| Summary: | 碩士 === 國立宜蘭大學 === 自然資源學系碩士班 === 98 === Coastal windbreak is an important natural environmental shelter for protecting in the coastal area. In the past, the coastal windbreak was built by Casuarina equisetifolia plantation in Taiwan. But some of Casuarina stand were declined and influenced the function of windbreak. We want to know evolution the Casuarina equisetifolia windbreak status and probe into effect factor that could be a reference to provide coastal protection forest sustainability development strategy. This study site was at south side coastal windbreak of Nan-ao area. We collected many different periods of aerial photography data. After digitizing and correcting the data, we assay the coastal forest scope and the stand attributes. We use a matrix of transfer ratio to assess the change of stand property and confer the integrity and healthy of Casuarina equisetifolia forest by analyzing the stand structure and space distribution of the Casuarina equisetifolia forest in being.
The result showed that the composition species windbreak near a claybank was replaced by Leucaena leucocephala, other hardwood forest, grass and shrub on the inside of the wind break near a claybank during 1983 to 2008. The natural renew was limited at Casuarina equisetifolia in the windbreak. At the same time, the typhoon also would effect them. Now, they only remnant in the skirts of windbreak and in banding distribution parallel to coastal line. The stand structure are in dispersing or small group. The larger class of Casuarina trees mostly were damaged by wind. It was implicated that the Casuarina equisetifolia forest are serious ageing, and need to restoration for maintaining the coastal windbreak function.
Key words: Coastal windbreak, Casuarina equisetifolia, stand health, aerial photo interpretation, stand dynamics
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