红树林和酸性潮滩土

红树林和酸性潮滩土是我国热带和亚热带沿海地区常见的一种生态系统。我国现有红树林面积35万亩,种类组成有21科38种,一般自南向北逐渐减少。红树林死亡后所遗留的根系和枝叶经分解可导致土壤酸化。酸性潮滩土主要性质:1.质地粘重以中壤土至轻粘土为主;2.土壤含盐量在0.3—4.2％之间,SO₄^2-含量0.6—18.4meq/100g±;3.有机质含量0.4—11.8％,C/N比较宽（11.3—44.5）,磷素养分较低,阳离子代换量9.1—17.6meq,100g±;4.pH变幅大,自3.0至6.9。酸性潮滩土主要开发模式是种水稻,其次是海水养殖。利用上的障碍性因素较突出,建议加强红树林管理:1.划定采伐区;2.建立保护区;3.开展红树林生态系统观察研究。

THE MANGROVE AND THE ACID TIDAL FLAT SOIL

The mangrove and the acid tidal flat soil constitute a common ecological system in the tropical and subtropical coasts of China. The areas of mangrove of China are about 2.3×103 ha. They have 38 species and 21 families. Their distribution gradually decreases from south to north. The leftover roots and leaves undergo decomposition to bring about acidification of soil after the mangrove dies. The main properties of the acid tidal flat soil are as follows:1. The soil texture is mainly middle loam to light clay with the physical clay (less than 0.02 mm in diameter) ranging from 30% to 82%;2. The total salt content is 0.3% to 4.2% and the content of SO₄^2- is 0-6 meq/100 g to 18.4 meq/100g;3. The content of organic matter is 0.4% to 11.8%, the C/N ranges from 11.3 to 44.5, the nutrient of phosphorus is rather low, and the CEC ranges from 9.1 meq/100g to 17.6 meq/ 100g;4. The pH ranges from 3.0 to 6.9.The developmental models are mainly to plant rice and to develop aquiculture. In utilization the disadvantageous factors are prominent. The management practices are to demarcate the cutting areas, to set up the protection areas and to promote researches on the ecological system of mangrove.