东寨港红树林群落退化特征与土壤理化性质的相关关系

The correlation between mangrove community degradation characteristics and soil physical and chemical properties in Dongzhai harbor

针对海南东寨港红树林退化现象，在东寨港长宁河沿岸设置样地，调查东寨港红树林退化特征和退化地区土壤的理化性质。结果表明：东寨港红树林群落呈明显的退化趋势，退化群落死亡率、退化率与群落郁闭度呈极显著负相关；死亡率和退化率与单位面积呼吸根数量呈显著负相关。退化特征值与表层土壤（0—30cm）容重、毛管孔隙度、总孔隙度未达到显著相关水平；退化率与下层土壤（30—60cm）的毛管孔隙度达到极显著相关水平（P〈0．01），死亡率与容重、毛管孔隙度也达到了显著相关水平（P〈0．05）。土壤的化学性质与红树林退化特征相关性较小。

Woth the mangrove degradation phenomenon in Dongzhai harbor on Hainan Island, we set sample plots along Changning river to investigate the mangrove degradation characteristics and soil physical and chemical properties. The results showed that the mangrove community was obviously degraded. The mortality and degradation rates were significantly negatively related to the canopy coverage, and they were also negatively related to the number of respiratory roots per unit area. Degradation rate was not significantly correlated with the bulk density, capillary porosi- ty and the total porosity of the upper soil layer （0-30 cm）. However, the degradation rate was significantly correlated with the capillary porosity of the lower soil layer （30-60 cm）. Moreover, the mortality rate was significantly correlated with the bulk density, total porosity and capillary porosity of the lower soil layer. Soil chemical properties were not correlated with mangrove degra- dation.