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


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Myristica swamps are the wetland forest ecosystems that are inundated fully or partially for the greater part of the year.These tropical freshwater swamps are characterized by the dominance of Myristicaceae family members like Myristica fatua var.magnifica (Bedd.)Sinclair and Gymnacranthera farquhariana (Wall.ex-Hook.fil.& Thomson) Warb.(Varghese & Menon 1999;Bhat & Kaveriappa 2009;Jose et al. 2014a;Sujitha et al. 2019).Myristica swamps are confined to valleys with flat bottoms and slow-moving streams in the altitude range of 100-200 m.Myristica swamps shelter several rare and threatened floral-faunal species (Vasudeva et al. 2001;Ganesan 2002;Ranganathan et al. 2022).Over six decades ago, myristica swamps were initially described by Krishnamoorthy (1960) from the Travancore region in Kerala State of southern Western Ghats.Champion & Seth (1968) named these tropical swamps as 'Myristica Swamp Forest' and categorized them under the sub group 4C.Rodgers & Panwar (1988) emphasized the importance of conservation of the vegetation.According to the data so far, in Kerala these swamps were mainly spanned in the valleys of Shendurney Wildlife Sanctuary, in Kulathupuzha Reserve Forests, and adjoining regions of the Anchal forest ranges in the southern Western Ghats (Krishnamoorthy 1960;Varghese & Kumar 1997;Varghese & Menon 1999;Nair et al. 2007;Roby 2011;Jose et al. 2014b).In addition to Kerala, myristica swamps have also been reported from Goa, Karnataka, and Maharashtra (Santhakumaran et al. 1995;Chandran et al. 1999;Sreedharan & Indulkar 2018).However, the once-pristine myristica swamps in the Western Ghats are presently encountering disruption and fragmentation due to increasing growing demands for land and water (Champion & Seth 1968;Chandran et al. 1999;Chandran & Mesta 2001;Ranganathan et al. 2022).Increasing forest surveys in recent times have led to the documentation of a few myristica swamps across Western Ghats (Sreedharan & Indulkar 2018).This paper reports the identification of a new myristica swamp ecosystems from Pathanapuram forest range in the southern part of the Western Ghats.
We have been sampling myristica swamp forests in southern Kerala for a proposed study on Myristicaceae members.On 20 April 2022, we found some canopy of Myristicaceae members in Pathanapuram forest range (9.08534 0 N, 76.8551 0 E) of Punalur division in Kollam District, Kerala, India (Figure 1).The observed Myristica swamps from Pathanapuram Forest Range fall within Ambanar Model Forest Station and Punnala Forest Station limits.During our first visit, we noticed the swampy habitat, as well as the occurrence of 'knee roots' and 'stilt roots' both of which are characteristics of myristica swamps.We have conducted 11 field surveys during the period from April 2022-June 2022.For the systematic study of vegetation, we chose 25 sample plots from both Ambanar and Punnala.Quadrats of 20 × 20 m were laid along the linear course of the swamps from Ambanar and Punnala respectively for the enumeration of trees having minimum grith ≥30 cm.Girth of all trees and shrubs was calculated using a measuring tape.For swamps smaller than 400 m 2 no quadrats were placed; instead, the species were simply listed.Both trees and underground vegetation were taken into consideration.Two sub-quadrats of 5 × 5 m were laid for the shrub layer within each tree quadrat (plants above one meter height).Within each of the 5 × 5 m quadrats, two smaller quadrats of 1 × 1 m were laid for the herb layer (plants less than one meter height).The plant species were identified by an expert and also by comparing pictures from published sources including the internet (Gamble & Fischer 1936;Varghese & Menon 1999;Sasidharan 2006;Nair et al. 2007).Geographic coordinates were recorded at each sampling point using Garmin® eTrex® 20x GPS.Image 1 shows some individual photographs of myristica swamps from both Ambanar and Punnala Forest Station.
The Ambanar Forest Station covers an area of 89.22587 km 2 .The area of research is 0.86 ha of the total forest area.The topographic conditions of Ambanar vary from 75-1,050 m asl.In general, red loamy soil which is rich in minerals is found.Apart from this, alluvial soil is also found in river banks and valleys.The degree of soil pH is 4.48-6.10.The climate of this forest area has an air temperature of 29 0 -31 0 C. Ambanar receives annual rainfall of 2,400 mm.Humidity is highest in the months of June, July, and August and lowest in February.The noted measures of general relative humidity at 0830 h IST and 1730 h IST from February to March are about 52% and 98%, respectively.
The Punnala Forest Station covers an area of 49.85 km 2 Compared to the surrounding level, this region has an elevation of about 10-400 m.In terms of climate, it experiences both moderately hot as well as humid conditions.The hottest period is from February-May and the coldest in December and January.The maximum and minimum reported temperatures are 37 0 C and 20 0 C, respectively.The area receives an average annual rainfall of 2,400 mm.The plants growing on the hills at higher altitudes are prone to severe damage made by the dry easterly winds.Humidity is highest in the months of June, July, and August and lowest in February.General relative humidity at 0830 h IST and 1730 h IST during February to March are about 52% to 98%, respectively.
All 18 patches of myristica swamps and the  geographical coordinates of the sampling points in the Ambanar area are presented in Table 1.Geographically, all these 18 patches are located in Manthadam region of the Ambanar.The region Manthadam comprises a small stream that maintains the distinctive swampy ecosystem.Olappara and Minnaminni are the places near Manthadam in which saplings of Myristicaceae family members are found.
In the Punnala Forest Station range, there are seven Myristica swamps present with a total area of 26.9 ha.They are Elappakkodu Bit 1, Elappakkodu Bit 2, Elappakkodu Bit 3, Pezhummodu, Verukuzhypacha Bit 1, Verukuzhypacha Bit 2, and Pannamood pacha.Most of the swamps in Punnala are inundated throughout the year due to the presence of three rivulets -Elappakkodu Thodu, Pezhumoodu Thodu, and Mukkalampadu Thodu.These three rivulets flow into the Kallada river.When examining the vegetation listed in Table 3, Gymnacranthera farquhariana, Myristica fatua var.magnifica, and Knema attenuata (Hook.f.& Thoms.)Warb.consistently appear in both the Ambanar and Punnala regions.These species seem to thrive in diverse environmental conditions represented in both the areas.However, Myristica dactyloides (Gaertn.)displays a distinct pattern, being present in Ambanar but remarkably absent in Punnala.Our observations suggest disparities in species distribution within Ambanar and Punnala highlight the intricate interplay of ecological forces, suggesting a dynamic and diverse nature shaped by a combination of microclimatic variations, historical influences, and human activities.A comparison of the distribution of non-Myristicaceae trees between Ambanar and Punnala shows notable differences in species presence.Based on our preliminary findings, we recognize the need for further investigation to better understand the disparities in species distribution among these sites.
Myristica swamps are rich with numerous invertebrates and vertebrates, both terrestrial and aquatic (Jose et al. 2014b;Sinu & Sharma 2013;Sujitha et al. 2019;Ranganathan et al. 2022).A pilot survey from these sites suggests they are abundant with various faunal and floral wealth.Studies documenting the biodiversity of flora and fauna, climatic factors, hydrology, and soil, and so forth of these ranges are not well studied and documented.For this reason, a clear picture of these factors is not available yet.As per the pilot study, we noticed plenty of juveniles of ecologically significant species present in these swamp forests.This indicates that numerous species use the Myristica swamps as breeding grounds (Abraham et al. 2018;Ranganathan et al. 2022).Mapping and documenting the specifics of these swamp forests is both important and potent for further research.Preventing the incursion of nonswampy plant species into the swamp helps to maintain the swampy habitat.Raising the status of these swamps will restrict the anthropogenic and natural disturbances.In order to ensure a long-term monitoring, incorporating the interests of local communities in the conservation and management activities are also desirable.With this new reporting, the revised Indian distribution of myristica swamps should include Ambanar and Punnala of Pathanapuram forest range.

Figure 1
Figure 1.A-map of Pathanapuram Forest Range Kerala, India showing the study sites, Ambanar and Punnala.Legend: Colours: Green-Reserve forests | Blue-Water body) | B-location of the Myristica swamps at Ambanar model forest station | C-locations of the Myristica swamps at Punnala forest station.Map courtesy: Pathanapuram Forest Department.
swamps: A-In Manthadam with the occurrence of pneumatophores | B-rivulet that flows through Elappakodu swamp | C-In Elappakodu Bit 1 | D-water inundation of Myristica swamp with the presence pneumatophores.© Niji Joseph.

of swamp Geo coordinates of the swamps Area (ha) Latitude ( 0 N) Longitude ( 0 E)
Table 2 shows the geo-coordinates of locations and the total

Table 2 . List of myristica swamps under Punnala forest area, Pathanapuram range. area
occupied by the myristica swamp in the Punnala region.There were large numbers of Myristica trees in Elappakodu swamps.Along with these seven sites, saplings of Myristica trees grow at Choorapacha, Thulasithara, and Therdhakkara in Punnala Forest Station.The neighbouring forest of these swamps is semi-evergreen in nature.The Kerala Forest Development Corporation (KFDC) Limited, Punalur Division is situated nearest to the Elappakodu swamp.Elappakodu and Pezhumood pacha are the reserved forests in Punnala.However, some regions of Elappakodu swamp are disturbed due to locally originated anthropogenic activities like fishing and crabbing.In Punnala Station limits, reserve forest is much smaller and therefore more vulnerable to local disturbances.Hence the swamps in Punnala need special attention from a management perspective.