Evaluation of heterogeneity in foliage distribution. How does the complexity of canopy structure affect on the gas-exchanges of forest ecosystem?

Research Project

Project/Area Number	15580129
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	林学・森林工学
Research Institution	Shizuoka University (2005-2006) Kagoshima University (2003-2004)
Principal Investigator	MIZUNAGA Hiromi Shizuoka-University, Agriculture, Professor, 農学部, 教授 (20291552)
Project Period (FY)	2003 – 2006
Project Status	Completed (Fiscal Year 2006)
Budget Amount *help	¥3,400,000 (Direct Cost: ¥3,400,000) Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 2004: ¥1,300,000 (Direct Cost: ¥1,300,000) Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Keywords	Heterogeneity of foliage distribution / Foliage cluster / Canopy / Gap mosaic structure / 森林の葉分布 / クラスター / 林冠のモザイク構造 / 着葉分布 / 林冠構造 / 葉分布 / 受光効率
Research Abstract	The spatial distribution of foliage in canopy represents an important aspect of the stand structure for silviculture, with determining the microclimates in the stand, gas-exchanges of forest ecosystems, and the stem shape. Foliage distributed discontinuously with constructing foliage cluster, and the foliage density is heterogeneous in canopy. The cluster formation and gap mosaics in the canopy enhance the heterogeneity of canopy structures. In spite of its importance, little quantitative information on three-dimensional foliage distribution pattern was available, because of the difficulty in making measurements in stands of tall trees. The structure of foliage cluster is poorly understood quantitatively. This study project aims to quantify the heterogeneity of foliage distribution, to clarify whether the complexity of foliage structure changes among species and stand stages, and to know the impact of heterogeneity of foliage distribution on gas-exchanges of forest ecosystem. 1. I quant … More ified the cluster structure of foliage within crown of C. japonica, and examined whether foliages within crowns of this species distribute more heterogeneous and clumpy with ageing. Old crowns (78yrs and 88yrs) had more heterogeneous and fragmented foliage clusters than young (20-yrs) and middle-aged crowns (40yrs) did. Foliage distributed more with ageing. These heterogeneities closely related to the gap proportion within a crown. 2. The structures of foliage clusters were compared between two evergreen broadleaved canopy trees ; Castanopsis cuspidata and Machilus thunbergii, through measuring three-dimensional distribution of foliages within crowns. C.cuspidata formed compact clusters, possibly due to its shoot architectures. 3. We measured three-dimensional foliage distribution within crowns of Fagus crenata. A model for predicting transpiration and photosynthetic rate of single tree was constructed through evaluating temporal and spatial light variance in a crown using parameters of foliage distribution. 4. Gap mosaic structure is one of important factor of complexity of canopy. I constructed a model for estimating the effect of gap mosaic structure on photosynthetic rates of seedlings. Gap mosaics had large impacts on spatial distribution of photosynthetic potential, and niches of seedlings. Less