臺灣北部楠櫧林帶柳杉人工林下層植群恢復之研究

Study on the Recovery of the Understory Vegetation in Cryptomeria japonica Plantations in Machilus-Castanopsis Forest Zone, Northern Taiwan

陳益明(Yi-Ming Chen)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 18卷3期 (2004/09) Pp. 153-170

https://doi.org/10.6542/EFNTU.200409_18(3).0002

摘要

The aim of this study was to analyze the species diversity of understory plants in Cryptomeria japonica plantations within Machilus-Castanopsis forest zone of northern Taiwan. The samples consisted of a series of different-aged stands, 35 plots and 55 plots for natural or semi-natural vegetation and plantation respectively. Beta diversity indices among plots above 750m in elevation showed a decreasing trend with stand age. Similarities of species composition along successional sere became increasingly higher and species turnover rates gradually decreased toward the later stages. However, beta diversity indices among plots below 750m in elevation showed a reverse trend with stand age.
The tree size structure analysis showed a clear demarcation between small size classes of woody understory species and medium size classes of Cryptomeria japonica. In Ctyptomeria japonica plantations aged from 23 to 46 years, the woody understory was replenished with canopy tree saplings from natural forests, suggesting the Cryptomeria japonica stands had entered the understory reinitiation stage.
The results of this study suggest the landscape mosaics around Mt. Ta-tong, mixing with natural forests and Cryptomeria japonica plantations, promote the recovery of native tree species diversity in Ctyplomeria japonica plantations.

關鍵字

楠櫧林帶 ； 柳杉 ； 棲地異質多樣指數 ； 下層再現解放期 ； 下層再現早期 ； 關鍵植物群

並列摘要

The aim of this study was to analyze the species diversity of understory plants in Cryptomeria japonica plantations within Machilus-Castanopsis forest zone of northern Taiwan. The samples consisted of a series of different-aged stands, 35 plots and 55 plots for natural or semi-natural vegetation and plantation respectively. Beta diversity indices among plots above 750m in elevation showed a decreasing trend with stand age. Similarities of species composition along successional sere became increasingly higher and species turnover rates gradually decreased toward the later stages. However, beta diversity indices among plots below 750m in elevation showed a reverse trend with stand age.
The tree size structure analysis showed a clear demarcation between small size classes of woody understory species and medium size classes of Cryptomeria japonica. In Ctyptomeria japonica plantations aged from 23 to 46 years, the woody understory was replenished with canopy tree saplings from natural forests, suggesting the Cryptomeria japonica stands had entered the understory reinitiation stage.
The results of this study suggest the landscape mosaics around Mt. Ta-tong, mixing with natural forests and Cryptomeria japonica plantations, promote the recovery of native tree species diversity in Ctyplomeria japonica plantations.

並列關鍵字

Machilus-Castanopsis Forest Zone ； Cryptomeria japonica ； habitat heterogeneity index ； understory release stage ； understory early stage ； key species groups