Results and Discussion

Gundia river basin (Figure 2) is situated along the narrow belt of evergreen and semi-evergreen climax and potentially related forests belonging to two categories (Pascal et.al, 1982).  The first category is Dipterocarpus indicus – Kingiodendron pinnatum – Humboldia brunonis type of low elevation (0-850 m elevation).  The second category is Mesua ferrea – Palaquium ellipticum type of medium elevation (650-1400 m). This river basin constitutes one of the prime centers of biodiversity in the central Western Ghats (Ramachandra et al., 2010).  Of the flowering plants collected from here 36% were Western Ghat endemics. Considering the ecological significance and rich biodiversity, and the threats looming large on the region, due to many unplanned developmental activities,  there is an urgent need for declaring the region as an Eco-sensitive one as per sub-section (1) with clause (v) of sub-section (2) of section 3 of the Environment (Protection) Act, 1986 (29 of 1986) and clause (d) of sub-rule (3) of rule 5 of the Environment (Protection) Rules, 1986 in concurrence with the provisions of the Indian Forests Act, 1927 (16 of 1927) and Forest (Conservation) Act, 1980 (69 of 1980) the Wildlife (Protection) Act, 1972 (53 of 1972) and also Biological diversity act 2002 (Ramachandra et al 2010).

Figure 2: Evergreen and semi-evergreen climax and potentially related forests of Gundia basin (source – Pascal et al., 1982)

The vegetation of the region (including the degradation stages of the major forest types mentioned and the humanized landscapes) can be broadly divided into the following different types:

1. Tropical wet evergreen to semi-evergreen rainforests
2. The riparian vegetation
3. Tropical wet deciduous forests
4. Scrub jungles
5. Grasslands and savannas
6. Scattered trees along plantations and abandoned fields

The tropical wet evergreen and semi-evergreen forests encompass a wide array of floristic diversity which includes angiosperms, pteridophytes, bryophytes, fungi, etc. The presence of many perennial streams, waterfalls and other moist habitats support rich growth of pteridophytes. Apart from the mention of 10 fern species of Thelypteridaceae family by Holttum (1976) from the Hassan district, there has been no other significant study enumerating or highlighting the pteridophytic wealth of this region. A comprehensive collection of ferns and fern allies have been archived at JCB herbarium of Centre for Ecological Sciences, Indian Institute of Science, Bangalore, many of which have been collected from this region too. Apart from our first hand field collection of pteridophyte specimens, we also referred the JCB herbarium collections and other available literatures to enumerate the pteridophytic wealth of this region.

In the current study, a total of 45 species of ferns and fern-allies belonging to 26 different genera and 19 different families (Table 1) were recorded. Some of the notable pteridophyte species of the study region are shown in Figure 3. The dominant families were Pteridaceae and Thelypteridaceae with 5 species each followed by Dryopteridaceae, Woodsiaceae and Selaginellaceae (4 species each). The most common and widely distributed species in the study area are Dicranopteris linearis, Blechnum orientale, Adiantum philippense L. subsp. philippense, Pityrogramma calomelanos, Tectaria coadunata, Thelypteris (Christella) parasitica and Thelypteris (Christella) dentata. The presence of South Indian endemic species Bolbitis semicordata, Bolbitis subcrenatoides, Osmunda huegeliana and Cyathea nilgirensis (Fraser-Jenkins, 2008b) in the study region adds to the exemplary biodiversity of the region. Of these, B. semicordata is a rare species in South India itself whereas C. nilgirensis is Near-threatened implying a high conservation status to them (Chandra et al, 2008).

Table 1: Pteridophytes recorded from the Sakleshpur taluk in central Western Ghats

Figure 3: Some notable pteridophytes in the study area

Each species of fern has its own preferences of micro habitat depending on the temperature, humidity, soil type,moisture, pH, light intensity, etc., and in many cases are very specific indicators of the conditions they need (Shaikh and Dongare, 2009). It is well observed and noted that most species of ferns succeed under high humidity andshade conditions (Page 1979), unless they are species that prefer more xeric conditions andare more heliophilous. Cyathea sps. and Angiopteris sp. are among those perennial ferns which prefer swampy/moist habitats with low light intensities for their growth. Similarly, another endemic fern Osmunda huegeliana prefers themoist and humid banks of free flowing perennial streams and rivers (Dudani et al 2012). Another endemic fern species Bolbitis subcrenatoides is commonly found growing as terrestrial inside the fully covered forest floors and sometimes along road cuttings or edges in the forest. Pteridium revolutum syn. Pteridium aquilinum is an adventive alien species (Jenkins, 2008a) of the region, an escape from gardens into the wild surroundings of Western Ghats, which has a preference for growing gregariously on fully exposed grassy slopes. Lygodium flexosum is the only scandent or climbing fern recorded in the current study prefers to grow among the bushes along the partially or fully exposed roadsides. The commonly growing terrestrial species such as Blechnum orientale and Dicranopteris linearis were observed to be growing abundantly and forming thickets in many places.The common lithophytic fern species in the study region were Pityrogramma calomelanos, Leucostegia truncata and Adiantum philippense while the common epiphytic fern species observed were Drynaria quercifolia and Lepisorus nudus.

Most of the pteridophytes recorded in this study have various medicinal and other miscellaneous applications. Among all, Pteridium revolutum is perhaps the most widely used terrestrial fern species for various purposes. The tender fronds of this fern are used as vegetables and also in soup preparations while the rhizomes are boiled or roasted and eaten. The rhizome of this fern is astringent, anthelmintic and is useful in diarrhea and inflammation of the gastric and intestinal mucous membranes. The rhizome is boiled in oil and is made into an ointment for wounds. The dried fronds of the fern are also employed as packaging material and have also been tried as a source for paper pulp (Manickam and Irudayaraj, 1992). Another widely occurring fern in the study region – Tectaria coadunata, has antibacterial properties and is used in the cases of asthma, bronchitis, honey bee stings and the cooked tender portion of this fern is employed for curing stomach trouble (Dixit and Vohra, 1984; Manandhar, 1996; Das, 1997). The climbing fern Lygodium flexosum is used as an expectorant and in the treatment of rheumatism, sprains, scabies, ulcers, eczema and coughs (Singh et al, 1989; Manandhar, 1996). Other important medicinal applications of the pteridophytes include: use of the rhizome of Drynaria quercifolia as antibacterial, anti-inflammatory, tonic, in the treatment of typhoid fever, dyspepsia, cough, diarrhea, ulcers and other inflammations (Dixit and Vohra, 1984; Warrier et al, 1996); use of the fronds of Osmunda huegeliana as tonic, styptic and also for the treatment of rickets, rheumatism and for intestinal gripping (Nair, 1959; Dixit and Vohra, 1984); use of the fronds of Pityrogramma calomelanos for the treatment of asthma, cold and chest congestion (Dixit and Vohra, 1984); use of the rhizome of Leucostegia truncata as antibacterial and in the treatment of constipation (Benjamin and Manickam, 2007).  Besides these exemplary medicinal properties, the pteridophytes have long been greatly valued as ornamentals. They are used to enhance the beauty of the landscape and find their place in gardens, nurseries and during functions for beautification purposes.

However, as the humid places and water bodies are prioritized by the humans for settlements, farming, power generation, setting up of industries etc. the most sensitive pteridophytes depending upon such habitats tend to vanish from the region. The Gundia river basin in Sakleshpur has already lost vast area of primary forests, evident from barren hill tops, stretches of secondary forests, scrub jungles, monoculture tree plantations and drying streams. It is unfortunate that this region has been experiencing heavy anthropogenic pressures since last two decades, especially from cultivation of coffee and cardamom and arecanut dominated spice gardens. Coupled with these factors, the incessant collection of ferns from the forests by visitors and locals for ornamental purposes, medicinal purposes and during excursions have also increased the pressure for survival on these plants.Such threats apart, nevertheless, the same region, one of the last bastions of pteridophytic wealth in the central Western Ghats, is being considered for the implementation of 200 MW hydel project in the Gundia river. However this proposal is kept in abeyancedue to the agitation by local people and considering the ecological sensitiveness of the region. There is a dire need to identify and conserve such threatened ecosystems which consist of the germplasm of most humid tropical pteridophytes of Western Ghats. Also, the sore lack of knowledge on pteridophytes among the public in general is a major issue to be addressed through awareness programmes for holistic habitat conservation.