Abstract
一、The effect of global warming has caused global climate changes, such as the amount and pattern of precipitation and resulting in drought or heavy rainfall. Such extreme weather will easily cause debris flows that are frequent phenomenon in Taiwan. As a result, the areas become infertile and plants can hardly grow there. In order to solve the problem, we need to conduct a research about how to improve afforestation technologies in infertile land, including finding what kind of trees which could grow better and quicker in infertile land. Not only soil analyses but also microclimate monitoring will be carried out in this project.
二、In April 2015, we selected Casuarina equisetifolia L., Acacia confusa Merr., Koelreuteria henryi Dummer, Fraxinus formosana Hayata, Terminalia catappa L., Pongamia pinnata (L.) Pierre ex Merr., Melia azedarach L., and Hibiscus tiliaceus L.speces that had been planted in experimental site, and were investigated the growth potential of species used in restorative reforestation in infertile land. The experiment site had beed divided into two blocks Each block was devided into 24 plots for a total of 48 plots.We used fertilization and non-fertilization treatments to realize the effect of the fertilization for testing trees,and each treatment used 8 tree species that was randomized planted with 3 plot repetitions., and in each plot (10m×10m), 36 trees of the same species were planed with a 2×2-m spacing.
三、Based on the survey results of April and October 2015, the average survival rate that was investigated in October 2015 was 90% on non-fertilization and 88% on fertilization treatment. The effect of fertilization wasn’t related to the survival rate. On non-fertilization treatment, Melia azedarach L. was the highest (100%), Koelreuteria henryi Dummer was the lowest (63%). On fertilization treatment, Melia azedarach L. and Terminalia catappa L. were the highest (100%), and Fraxinus formosana Hayata was the lowest (73%).The average net basal growth on non-fertilization treatment, Casuarina equisetifolia L was the highest (0.6cm), Fraxinus formosana Hayata was the lowest (0cm). On fertilization treatment, Terminalia catappa L. were the highest (0.9cm), Fraxinus formosana Hayata was the lowest (0.1cm).The average net hight growth on non-fertilization treatment, Casuarina equisetifolia L. L was the highest (25cm), Koelreuteria henryi Dummer was the lowest (-20cm). On fertilization treatment, Casuarina equisetifolia L. were the highest (48cm), Fraxinus formosana Hayata was the lowest (1cm).The average net crown diameter growth on non-fertilization treatment, Casuarina equisetifolia L. L was the highest (54cm), Koelreuteria henryi Dummer was the lowest (-10cm). On fertilization treatment, Casuarina equisetifolia L. were the highest (68cm), Fraxinus formosana Hayata was the lowest (7cm).
四、According to the results of the investigation, the growth performance of Casuarina equisetifolia L. was greater than others. Hibiscus tiliaceus L., Terminalia catappa L., Pongamia pinnata (L.) Pierre ex Merr., and Pongamia pinnata (L.) Pierre ex Merr. were also able to grow in infertile land and endure the high temperature during the summer. With the effect of the fertilization, the growth performance of Terminalia catappa L., Melia azedarach L.and Hibiscus tiliaceus L. grew better and quicker in infertile.