Coastal forests are located on sandy shores on the east coast of Taiwan, where they are often hit
by storm surges causing trees to die and producing gaps that impact the protective functions of the
forests. To offer a method of afforestation in areas of high risk of damage from storm surges in eastern
coastal areas and develop a practical silvicultural technique for the direct seeding for afforestation, this
study investigated the effects of fertilization, the light environment, and seedling density on the initial
growth of Casuarina equisetifolia. Seedlings were cultivated by the silvicultural regime of indentation
seeding with seed shelters fertilized with 3~5 g of controlled-release fertilizer. Results revealed that this
method was able to efficiently promote the initial growth of seedlings, which was sufficient for practical
operations. The initial growth of seedlings was promoted by fertilizer, but no significant differences
were found between top-dressing and no top-dressing treatments for 1-yr-old seedlings. At 1 yr after
the experiment of thinning of 1-yr-old seedlings, in addition to the tree height, we found that saplings
exhibited a significant growth increment under thinning treatment with 2.5±0.0 cm in average basal
stem diameter (vs. 1.8±0.1 cm in the control), 161±2 cm in tree height (vs. 142±4 cm in the control),
119±2 cm in canopy diameter (vs. 91±4 cm in the control), and 6°±0° in the angle of inclination of
the trunk (vs. 10°±1° in the control). The relative light intensity in the tube of the seed shelter required
over 40% which was vital for the initial growth of seedlings. Results of this study offer application of
practical operations for direct seeding of coastal forests, which can efficiently promote seedling growth,
morphological quality, and seedling establishment.