1） There were the significant difference of the N contents in field and rhizosphere soils between the pure and mixed Eucalyptus plantations.The N content of rhizosphere soil in pure plantation was 87.7% higher than the mixed one while P content was not significant.2） For the activity of urease,the value in the surface soils of mixed forest was higher than that of pure forest,however,the acid phosphatase activity was opposite.For the rhizosphere soil,acid phosphatase activities showed the similar characteristics to urease activity as the both of enzyme activities in the rhizosphere soil of Eucalyptus in mixed plantation were significantly lower than that of Eucaplytus in pure plantation and Dalbergia odorifera in the mixed plantation.3） The contents of total phenol and composite phenol in the rhizosphere soil of pure Eucalyptus plantation were higher than those of mixed plantation although the content ofwater soluble phenol was lower.The content of water soluble phenol in the rhizosphere soil of Dalbergia odorifera was obviously higher than the values of Eucalyptus in both of plantations by 32.40% and 43.86% variation respectively.4） The ratios of N/P in rhizosphere soil were no significant while the field soil N/P was 238.8%higher than the mixed plantation.The ratio of N/P had the significant positive correlation with content P while negative correlation with acid phosphatase activity.However,no significant correlation appeared between the ratio of N/P and the content of phenol.There was the extremely significant negative correlation between the types forms of phenol.