杉木林改造成阔叶林对根际和非根际土壤磷组分和转化的影响

Effects of conversion of Chinese fir forest to broad-leaved forests on phosphorus components and transformation in rhizosphere and non-rhizosphere soils

关键词:  杉木林, 阔叶树种, 根际土壤, 磷组分, 南亚热带

Key words:  Cunninghamia lanceolata (Chinese fir)plantation,broad-leaved species,rhizosphere soil,phosphorus component, south subtropics

摘要:

磷(P)是维持亚热带森林生态系统生产力的关键因子。杉木主要分布于我国亚热带地区,杉木林的土壤酸化,P利用效率低,研究杉木林转化后对土壤P的影响、对生态系统的稳定和森林可持续经营具有重要意义。该研究以南亚热带杉木林采伐迹地上重新种植的杉木林、红锥林、米老排林和红锥/米老排混交林为研究对象,采集根际土和非根际土,重点探究南亚热带杉木人工林改造成阔叶林后土壤P组分及转化的影响。结果表明:(1)改造后的红锥林、米老排林和红锥/米老排混交林的根际和非根际土壤的微生物生物量P含量及酸性磷酸酶活性均显著高于杉木林,红锥林和红锥/米老排混交林的土壤全P比杉木林和米老排林更容易转化为速效P。(2)红锥林和红锥/米老排混交林的根际和非根际土壤中氯化钙提取P的含量均显著高于杉木林和米老排林,米老排林和红锥/米老排混交林根际和非根际土壤中酶提取P、盐酸提取P和柠檬酸提取P的含量显著高于杉木林和红锥林。(3)RDA结果显示,调控根际和非根际土壤P组分的关键因子分别是土壤含水量和微生物生物量碳。综上认为,将杉木林改造成阔叶林有利于森林土壤P的储存和供应,该研究结果为提高南亚热带人工林土壤P有效性的树种选择和经营管理策略等提供了重要科学依据。

Abstract:

Phosphorus(P)is one of the essential elements for plant growth and is a key factor in maintaining the productivity of subtropical forest ecosystems. Chinese fir(Cunninghamia lanceolata)is mainly distributed in subtropical areas of China, and its soil acidification and phosphorus utilization efficiency are low. It is of great significance to study the effects of Chinese fir plantation transformation on soil P for the stability of ecosystem and sustainable forest management. In this study, the rhizosphere and non-rhizosphere soils were collected from the replanted Chinese fir plantation, Castanopsis hystrix plantation, Mytilaria laosensis plantation and the mixed plantation of Castanopsis hystrix and Mytilaria laosensis on the cutting-blank of Chinese fir plantation in South Asia, and the effects of soil P component and transformation on the transformation of Chinese fir plantation into broad-leaved forest were studied. The results were as follows:(1)The content of microbial biomass phosphorus and the activity of acid phosphatase in rhizosphere and non-rhizosphere soil of the modified Castanopsis hystrix plantation, Mytilaria laosensis plantation and the mixed plantation of Castanopsis hystrix and Mytilaria laosensis were significantly higher than those of Chinese fir plantation. The contents soil total phosphorus of Castanopsis hystrix plantation and the mixed plantation of C. hystrix and Mytilaria laosensis were more easily converted to quick available phosphorus than those of Chinese fir plantation and M. laosensis plantation.(2)The contents of calcium chloride extraction phosphorus in rhizosphere and non-rhizosphere soils of Castanopsis hystrix plantation and the mixed plantation of C. hystrix and Mytilaria laosensis were significantly higher than those of Chinese fir plantation and M. laosensis plantation, and the contents of enzyme extraction phosphorus, hydrochloric acid extraction phosphorus and citric acid extraction phosphorus in rhizosphere and non-rhizosphere soils of M. laosensis plantation and Castanopsis hystrix/Mytilaria laosensis mixed plantation were significantly higher than those of Chinese fir plantation and Castanopsis hystrix plantation.(3)RDA results showed that soil water content and microbial biomass carbon were the key factors regulating P components in rhizosphere and non-rhizosphere soils, respectively. In summary, the transformation of Chinese fir plantation into broad-leaved forest is conducive to the storage and supply of forest soil P, and this study provides an important scientific reference for tree species selection and management strategies to improve soil P availability in south subtropical plantations.