保護管凹地直播及施肥處理對木賊葉木麻黃幼苗生長之影響

木麻黃林分在臺灣海岸地區長期遭受環境逆境危害，造成林分劣化產生孔隙，影響海岸林保安功能。雖然木賊葉木麻黃具有天然更新之障礙，但仍有少量天然更新幼苗發生。本研究試驗以保護管凹地直播及施肥處理探討木賊葉木麻黃更新造林的可行性。試驗結果發現在臺東海岸具有消波塊屏障，且地被覆蓋率 Casuarina stands often suffer from stresses in coastal areas of Taiwan. These degraded stands and gaps impact the protection functions of coastal forests. Although Casuarina equisetifolia has difficulty to regenerate naturally, still some natural seedlings can be established. The purpose of this study is to explore the feasibility of C. equisetifolia regeneration afforestation by using direct seeding with seed shelters on concave ground and fertilization. The results showed that the afforestation target can be achieved by diect seeding in gaps of coastal forests in Taitung, where vegetation coverage were under 10% with the protection of arm blocks. After 3 years of direct seeding, the percentage of seedling establishment with fertilization treatment was 58±5%, average basal stem diameter was 3.7±0.5 cm, tree height was 291±15 cm and canopy diameter was 155±14 cm. Fertilization effectively promoted the initial growth of the seedlings, and in turn increased the seedling survivorship during the first year after sowing. However, there was no significant difference in growth between with or without fertilization after 30 months of direct seeding. Heat and the evaporation rate at the seedling microenvironment during daytime were lower with the protection of seed shelters. Soil moisture at the bottom of seed shelters offered a favorable environment for seedlings growth. As the establishment and survivorship of C. equisetifolia seedlings were improved, the method in this study can be applied to afforestation of coastal forests on the coast of Taitung.