澎湖群島地形平坦，早年積極建造海岸防風林以維護內陸村落作物及公共設施，免於受海風肆虐。本研究長期監測澎湖本島南北側防風林發展趨勢，監測期間共記錄植物44科103種，包括裸子植物2科3種、雙子葉植物37科82種及單子葉植物5科18種，就小區域環境而言，植物物種多樣性尚稱豐富。澎湖海岸防風林早期造林樹種以建構木麻黃(Casuarina equisetifolia)單純林爲主，近期改由喬木相如華北檉柳(Tamarix juniperina)及苦楝(Melia azedarach)所構成的混合林爲主，增加樹種多樣性。銀合歡(Leucaena glauca)亦入侵成爲優勢或次優勢物種。監測結果顯示，調查期間木麻黃、大葉合歡(Albizzia lebbeck)與銀合歡影生長勢未達顯著差異，而華北檉柳、黃槿(Hibiscus tiliaceus)與苦楝受颱風影響生長勢呈現極顯著差異，有逐年下降趨勢，因此應持續進行實施適當的造林撫育，以確保防風林之功能。
The object of this study is to evaluate the growth tendency of coastal windbreak trees of a long-tern monitoring in Penghu. We investigated the coastal winebreaks for 30 seasons and recorded 44 families 103 species, including 3 Gymnosperm, 82 Dicotyledon, and 18 Monocotyledon. The species richness in such small area can be considered relatively high. Casuarina equisetifolia is the conventional coastal windbreak tree in Penghu. Multiple layer sylviculture was encouraged and applied in recent years that made the structure of plantation become diverse and Tamarix juniperina and Melia azedarach in different sampling plots become the dominant or subdominant species. The investigation of years, seasons, and their interaction from ANOVA of important value index (IVI) indicated that the Casuarina equisetifolia, Albizzia lebbeck, and Leucaena glauca are not significant; while Tamarix juniperina is significant and Hibiscus tiliaceus and Melia azedarach are extreme significant. Leucaena glauca is considered as an invader in the windbreaks and has been removed in the tending of windbreaks so that the important value index is decrease during the monitoring years. The analytical results showed that proper plantation and nursing to maintain the basic function of windbreaks is necessary in the crucible environment.
