林分孔隙分布圖之繪製及其應用探討：以花蓮德燕海岸林為例

Investigation of Mapping and Application of a Stand Gap Distribution Map Using the Deyan Coastal Forest in Hualien as an Example

邱祈榮(Chyi-Rong Chiou) ； 趙明君(Ming-Chun Chao) ； 林朝欽(Chau-Chin Lin) ； 陳財輝(Tsai-Huei Chen)

《台灣林業科學》 22卷2期 (2007/06) Pp. 159-172

https://doi.org/10.7075/TJFS.200706.0159

摘要

本研究於花蓮七星潭海岸林地，應用7期之SPOT、自然正射航照及遙控直昇機空拍的遙測影像資料，繪製出不同時期形成孔隙的分布圖，做為選取不同形成時期植群調查樣區之依據；經選取不同形成時問的孔隙樣區，共有21個地面樣點，進行植群調查與分析，比較其植群組成的差異。結果顯示在不同階段孔隙形成時期，孔隙內植物組成確有顯著差異，其中木本分為3種植群型，當孔隙形成在5年以內，為「月橘－木麻黃」林型，當孔隙形成5~7年則開始有血桐出現，為「月橘－血桐－木麻黃」林型，孔隙形成7年以上即為「芒草－血桐－構樹」林型，以陽性之芒草及構樹混生。另外，草本植物社會則有2群，分別為芒草型及飛龍掌血型。本研究亦發現在木麻黃林內當有孔隙形成後，則逐年隨之擴大，造成林分孔隙達62%，主要是因為颱風之累積效應已高於植物自行恢復生長的速率，導致原本「月橘－木麻黃」林型被陽性之「芒草－血桐－構樹」的植群型取代，颱風實為花蓮海岸地區最大的自然災害干擾來源。

關鍵字

遙測影像 ； 海岸林 ； 颱風干擾 ； 孔隙圖 ； 植群分析

並列摘要

This study utilized SPOT image data of 7 different periods and images from ortho aerial photography by plane and aerial photography by remote-controlled helicopter to produce gap distribution maps of all 7 periods for the Chihsingtan coastal forest in Hualien, east-central Taiwan. These maps were based on choosing vegetation plots of different gap formation periods, and 21 plots were established. Through a vegetation investigation and analysis of the plot's data in different periods, we compared differences in vegetation compositions of these chosen plots. Consequently, we determined a way to theorize the time at which gaps occurred in the forest stands and fhrther investigated the reason; analyzing connections between the time length of gap formation and variations in the vegetation composition might be a feasible direction for studying gap formation in forest stands. The results showed that gaps formed in different periods had different species compositions. Three main vegetation types were recognized: gaps formed in the past 5 yr were classified as the Murraya paniculata-Casuarina equisetfolia type; gaps formed in the past 5~7 yr began to show Macaranga tanarius, and were classified as the Murraya paniculata-Macaranga tanarius-Casuarina equisetifolia type; while gaps formed over 7 yr ago were classified as the Miscanthus floridulus-Macaranga tanarius-Broussonetia papyrifera type, with mixed Miscanthus fioridulus and Broussonetia papyrfera. In addition, 2 main herbal vegetation types were the Miscanthus floridulus type and Toddalia asiatica type. In this study area, another important discovery was that the formation of gaps was found in the Casuarina equisetolia stand, and the gaps expanded with age. The forest gaps reached 62% at the total area; the main reason for this is that the impacts of frequent typhoons are higher than the recovery ability of the Casuarina equisetfolia stands. Eventually, the Casuarina equisetfolia stands became the Miscanthus fioridulus-Macaranga tanarius-Broussonetia papyrifera type. It is obvious that typhoons represent the greatest natural disturbance in this coastal area.

並列關鍵字

remote sensing image ； coastal forest ； typhoon disturbance ； gap map ； vegetation analysis