Addition of 96 lichen species to the state of Odisha from Similipal Biosphere Reserve

A total of 96 species of lichens taxa belonging to 45 genera and 20 families are enumerated from Similipal Biosphere Reserve, in Mayurbhanj district as an addition to the lichen biota of Odisha, India. Most of the crustose lichen taxa usually growing as epiphytes on different phorophytes of the biosphere reserve exhibit their dominance. Among crustose lichens the members of family Graphidaceae with 26 species of 14 genera shown their maximum dominance. Together with Graphidaceae the lichen genus Pyrenula represented by 15 species found growing luxuriantly on smooth barked trees of the biosphere reserve. The dominant trees in the biosphere such as Shorea robusta Gaertn. followed by Mangifera indica L., Simarouba glauca DC. and Madhuca longifolia (L.) J. F. Macbr., provided suitable habitat for a number of lichen taxa to colonize. The south-west (SW) region of Similipal Biosphere Reserve exhibits the maximum additions of lichens, followed by north-west (NW), north-east (NE) and south-east (SE) respectively.


Introduction
Indian lichen flora is represented by 2714 species belonging to 324 genera and 78 families (Sinha et al. 2018). In the state of Odisha, a number of offhand collections were carried out for exploration of lichens in different parts of the state including Jharsuguda district (Upreti (1996)), Kapilash Reserve forest (Nayak et al. 2015), Utkal University campus , Bhitarkanika National park (Panda et al. 2017), Mahendragiri hill (Swarnalatha (2017)), Sun Temple of Konark , Satkoshia hill range , Khandagiri and Udayagiri (Pradhan et al. 2020) and Puri (Majhi and Pradhan 2020). The lichen taxa enumerated in earlier studies were compiled by , revealing the occurrence of 252 species of lichens belonging to 81 genera and 35 families. Nayak et al. (2018), also studied lichens growing on different monuments of the state and reported species of lichen genus Lecidella, Buellia , Lecanora and Lepraria, growing luxuriantly on historical monuments of Ratnagiri and Udayagiri in Jajpur district. , described a new species Cryptothecia odishensis R. Bajpai, S. Joseph & Upreti, from Jharsuguda district (Das et al. 2018).
Mayurbhanj, one of the biggest districts of Odisha, exhibits a large tract of dry deciduous forest with the dominance of Shorea robusta trees. The climatic condition of the district is suitable for the luxuriant growth of various plant species including lichens. The lichen diversity of the region has been poorly known as compared to other districts of the state because of the few cursory lichen explorations were carried in this region. Singh and Kamal (2012), Sahoo and Pradhan (2020) and Pradhan and Satapathy (2020) though explored some localities of the district, which were confined to a particular area of Similipal Biosphere Reserve and reported 141, 19 and 32 species of lichens respectively. Apart from the Biosphere region of Mayurbhanj district, community forest areas like Udala explored by Pradhan et al. (2018) reported the occurrence of 22 common species to the area. In the present study, some unexplored localities such as Devkund, Lullung, Karkatbeda, Sitakund, Talabandh, Pantho and Jamuani, which are situated in the different transitional areas of the Similipal Biosphere Reserve are systematically explored for their lichens and a total of 96 lichen taxa are enumerated as an addition to the lichen biota for the state of Odisha.

Methodology
More than 1000 lichen specimens were collected from different localities of the Mayurbhanj district. The specimens were identified morphologically, anatomically and chemically following the available literature Awasthi (1991), Awasthi (2000), Divakar and Upreti (2005), Nayaka (2004) and Joshi (2008). The colour tests were carried out with aqueous potassium hydroxide (K), Steiner's stable paraphenylenediamine (PD) and aqueous calcium hypochlorite (C). The identified samples deposited in the lichen herbarium of CSIR-National Botanical Research Institute, Lucknow (LWG).

Results and Discussion
The present study revealed the occurrence of 96 species belonging to 45 genera and 20 families as an addition to the lichen biota of Odisha. The Similipal Biosphere Reserve is dominated by Shorea robusta Gaertn., as major tree vegetation, which ultimately provides the best suitable substratum for the luxuriant growth of lichens. The variability in bark properties at different parts of the tree i.e. within a single tree ecosystem it provides 4 different types of micro-ecosystem as well as different bark texture and fissures at base and above base, provide extra space to the propagules to get established successfully (Satya et al. 2005). Karnik et al. (1968) reported similar findings where they have concluded that the presence of triterpene and oleanolic acid, bark properties support luxuriant growth of lichens on the bark of Sal or Serga.
The rocks near stream and under forest in shady places exhibits rich growth of lichens than the exposed rocks. Species of genus Allographa, Astrothelium, Bacidia, Cryptothecia, Fissurina, Hemithecium, Pertusaria and Pyrenula grow luxuriantly in the shady places, while species of Cryptothecia, Diploschistes, Lecanora and Porina grow on exposed dry rocks. The corticolous lichen communities dominate the area represented by 91 species (45 genera), followed by rock inhabitant species represented by 5 species belongs to 4 genera ( Table 1). The crustose lichens predominate the study area represented by 90 species (41 genera) of lichens, followed by foliose forms represented by 6 species (4 genera). The genus Pyrenula is found to be the most dominant genera represented by 15 species (Fig. 2). The lichen family Graphidaceae exhibits its dominance in the area represented by 26 species (14 genera), followed by Pyrenulaceae with 18 species belongs to 3 genera ( Table 2).
The localities surveyed for lichens showed diversified groups of lichen genera both in disturbed, thin out forest and undisturbed sites. However, the south-west region of the Similipal Biosphere Reserve exhibits rich diversity of lichen represented by 44 species belongs to 29 genera, within localities of Sadanand, Karkatbeda, Badabaliposi and Ranibhol (Fig. 3). The north-west, north-east and south-east region is represented by the occurrence of 41 species (27 genera), 28 species (19 genera) and 11 species (9 genera) respectively (Fig. 4). Similar to the evergreen moist forest of India, the Graphidaceous and Pyrenocarpous lichens exhibit their rich occurance in the study area clearly indicate the localities of biosphere reserve are still not affected by the human attributes due to heavy tourist pressure.

Conclusions
Since the lichen exploration in the Similipal Biosphere Reserve for the present study was more concentrated in the transitional zones, an intensive exploration for lichens in the buffer and core zone of the biosphere will definitely add more interesting lichen taxa to the lichen biota of the state of Odisha in particular and of the country in general.

Author contributions
SP, DK-U and KB-S have equally contributed for sampling. SP was reponsible for data compilation and analysis. SP and KB-S has checked the final species list. SP and DK-U contributed for identifying the lichen taxa and drafting first manuscript. All authors have collaboratively contributed for interpretation of data and finalized the manuscript.

Conflicts of interest
The authors declare that there is no conflict of interest.      List of dominant lichen families.