Endemism-based butterfly conservation: insights from a study in Southern Western Ghats, India

Rattans, the spiny climbing palms of Arecaceae (Palmae) family exhibit high endemism to the biodiversity hot spots in India. Of the five rattan genera, Calamus is the only genus found in peninsular India with 15 of 21 species, endemic to the Western Ghats. The extensive utilization of rattans owing to their strength, durability and huge demand has resulted in depletion of their natural resources. Of the 15 endemic species, C. nagbettai is the most affected species on account of endemism, low population size and restricted distribution with fragmented populations. The present study revealed high amount of genetic diversity in the surviving scattered populations of the species using microsatellite markers. High gene flow (Nm = 1.498) observed across the populations resulted in low genetic differentiation (14%). A clear genetic admixture could be seen in Kerala as well as one of the Karnataka's populations while the remaining two populations were genetically distinct. UPGMA, PCoA and STRUCTURE analyses showed significantly different genetic composition in Kerala population compared to other populations. Kerala and Karnataka populations of C. nagbettai were also unique in their genetic structure and allelic composition. Therefore, effective management and conservation strategies have to be implemented to preserve the rarealleles with adaptive potential to protect this economically valuable Calamus species from endangerment. Over exploitation, low seed set and poor regeneration, as well as habitat fragmentation can further threaten the survival of this endemic, narrowly distributed dioecious rattan species in the Western Ghats region.

Investigation on the distribution patterns and habitat requirements of the butterfly tribe, Troidini was carried out in undisturbed forest habitats and disturbed, human-modiûed habitats in the Western Ghats, a biodiversity hotspot in south India. Compared various ecological and biological traits of the four species of this group which included a CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) listed species, Troides minos Cramer, an endemic species Pachliopta pandiyana Moore, a protected species, Pachliopta hector Fabricius and Pachilopta aristolochiae Linnaeus. Comparisons were based on transect counts conducted at 66 transects in 22 locations covering six types of habitat systems with a gradient of disturbance and management regimes during 2009 and 2010. Results indicated that P. aristolochiae was the most widely distributed species occurring in 90% of the transects sampled and P. pandiyana had a restricted distribution (36 %), while both P. hector and T. minos were observed in 73% of the transects. Sampling of the juveniles on the six species of host plants in the various habitats provided insights into host plant partitioning between these species in the different habitats. Life history traits and morphological characteristics of adult troidines, larval host plant characteristics and habitat characteristics were evaluated and characterized.

This study presents the contrasting trends of rainfall in the northern and southern Western Ghats (WG) and examines possible reasons for the phenomenon. The WG is one of the important mountain ranges that run parallel to the west coast of India. The mountain chain lies almost perpendicular to the low level jet stream (LLJ) and hence, receives about three times the average rainfall in India. The onset of southwest monsoon also occurs at this region, and thus WG plays a key role in regulating Indian climate through regional climate modulations. Therefore, detecting changes in the rainfall in WG is necessary to identify changes in regional climate. Here, we examine the features of rainfall received and reasons for the observed rainfall patterns in the northern and southern WG. In general, the rainfall peaks are observed in low elevated areas with high inter-annual variability. We find an increase (decrease) southwest monsoon rainfall of about 1.6 mm day−1 decade−1 in certain pockets of the northern (southern) WG. However, an average trend of + 0.3 (− 0.39) mm day−1 decade−1 is estimated in the northern (southern) WG for the 1931–2015 period. Our analyses reveal that this contrasting trend in rainfall (i.e. positive in the north and negative in the south WG) is due to the northward movement of LLJ; from 10°N to 15°N. This shift in LLJ is triggered by an abnormal increase in the surface temperature of the northern Arabian Sea and tropospheric temperature of the north India in the recent decades. The warming helped the LLJ core to move northwards and that weakened (strengthened) the westerly winds over the southern (northern) WG to significantly change the pattern of southwest monsoon rainfall. Henceforth, this study cautions the changes in the rainfall pattern over WG, which can have significant long-term implications for regional climate change.

India is one of the 12 mega biodiversity countries of the world, which represents 11% of world's flora in about 2.4% of global land mass. Approximately 28% of the total Indian flora and 33% of angiosperms occurring in India are endemic. Higher human population density in biodiversity hotspots in India puts undue pressure on these sensitive eco-regions. In the present study, we predict the future distribution of 637 endemic plant species from three biodiversity hotspots in India; Himalaya, Western Ghats, Indo-Burma, based on A1B scenario for year 2050 and 2080. We develop individual variable based models as well as mixed models in MaxEnt by combining ten least co-related bioclimatic variables, two disturbance variables and one physiography variable as predictor variables. The projected changes suggest that the endemic flora will be adversely impacted, even under such a moderate climate scenario. The future distribution is predicted to shift in northern and north-eastern direction in Himalaya and Indo-Burma, while in southern and south-western direction in Western Ghats, due to cooler climatic conditions in these regions. In the future distribution of endemic plants, we observe a significant shift and reduction in the distribution range compared to the present distribution. The model predicts a 23.99% range reduction and a 7.70% range expansion in future distribution by 2050, while a 41.34% range reduction and a 24.10% range expansion by 2080. Integration of disturbance and physiography variables along with bioclimatic variables in the models improved the prediction accuracy. Mixed models provide most accurate results for most of the combinations of climatic and non-climatic variables as compared to individual variable based models. We conclude that a) regions with cooler climates and higher moisture availability could serve as refugia for endemic plants in future climatic conditions; b) mixed models provide more accurate results, compared to single variable based models.

Parks protect forest cover in a tropical biodiversity hotspot, but high human population densities can limit success

<p>The Western Ghats (WG), an elevated passive continental margin along the southwestern coast of India, is the most widely populated biodiversity hot spot in the world. Monsoon climate is prevalent throughout the length of the Western Ghats. The WG region is prone to the occurrence of various hydro-climatic disasters such as extreme rainfall-driven floods and landslides. During the past 100 years, landslides and floods caused by extreme rainfall events in the WG have occurred in 1924 and 1979; but the most disastrous event, in terms of area of impact, loss of life and economic impact, occurred in August 2018. Generally, the south-west monsoon (Indian summer monsoon) occurs in the first week of June and extends up to September and the Indian Meteorological Department (IMD) predicted above-normal rainfall of 13% during the month of August 2018. But the State received an excess of 96% during the period from 1st to 30th August 2018, and 33% during the entire monsoon period till the end of August. The unprecedented heavy rains, storms, floods and associated thousands of landslides have caused exorbitant losses including 400 life losses, over 2.20 lakh people were displaced, and 20000 homes and 80 dams were damaged or destructed. This study aimed to elucidate the reasons behind the thousands of landslides caused in WG using observed and field evidences. Changes in south-west monsoon pattern and rainfall intensity played a vital role in the occurrence of landslides in WG. Further, the extensive causalities are the result of anthropogenic disturbances including landscape alterations and improper landuse practices in the hilly tracks of WG. The major causative factors for series of landslides in various segments of WG is due to hindrance of lower order streams/springs, vertical cutting, intensive quarrying, unscientific rain pits & man-made structures together with erratic rainfall triggered major and minor landslides in various segments of WG. The present investigation concludes that a scientific landuse policy and geoscientific awareness is essential to mitigate the environment.</p>

We studied the Agasthyamalai region of the Western Ghats to identify and prioritize potential areas to declare as Conservation Reserves using biological and social values in the southern Western Ghats. In this two phase study, throughthe desktop analysis (ERDAS Imagine, IRS-LISS4 data) identified four major forest patches viz., Kallar (24.05 km2), Ponmudi (57.17 km2), Chankili (119.64 km2) and Achancovil (7.55 km2) under the Palode and Kulathupuzha Forest Ranges of Thiruvananthapuram Forest Division (FD) and Achancovil Range of Achancovil FD. Second phase aggregated data pertaining to above four patches on presence of climax type of forests, biological wealth indicated by species richness, presence of endemic and critical species of plants and animals (vertebrate species excluding mammals) and indigenous peoples’ reliance on natural resources like water and NTFP. An overlay analysis using Arc GIS 9.1, the thematic layers have been created and subsequently integrated to infer the hierarchy within the four patches. The highest weighted average conservation value (=117.5) was scored by Ponmudi, followed by (=100) Chankili and (=90) Achancovil, where as lowest score of 67.5 attributed to Kallar patch. Highest dependency value of 40 was attributed to Achancovil, followed by Ponmudi and Chankili equally scored (=35), while the Kallar scored only 25. Based on sum of conservation and dependency values, Ponmudi patch stands out with highest priority (=152.5) in Agasthyamalai Biosphere Reserve, and others trail behind respectively.

This study examines the morphometric and genetic diversity of frog species in the agro ecosystems of Kadayam region part of the Western Ghats, a biodiversity hotspot in India. By conducting an amphibian survey in Kadayam, Southern Western Ghats, eight species from three families were documented, with Dicroglossidae showing the highest species representation. Amphibians were sampled from various habitats-forests, water bodies, and cultivated lands between January and March 2017, with notable species Duttaphrynus melanostictus showing a high abundance in human occupied areas. Morphometric analyses were performed on features such as snout-vent length, head length, (SVL–SNOW-VENT LENGTH; HL - HEAD LENGTH; HW-HEAD WIDTH; LHU–LENGTH OF THE HUMERUS; FOL-FOREARM LENGTH; THL-THIGH LENGTH; TL-TIBIA LENGTH; IOD-INTERORBITAL DIAMETER; IND-INTER NOSTRIL DISTANCE; ED-EYE DIAMETER; END–EYE–NOSTRIL DISTANCE; and FL -FOOT LENGTH) and limb proportions across species, correlating these to understand habitat adaptations. Results indicated high endemism and diversity within frog populations of the Western Ghats, highlighting conservation needs due to threats like habitat modification and pollution. The high positive correlations among primary body dimensions (such as SVL, head length, and total length) suggest that these species exhibit proportional growth in these features, a common trait in morphometric analyses. This study underscores the significance of morphometric approaches in amphibian biodiversity assessments in ecologically sensitive regions.

Unraveling the drivers of intensified landslide regimes in Western Ghats, India

Mountain ranges are hotspots of biodiversity. However, the mechanisms that generate biodiversity patterns in different mountainous regions and taxa are not apparent. The Western Ghats (WG) escarpment in India is a globally recognized biodiversity hotspot with high species richness and endemism. Most studies have either invoked paleoclimatic conditions or climatic stability in the southern WG refugium to explain this high diversity and endemism. However, the factors driving macroevolutionary change remain unexplored for most taxa. Here, we generated the most comprehensive dated phylogeny to date for ranoid frogs in the WG and tested the role of paleoclimatic events or climatic stability in influencing frog diversification. We found that the diversity of different ranoid frog clades in the WG either accumulated at a constant rate through time or underwent a decrease in speciation rates around 3-2.5 Ma during the Pleistocene glaciation cycles. We also find no significant difference in diversification rate estimates across elevational gradients and the three broad biogeographic zones in the WG (northern, central, and southern WG). However, time-for-speciation explained regional species richness within clades, wherein older lineages have more extant species diversity. Overall, we find that global paleoclimatic events have had little impact on WG frog diversification throughout most of its early history until the Quaternary and that the WG may have been climatically stable allowing lineages to accumulate and persist over evolutionary time.

Three new species of Protosticta Selys, 1885 (Odonata: Zygoptera: Platystictidae) from the Western Ghats biodiversity hotspot in India: P. cyanofemora sp. nov. (wet evergreen forests in Shendurney Wildlife Sanctuary, Kollam, Kerala and Kalakkad Mundanthurai Tiger Reserve, Tirunelveli, Tamil Nadu), P. myristicaensis sp. nov. (Myristica swamp at Kathalekan, Shivamogga, Karnataka) and P. sholai sp. nov. (montane sholas of Upper Manalar, Meghamalai Wildlife Sanctuary, Theni, Tamil Nadu) are described and illustrated. We compare these three new species with other Protosticta spp. from the Western Ghats based on new material and provide comprehensive differential diagnoses with determination key for males of all species occurring in the Western Ghats. The taxonomic validity of P. mortoni Fraser, 1922 is established with fresh specimens from Hassan, Karnataka, and rediscovery of P. rufostigma Kimmins, 1958 is reported from Kanyakumari Wildlife Sanctuary, Tamil Nadu.

Plant-diversity hotspots on a global scale are well established, but smaller local hotspots within these must be identified for effective conservation of plants at the global and local scales. We used the distributions of endemic and endemic-threatened species of Myrtaceae to indicate areas of plant diversity and conservation importance within the Atlantic coastal forests (Mata Atlântica) of Brazil. We applied 3 simple, inexpensive geographic information system (GIS) techniques to a herbarium specimen database: predictive species-distribution modeling (Maxent); complementarity analysis (DIVA-GIS); and mapping of herbarium specimen collection locations. We also considered collecting intensity, which is an inherent limitation of use of natural history records for biodiversity studies. Two separate areas of endemism were evident: the Serra do Mar mountain range from Paraná to Rio de Janeiro and the coastal forests of northern Espírito Santo and southern Bahia. We identified 12 areas of approximately 35 km(2) each as priority areas for conservation. These areas had the highest species richness and were highly threatened by urban and agricultural expansion. Observed species occurrences, species occurrences predicted from the model, and results of our complementarity analysis were congruent in identifying those areas with the most endemic species. These areas were then prioritized for conservation importance by comparing ecological data for each.

<p>The systematic and random errors in different remotely sensed (RS) precipitation products varies spatially and seasonally.  Error characterisation of the satellite precipitation products is vital for improved hydrologic and climatic modelling as precipitation is the key component of surface and subsurface hydrologic system. In this study, a new approach is developed for the bias correction of different satellite and processed rainfall products across Western Ghats region of India. The Western Ghats are mountainous ranges of about 1600 Kms length parallel to west coast of peninsular India, which consists the largest tropical rainforest in India.  Many studies have reported that most of the RS rainfall products are underestimated in Western Ghats region. In the present study, a multiplicative error distribution model for the entire Western Ghats for each of the RS precipitation products used is developed. Quality controlled interpolated gridded rain gauge data from Indian Meteorological Department (IMD) is used as the base. The IMD rainfall data is cross validated with available rain gauge data in the Western Ghats region. The bias correction of four multisatellite high-resolution precipitation products namely, Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) precipitation products, 3B42 version 7 and TMPA-3B42RT (Real Time) version 7 and Precipitation data from NASA (National Aeronautics and Space Administration) Modern-Era Retrospective Analysis for Research and Applications (MERRA) is performed in this study. The multiplicative monthly bias factor for each grid cell of Western Ghats is generated with the IMD rainfall as reference and it is found that the monthly multiplicative error for Western Ghats fluctuates around a common mean for each of the grid cell. Based on this a rainfall multiplicative error distribution is generated for each month for the Western Ghats regions. Systematic errors in rainfall were corrected using this distribution and the efficacy of error-corrected rainfall is evaluated with the help of conceptual rainfall-runoff models. The results depict that the proposed method helps to reduce the bias in different rainfall products and provide improved runoff estimations at Western Ghats.</p>

North-Eastern Himalayas and Western Ghats are two hot spots of global biodiversity, showcasing the rich diversity in wild relatives of root and tuber crops, especially Dioscorea. Fifty different species of Dioscorea are reported from India, of which 44% are endemic and 16 of them occur in the southern Western Ghats. The Central Tuber Crops Research Institute (CTCRI) being the National Active Germplasm Site (NAGS) for tropical tuber crops addresses issues like collection/augmentation, characterization, evaluation, conservation, exchange and breeding work on yams. 5175 yam accessions consisting of 50 species including 231 accessions of wild Dioscorea collected from different agro-climatic regions of India are conserved here. The present investigation focuses on the in vitro propagation studies of eight endemic wild edible yam species, with distribution in the southern Western Ghats. These species are ethnically important as secondary staple among the local tribal population. Protocols were standardized for rapid clonal multiplication of these species through nodal segment culture, direct organogenesis as well as in vitro bulbil induction, which facilitated multiplication of true to type plants and dissemination of these valuable wild clonal materials to national programmes and their conservation. In vitro bulbil induction was achieved in the non-bulbil bearing species which is an excellent tool for conservation and international exchange programmes. Cytokinins (BAP/Kin/TDZ) alone or in combination proved best for direct de novo shoot organogenesis. Successful rooting and hardening with 85-94% survival of regenerants with underground tuber development enabled us to design effective management and conservation strategies for their sustainable utilization in crop improvement programmes.

<p>Article published in the journal Tropical Lepidoptera Research</p>