Soil Nutrient Dynamics of Major Vegetation Types at Mt. Shei Alpine Ecosystem

• Main Authors: Ching-Yuan Chang, 張競元
• Other Authors: 顏江河
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/42483039426839974955

碩士 === 國立中興大學 === 森林學系所 === 100 === The main objective of this study was to investigate the soil nutrient dynamics of five vegetation types at Mt. Shei alpine ecosystem. Five main collection points along the line of Mt. Shei were chosen (1) 2,500 m Chica-Cabin, with dominant species Neolitsea acuminatissima and Cyclobalanopsis stenophylla, (2) 2,800 m Crying-Slope, with dominant species Yushania niitakayamensis and Miscanthus transmorrisonensis, and with minor species Picea morrisonicola. (3) 3,200 m Burned Land, with dominant species Yushania niitakayamensis and Miscanthus transmorrisonensis. (4) 3,500 m Black Forest, with dominant species Abies kawakamii. (5) 3,650 m Land Cirque, with dominant species Juniperus squamata and Rhododendron pseudochrysanthum. Samples included litter layer, humus layer and soil of depth 0~10 cm, 20~10cm, 20~40 cm. These samples were weighed and analyzed with respect to their soil nutrients, and the factors which affected the observed soil nutrients were discussed. The results showed that the stone rate of the region varied significantly (between 0.98 to 25.54 %). Soil pH ranged between 3.65 to 5.16 which was highly acidic, and soil pH increased with increasing soil depth. The content of soil organic carbon was high (between 2.23 to 16.04%), and this was due to higher altitude, lower temperature and slower litter decomposition. Total soil nitrogen ranged between 0.07 to 1.22%, which was in normal concentrations and were suitable for plant growth. This means nitrogen is not a limiting factor for plant growth in this region. There was a strong positive correlation between total soil nitrogen and soil organic carbon, and the C/N ratio ranged between 11.0 to 33.3. Most of the sampling points were in the range of net mineralization. Soil available phosphorus concentration ranged between 0.26 to 8.40 ppm. The majority of the sampling points demonstrated phosphorous deficiency, with the exception of burned soil, in which a higher concentration of phosphorous was observed. The soil cation exchange capacity was very high (between 5.57 to 49.20 m.e. /100g), and exhibited a positive correlation with organic carbon as well as total nitrogen. The exchangeable potassium, sodium, calcium and magnesium are very low. The base saturation ranged between 1.4 to 13.92%, in which Crying-Slope and Burned Land exhibited significantly higher values than those of other sampling points (p<0.05). The exchangeable aluminum was high in the all regions (between 2.02 to 13.28 m.e. /100g). In summary, it was observed that the lowest value of stone rate, soil organic carbon, soil nitrogen and CEC was all from the sampling points in the highest Chica-Cabin of Land Cirque. This leads to the conclusion that most of the nutrients described in this study with the exception of exchangeable aluminum showed a trend, viz the amounts of nutrients reduced with increased soil depth.