Forest Dynamics And Natural Regeneration Of Long-term Dynamics Plot In Fagus hayatae Forest Of Tongshan, Yi-lan County

• Main Authors: Pin-Yi Chen, 陳品邑
• Other Authors: Tze-Ying Chen
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/70057633084522782721

碩士 === 國立宜蘭大學 === 森林暨自然資源學系碩士班 === 100 === This study is discussing the forest composition and dynamics in long-term dynamics plot of beech forest of Tongshan, and the natural regeneration of Fagus hayatae. The survey area is 2.2 ha, where a 2 ha plot area had been surveyed repeatedly at 2005 and 2009, and recorded DBH, height and position of each trees. There are 24 families, 35 genera, and 44 species woody plants in 2.2 ha plot. The dominant species of canopy is Fagus hayatae; the species of subcanopy are Illicium anisatum, Pasania hancei var. ternaticupula, Styrax formosana and Litsea elongata var. mushaensis; the species of lower layer are Symplocos arisanensis, Neolitsea acuminatissima, Camellia brevistyla and Eurya crenatifolia; the dominant species of understory is Yushania niitakayamensis. Tree composition of 2005 and 2009 are similar, which only 1 species eliminated from the plot, total density and total basal area were reduce in 4 years. Recruitment stems, mortality stems and recruitment basal area gather on lower layer species, and most species are mortality rate larger than recruitment rate; basal area loss by death of stems gather on the species of canopy and subcanopy. Summation of the basal area gain by growth of surviving stems and recruitment stems are lower than basal area loss by death of stems. In the result of polar ordination, the 2.2 ha plot distinguish 4 vegetation community: (1)Fagus hayatae type, include Illicium anisatum-Fagus hayatae subtype and Viburnum sympodiale- Fagus hayatae subtype;(2)Illicium anisatum type and(3)Lyonia ovalifolia type. Compared with Illicium anisatum-Fagus hayatae subtype and Viburnum sympodiale- Fagus hayatae subtype, where the Viburnum sympodiale- Fagus hayatae subtype had lower average height of bamboo, steeper slope, and more Fagus hayatae that launch earlier than another, so speculate that the environment of Viburnum sympodiale- Fagus hayatae subtype is wider. In the result of chi-squared analysis, beech saplings, small diameter trees and medium trees gather in Viburnum sympodiale- Fagus hayatae subtype, where saplings gather in gaps; on the other hand, saplings don’t gather in gaps of Illicium anisatum-Fagus hayatae subtype. Because of the lower average height of Yushania niitakayamensis of Viburnum sympodiale- Fagus hayatae subtype, and the gaps appeared, seems to be helpful to saplings of Fagus hayatae occured. The regeneration cohorts of Fagus hayatae have periodicity, the reason of the phenomenon may that be the Yushania niitakayamensis bloomed periodically, possibly the seedlings of Fagus hayatae occured abundantly. The patterns of radial growth show that most growth processes of Fagus hayatae are “suppress-release repeatedly” model, speculate that the regeneration of Fagus hayatae usually used small gap, and the longest period of suppression till 38 years. In the growth process of Fagus hayatae, bamboo is first sieve that impede the regeneration of seedlings, and stems of other trees are the second. If Fagus hayatae passed two sieves, it could grew through the gap to canopy.