Estimate of Coarse Root Biomass and Nutrient Contents of Trees in a Subtropical Broadleaf Forest in Taiwan

亞熱帶闊葉林林木粗根生物量和養分含量之估算

林國銓(Kuo-Chuan Lin) ； 杜清澤(Chin-Tzer Duh) ； 黃菊美(Chu-Mei Huang) ； 王巧萍(Chiao-Ping Wang)

《台灣林業科學》 21卷2期 (2006/06) Pp. 155-166

https://doi.org/10.7075/TJFS.200606.0155

摘要

本研究調查位於台灣東北部福山亞熱帶天然闊葉林林木（胸徑≥10cm)粗根(根徑≥5mm）的生物量，並估算其養分含量。由8株樣木(7種樹)伐倒挖根調查結果顯示：樣木粗根生物量佔全株生物量的百分比為13.4~30.2%；此一比例與胸徑不具相關性。各根徑級及總粗根生物量，以胸徑建立之自然對數迴歸式皆呈顯著差異。林分林木粗根中以根頭及≥100mm根徑級其生物量佔比例最高，各約佔粗根生物量的30.0%。粗根生物量佔全株生物量的21.9%，佔地上部生物量的28.0%。福山林木粗根生物量為65.1Mg ha^(-1)，高於熱帶常綠林的根平均生物量，且粗根根莖比為0.28，高於熱帶地區及全球的平均值。其根莖比較高的原因之一為枝條和葉受颱風干擾，地上部生物量偏低之故。至於，福山闊葉林林木其養分分佈的比例則與溫帶闊葉林者相近。

關鍵字

亞熱帶闊葉林 ； 迴歸模式 ； 根莖比 ； 碳貯存 ； 養分含量

並列摘要

In this paper, we studied the biomass and estimated the nutrient content of coarse roots (≥5mm) of trees (dbh≥10cm) in a subtropical broadleaf forest at Fushan, northeastern Taiwan. The results from excavating 8 trees of 7 species indicated that the biomass of coarse roots accounted for 13.4~30.2% of the total tree biomass. This percentage was not correlated to the diameter at breast height (dbh). Based on the natural logarithmic regression established by sample trees, the biomass of each category and the total biomass of coarse roots were highly significantly related to dbh. In the coarse roots, the stump and ≥ 100-mm roots had the highest percentage of biomass, each accounting for approximately 30.0% of the coarse root biomass. Comparatively, the biomass of coarse roots accounted for 21.9% of the total tree biomass and 28.0% of aboveground biomass. The biomass of coarse roots of trees was 65.1 Mg ha^(-1), which is higher than the average root biomass of tropical evergreen forests reported in the literature. The root/shoot ratio calculated from coarse roots was 0.28, higher than those for both tropical forests and the global average. The higher root/shoot ratio of the Fushan forest is likely a result of severe branch and leaf damage caused by frequent typhoons, leaving the forest with lower aboveground biomass. The nutrient allocation of coarse roots in trees of the Fushan forest is similar to that of temperate broadleaf forests.

並列關鍵字

subtropical broadleaf forest ； regression model ； root/shoot ratio ； carbon storage ； nutrient content