恆春半島高士佛常綠闊葉林14年份短期動態

Fourteen Years of Stand Dynamics of an Evergreen Forest in the Kaoshifo Experimental Forest, Southern Taiwan

張勵婉(Li-Wan Chang) ； 葉定宏(Ding-Hong Yeh) ； 黃正良(Jeen-Lian Huang) ； 陳意婷(Yi-Ting Chen)

《台灣林業科學》 30卷4期 (2015/12) Pp. 271-280

https://doi.org/10.7075/TJFS.201512_30(4).0005

摘要

高士佛試驗林地0.6 ha（300×20 m）永久樣區設立於1995年，後續於2002及2009年進行兩次木本植物複查。本研究分析2002~2009年第2次調查結果，並結合第1次調查資料，比較樣區樹木14年來之新增、死亡、密度、胸高斷面積、徑級結構之動態變化及探討可能的原因。結果顯示高士佛森林14年來，因少量物種移出或移入，造成物種組成少許變動；樹木底面積持續增加，但密度下降，數量優勢物種及胸高斷面積優勢種皆變動不大，而各物種的表現卻不一致，可能為單一特殊的原因造成物種變動趨勢和總體變化趨勢有差異；各徑級死亡率皆隨徑級增大而遞減，顯示個體競爭可能是控制死亡率的主要因子，而整體樹木徑級結構有往大徑級移動之現象。依海拔高低將樣區劃分為稜線上坡、中坡、下坡三個微生育地，比較各微生育地內物種的新增率、死亡率發現，下坡持續呈現高死亡率、新增率變動幅度大之趨勢，而稜線上坡區之死亡率及新增率變動幅度則相對穩定，可能為下坡區坡度較陡，產生許多小面積滑坡造成植株死亡。總體而言，高士佛森林在長期頻繁颱風侵襲下，植株已發展出一定程度的適應性，為一受擾動後但趨於穩定的森林。

關鍵字

高士佛常綠闊葉林 ； 複查 ； 森林動態 ； 台灣

並列摘要

In 1995, a 0.6-ha (300×20 m) permanent forest plot was established in the Kaohifo Experimental Forest, southern Taiwan. The second and third censuses were done in 2002 and 2009, respectively. In this study, we reveal demographic patterns of recruitment, mortality, abundance, basal area, and structure of size classes of diameter at breast height in both census intervals. During the past 14 years, the species composition was almost the same except for a few species for which a few individuals moved into or moved out the plot. Both census intervals showed the same pattern of increased basal area and decreased number of individuals. The rank of the top 10 dominant species changed slightly. Not all species had the same pattern of change, because species responded to fluctuations of the environment differently in the time series. The mortality rate decreased with the size class increment indicating that individual tree competition was the main mechanism controlling the mortality pattern. Comparing the demographics of 3 habitats defined by the positions on slopes, the lower slopes had a higher mortality rate and more-variable recruitment rate than the other 2 habitats. On the other hand, the upper slopes had more-stable mortality and recruitment rates. This pattern might have been caused by small-scale landslides which more frequently occurred on the steep lower slopes after typhoons than on the gentle upper slopes. After the these 2 censuses, we concluded that the Kaoshifo forest might be adapted to frequent typhoon influence. The forest has maintained a stable species composition, and the structure of diameter at breast height is shifting to larger size classes.

並列關鍵字

Kaoshifo evergreen forest ； re-census ； stand dynamics ； Taiwan