Effects of ground bryophytes on nutrient cycling of YYL forest ecosystem

• Main Authors: Mei-Chuan Liu, 劉美娟
• Other Authors: Shih-Chieh Chang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/82823190124224521280

碩士 === 國立東華大學 === 自然資源管理研究所 === 92 === Abstract Bryophytes usually develop into a noticeable component of forest floor in humid temperate and tropical climates and affect the process of hydrological balance and nutrient cycling through the prominent coverage, biomass and nutrient content. The objectives of this study were to investigate (1) the biomass and nutrient content of forest floor bryophytes, (2) the effects of different bryophytes on canopy throughfall that percolated through them, and (3) the role of forest floor on the hydrological and nutrient budgets in Yuan-Yang Lake forest ecosystem in northeastern Taiwan. The layer of ground bryophytes of this site has well developed and the coverage was up to 83%. Totally 35 bryophyte species were identified, representing 45% of total number of species of the forest floor plants. The biomass of forest floor plants was 835 ±40 kg ha-1, of which the bryophytes accounted for 83%(695 ±38 kg ha-1). The nutrient pool of total carbon, total nitrogen, Ca, K, Mg, Na, and P of forest floor was 375, 14, 3.9, 11.6, 1.0, 0.2, and 2.6 kg ha-1, respectively. Bryophytes accounted for 73-90% of these nutrient stocks. Bryophyte species of this study were L. fauriana, T. tomentella, P. ovalifolia, P. latifolium and S. palustre. From July 2003 to May 2004 the total flux of bulk precipitation was 2618 mm, canopy throughfall was 2337 mm, while the total flux of bryophyte leachate (BL) was 1122mm, accounting for 49% of the input precipitation (BI). The chemical composition of BI changed as the precipitation passed through the bryophytes. A part of K+, Na+, and NO3--N in the BI was retained in the bryophytes, while some H+, Ca2+, and total N were released from them. Compared with other bryophyte species, L. fauriana showed the highest ability to retain NO3--N, Na+, Mg2+and so on, while P. latifolium showed the highest ability to retain NH4+-N. Ground bryophytes of YYL site retained water (31%), Mn2+ (43%), NO3--N (35%), and Mg2+(30%) from throughfall, and released H+(0.01kg ha-1), Ca2+(0.2kg ha-1), and total N(0.8kg ha-1) into the soil layer. Soil water and ions input were lower through forest floor covered with bryophytes than that through non-bryophytes ground. For this reason, ground bryophytes induced the spatial heterogeneity of soil water input.