鄱阳湖沙山土壤养分特征与植被恢复方向探讨

对鄱阳湖沙山不同沙化程度下土壤养分进行了分析,结果表明:研究区除土壤全钾(2.03%±0.28%)含量较高外,有机质(0.99%±0.42%)、全氮(0.036%±0.022%)、全磷(0.018%±0.007%)含量均处于较低水平。随沙化强度增加,土壤有机质、全氮、全磷含量呈现降低趋势,且重度、中度及轻度沙化区存在显著差异(P<0.01)。土壤速效养分(氮、磷、钾)随沙化强度变化趋势不明显,均处于十分缺乏的水平。地表植被覆盖低及土壤质地粗是导致沙山养分匮乏的主要原因。养分与水分是鄱阳湖沙山植物生长的限制因子,沙山植被恢复的关键在于所筛选的物种及所构建的群落结构能够保障新生植物能适应养分、水分匮乏的生态条件并迅速扩展其生态位。

Characteristics of Soil Nutrients and Direction of Vegetation Restoration on Sandy Hills Area of Poyang Lake

Soil nutrients of sandy hills area of Poyang Lake were analyzed along desertification gradient.The results showed the content of soil organic matter(0.99%±0.42%),total nitrogen(0.036%±0.022%) and phosphorus(0.018%±0.007%) were all at low level,except total potassium(2.03%±0.28%).Moreover,the nutrients decreased with desertification intensity,and there were significant difference among the areas with different desertification intensity.The available nutrients were also at low level,and showed no clear variation trend.Low vegetation coverage and coarse soil texture were the main factors resulting in low soil nutrients.Soil nutrients and water availability were the limit factors for the plant species living on the sandy hills.Consequently,the key to the vegetation restoration on sandy hills was that the selected plant species could adapt to the local environment with low soil nutrients and water availability and expand their ecological niches rapidly.