华南丘陵区村级景观下土地利用/土地覆盖对土壤质量的影响

SOIL QUALITY IN RELATION TO LAND USE/COVER IN LANDSCAPE AT A VILLAGE LEVEL IN HILLY REGIONS SOUTH CHINA

利用IKONOS高分辨率（1m）卫星遥感图，根据Ellis提出的村级景观分类体系，研究华南丘陵区村级景观中的土壤容重、土壤有机质、土壤全氮和土壤全磷的含量和分布特征。结果表明：不同土地利用景观中，表层土壤（0～15cm）的土壤容重、有机质和全氮均有显著差异，最大值分别为：1．42gcm^-3（建设用地）、18．67g kg^-1（水田）和0．95g kg^-1（水田），而全磷差异不显著。由于林地面积最大，其土壤养分储量也最大，表层土壤有机质、全氮、全磷储量分别占整个地区表层总储量的55．05％、53．88％、46．23％。不同土地覆盖景观中，表层土壤的土壤容重、有机质、全氮也都有显著差异，最大值分别为：1．42gcm^-3（硬化地面）、15．96g kg^-1（混合植被）和0．68g kg^-1（混合植被），而全磷差异也不显著。多年生植被在土地覆盖景观中所占面积最大，其表层土壤有机质、全氮、全磷储量分别占整个地区表层总储量的55．01％、54．53％、59．02％。由于下层受人为干扰较小，不论是在不同土地利用方式还是在土地覆盖下，下层土壤（15～30cm）的土壤容重、有机质、全氮和全磷均无显著差异。人为强烈干扰下，植被覆盖度低的交通用地、房屋及其附近的干扰地和荒地与植被覆盖度高的林地、水田相比较，土壤容重高，而土壤有机质、土壤全氮和土壤全磷含量低。

To analyze soil quality in relationship to land use/cover in landscape at a village level in hilly regions South China, village landscape maps were plotted out of high resolution （ 1 m） IKONOS satellite imagery using a standardized ecological landscape classification （land form, land use, land cover, ecotope） and mapping system. Results demonstrate that： Under different land use landscapes, soils in the 0 - 15 cm layer differ sharply in soil bulk density （SBD） （highest in Constructed of 1.42 gcm^-3 , soil organic material （SOM） （highest in Paddy soil of 18.67 g kg^-1） and soil total nitrogen （TN） （highest in Paddy soil of 0. 95 g kg^- 1 ） . The land use landscape of the region mostly consists of Forests （ 52.05 % ）, Rainfed land （22.30%） and Paddy soil （11.6%）. The stock of soil nutrients is mainly affected by soil area. In the 0- 15 cm soil layer, the Forest has the highest soil nutrient stock, about 55.05% in SOM, 53.88% in TN, and 46.23% in soil total phosphorus （TP） of total region, respectively. Under different land cover landscapes, there also are significant differences in SBD （highest in Sealed cover of 1.42 g cm^-3）, SOM （highest in Mixed cover of 15.96 g kg^-1） and TN （highest in Mixed cover of 0.68 g kg^- 1 ） . The land cover landscape of the region is composed of Perennial cover （54.50%） , Annual cover （ 15.15 % ） and Mixed cover （22.92%）. The soils nutrient stock in the 0 - 15 cm layer under Perennial cover are the highest, about 55.01%, 54.53% , and 59.02% in SOM, TN and TP of total region, respectively. Because of little human disturbance, no significant difference is found in SBD, SOM, TN and TP of 15 - 30 cm soil layer in different types of land use/cover. Compared with soils in woodlands and paddy fields with high in vegetation cover, soils in residential areas, barelands under intensive human disturbance and lands with low in vegetation cover are high in SBD but low in soil nutrient content.