火燒及植被對七星山土壤溫度及化學性質之影響

Effects of Fire and Vegetation Types on Soil Temperature and Chemistry at Chihsing Mountain, Taiwan

王巧萍(Chiao-Ping Wang) ； 劉美娟(Mei-Chuan Liu) ； 林國銓(Kuo-Chuan Lin) ； 王立志(Lih-Jih Wang)

《台灣林業科學》 18卷1期 (2003/03) Pp. 43-54

https://doi.org/10.7075/TJFS.200303.0043

摘要

A grass land (Miscanthusfloridulus (Labill.) Warb) at Chihsing Mountain, northern Taiwan, was burned in July 2001. Soil temperature at 5-cm depth of burned (burned grassland) and undisturbed (grassland and natural forest) sites was monitored. Soil chemical properties of the burned grassland, grassland, natural forest, and dwarf-bamboo (Pseudosassa usawai) sites were analyzed to reveal the effects of fire and vegetation types on soil chemistry. The variation of daily temperature in soil of the burned grassland was 6℃, which was 4.5℃ higher than that under a natural forest. However, this phenomenon disappeared with in 4 mon due to fast regeneration of the grass. Increases in concentrations of nutrients arising from the additions of fine ash at the burned grassland were not observed in this study. Contrarily, burning increased the soil bulk density of the grassland and decreased the soil pH value, SOM, concentrations of exchangeable cations, CEC, and base saturation. Exposure of soils after fire in this steep area with abundant precipitation may lead to serious soil erosion and nutrient loss. Significant decreases in soil carbon and nitrogen contents were also found in the burned grassland. Determination of the loss of soil C and N caused by intensified mineralization of the organic matter needs further study. Soils from the study sites show the typical characteristics of an Andisol, being strongly acidic, with fewer exchangeable cations, a low base saturation (＜3%), and an accumulation of soil organic matter with Al-compounds which are recalcitrant to decomposition. Therefore, the effects of vegetation types (grassland and natural forest) on the contents of SOM, TC, TN, and CEC were not significant. Since bamboo shoots are collected by local people, nutrients may be continuously removed from the site with bamboo resulting in lower concentrations of exchangeable cations, CEC, and SOM compared to the undisturbed grassland and natural forest.

關鍵字

火 ； 土壤溫度 ； 土壤化學 ； 五節芒 ； 天然闊葉林 ； 包籜矢竹林

並列摘要

A grass land (Miscanthusfloridulus (Labill.) Warb) at Chihsing Mountain, northern Taiwan, was burned in July 2001. Soil temperature at 5-cm depth of burned (burned grassland) and undisturbed (grassland and natural forest) sites was monitored. Soil chemical properties of the burned grassland, grassland, natural forest, and dwarf-bamboo (Pseudosassa usawai) sites were analyzed to reveal the effects of fire and vegetation types on soil chemistry. The variation of daily temperature in soil of the burned grassland was 6℃, which was 4.5℃ higher than that under a natural forest. However, this phenomenon disappeared with in 4 mon due to fast regeneration of the grass. Increases in concentrations of nutrients arising from the additions of fine ash at the burned grassland were not observed in this study. Contrarily, burning increased the soil bulk density of the grassland and decreased the soil pH value, SOM, concentrations of exchangeable cations, CEC, and base saturation. Exposure of soils after fire in this steep area with abundant precipitation may lead to serious soil erosion and nutrient loss. Significant decreases in soil carbon and nitrogen contents were also found in the burned grassland. Determination of the loss of soil C and N caused by intensified mineralization of the organic matter needs further study. Soils from the study sites show the typical characteristics of an Andisol, being strongly acidic, with fewer exchangeable cations, a low base saturation (＜3%), and an accumulation of soil organic matter with Al-compounds which are recalcitrant to decomposition. Therefore, the effects of vegetation types (grassland and natural forest) on the contents of SOM, TC, TN, and CEC were not significant. Since bamboo shoots are collected by local people, nutrients may be continuously removed from the site with bamboo resulting in lower concentrations of exchangeable cations, CEC, and SOM compared to the undisturbed grassland and natural forest.

並列關鍵字

fire ； soil temperature ； soil chemistry ； grassland ； natural forest ； dwarf-bamboo