Department of Botany, University of Delhi, Delhi 110 007, INDIA.
The thesis embodies the results of morpho-taxonomic studies carried out on the mosses occurring in Idukki district in Kerala, India since April 2005, with the objectives, (a) Survey of mosses of Idukki district through field studies and available literature. (b) Documentation and enriching herbarium of mosses of Idukki district. (c) To provide illustrations of preferably all the mosses of Idukki district for easy identification. (d) Preliminary evaluation of mosses for their habitat preference. (e) To bring out illustrated moss flora of Idukki district. The study is based on more than 500 samples of 135 specimens collected during extensive and intensive field tours undertaken to different ecoregions of Idukki district during 2005-2008 in different seasons. All the specimens have been deposited in the herbarium of Department of Botany, University of Delhi, India.
Mosses have always been linked to the terrestrial environment and have been achieved their greatest diversity in cool, moist, oceanic climates found at higher latitudes and altitudes. Several species have potential to adapt the changing climates of this area. The considerable extant diversity of these groups reflect the genetic plasticity of the ancestral populations and their great success in occupying the many new and edaphically and hospitable niches created by the rise of the angiosperms. Differences in habitat ecology of mosses are commonly used as an aid in their identification, at any taxonomic level, used in conjunction with the morphological characters. It is also concluded that the real differences between species are in the field, where whole populations and their reaction to environmental factors can be clearly observed. The growth of tourism and other recreational activities as well as the agricultural and industrial development of the area are destroying the habitat of mosses and the population size of mosses is decreasing. The preparation of generic floras and keys of south India is needed urgently.
Present study deals with a comprehensive morphological study and illustrated account of 135 species of mosses belonging to 75 genera and 25 families from Idukki district, specially the hilly areas of Munnar and its surrounding, representing several interesting taxa from just 13.07% of the total geographical area of the state of Kerala.
Within the study area, Eubryales with 38 species belonging to 16 genera and 3 families is found to be the largest order followed by Dicranales with 31 species belonging to 15 genera and 3 families. Fissidentales is represented by 4 species only of the genus Fissidens. The family Bryaceae with 32 species and 12 genera is the largest represented family in the study area followed by Dicranaceae (20 species and 10 genera) and Polytrichaceae (10 species and 3 genera). The families Mniaceae, Cryphaeaceae, Trachypodaceae, Fabronaceae, Amblystegiaceae and Plagiotheciaceae are represented by single species in each.
At the generic level, genus Bryum Hedw. with 9 species was found to have highest number of species followed by Campylopus Brid. and Brachymenium Schwaegr. (with 7 species of each) while 51 genera viz., Polytrichum Hedw., Pleuridium Brid., Garckea C.Muell., Ceratodon Brid., Anisothecium Mitt., Microdus Schimp., Campylopodiella Card., Dicranodontium B.S.G., Rhabdoweisia B.S.G., Dicranoweisia Mild., Timmiella (De Not.) Limpr., Hydrogonium (C.Muell.) Jaeg., Mielichhoferia Nees & Hornsch., Orthodontium Schwaegr., Haplodontium Hamp., Leptobryum (B.S.G.) Wils., Mniobryum Limpr., Plagiobryum B.S.G., Ptychostomum Hornschuch, Mnium Hedw., Anacolia Schimp., Bartramidula B.S.G., Orthotrichum Hedw., Macromitrium Brid., Schoenobryum Doz. & Molk., Trachypodopsis Fleisch., Garovaglia Endl., Symphysodontella Fleisch., Cryptopapillaria Menzel, Meteoriella Okam., Barbella Fleisch., Fabronia Raddi, Regmatodon Brid., Lescuraea B.S.G., Herpetineuron (C.Muell.) Card., Claopodium (Lesq. & Jam.) Ren. & Card., Haplocladium (C. Muell.) C. Muell., Pelekium Mitt., Calliergon (Sull.) Kindb., Pterigynandrum Hedw., Entodon C. Muell., Erythrodontium Hamp., Plagiothecium B.S.G., Hageniella Broth., Clastobryopsis Fleisch., Chionostomum C. Muell., Meiothecium Mitt., Pylaisiadelpha Card., Brotherella Loesk. Ex Fleisch., Trichosteleum Mitt., Ctenidium (Schimp.) Mitt. are represented by one species each.
The most favourable altitudinal range for the growth of mosses is approximately 1600m where a total of 45 taxa have been reported belonging to 14 families and 27 genera, followed by 1700m where a total of 26 taxa have been reported belonging to 16 families and 24 genera and least number of taxa were collected from the altitudinal range of approximately 1300m with a total of 10 taxa belonging to 4 families and 9 genera.
Of the total 135 taxa of mosses reported from the study area, 70 taxa are lithophytic belonging to 44 genera and 17 families. 34 taxa are terrestrial belonging to 9 families and 18 genera. A total of 27 taxa belonging to 16 families and 24 genera have been reported from epiphytic habitat. 4 taxa belonging to 2 genera and families have been recorded from construction sites (such as old walls) whereas 2 taxa belonging to 2 genera and a single family have been reported from litters also. Out of the total 135 taxa reported from the study area 13 taxa belonging to 9 genera and 8 families are found to be widely distributed at open as well as forested sites such as Atrichum obtusulum, Ceratodon purpureus, Campylopus flexuosus, etc. 28 taxa belonging to 20 genera and 13 species are frequent as they were reported from many forested sites, 38 taxa belonging to 27 genera and 14 families are moderately present or infrequent as they were reported from 5 to 10 site only in moist habitat. 34 taxa belonging to 21 genera and 10 families are sparse as they were reported from 3 to 4 sites only whereas 22 genera belonging to 11 families have been found to be rare as these are represented by just single collection only such as Pogonatum cirratum, Pleuridium tenue, Garckea flexuosa, etc. Out of the 135 taxa reported from the study area, 24 taxa are endemic to India.
Before taking up the present study, a total of 465 bryophyte taxa comprising 148 taxa of liverworts, 10 taxa of hornworts and 307 taxa of mosses were reported from Kerala (Nair et al., 2008). The present study has added 83 taxa of mosses comprising 51 new genera belonging to 18 families to the hitherto known bryoflora of the study area which is only 13.07% of the total geographical area of the state of Kerala.
The following conclusions were drawn from the present study:
Present study shows that the area is rich in bryophyte species and harbours many of the endemic taxa.
Developmental activities are threatening the bryophyte species and also the associated organisms.
Some of the areas should be protected for the habitat for bryophytes and to be declared as moss gardens.
Epiphytic species play an important role in protecting the host species by providing continuous moisture.