木麻黃防風林斥水層復育之研究

臺中港木麻黃防風林地斥水情形嚴重，本研究係以該個案探討斥水物質成因、對土層養分運移之影響以及其復育之可行性。所得結果摘述如下：木麻黃防風林之斥水現象發生於枯枝葉層與表土層。枯枝葉層之斥水主要是由於眞菌菌絲的網結，分離菌株之菌絲皆具斥水現象。代號TCHC-5與TCHC-20眞菌的代謝物質呈現斥水，其餘分離株代謝物之斥水不明顯。另林地表土層嚴重斥水，主要是土壤中的腐植質所致。腐植質可鉗合鐵、鋁等金屬離子之氧化物，減少土層中磷被固定的機率，此雖對生態系之磷循環有利；但樣區之腐植質亦具強度斥水特性，若過量存在而嚴重斥水，水分入滲不易，反而不利養分在土層中之運移。脂肪族性高之腐植質爲斥水土層中的主要疏水物質，濕潤劑可破壞脂肪族之鏈結。市售淸潔劑之稀釋液雖可有效的降低斥水土層之抗水現象，唯其施用有汚染土壤之虞。腐植質之斥水性隨pH之增加而降低，利用石灰改良土層之pH値，可減低腐植質之斥水強度，促增林地養分循環，又不會汚染土壤，是經濟可行的方法。

關鍵字

復育；木麻黃；斥水層；疏水物質；濕潤劑

並列摘要

The hydrophobic soils collected from the Casuarina windbreak at Taichung Harbor were used to study the formation of hydrophobic substances, and its effects on nutrient transportation. The reclamation of hydrophobic substances were also studied. Water repellent layer s (WRL) in litter layers are mainly due to the dense fungal filaments. Filaments of all the isolated strains are highly hydrophobic. Among the isolated strains, only TCHC-5 and TCHC-20 show hydrophobic substance in the process of metabolism. WRL in surface soil is caused by the humic substance which could chelate iron and alumium sesquioxides and thus decrease phosphorus fixation. Humic substance play crucial roles in phosphorus cycling of the ecosystems, but its hydrophobic properties are unfavorable for the nutrient cycling. Highly aliphatic humic substance is the main component causing WRL in soils. Wetting agents could destroy the aliphatic chain and decrease water repellency. Diluted solution of commercial detergent can be used as wetting agent for reclamation, but its cost and contamination have to be considered. The hydrophobic potential of humic substances decrease with increasing pH value. Lime application which increase soil pH is a feasible way to decrease hydrophobic potential and to enhance nutrient cycling, but does not pollute the soils.

並列關鍵字

Reclamation ； Casuarina Forest ； Water Repellent Layer ； Hydrophobic Substance ； Wetting Agent

國際替代計量

木麻黃防風林斥水層復育之研究

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