東北季風對南仁山迎風與背風坡生育地樹種苗木形態及生長之影響

Effects of Northeasterly Monsoon on the Morphology and Growth of Seedling of Windward and Leeward Tree Species at Nanjenshan

李文媛(Wen-Yuan Li)

指導教授 ： 郭耀綸

國立屏東科技大學/農學院/熱帶農業暨國際合作系所/碩士(2011年)

https://doi.org/10.6346/NPUST.2011.00037

摘要

本研究目的為比較生長在南仁山迎風坡與背風坡樹種的苗木，在東北季風擾動下，苗木生長及葉部損傷表現的差異。我們提出的假說為原本生長在迎風坡的樹種，能忍受風的機械傷害，而背風樹種不能適應風吹環境，苗木生長及葉部形態會因風吹而顯著受害。試驗方法為在南仁湖邊設置利用透明塑膠布圈圍之遮風設施(擋風樣區)與無任何遮風設施(吹風樣區)兩處理。兩設施內均栽植當地8種迎風樹種及9種背風樹種的苗木各17株。試驗期間吹風樣區平均風速為2.0 m s-1，最大風速可達到13.2 m s-1，而擋風樣區平均風速僅為0.5 m s-1，最大風速只達4.6 m s-1。第一次試驗經過4個月(2009年10月至2010年1月)處理發現，迎風樹種之苗高相對生長率、葉片數、單株葉面積、生物量及葉片受傷程度在兩樣區間大多無顯著差異，然而背風樹種的苗木在吹風樣區與擋風樣區多有顯著差異，例如在吹風樣區植物生物量較擋風樣區降低35~70%；背風樹種葉片在擋風樣區無機械損傷，而在吹風樣區則受害嚴重(83.8%)。而第二次試驗經過2個月(2010年2月至2010年4月)處理發現，受傷程度並沒有第一次嚴重。其中有3種樹種與第一次相同，比較結果受傷較第一次輕微。但背風樹種依然有受傷情形發生，但卻沒有第一次試驗受傷來得嚴重。推論為東北季風風速有減弱趨勢，故對植物傷害並不嚴重。綜上所述，迎風樹種苗木的生長不受東北季風影響，可生存在吹風環境，而背風樹種苗木的生長發育會遭受風的嚴重機械傷害，不適合生存於吹風環境，試驗結果支持本研究的假說。

關鍵字

生物量 ； 風的機械傷害 ； 苗高相對生長率 ； 遮風設施 ； 風速

並列摘要

This research aimed at comparing the differences in growth performance and leaf damage levels of seedlings growing at windward and leeward sites of Nanjenshan forests under the disturbance of northeast monsoon.
We set up a wind-shielded plot, which was surrounded by transparent plastic sheets, and a non-shielded wind-exposed plot. In each plot, 10 seedlings each of 8 windward species and 9 leeward species were planted. We proposed that for those species originally growing at the windward sites, their seedlings’ growth would not be affected by wind; for those growing at the leeward sites, their growth would be inhibited and leaves damaged by wind. Results showed that average wind speed was 2.0 m s-1 with a maximum speed to be as high as 13.2 m s-1 at the wind-exposed plot, while the average was only 0.5 m s-1 with a maximum of only 4.6 m s-1 at wind-shielded plot from October 2009 to January 2010. After four months of treatment, we found that the biomass, relative height growth rate, number of leaves, leaf area per seedling, and damaged leaves were all not significantly different between the two plots for windward species. Yet, most of the measurements were significantly different between the two plots for leeward species. For example, biomass of leeward seedlings in the wind-exposed plot was 35~70% less than seedlings in the wind-shielded plot; 83.8% of leaves were damaged in the wind-exposed plot while no damaged in the wind-shielded plot. The second during two month treatment ,which had three species repeated with first experiement, we found that the damage rate were less serious than previous treatment, the leeward species still had damage on leaves, but was not less seriously than the leeward species in first treatment. Conclusively, growth of windward species was not affected by northeast monsoon and could survive in windy environments. On the other hand, growth and development of seedlings of leeward species would suffer severe mechanical damage caused by wind, so they are not suitable for growing in windy environment. The proposed hypothesis is thus supported by our results.

並列關鍵字

biomass ； mechanical damage by winds ； relative height growth rate ； wind-shielded facility ； wind speed

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