Effects of wildfires on the main forest ecosystems in Taiwan

• Main Authors: LYU,JIN-CHENG, 呂金誠
• Other Authors: CHEN,MING-YI
• Format: Others
• Language: zh-TW
• Published: 1990
• Online Access: http://ndltd.ncl.edu.tw/handle/90754154328439445560

博士 === 國立中興大學 === 植物學研究所 === 78 === wildfere is an important factor disturbing forest ecosystems. The effects of wildfire an Taiwan red-pine forest, Taiwan acacia forest, monsoon forest, alpine grassland and Pandanus shrub were studied. Results obtained are summarized as follows: 1.Forest fire occurred frequently in the dry season, especially at Taiwan red-pine forest and Pandanus shrub community. During 1967~1988, 706 fires occurred and 127,647.73 hectares were burned. During the past 10 yrars, The frequency of fires caused by illegal farming decreased, but those caused by campfire and unknown reasons increased. 2.Dre to crown opening and albedo effect, the highest daytime temperature at surface soil increased up to 16.2＠ after burning. 3.Post-fire runoff and erosion increased resulted from the decrease of soilporosity and crown interception as will as the consumption of litter layer. During the first rainy season after fire at Tou-mou Mt., runoff increased by 45% and 170 （圖表省略） /ha surface soil was eroded. 4.Abundant nutrients were released form litter layer and plant body after been burning. Both available nutrients and soil pH value were increased after burning. 5.Mortality of pine trees by fire was 50~100%, but it was only 1~19% for hardwoods due to their vigorous sprouting ability Mortality rate. For survived hardwoods,60~90% showed basal sprouting; the others showed epicorrmic growth. 6.Flowering, fruiting and spore-bearing were enhanced after fire due to the increase of nutrient availability, lighy radiation and soil temperature fluctuation. Following burning, spore-bearing indivedual of Brainea insignis increased by 23 times; spikelet number of Lophatherum gracile increased by 1.7 times. 7.Natural seedlings of shade-intolerant Pinus taiwanensis, Crassocephalum crepidioides, Brainea insignis, etc., were abundant following burning. Periodic fires might be beneficial for the subsistence of rare Brainea insignis. 8.It is suggested that, Taiwan red-pine forest and alpine grassland are fire-dependent communities. Pinus taiwanensis, Miscanthus spp., Pteridium aquilinum subsp.wightianum, and Yushania niitakayamensis cam accumulate abundant fuel and induce the occurence of fires and thus maintaining their dominance. Most fires in Taiwan acacia forest and monsoon forest were incidently man-caused or burned for certain purpose. These two forest types ane not fire-dependent communities. The Pandanus shrub at coastal area could be considered as intermediate to resist. wildfires.