臺東金崙大橋興建毀損海岸地復育造林成效初探

Preliminary study on the effect of forest restoration after the Jinlun Bridge construction in Taitung

臺9線金崙高架道路工程環評承諾必須進行海岸林植生復育造林。該基地面積2.24 ha，可分為南、北兩區塊，北區有較厚實土壤，南區為海濱沙灘地。2018年5-6月間採用22種原生海岸植物，以植苗及直播二方式完成復育造林作業，調查前的植栽密度3,995株／ha。於植生工作完成後1.5年啟動調查，累積1.5年資料，據以分析各區之各種類生長表現。土壤調查結果顯示，北區土壤的有機質及多數植物生長重要化學養分（磷、鉀、鈣、鎂）含量都優於南區土壤；調查樣帶中紀錄22種栽植苗木，地徑及高生長調查結果亦顯示，多數種類在北區的生長明顯優於南區。存活率低於80%僅北區的文珠蘭（71%）、南區的紅柴（67%），以及南、北兩區的蘭嶼樹杞（42%, 75%）。地徑相對生長率於北區最佳的是葛塔德木（255.2%），次佳黃槿（178.7%），最差蘭嶼樹杞（0.0%），次差紅柴（18.2%）；南區最佳的是欖仁（106.7%），次佳黃槿（96.8%），最差紅柴（0.9%），次差蘭嶼樹杞（17.3%）。樹高相對生長率於北區最佳的是黃槿（184.1%），次佳葛塔德木（171.1%），最差蘭嶼樹杞（-48.7%），次差苦林盤（29.7%）；南區最佳的是黃槿（137.7%），次佳欖仁（130.0%），最差文珠蘭（-5.9%），次差蘭嶼樹杞（5.0%）。此復育造林地的存活、生長情形良好，但植株間已明顯呈現競爭狀態，可供進一步觀察研究。本研究顯示參照物種存活率、相對生長率，黃槿、葛塔德木、瓊崖海棠、欖仁、海檬果、水黃皮、苦林盤、繖楊、臭娘子及林投為可適用於臺東砂質海岸造林的樹種。

The Jinlun Elevated Road Project of the No. 9th provincial highway of Taiwan promises that coastal area must be reforested. The 2.24 ha reforestation area can be divided into south and the north blocks. The north block has relatively thick soil, and the south area is the sand-beach. Afforestation was carried out by planting seedlings and direct seeding, and the seedling density before the survey was 3,995/ ha. The survey was started 1.5 years after the afforestation, and the data was accumulated for 1.5 years to analyze the growth performance of various species in each block. The soil survey results showed that organic matter and important chemical nutrients (P, K, Ca, Mg) in the soil of the northern block were better than those in the southern block. the results of the ground diameter and height growth of the seedlings also showed that the growth of most species in the northern region was significantly better than those in the southern region. Twenty-two species were recorded in the sampling transects. Only few species' survival rate was lower than 80%, including Crinum asiaticum in the northern block (71%), Aglaia formosana in the southern block (67%), and Ardisia elliptica in the southern and northern blocks (42%, 75%). The species showed the best ground diameter growth in the northern block is Guettarda speciosa (255.2%), followed by Hibiscus tiliaceus (178.7%), whereas the species showed the worst ground diameter growth is Ardisia elliptica (0.0%), and the second worst is Aglaia formosana (18.2%); the best ground diameter growing in the south block is Terminalia catappa (106.7%), the second best is Hibiscus tiliaceus (96.8%), the worst is Aglaia formosana (0.9%), and the second worst is Ardisia elliptica (17.3%). The best tree heights in the northern block is Hibiscus tiliaceus (184.1%), the second best is Guettarda speciosa (171.1%), the worst is Ardisia elliptica (-48.7%), and the second worst is Clerodendrum inerme (29.7%); The best tree heights in the southern block is Hibiscus tiliaceus (137.7%), the second best is Terminalia catappa (130.0%), the worst is Crinum asiaticum (-5.9%), and the second worst is Ardisia elliptica (5.0%). The cold and warm seasons had a great influence on the growth of tree height, but not on ground diameter. The survival and growth of planting seedling in the reforestation area is good, and the competition between plants has obviously appeared, which can be further observed and studied. This study suggested Hibiscus tiliaceus, Guettarda speciosa, Calophyllum inophyllum, Terminalia catappa, Cerbera manghas, Millettia pinnata, Clerodendrum inerme, Thespesia populnea, Premna serratifolia and Pandanus odoratissimus as framework species for Taitung sandy coast reforestation.