印度Chotanagpur高原蘭科植物石斛蘭屬之生態與多樣性

Diversity and Ecology of Dendrobiums (Orchidaceae) in Chotanagpur Plateau, India

因執行「全印度系統分類合作研究計畫」（AICOPTAX）之蘭科植物部分，在2002~2006年間，在Chotanagpur高原擴大調查記錄蘭科植物的種類和分布。在63種蘭科植物中，石斛蘭屬是附生蘭屬最大的一類且多出現在以龍腦香科梭羅雙樹（Shorea robusta）為優勢種的森林中，共包括：兜唇石斛（Dendrobium aphyllum）、D. bicameratum、玫瑰石斛（D. crepidatum）、D. cucullatum、D. formosum、流蘇石斛（D. fimbriatum）、D. herbaceum、杓唇石斛（D. moschatum）、D. peguanum、D. regium及D. transparens等11種，本生態調查是以分層隨機取樣的方式在此森林進行，結果顯示兜唇石斛幾乎在各個海拔均可以發現，也是這11種石斛蘭中分布最廣，其餘種類多在較高海拔地區；Dendrobium herbaceum則主要出現在本高原海拔900至1000公尺間，玫瑰石斛則同時為附生蘭且亦生長於石頭上，而杓唇石斛僅出現於溪邊的石頭上，其餘的種類全是附生。本文同時指出一些影響其分布的微棲地特徵且併入檢索表中協助鑑定。

As part of All India Coordinated Research Project on Taxonomy of orchids (AICOPTAX) Chotanagpur Plateau was surveyed extensively for documentation of orchid species and distribution during 2002 -2006. Sixty three species were collected from the study area with Dendrobium as one of the largest group of epiphytic orchids comprising of 11 species, namely, Dendrobium aphyllum, D. bicameratum, D. cucullatum, D. crepidatum, D. formosum, D. fimbriatum, D. herbaceum, D. moschatum, D. peguanum, D. regium and D. transparens. Most of the species were found in the Sal (Shorea robusta) dominated forests. Stratified Random Sampling was used for ecological studies in the forested regions on the plateau. Results show that D. aphyllum was the most common amongst 11 species and it was distributed through out the altitudinal gradient, whereas, rest of the orchid species were found to be localised at comparatively higher altitudes. D. herbaceum was always found on the upper areas of the plateaus between 900-1000 m asl. D. crepidatum was seen in both epiphytic as well as lithophytic conditions, whereas D. moschatum were found growing as lithophytes along the streams. Rest of the species were epithytic. The paper also deals with some microhabitat features governing the distribution of these orchids on the plateau along with their key for identification.