Proc. Indian Acad. Sci. ( Sci.), Vol. 89, Number 4, August 1980, pp. 307-313. 9 Printed in India.

Ecological and phytogeographical observations on the and - allies of Nagpur block (Chamoli Garhwal), Western

D K AWASTHI and M P SHARMA Department of , M M PG College, Modinagar 201 204, India

MS received 3 December 1979; revised 27 June 1980

Abstract. The ferns and fern-allies of Nagpur block (Chamoli Garhwal), Western Himalayas are discussed. In all 79 (74 ferns and 5 fern-allies) have boon collected of which eight species are new record for the western Himalayas. Botrychium daucifolium have been recorded for the first time from the Himalayas. Ecological observations for each species have been recorded. This region is rich in epiphytie . Among the fern-allies Lycopodium lucidulum and L. setaceum constitute a part of epiphytic vegetation. The ferns and fern-allies of the region are more akin to Eastern Himalayan species as 81% species are common to both the regions.

Keywords. Ecology; phytogeography; ferns.

1. Introduction

A review of earlier literature reveals very little published data on the ferns and fern-Miles in Garhwal region of Western Himalayas. Clarke (1880) collected 388 species of ferns from northern India. Of these, only a few were collected from Garhwal. Later, Rau (1961) surveyed the area for the northern circle of Botanical survey of India and recorded 738 species of which include a few species of ferns and fern-allies from North Garhwal. Nathani (1967) also contri- buted to the systematics of this region by listing 201 species of flowering plants and ferns from this region. In this paper an attempt has been made to explore this region to study the ecological distribution of ferns and fern-allies. This region has attracted our attention because of the fact that it lies in the middle of the Western Himalayas. Moreover, no detailed report for this region is available while the other regions in the Western Himalayas have been explored by different workers (Beddome 1883; Hope 1899-1904; Mehra 1939; Stewart 1942, 1945, 1951; Schelpe 1954; Loyal and Verma 1960; Bir 1963; Mehra and Bir 1964; Mehra and Dhir 1968 ; Pande 1973 ; Dhir and Sheera 1975).

2. Garhwal region lies in the Western Himalayan Chain. To the east of Garhwal lie the districts of Nainital, Almora and Pithoragarh, on the west it is separated

3O7 308 D K Awasthi and M P Sharma from Himachal Pradesh by the Tons, and on the north by the snow-clad peaks of Tibet (Kharkwal 1977). Topographically, this region has been divided into five districts viz. Uttarkashi, Chamoli, Tehri, Pauri Garhwal and Dehradun. The district Chamoli lies 29.55' x 32" and 31.4' x 22" latitude and 78.54' x 26" and 80.6' x 4" longitude, almost entirely bordered by the high peaks of Nilkantha, Chaukhamba, Trisul and Nandadevi. The Nagpur block which the authors have explored, fails in the limits of Chamoli District. For convenience, it is divided into nine sectors viz., Brahmin khal (1200 m), Nagnath (2400 m), Bhikona (1800 m), Mohankhal (2400 m), Gaduna (1200 m), Choptta (2100 m), Bamoth (700m), Langasu (900m), and Kugasu (1500 m). Each sector was visited frequently in four consecutive years (July 1975 to September 1979) so as to collect as many plants as possible and to make a complete note of different habitats of the species.

3. Climate anti soil

The conspicuous features of the weather of this region are valley winds in narrow valleys, heavy fog during winters in wide valleys, variation of exposure to sun- light and to rain bearing winds. All these factors contribute to a very compli- cated pattern of local climate. Therefore, in such an area microclimates are of considerable importance in comparison to macroclimate. The climate of this region exhibits seasonal fluctuations. The monsoon breaks in these hills usually by the end of June and lasts generally till the middle of September. The zone of maximum precipitation during both summer and winter lies between 1200-- 2400 m. The precipitation of every locality is directly related to both the altitudinal zone in which it exists and to its situation in relation to the ridge. The coldest months are December and January. Mohankhal and Nagnath are usually covered with snow in the month of January. April and May are marked by thunder and occasional hailstorms. The soil in this area is generally sandy to gravelly with large stones and at places clayey in patches. The colour of the soil is generally brownish black to grey. The nature of the soil is generally alkaline. In the regions it is covered with humus and organic matter. The area can edaphically be characterised into three categories : (i) alluvial soils which are mainly restricted to lower altitudes i.e., 900 m, (ii) brown forest soils at 900-1800 m altitude, and (iii) brown soil in and grey soil in coniferous at 1800-2400 m altitude.

4. General vegetation The major part (62~o) of the region is covered with forests of mixed type of vegetation constituting an enormous wealth of the region. On the drier and exposed sides of hills Pinus roxburghii is the dominant species between 1500 and 1800 m and above this it is replaced by Cedrus deodara Lound. In Pinus and Cedrus forests the ground generally consist of grasses and few herbs viz., Desmodium, Crotolaria, Flemingia, Campylotropis, etc. Towards its lower limits Pinus forests pave into forests of mixed species viz., Phyllanthus emblica Linn., Ecology and phytogeography of ferns and fern-allies 309 Eugenia sp., Bauhenia variegata Linn., Ficus roxhburghii wall., and Hameltonia species. In the forests of Quercus dilatata Lindi. which is ordinarily found between 1650-2400 m, few common undercover plants are Berberis asiatica Roxbo ex DC., B. chitria Flare. ex. Don., Desmodium tilioefolium Don., Indigofera gerardiana wall., Myrisine africana Linn., Strobilanthes alatus Nees., S. dalhausianus C. B. Clarke, and Elscholtzia tiara Benth. On the shaded side humus accumulates and is very much favourable for the lush growth of ferns. The vegetation on the shaded side of the slope is of mixed type and is represented by different species viz., Quercus semicarpifolia Sin., Q. dilatata Lindl., along with Rhododendron arboreum Smith., Lyonia ovalifolia (Wail.) Drude., Viburnum, Litsea, Myricanagi Thunb., Comus capitata wallq Alnus nepalensis Don., Caprinus, Ilex, etc. Occasionally a few individuals of Cupressus torulosa Don., Taxus baccata Linn., Picea smithiana Limk., Aesculus indica colebr., Juglans regia finn. etc. may be seen between 1200-2100 m. The deciduous forests are found upto 1800 m. The common are Terminalia tomentosa W. and A. Prodr., Bauhenia variegata Linn. B. retusa Buch., Mallotus, philippinensis Muell., Sapium insigne Benth., Sterculia villosa Roxb., [ are largely subdeeiduous such as Indigofera pulchella Roxb., Rhus parviflora Roxb. Woodfordia fructicosa (L.) Kurz., Murraya koengii Spreng., or shrubs are Adhatoda vesica Nees., Colebrookia oppositafolia Sin., Nyctanthes arbor-tristis Linn., Pogostemon plactranthoides Desf., Spermodictyon, etc.

5. Ecological observations On the basis of habitat the ferns and fern-allies have been grouped into following categories. 5.1. Epiphytes The epiphytes form an important part of vegetation in this area. They are mainly restricted to the higher elevations (above 2100 m) only viz., Mohankhal, Choptta, and Nagnath hills which experience snow fall during January-February. These ephiphytes grow on trunks of mainly Quercus species and occasionally on Rhododendron species. The conifers harbour very little epiphytic vegetation. Only two species of ferns viz., Lepisorus nudus (Hook) Ching. and L. excavatus (Bory.) Ching. are found growing on the conifers and also on the Quercus species in the thick spongy mats of mosses storing large amount of water and humus. The rhizomos of epiphytes ramify in the spongy mats and perenates over the dormant period, when the fronds wither away. In February to April the grows vigorously producing new off springs and new fronds. Among the fern-allies Lycopodium lucidulum Michx., L. setaceum Ham. in Don., occur as epiphytes on trunks of Quercus and Rhododendron species. These have pendulous aerial branches and form thick patches on the tree trunks and preferably at the point of branching where humus accumulates. Some ferns e.g., Sphenomeris chinensis (L.) Maxon, Athyrium puncticaule (BI.) Moore, Polystichum obliquum (D. Don) Moore, Oleandra pistillaris (Sw.) C. Chr., O. wallichi (Hook.) Pr., Araiostegia pseudocystopteris (Kze.) Copel., A. multi- dentata (Wall.)Bedd., Asplenium dalhousiae Hook., Cyclosorus megaphyllus 310 i) K Awasthl and M P Sharma (Mett.) Ching, Loxogramme involuta (D. Don) Presl., Pyrrosia mollis (Kze.) Chlng., Polypodium argutum Wail., P. microrhizoma clarke ex Bak., Microsorium membra- naeeum (D. Don) Ching., M. pteropus (B1.) Copel, Phymatodes malacodon (Hook.) Copel., P. stewartii (Bedd.) Copel., P. oxyloba (Wall.) Presl., etc., are also common epiphytes on the tree trunks of Quercus and Rhododendron species, on the shaded side of the hills at 2100-2400 m altitude. Like the Lycopodium species, these ferns also form thick patches on the tree trunks. Polypodium argutum Wall. have pendant fronds like that of Lycopodium lucidulum Michx, The closeups of Microsorium membranaceum (D. Don) Ching. are reported from Bhikona and Nagnath growing at the base of trees under shade in excessive humus. Pyrrosia mollis (Kze.) Ching. (from Bhikona) on the other hand grows on the top of the branches and is thus exposed to direct sunlight. Botrychium lanugi- nosum Wall. and B. lunaria (L.) Sw. also accordingly grow as epiphytes on Quercus and Rhododendron trees. 5.2. Terrestrial species 5.2a. Climbers: Only two species were found growing as climbers. They are Lygodium flexuosum (L.) Sw. and L.japonicum (Thunb.) Sw. L.flexuosum was very common in Pine forests and grows profusely in the dry soil in association with plants of Gramineae and Leguminoseae at 1200 m altitude near Gaduna. The aerial branches twine around the branches of small shrubs. L.japonicum was rare and found along the briddle paths at Kald Baggarh in the dry soil directly exposed to sunlight. 5.2b. Ferns forming and tufts : Species of Polystichum viz. P. squar- rosum (D. Don) Fee. and P. aculeatum (L.) Roth were found growing on exposed rocks and in deep narrow gorges forming pure tufts. Both the species are densely tufted and grows in moderately dry soil in coniferous forests exposed to direct sunlight. These are common from 1200-2400m at Brahminkhal to Nagnath, Dryopteris sparsa (Complex) (Hum. ex. Don ) O. Ktze., is another fern which forms pure tufts but under shade at 2400 m altitude near Nagnath and has deli- cate fronds in comparison to that of Polystichum species fronds. Dicranopteris linearis (Burro.) Underwood, is an interesting fern which grows profusdy forming thickets in the forests on the shaded side of hills at 2100 m altitude at choptta. 5.2c. Ravine ferns : Few ferns grow on the rocks by the side of ravines along water channels or water streams. Some of them frequently being bathed with water. The temperature in these ravines is low with high humidity. In such a type of climate ferns with large, thin and delicate fronds prefer to grow but we have observed some ferns e.g., Pteridium aquilinum L., Pteris longipes D.Don., P. vittata Linn., Abacopteris multilineata (Wall.) Ching., Thelypteris erubescens (Wall.) ex Hook. etc., which have thick and tough fronds. Among these Abacop- teris multilineata is a very common fern found growing along the water streams. Species with thin and delicate fronds Cyclosorus parasiticus (L.) Tardieu ex. Tardieu, (7. truncatus (Poir. ex /.am.) Tardieu ex. Tardieu C. Chr., Athyrium japonicum (Thbg.) Copel., Adiantum capillus-veneris Linn., Diplazium polypodioides B1., etc., were also found growing near water at Brahminkhal, Kugasu, and Gaduna. Along the water streams at some places the soil becomes sandy a~d caleareous where Equisetum diffusum D. Don. grows profusely both in the shady and exposed places at 1200 m altitude near Brahminkhal. Ecology and phytogeography of ferns and fern-allies 311 5.2d. Ferns inhabiting forest floors and forest borders : Forest floor above- 1200-2400 m altitude is a good niche which is not directly exposed to diurnal fluctuations and thus is suitable for the lush growth of ferns whereas forests which are at low altitude (900 m) are not dense and the diurnal fluctuations are so marked that these forests become unsuitable for their growth. The mixed and deciduous forests are the most favourable fern habitats as compared to pure coniferous forests, where very few ferns and fern-allies viz., Polystichum aculeatum (L.) Roth, P. squarrosum. (D. Don) Fee, Dryopteris cochleata (Don) C.Chr., D. chrysocoma (Christ) C.Chr. and Ophioglossum vulgatum Linn., grow in the humus formed by the decomposition of coniferous needles. O. vulgatum is found growing in abundance at 1500 m altitude from Kujasu, while other ferns are found at an altitudinal range of 1200-2400 m. Species of Pteris viz., P. cretica Linn., P. longipes D. Don., P. quadriarui Retz., show luxuriant growth in the mixed and deciduous forests. Their distribution ranges from 1200-2400m altitude. Dryopteris odontoloma (Moore) C.Chr., and Coniogramme indica Fee. are found growing in abundance under the shade of trees only in the damp places in the forests. Other species which are common in the deciduous forests at Brahminkhal, Mohankhal and Nagnath are Athyrium schimperii Moug. ex. Fee., A. acrostichoides (Sw.) Diels,, Adiantum venusutum Don., Hypolepis punctata (Thbg.) Mett. ex Kuhn., Onychium siliculosum (Desv.) C.Chr., O. contiguum (Wall.) Hope., etc. Gymnopteris vestita (Wall.) Und. is found bordering the forests at 2400 m (Nagnath) in small pure thickets. Nephrolepis cordifolia (L.) Pr. is very common fern inhabiting forest borders from 900-1200 m. It is very dense and frequent upto 1800 m and after that it is completely absent. Besides occurring as epiphytes, some of the ferns established well on the forest floor also viz., Botrychium lanuginosum Wall., B. daucifolium Wall. ex Hook., is found growing in moist and shady places in the forests. Lycopodium clavatum Linn. was very frequent on the exposed forest floors above 2100 m in pine forests.

5.3. Lithophytes 5.3a. Ferns preferring moist and shady rocks : Onychium japonicum (Thbg.) Kze., O. siliculosum (Desv.) C.Chr., Asplenium indicum Sledge., A. dalhousiae Hook., A. aethiopicum (Burmf.) Becherer, Athyrium pectinatum (Wall.)Pr., A.falcatum Bedd., Polystichum stimulans Pr., etc., are found growing vigorously in tufts on the moist rocks near Nagnath, Brahminkhal, Mohankhal, Bhikona, etc. Selaginella chrysocaulos also forms lush green mats on the moist and shady rocks. It was found growing from 900-2100 m altitude. 5.3b. Ferns preferring exposed rocks along road sides : At 900-2100 m along briddle paths Adiantum incisum Forskal. has been found growing in abundance along with Cheilanthes farinosa (Forsk.) Klf., C. dalhousiae Hook. C. albomarginata Clarke, etc. The of these plants are covered with thick growth of mosses and liverworts. Woodsia elongata Hook., Tectaria macrodonta (Fee.) C.Chr., etc., are the other ferns which prefer to grow on rocks directly exposed to sunlight. Among the polypodiaceous ferns Lepisorus excavatus (Bory.) Ching., L. thunber. gianus (Kaulf.) Ching., Polypodium amoenum Wall., Microsorium pteropus (BI.) Nayar, Arthromeris wallichiana (Spr.) Ching., Phymatodes hastatus (Thunb.)

P.~--7 312 D K Awasthi and M P Sharma Copel., were the common ferns flourishing under direct sunlight on exposed rocks at 1800-2400 m altitude. 5.3c. Ferns preferring rock crevices and stony old walls : Asplenium dalhousiae Hook. establishes itself well as an epiphyte as well as terrestrial. Occasionally, it is also found growing in rock crevices. Similarly, Araiostegia pseudocystopte~is (Kze.) Copel., which is commonly found as an epiphyte, is also found growing in ~ock crevices. Hypodematium crenatum (Forsk.) Kuhn, and Polystichum squarrosum (D. Don) Fee. grows well under direct sunlight in rock crevices. The old walls are occupied by Adiantum philippense L. in abundance in isolated stands under direct sunlight. Selaginella chrysocaulos a/so flourishes well on old walls under moist and shady climate.

6. Phytogeographical observations

From this region 79 species of ferns and fern-allies (74 fern + 5 fern-allies) have been collected and reported in this paper. A majority of them are epiphytic (30"3~o). Tree ferns are lacking in this region. Sixtyfour (81%) species are common to the list of ferns and fern-allies of Sikkim and Darjeeling Himalayas (Mehra and Bir 1964). Out of these 64 species, eight species are newrecords for the western Himalayas. They are Lycopodium clavatum, L. lucidulum, L. setaceum, Pteris longipes, Cyclosorus parasiticus, C. truncatus, Dicranopteris linearis and Microsorium pteropus. Twentynine (36-7~o) species are common with the South Indian species and of these Botrychium daucifolium Wall. is the one which has not been reported earlier from the Himalayas. The ferns and fern-allies of this region also resemble those met within the adjoining hills. Fiftythree (67%) species are common with the Himachal Pradesh hills (which include Dalhausiae, Dharamsala, Kangra and Simla Hills) and 65:8~ (52) species with Kumaon Hills (which include Almora, Nainital, and Ranikhet). Few important and interesting species from distributional point of view are Botrychium lunaria, Lygodium japonicum, Onychium siliculosum, Coniogramme indica, Sphenomeris chinensis, Athyrium puncticaule, A. acrostichoides, Woodsia elongata, Abacopteris multilineata, Cyclosorus megaphyllus, Polypodium argutum, Arthromeris wallichiana, Phymatodes hastatus, P. malacodon, P. stewartii, etc. The above phytogeographical observations reveal that though the pteridophytic flora of this region is more akin to Eastern Himalayas (81~o) yet some species are also common to Western Himalayas.

Acknowledgements The authors are thankful to Prof. S S Bir for identification, Dr V P Dube for his interest and encouragement and to Dr V Kumar for going through the manu- script critical/y.

References

Boddomo R H 1883 Hand book to the ferns of British India, Ceylon and Malaya Peninsula (Calcutta: Thack9 Spink) Ecology and phytogeography of ferns and fern-allies 313

Bir S S 1963 Observations on the pteridophytie flora of Simla Hills (North-Western Himalayas) ; Bull. Bet. Surv. India 5 151-161 Clarke C B 1880 A review of the ferns of northern India ; Trans. Linn. See. (London) 1 425-611 Dhir K K and Sheera P S 1975 Ecological and phytogeographieal observations on the pterido- phytes of Dharamsala Hills (N.W. Himalayas); Nova Hedwigia Z. Kryptogamen. 26 353-371 Hope C W 1899-1904 Ferns of north-western India ; J. Bombay Nat. Hist. See. 12 527-538, 621-633; 13 25-36, 236-251, 443-461, 657-671; 14 119-127, 252-266, 458-480, 720-749 ; 15 67-111, 415-429 Kharkwal S C 1977 Geographic personality of Garhwal ; The Himalaya 1 3-13 Loyal D S and Verma S C 1960 Ferns of Nainital ; ar. Bombay Nat. Hist. Soc. 57 479-490 Mehra P N 1939 Ferns of Mussoorie, Lahore (Punjab Univ. Publ.) Mehra P H and Bir S S 1964 Pteddophytic flora of Darjeeling and Sikkim Himalayas ; Res. Bull. Punjab Univ. 15 69-182 Mehra P N and Dhir K K 1968 Ferns and fern-allies of Dalhousie Hills; Bull. Bet. Surv. India 10 296-308 Nathani B D 1967 Plant collection with the Kedarnath Parbat expedition; Bull. Bet. Surv. India 11 224-233 Pandey P C 1973 Pteridophytic flora of Ranikhet ; Indian For. 99 49-52 Rau M A 1961 Flowering plants and ferns of north Garhwal, U.P., India; Bull. Bet. Surv. Iudia 3 215-251 Sch9 E A C L E 1954 Ecological observations on in the Kar~gra Himalayas ; Am. Fern J. 44 49-65 Stewart R R 1942 The ferns of Mussoorir and Dehra Dun (150th Anniversary Vol) R. Bet. Gard. Calcutta 3 159-172 Stewart R R 1945 The ferns of Kashmir; Bull. Torrey Bet. Club 72 339-426 Stewart R R 1951 Tim ferns of Pahlgam (Kashmir) ; J. Indian Bet. Soc. 30 137-142