南仁山區亞熱帶雨林地被層植物之研究

Abstract

於南仁山區3公頃永久樣區內設7條5×300m東西向帶狀樣區，以截線穿越法，調查區內草本植物之覆蓋度及組成，以建立永久樣區更完整之資料，並首度嘗試進行林下草本植群的分類。 共記錄94種植物，排除部份非木質藤本及樹蕨類等，計得74種草本植物。除少數屬恆春半島、綠島及蘭嶼分佈型之植物外，其他均屬本省低地森林林下草本植物，且大部份均?二年生和多年生草本植物。種類組成以蕨類植物和單子葉植物?主，優勢度集中於少數種類。 經由雙向列表分析法（TWINSPAN）將樣區切分成2大類型，分別?迎風坡型與背風坡型，可再細分成四個亞型。二大類型間優勢種類明顯不同，迎風坡以單子葉植物?優勢，背風坡以蕨類植物?優勢，反應出二型生育地的差異。同時將草本植群分類結果與樹冠層之結果比較，二者結果頗?吻合，因此由林下層亦能精準反應生育地的異質性。 以典型對應分法（canonical correspondence analysis, CCA）分析與植群變異相關的環境因數。坡向、風力效應與海拔高度三因數與植群變異具相關性，而直接反應草本植群差異的因數應?水份因數。根據植物分佈生育地之差異可分成三種不同的草本植物分佈類型（distribution pattern），分別?迎風坡型植物、背風溪穀型植物和廣泛分佈型植物。

Seven 5×300m transits were established in a Nanjenshan permenant plot to study herbaceous plant distribution pattern and into relationship with environmental factors. All herbacous plants in these transits were identified and the coverage for each plant were recorded as well. There are total of 74 plant species after excluded non-woody lianas and tree-ferns. Most herbaceous species occurred in Nanjenshan are also occurred throughout the understory of lowland forest around Taiwan. However, there are some species, only found in Hengchun Peninsula. All berbaceous plant found in the plot are pereminals. Pteridophytes and Monocotyledons are the most important understory component in thes forest. And the dominant spp. are Carex cruciata, and D iplazium donianum. According to TWINSPAN analysis, the herbaceous plant community in the study plot could be divided into two groups, and these two groups could be further divided into four subgroups. Group I which dominant by Carex cruciata is windward type, and Group II which dominant by Pteridophytes Diplazium donianum is leeward type. Canonical correspondence analysis (CCA) indicated that aspect, wind and altitude are the environmental factors related to vegetation distribution. Moreover, soil moisture is the direct factor that affect plant distribution.