Myristica Swamps Research Articles

Discovery of a new Myristica swamp in the northern Western Ghats of India

Myristica swamps are one of the world’s unique freshwater ecosystems. In recent years there has been an increase in reports about their distribution along the Western Ghats. In this paper, we present a new distribution record for Myristica swamps in the northern part of the Western Ghats in Maharashtra. The Myristica swamp is located within the Bhalandeshwar Sacred Grove of Kumbral Bagwadi, Dodamarg Maharastra, India. This forms the second report from the state of Maharastra. Frequent field visits were made to study and document the floral assemblage and biodiversity in the swamp from November 2023 to January 2024. The swamp is dominated by Myristica magnifica Bedd. and is part of a sacred grove protected by villagers due to religious beliefs. The second discovery of a Myristica swamp with a gap of just six years points out to the potential existence of more swamps in the region. Therefore, systematic surveys are needed to document undocumented swamps in various areas.

Report of new myristica swamp ecosystems from the Western Ghats at Pathanapuram, Kerala, India

We present a new distributional report of myristica swamp ecosystems in the Western Ghats at Pathanapuram, Kerala, India based on several distinct field surveys from April 2022 to June 2022. From Kerala, myristica swamp has previously been reported mainly from Shendurney Wildlife Sanctuary, Kulathupuzha Reserve Forests, and adjoining regions of the Anchal forest ranges in southern Western Ghats. The present study described and illustrated the occurrence of myristica swamp from the Pathanapuram forest range in Kerala for the first time. The observed myristica swamps from the Pathanapuram forest range are seen inside the Ambanar model forest station and Punnala forest station limits. A total of 18 myristica swamp patches from Ambanar and seven myristica swamps from Punnala were reported and captured. A pilot survey from these sites suggests they are abundant with various faunal and floral wealth. Therefore, recognition and conservation of these ecosystems are essential and vital and suggest further surveys and conservation efforts.

Embryo maturation, dormancy and seed storage behaviour of Gymnacranthera canarica (King) Warb., a threatened endemic tree species of Southern Western Ghats

Gymnacranthera canarica is a severely endangered endemic tree species found in the Myristica swamps of the Southern Western Ghats. Seed storage behaviour is an essential factor to consider when developing effective conservation methods for plant genetic resources whose ex-situ preservation is unclear. The seed storage behaviour, seed dormancy state, dormancy breaking treatments, germination, and phytohormonal analysis of G. canarica were explored in this work. G. canarica seed moisture at shedding was 28.86%, germinated to 34% at 25ºC, and had a low germination rate in natural conditions. Germination was considerably aided by Gibberellic acid pretreatment and drying stratification. G. canarica seeds may have non-deep simple morphophysiological dormancy, as evidenced by the fact that their embryos grew at temperatures between 20 and 25ºC (MPD). Seeds can be stored for up to 60 days at 20ºC after being desiccated to 19.37% suggest that G. canarica seeds are recalcitrant, with non-deep simple morphophysiological dormancy, and that seed pretreatment with Gibberellic acid prior to germination could be a viable approach for mass propagation and long term ex-situ conservation could be the potential storage of this critically endangered species.

Assessment of Water Quality Parameters in Selected Myristica Swamps, Western Ghats, India

Assessment of Water Quality Parameters in Selected Myristica Swamps, Western Ghats, India

Desiccation induced physiological and biochemical changes of Gymnacranthera canarica (King.) Warb. seeds in the Myristica swamp forests, Southern Western Ghats, India

Gymnacranthera canarica (King.) Warb. is an endemic tree species that dominates the Myristica swamp ecosystem of southern Western Ghats. This tropical tree species has become more threatened due to limited natural seed germination and habitat loss. Mature seeds were collected from the myristica swamp ecosystem subjected to desiccation study. This research evaluated the physiological (moisture content, tetrazolium reduction, lipid peroxidation, electrolyte leakage) and biochemical response of seeds during different desiccation treatments. Results showed that G. canarica seeds are highly sensitive to desiccation and total viability loss was seen within 15 days following harvest indicating the active seed metabolism of mature seeds showing absence of metabolic arrest. Desiccation enhanced malondialdehyde and electrolyte leakage while reducing formazan formation. Seed desiccation increases protease activity, which peaks when viability is lost. Desiccation reduced the quantity of phenol and starch, whereas proline, fat, sucrose and total soluble carbohydrates increased. The early viability loss in G. canarica seeds could be due to loss of membrane integrity, which was linked to ROS formation and associated lipid peroxidation products indicating seeds are truly recalcitrant.

Response of Diatoms to the Changing Water Quality in the Myristica Swamps of the Western Ghats, India

Myristica swamps are one of the rarest wetland ecosystems within the sub-tropical evergreen forests of the Western Ghats, India. As their name indicates, they harbor trees belonging to the ancient family Myristicaceae. Due to the waterlogged conditions and high humic decomposition, these swamps are acidic, harbor rare and endemic biotas, and provide ecosystem services to humans. Monitoring this rare ecosystem is crucial because the swamps that once formed a large hydrological network across the Western Ghats are now confined to isolated patches due to human disturbance such as agricultural interventions, roads, and dam construction. Due to the change in land use, there is also a drastic change in water chemistry and associated biodiversity. Biomonitoring is more precise than physical and chemical monitoring. So, the current study aimed to undertake a comprehensive analysis of the physical, chemical, and biological assessment of these swamps. The diatom assemblages are strongly affected by water chemistry and serve as a powerful indicator of environmental changes in the freshwater aquatic systems. However, there is no information on diatom assemblages in these swamps, and the present study aimed to determine the diatom assemblage structure in the Myristica swamps and their response to changing water quality. Diatom samples were taken at 17 different swamps across the central Western Ghats, and a set of environmental parameters was evaluated. Analysis revealed a total of 91 species of diatoms belonging to 27 genera across the 17 sites, from which 44 diatom species showed restricted distribution to this unique environment. Overall, the dominant diatom genera inside the swamps included, Navicula (19.8%), Gomphonema (16%), Eunotia (13.3%), Ulnaria (9.4%), Achnanthidium (8%), Frustulia (6.2%), Planothidium (5.2%), and Brachysira (2.8%). High diatom species richness was observed in the swamps having less anthropogenic disturbance, and diatom assemblage composition was primarily determined by dissolved oxygen, pH, and conductivity. The significant number of geographically restricted taxa in this study points towards our limited understanding of this tropical biome and calls for a dire need for more studies from here, not only to improve our knowledge concerning the diversity, ecology, and biogeography of these diatoms but to further encourage their use in applied (paleo) environmental sciences. Our results indicate that diatoms can prove useful environmental indicators even in harsh environments like swamps and can be a potential tool for assessing ecological and climatic change.

A review of research and conservation of Myristica swamps, a threatened freshwater swamp of the Western Ghats, India

A review of research and conservation of Myristica swamps, a threatened freshwater swamp of the Western Ghats, India

Distribution of Syzygium travancoricum Gamble (Myrtaceae), a Critically Endangered tree species from Kerala part of Western Ghats, India

Syzygium travancoricum Gamble is an endemic, Critically Endangered tree species found in marshy swamps of the Western Ghats. An assessment was conducted on existing distribution pattern and population structure of this species in Kerala. Most of the existing populations are mainly located in sacred groves and this tree is an ideal example on role of sacred groves in conserving biodiversity especially IUCN red listed species. A total of 465 individuals were recorded in which maximum number of sapling density was recorded in Kalasamala Sacred grove followed by patches of Myristica swamps in Kulathupuzha. Fragmentation of populations, habitat modification, over exploitation, pollution and invasion of exotics are major threats to S. travancoricum. Hence urgent intervention is required for restoration programmes, management of habitat and subsequently delisting this species from IUCN red list of threatened species.

Three new species of Protosticta Selys, 1885 (Odonata: Zygoptera: Platystictidae) from the Western Ghats, India, with taxonomic notes on P. mortoni Fraser, 1922 and rediscovery of P. rufostigma Kimmins, 1958.

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.

A new species of Germainiella (Bacillariophyta) from the Myristica swamps of the Western Ghats, India

Germainiella chandranii sp. nov. is described from a Myristica swamp of the Western Ghats, India, on the basis of light and scanning electron microscopy. The new species resembles two related genera, Fallacia Stickle & D.G. Mann and Germainiella Lange–Bertalot & Metzeltin on the basis of valve morphology, but a thorough investigation of valve ultrastructure confirms its placement in Germainiella. External valve outline and morphology, large conopeum covering the entire face of the valve, siliceous struts running perpendicular to the raphe support the generic assignment. The main diagnostic features of the new species are the presence of small tubules running perpendicular to the raphe, striae composed of a series of round to elongated areolae, which are not covered internally by hymenes, and a larger central area. The new species occurs in acidic waters of the Myristica swamps of the Western Ghats and it can be considered as an indicator of the acidic condition.

Butterflies of the myristica swamp forests of Shendurney Wildlife Sanctuary in the southern Western Ghats, Kerala, India

Myristica swamps are unique freshwater swamp forests characterised by predominance of tree species of the Myristicaceae family. There have been few published works on the flora and fauna of myristica swamps but studies on butterflies have been scanty. This work was done in the myristica swamps of Kattilapara in Shendurney Wildlife Sanctuary, Kollam district, Kerala, located in the northern aspect of the Agasthyamalai Hills of the southern Western Ghats. Data on the butterflies were collected over a period of two years supplemented with data from previous visits using Transect method. Butterflies were identified based on field photographs and relevant literature. We recorded 206 species of butterflies belonging to 6 families from the myristica swamps. This included 17 species of Papilionidae, 20 species of Pieridae, 65 species of Nymphalidae, 56 species of Lycaenidae, two species of Riodinidae and 46 species of Hesperiidae.Of the total, 19 species of butterflies were Western Ghat endemics. A checklist of butterflies of the myristica swamp, larval hostplants, status with respect to IUCN criteria, endemicity, and classification as per Indian Wildlife Protection Act (WPA) of 1972 are also provided. Eighty-two species of plants were listed as butterfly larval hosts in the myristica swamp ecosystem, with 27 species being new host records for Western Ghats. None of the butterflies recorded were using plants of Myristicaceae family as larval hosts. A simple index—the percentage occurrence—is proposed to delineate the habitat affinity of species.

Disturbance to Myristica swamps: Influence on Specific Gravity and Fibre Length of an Endemic and Endangered Tree Species of Western Ghats

Disturbance to Myristica swamps: Influence on Specific Gravity and Fibre Length of an Endemic and Endangered Tree Species of Western Ghats

Reproduction and metamorphosis in the Myristica Swamp tree frog, Mercurana myristicapalustris (Anura: Rhacophoridae).

The reproductive biology of the Myristica Swamp tree frog (Mercurana myristicapalustris), a monotypic rhacophorid frog endemic to the foothills of the Western Ghats mountains of India, has remained unknown since the description of the genus and species. We monitored individuals from parental generation amplexus to the completion of offspring generation tadpole metamorphosis. Surprisingly, our observations revealed that this species exhibits many previously unknown characteristics, including the first ever record of the female, and a diverse call repertoire, consisting of five different call types (the functions of which remain incompletely known). We were also able to determine that reproductive activity peaked during the late pre-monsoon season, that males engaged in intraspecific aggressive encounters to occupy and to defend desirable territories, and that oviposition took place in terrestrial nests made by females. Embryonic development in the unattended nest was followed by tadpole development, which concluded within 40 days. The specific breeding mode employed by Mercurana, which restricts its range to the endangered Myristica swamp ecosystem, likely renders it susceptible to multiple threats, which should be considered jointly in future conservation planning.

Intersexual mimicry and flowering phenology facilitate pollination in a dioecious habitat specialist species, Myristica fatua (Myristicaceae)

Myristica fatua is a dioecious specialist species restricted to the endangered, freshwater Myristica swamp forests in the Western Ghats, India. Earlier studies have alluded to pollination by deception in members of the Myristica genus, and thus we examined the pollination ecology comprising floral biology, flower production, flower visitors, and reproductive success in M. fatua and inferred the potential strategies that could permit such deception in this habitat specialist tree. Male flowers provide pollen rewards for an extended period of time while female flowers are rewardless and both sexes are visited by generalist insects, mainly by honeybees and stingless bees. Bee visits were significantly more frequent and longer on male than on female flowers as bees collected pollen from male flowers. We found that flower production patterns create a preponderance of males compared to females in the swamp populations. Using a model of honeybee color vision, we found the distance between the color loci of male and female flowers and based on minimum visual angle subtended by these flowers, we suggest that the two floral sexes cannot be discriminated by bees. Bees are likely deceived by the perceptual similarity of rewardless female flowers to pollen-offering male flowers and pollination is the consequence of foraging errors made by pollinators that encounter largely male–rarely female flower mosaics as they forage among clump-distributed M. fatua trees in the swamp habitat.

Phytosociological Analysis of <i>Myristica</i> Swamp Forests of Kulathupuzha, Kerala, India

The vegetation of Myristica swamp forests in Kulathupuzha, southern Kerala, India, was examined with reference to floristic composition, structure and diversity. Quadrates of 100  10 m were laid inside (17) and outside the swamps (14), and trees >10 cm girth at breast height were enumerated. A total of 2246 individual trees belonging to 58 species were recorded inside the swamps as against 1203 trees belonging to 89 species from outside the swamps. A total of 1775 shrubs belonging to 46 species and 26 species of herbs with 1082 individuals were recorded from inside the swamps. A total of 3535 shrubs belonging to 83 species and 491 herbs belonging to 30 species were recorded from outside the swamps. The Myristica swamp forests showed less diversity when compared to other forest types and was dominated by two Myristicaceae species, Myristica fatua var. magnifica and Gymnacranthera farquhariana . Comparison with Myristica swamps in other regions indicates that the Kulathupuzha region has the largest populations of the endangered M. fatua var. magnifica . Immediate steps for conservation are suggested.

Tree Species Composition and Distribution Pattern in a Myristica Swamp of Northern Kerala, India

Knema Phytosociological studies have been carried out in a Myristica swamp in Northern Kerala to reveal the composition and distribution pattern of different tree species. On the basis of IVI, the family Myristicaceae was dominant and the association is attenuata - Myristica malabarica -Holigarna arnottiana type. The species like Gymnacranthera canarica and Myristica fatua var. magnifica, which are believed to be the essential elements of Myristica swamps, are totally absent here. A total 403 individuals (gbh > 10.1 cm) were recorded with a basal area of 34.25 m2 ha-1 in 0.5 ha. area. Total number of species recorded was 28, which represent 21families in which Myristicaceae represents 48.18% of total IVI. Among two dominant species, Myristica malabarica prefer swampy area hence their number of individual shows decreasing trend when we move from the swamp while the second dominant species Knema attenuata showing a reverse trend and was completely absent in the first five quadrats where soil water content is too high. Species specific eco-physiological studies are required to understand the reasons for change in the distribution pattern of these dominant species.

English

Flora of Vallikkaattu Kaavu, a sacred grove of Kozhikode District, Kerala, India with their botanical name, family, conservation status, endemic status, medicinal status and habit has been presented in detail. This sacred grove associated with the Sree Vana Durga Bhagavathi Temple located 20 km north of Kozhikode at Edakkara in Thalakkalathur Panchayat, is the largest sacred grove in Kozhikode District with an extent of 6.5 ha. Floristic studies of this sacred grove recorded 245 flowering species belonging to 209 genera and 77 families. Among the 245 species, 75 are herbs, 71 are trees, 55 are shrubs and 44 are climbers. Out of the 245, 44 are endemics - 16 endemic to Southern Western Ghats, 3 endemic to Southern Western Ghats (Kerala), 13 endemic to Western Ghats, 9 endemic to Peninsular, India, 2 endemic to India and 1 endemic to South India (Kerala).  Thirty four threatened plants were reported, out of which 3 are Critically Endangered, 5 are Endangered, 4 are Near Threatened, 1 is at Low Risk and Near Threatened, 16 are Vulnerable and 3 are with Data-Deficient status. Species with Not Evaluated status and Least Concern status were also listed. Endemic plants like Sonerila rheedei, Litsea ghatica, Lagenandra meeboldii and Ischaemum tumidum var. calicutensis, threatened and endemic plants like Anaphyllum wightii and Kunstleria keralensis and Acorus calamus with endangered status were recorded. Myristica swamps having dense prominent stilt and breathing roots represented mainly by Gymnacranthera farquhariana and the endemic and threatened species, Myristica fatua var. magnifica and M. malabarica were also recorded from this sacred grove. Out of the 245 species listed, 236 are medicinal, constituting 96% of the total flowering plants reported from this sacred grove. Key words: Endemic, threatened, critically endangered, vulnerable, Gymnacranthera farquhariana, Myristica fatua var. magnifica.

Late Pleistocene–Holocene monsoon variations on climate, landforms and vegetation cover in southwestern India: An overview

Signatures of monsoon variability preserved in the Late Quaternary sediments of southwestern India have been decoded and addressed using biological proxies along with geochronological data. Barring sediments beyond the threshold for conventional 14C dating, Late Pleistocene sequences have been recognized both in Konkan and Kerala basins. Konkan area has only subsurface continental/lacustrine Late Pleistocene, whereas Kerala coast has mixed facies. The landscape as well as the vegetation cover has been substantially modified and the fossil contents and related palaeoenvironment provided ample evidence to demonstrate the landscape and vegetation dynamics since Late Pleistocene. Evidence of Myristica swamps until Late Pleistocene and its subsequent replacement by riparian forest towards Late Holocene in Konkan has been a significant impact of monsoon variations on the tropical rain forests. The prevalence of such freshwater swamps and a sensitive habitat indicated that Konkan had enjoyed an extended period of rainfall due to the combined effects of both SW and NE monsoons until the Late Pleistocene. The tropical rainforest cover along Kerala coast has shrunken considerably and pieces of evidence suggest that the entire terrain west of Sahyadri (Western Ghats) was under dense forest cover during the Holocene Climatic Optimum (9.0–6.0 k yrs BP) when the region had witnessed heavy precipitation much higher than that of the present. The forest land has been converted into major wetlands and present ecology is unsuitable to support evergreen forests and it can be concluded that coastal plains and associated landforms were covered by thick tropical evergreen forests which got destroyed by flooding towards Middle Holocene. Development of a chain of wetland system all along Kerala coast, loss of sheltered habitat and mangrove cover, and loss of sensitive freshwater Myristica swamps are some of the significant aspects brought in while addressing the monsoon variability in southwestern India.

Seed germination studies on Gymnacranthera canarica (King) Warb. - a Vulnerable tree species of a highly threatened Myristica swamp ecosystem

Gymnacranthera canarica (King) Warb. is an exclusive Myristica swamp species endemic to the Western Ghats. The Myristica swamp is a Critically Endangered ecosystem. Studies were carried out to assess the viability, germination and storage behaviour of Gymnacranthera canarica seeds. In the present study, it was observed that seeds have shown an initiation of germination after two weeks. A maximum of 90% germination was recorded when the initial moisture content was 38.04 ± 1.75 %. A decreased percentage (3%) was observed when the moisture content reached 14.26 ± 2.3 after 70 days of storage. Seeds failed to germinate beyond this moisture level. A desiccation study showed recalcitrant behaviour and seeds can be stored in lab conditions for up to two and half months.

Spatiotemporal strategies that facilitate recruitment in a habitat specialist tree species.

Our understanding of processes underlying plant recruitment emerges from species and habitats that are widely distributed at regional and global scales. However, the applicability of dispersal-recruitment models and the role of dispersal limitation versus microsite limitation have not been examined for specialized habitats. In patchy, freshwater Myristica swamp forests (Western Ghats, India), we examine the roles of primary seed dispersal, secondary seed removal and microsite suitability for the establishment of a swamp specialist tree, Myristica fatua We estimated primary seed shadows, performed secondary removal experiments and enumerated recruits in swamp sites. Steady-state fruiting was observed with the extended production (>7 months) of small numbers of fruits. Frugivores dropped most of the large and heavy seeds under parent crowns, while a few seeds were transported over short distances by hornbills. Seed placement experiments indicated that removal, germination and establishment were similar within swamp microsites, while seeds failed to survive in matrix habitats surrounding the swamp. Crabs, which were major secondary removers of M. fatua, did not alter the initial seed dispersal patterns substantially, which led to the retention of seeds within the swamp. Distribution of saplings and adults from previous seasons also suggest that dispersal-recruitment dynamics in the swamp specialist M. fatua did not strictly follow predictions of Janzen-Connell model while abiotic effects were significant. Large seeds, steady-state fruiting and small crop sizes may be significant selective forces facilitating escape from density and distance-dependent effects in space and time in specialist plant species such as M. fatua.