| Summary: | 碩士 === 國立屏東科技大學 === 熱帶農業暨國際合作系所 === 99 === 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.
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