This is a newly published, 5 chapter volume edited by Rai & Upreti. Learn more here (Springer page) and here (Google site). There is also a volume 2 on Morphotaxonomic studies.
Rai, Himanshu; Khare, Roshni; Upreti, Dalip Kumar
The symbiotic association of fungi and algae/cyanobacteria, known as lichen, is one of the most successful associations in nature. Dominated by ascomycetous mycobiont majority (85 %) of lichens have green algae as their photobionts, rest (15 %) have cyanobacteria as their primary or secondary photobionts. Cyanolichens, owing to their ability to fix atmospheric nitrogen, help in nitrogen dynamics of terrestrial biomes. On the basis of substratum, lichens are categorized into saxicolous (inhabiting rocks and stones), corticolous (growing on tree barks), terricolous (soil inhabiting), ramicolous (growing on twigs), muscicolous (growing over mosses), and omnicolous (inhabiting various substrates and manmade structures). Among these, soil-inhabiting terricolous lichens are among the most sensitive lichens, used in biomonitoring studies. Lichenological researches in India in the past 50 years have accumulated a good amount of taxonomic knowledge and now, applied fields of lichenological researches are being explored such as bioprospection of lichen metabolites, lichen-based pollution monitoring, ethnopharmacological uses of lichens and functional ecophysiology of lichens. Indian terricolous lichens, besides being mentioned in taxonomic records and enumerations, have also been studied for their ethnopharmacological uses and their role in functional ecology (nutrient dynamics, photobiont specificity, altitudinal optimum, and biomonitoring of zooanthropogenic pressures) of their habitats.
2. Distribution Ecology of Soil Crust Lichens in India: A Comparative Assessment with Global Patterns
Rosentreter, Roger; Rai, Himanshu; Upreti, Dalip Kumar
Soil-inhabiting terricolous lichens along with other cryptogams such as mosses and cyanobacteria form a functional entity, referred to as biological soil crust (BSC). Lichen-dominated BSCs occur worldwide. The formation of BSCs and their species diversity is governed by factors such as, climate, soil-type, calcareousness, soil-texture, hydrology, and zooanthropogenic pressures. In India, soil crust formation and terricolous lichen diversity is governed by the same set of factors that govern soil crusts globally. The western dryer region of the country is poor in soil crust lichens due to dryer climate, sandy-textured soils, and high zooanthropogenic perturbations. Terricolous lichens in these regions are restricted to some high altitude, moist habitats and largely composed of calcicolous species such as the genus Collema. The Himalayan habitats harbour maximum diversity of biological soil crusts and terricolous lichens dominated by species of Stereocaulon and Cladonia, followed by Peltigeraand Xanthoparmelia. The soil crust lichens in these temperate habitats are constrained by grazing pressures and decrease in soil cover along increasing altitudinal gradient.
Baniya, Chitra Bahadur; Rai, Himanshu; Upreti, Dalip Kumar
Despite the great importance of terricolous lichens very few efforts have been done towards the elevational richness pattern and their ecology from the Himalayas. In present study elevational ranges of terricolous lichen richness were interpolated at every 100 m altitudinal band. They were found distributed from 100 to 6,000 m. A total of 212 terricolous lichen species under 54 genera and 24 families were found recorded in India and Nepal. These terricolous lichen species showed a highly significant unimodal elevational declining pattern with dominant peak at 2,400 m. This unimodal richness pattern was also followed by their dominant families but differed in elevation of peak richness. The zones of dominance and diversity richness of terricolous lichen species were discussed with reference to natural and anthropogenic factors specific to Himalayan habitats.
4. Photobiont Diversity in Indian Cladonia Lichens, with Special Emphasis on the Geographical Patterns
Řídká, Tereza; Peksa, Ondřej; Rai, Himanshu; Upreti, Dalip Kumar; Škaloud, Pavel
The biogeography of lichen photobionts is still poorly known, in particular, as the majority of reports have been published from Europe and North America. In this study, we examined the diversity of Asterochloris photobionts from terricolous lichens (Cladonia spp.) collected in five different areas in India and Nepal during the years 2007 and 2010. In total, we obtained 20 internal transcribed spacer (ITS) ribosomal DNA (rDNA) photobiont sequences from 11 different Cladonia species. The phylogenetic position of Asterochloris photobionts was investigated by the phylogenetic analysis based on the concatenated ITS rDNA and actin type I intron dataset. The newly obtained photobiont sequences were inferred in six clades, including two novel clades exclusively formed by photobionts of Indian Cladonia lichens. As the sequences of these two clades were genetically considerably different from all other known Asterochloris lineages, they most probably represent new, undescribed photobiont species. According to our data, three clades seem to have rather restricted distribution, reported so far only from Europe and Asia, respectively. However, we propose that the restricted distribution of these three photobiont clades is not caused by either historic or biological factors, but more likely by specific climatic or habitat preferences and the under-exploration of such habitats in different regions.
5. Photobiont Diversity of Soil Crust Lichens Along Substrate Ecology and Altitudinal Gradients in Himalayas: A Case Study from Garhwal Himalaya
Anna, Voytsekhovich; Dymytrova, Lyudmyla; Rai, Himanshu; Upreti, Dalip Kumar
The symbiotic coevolution of algae and fungi in lichens has been instrumental in overall success of lichens in some of the most unfavourable habitats of the planet. Himalayas by virtue of their fragile temperature regime and diverse topography allow variety of lichen functional groups to flourish. Among these, soil-inhabiting terricolous lichens have proved to be good indicators of habitat heterogeneity and zooanthropogenic pressures. Photobiont diversity of terricolous lichens of Garhwal Himalayas showed the dominance of Chlorophyta (70 %) over Cyanoprokaryota (30 %) as photobionts. The ecological preference analysis of the photobionts indicated that majority of photobionts preferred lichens belonging to terricolous or terricolous–rupicolous ecological subgroups. Asterochloris dominated in the both subgroups, whereas Nostoc was common in muscicolous–rupicolous subgroup. The comparative dominance of the photobionts in ecological subgroups was a function of hydration preferences of photobionts. Cyanobionts dominate niches which can hold water for longer period, whereas dominate green algal chlorobionts dominate the rest. The altitudinal preferences showed that lichen species with Asterochloris were found in the range of 2,300–3,700 m, followed by Scytonema at 1,700–3,900 m, Nostoc at 2,100–3,500 m andTrebouxia at 2,800–4,000 m. As the maximum richness was within the range of 2,800–3,500-m altitude, it is evident that the diversity drivers of lichen photobionts were climatic factors (i.e. light intensity, humidity/precipitation and temperature).