Abstract

Mosses are remarkably successful colonizer on the variety of habitats. They can survive in extreme environmental conditions where only a few other plants grow. The main attributes of mosses are compact growth form, ability to retain moisture, ectohydric nature, poikilohydry and low growing habit. The occurrence of a particular species may reflect the microclimate of the locality. The present study reveals 75 species of acrocarpous mosses belonging to 23 genera and nine families from Imphal district which is an urban site of tropical climate. The most frequently occurring family is observed to be Pottiaceae with 28 species and 11 genera. The genus Bryum with 13 species is found to have highest number of species followed by Fissidens and Physcomitrium. Splachnobryum sp. and Bryum argenteum are found to be distributed on the nitrophilous substrata. It seems that changing climatic conditions and pollution are restricting the sexual reproduction and subsequently the genetic variability and adaptability in the moss taxa.

中文摘要

苔類植物是一群可以成功建立於各種生境的拓殖者。他們能生活於僅少數植物能生長的極端環境條件之中。苔類植物主要的特徵有：袖珍而完整的生長方式、維持潮濕的能力、外導水的（ectohydric）特性、缺乏抗乾燥機制的變水性質（poikilohydry），及低小的生活型體。苔類物種也具有指標性，某一特定物種的出現可能反映該地區的微氣候環境。本研究報導於一個地處熱帶氣候的都市 – 因帕爾地區，當地的苔類植物相；研究中共調查到9科，23屬，75種頂生蒴的苔類植物。其中所觀察到的科頻率最高為Pottiaceae具有11屬，28種。Bryum包含有13個物種為最多物種的屬，其次為Fissidens和Physcomitrium二屬。Splachnobryum sp. 及 Bryum argenteum被發現分布於高含氮的基質。本文顯示氣候條件的改變及環境的污染正約制著苔類植物的有性繁殖，隨後可能減低苔類植物的遺傳變異以及其適應性。

Keyword: Habitat specificity, Imphal, mosses, nitrophilous.