中亚热带区域几种典型生态系统土壤质量评价 Ⅱ.不同生态系统对土壤质量的影响

Soil quality assessment under several typical ecosystems in mid-subtropical region:Ⅱ. Effects of several typical Ecosystems on soil qualities

采用定位研究方法,以中亚热带区域七种典型森林生态系统为研究对象,探讨了不同生态系统对土壤生物学肥力指数、内梅罗土壤质量指数、土壤退化指数的影响,以及各指数之间的相互关系。结果表明,土壤生物学肥力指数和内梅罗土壤质量指数都是以常绿阔叶林最高,其次是混交林和阔叶纯林,连栽杉木纯林最低。土壤退化指数与内梅罗土壤质量指数正好相反,连栽杉木纯林土壤退化指数最高,混交林和阔叶纯林稍低。另外,混交树种不同,土壤质量指数也有差异。相关分析表明,内梅罗土壤质量指数、土壤退化指数与土壤生物学肥力指数相互之间存在正的相关性;另外,这3种土壤质量指示指标分别和林下植被层、森林凋落物现存量之间也有着显著的正相关。

Localized method was adopted in this study, and seven forests in central production region of Chinese fir in subtropics were studied. The effects of different ecosystems on biological index of fertility （BIF）, nemoro soil quality index （NSQI） and soil degeneration index （SDI）, and the relationship between the soil quality indexes, were discussed. The main research results were summarized as follows： The assessment values of BIF and NSQI were the highest under the evergreen broad-leaved forest, and then by the mixtures and the pure broadleaves, and the lowest under successive Chinese fir forests. But the assessment values of SDI showed a contrary trend to BIF and NSQI, and a relatively high value in SDI under the successive Chinese fir forests was found. The effects of different types of mixtures on the soil quality indexes were inconsistent, and the mixture with N-fixing tree species exerted a better effect on soil quality than the mixture with non-N-fixing tree species. The highly correlations between BIF, NSQI and SDI and were also detected. In addition, BIF, NSQI and SDI were, respectively positively correlated with the biomass in understory and litter layer, but not with the belowground biomass and the total biomass of stand.