臺灣東北部天然闊葉林林內降雨及林冠截留之研究

A Study on Rainfall Interception of a Natural Hardwood Forest in Northeastern Taiwan

林登秋(Teng-Chiu Lin) ； 夏禹九(Yue-Joe Hsia) ； 金恆鑣(Hen-Biau King)

《台灣林業科學》 11卷4期 (1996/12) Pp. 393-400

https://doi.org/10.7075/TJFS.199612.0393

摘要

本試驗研究福山地區天然闊葉樹林林冠截留現象及其季節性差異，以探討氣候及降雨型態對林內降雨及林冠截留的影響。1994年共收得有效收集53次，2346.8mm的雨量，相對的穿落雨量為2087.1mm，而截留損失量為259.7mm佔林外雨量的11.1%。此結果與臺灣其它天然闊葉林所做的監測結果相當。相較於許多熱帶雨林則偏低。若以總量而言，夏季總穿落量佔林外雨量91.4%，而冬季總穿落雨量佔林外雨量87.0%。此結果顯示林冠截留容量夏季高於冬季，但林冠截留率則冬季高於夏季。溫度較高、相對溼度較低、蒸發散率較高，所造成葉面較乾是造成夏季高截留容量的重要原因，而冬季高截留率可能的原因包括（一）每場雨之雨量小使林冠截留容量佔林外降雨的比率高，（二）每次收集到的降雨資料涵蓋較長的降雨時間，使得降雨時的蒸發散對林冠截留量的貢獻增大以及（三）較小的降雨強度使林冠能有效截留降雨，減少因雨滴動量過大而無法被林冠截留的量。本文並導出穿落雨量(TF)及林冠截留量(Ⅰ)與林外降雨量(Rain)的線性迴歸式。

關鍵字

穿落雨 ； 林冠截留 ； 蒸發散 ； 降雨強度

並列摘要

This study examined canopy interception and its seasonal variations in the Fushan broadleaf forest The objective was to address climatic influences and the significance of rainfall characteristics on throughfall and canopy interception. There were 53 effective collections during the year of 1994 with a total rainfall of 2346.8mm, throughfall of 2087.1mm, and interception loss of 259.7mm. These values are similar to those observed in other broadleaf forests in Taiwan but lower than those of tropical forests. The total throughfall was 91.4% and 87% of the rainfall in summer and winter, respectively. The result indicates that interception loss on a percent basis was greater in winter, but canopy storage capacity was greater in summer. Higher temperatures, lower relative humidities, higher evapotranspiration rates and drier leaf surfaces were possible causes for the higher summer canopy storage capacity, The higher winter canopy interception loss may have resulted from (1) rainfall events being lighter and as such, canopy loss on a percent basis being greater; (2) winter rainfall lasting for longer periods and as such, evapotranspiration during the rainfall events having a high contribution to canopy loss; and (3) rainfall intensities being lower in the winter such that the canopy was able to intercept rainfall more effectively in comparison to summer when the momentum of rainfall would be too high for the canopy to intercept effectively. The relation of throughfall (TF) and interception (Ⅰ) to rainfall (Rain) on an annual basis was derived using a simple linear regression.

並列關鍵字

throughfall ； canopy interception ； evapotranspiration ； rainfall intensity