RESULTS AND DISCUSSION

General floristic composition
Analysis of data (compiled through transects based quadrats and opportunistic surveys) revealed the presence of 154 species of 68 families and 126 genera. Habit wise analyses indicate that 21 were climbers, 24 herbs, 29 shrubs, and 80 tree species. Rubiaceae (11 sp) was the most represented family in terms of number of species followed by Lauraceae (7 sp) and Anacardiaceae (6 sp). Other family represented with five species include Ebenaceae, Apocynaceae, Euphorbiaceae and Myrtaceae .

Floristic diversity and Structure

Shirgunji MPCA forest though primarily composed of evergreen to semi-evergreen forest species has been subjected to exploitation of minor forest produce resulting in degradation, evident from domination of shrub vegetation at Shirgunji-31-T1 transect. However, due to control of fire, the region is rich in evergreen species at Shirgunji-mabgi-T2 (36 sp) followed by Shirgunji-T5 (33 sp). The increase in number of species is due to deciduous species regeneration in degraded forest patches. Lowest number of species is seen in minor forest Shirgunji-31-T1 (22 sp).

Table 1: forest composition and basal area in Shirgunji

Important Value Index (IVI) and Endemism

Most of the forests though having high number of evergreen species, also have mix of deciduous species, coming under higher IVI. Knema attenuata was found in higher numbers in four transects followed by Holigarna ferrugeniana (one transect). Lophopetalum wightianum (Banate) a huge emergent tree having medicinal properties constitute next higher IVI in Shirgunji-Mabgi-T2 and Shirgunji-Mastikallu-T3 indicating existence of richer forests in the past. Occurrence of deciduous species in higher numbers in most of these transects highlights of logging, fire, and other extraction pressures. Vitex altissima (Bharanige), Terminalia paniculata (Kindal), Lagerstroemia microcarpa (Nandi), Stereospermum colais (Patali) were present in good numbers in most of transects. Although many of these are medicinally important plants, but their occurrence inside the evergreen to semi-evergreen along with Aporosa lindleyana and Olea dioica indicates disturbances. As forests get degraded from evergreen to secondary deciduous forest, gives way to generalist and wide-spread medicinal plants than sensitive ones. Due to high extraction pressure, sensitive medicinal plants such as Saraca asoca (Ashoka), Salacia sp (Ekanayaka), Coscinium fenestratum, Embelia ribes (Vayuvilanga) etc., have become scanty due to absence of suitable microhabitats. Most of the sampled transect are semi-evergreen with only one evergreen transect. Western Ghats tree endemism was higher in most transect (>60%) except in Shirgunji-Mastikallu-T3 (34.3%) due to the presence of Knema attenuata, Hopea ponga, Holigarna sp etc.  

Diversity of medicinal plants
A total of 122 medicinal plants were recorded during the field sampling.  These include 61 medicinal trees, 21 shrubs, 20 climbers, and 20 herbs. Habitat wise evergreen to semi-evergreen forest had 50 medicinal species; evergreen–moist deciduous complex had 25 sp., while 16 species in moist deciduous-scrub savanna areas. Remaining was found in other habitats such as grasslands, streamside, marshes, etc., or in combination of different habitats (Annexure 1). Shirgunji MPCA had high disturbances due its proximity to villages, evident from canopy openings with domination of weeds and common medicinal plants.

Transect wise medicinal plant composition

Transect-wise 92 medicinal species were noted with highest for Shirgunji-T5 (24 sp). Highest medicinal individuals were at Shirgunji-Mastikallu-T4 (112), while lowest was in minor forest Shirgunji-31-T1 (15 sp).

Table 2: Transect wise total medicinal plant species composition

Most other transects had medicinal plants > 60 % with known medicinal properties, and being used in folk medicine. Highest medicinal plants were in Shirgunji-Mastikallu-T3 (84.6 %). Thick canopy shaded region with higher moisture content is habitat for rare medicinal species while common species occurs predominantly in open areas.

Girth classes

Girth class structure of Shirgunji tree community, especially of climax species and medicinal trees, shows a regular inverted “J” curve with highest number of stems found in lower girth class (30-59 cm range) representing growing stock (Figure 1). The paucity of trees in higher girth classes (>200 cm class) reflects disturbances. Reduced population of mature medicinal trees will also affect the regeneration due to unavailability of seeds. Hence for effective conservation of species of medicinal importance, trees and shrubs of all age classes are important in a community. Details of the regeneration in seedling and sapling stages and in their higher girth classes are listed in Table 3. Regeneration of medicinal shrubs and climbers is given in Figure 2. 

Figure 1: Girth class individuals/ha., for important medicinal and climax tree species in Shirgunji MPCA area

Table 3:  Important medicinal and climax trees individuals/ha in seedling, sapling and tree class)

Species such as Knema attenuata, Nothopegia sp, etc., occur in higher proportion compared to sensitive climax species.  The ground layer vegetation was dominated by hardy evergreens like Ixora brachiata, Olea dioica, Aporosa lindleyana, Holigarna arnottiana etc., indicating  disturbances. There is a need to improve the regeneration and survival of Uppage (Garcinia camboga, (syn G. gummigutta) and Kokum (Garcinia indica) and other fast emerging endemic medicinal plants, to cater to the rising market demands. Currently these species occur in seedlings and sapling stages than as trees.  Mallotus phillippensis also occur as shrubs and can be grown in less shaded areas. Medicinally very important species Persea macrantha, Cinnamomum malabathrum, Myristica malabarica, Terminalia bellirica etc., have potential habitats within MPCA and requires appropriate management attention. Nothapodytes nimmoniana and Strychnox nux-vomica may be grown experimentally, as this region is their natural habitat.  Important medicinal plants such as Salacia, Saraca, Embelia, Coscinium fenestratum etc., not noticed during the survey, due to over-exploitation, may be planted in appropriate micro-habitats of MPCA.

Fig. 2: Estimated climber and shrub population per ha in Shirgunji MPCA

Some of the medicinal plants which require attention in Shirgunji MPCA are:

• Garcinia indica (Kokum; Murgila): has high demand for medicinal, culinary uses and as beverage. The distribution of this medicinal plant is good and occurs in most forest edges and other open areas. However, with increasing anthropogenic pressure this tree is under threat and needs in situ conservation measures. Restoration measures such as planting in forest open areas and edges will naturally increase the species survival.
• Garcinia cambogia: hashigh global demand for extraction of HCA.
• Abrus precatorius (Gulgunji): Mostly found in semi-evergreen areas. It also occurs in minor forests with high disturbance. Hence this species is suitable for in situ conservation in open forests.
• Asparagus racemosus (Shatavari): This important medicinal plant is found distributed in semi-evergreen forest and can be very important addition during planting with other medicinal plants in more shaded fragmented areas.
• Celastrus paniculatus (Jotishmati): Highly traded medicinal plant found in small number in these areas can be more intensively planted in open forest areas and edges.
• Rauvolfia serpetina (Sarpagandha): A valuable and highly traded and over-exploited medicinal plant found in the open degraded forest areas needs more intensive in-situ conservation. Scrubby forest areas are ideal.
• Alstonia scholaris (Halemara, Saptaparni): Found distributed more in semi-evergreen forest. This tree is suitable for forest openings and semi-evergreen degraded forest areas.
• Other less seen medicinal plants, mainly evergreens, in high demand for consideration are: Cinnamomum sulphuratum. C.malabatrum (Dalchini), Gmelina arborea (Shivuni), Myristica malabarica (Rampatri), Artocarpus hirsitus (Hebbalasu), Calophyllum apetalum (Bobbi). Shrubs and climbers such as Salacia chinensis (Ekanayaka), Nothopodytes nimmoniana, Rubia cordifolia (Majishta), Smilax sp., (Kaadu-hambu), Tinospora cordifolia (Amruthaballi), Piper spp (Kaadu-menasu; wild pepper), Coscinium fenestratum (Tree turmeric), Acacia concinna (shikekai), Gloriosa superba etc. can be more planted in disturbed forest areas.
• Deciduous species: Many important deciduous tree medicinal plants well distributed here includes Buchnania lanzan (Nurkalu), Careya arborea (Kaval-mara), Terminalia bellirica (Tari), Phyllanthus emblica (Nellikai), Bombax insigne etc. These also can be used in in-situ conservation for planting in highly degraded scrub areas.
• Cultivable species: Many medicinal plants have very high demand which cannot be catered to from wild sources only. Hence these can be brought into cultivation with the local farmers and medicinal gardens. Important medicinal plants such as Adhadhoda zeylanica (Vasaka; Adusoke), Andrographis paniculata (Kiriyata), Baliospermum montanum, Bacopa monnerie (Brahmi), Gloriosa superba, Piper longum (Hippali; Long pepper), Tinospora cordifolia (Amruthaballi), Curcuma zerumbet (Kasthuri), Cyclea peltata, etc., are cultivable, have high demand and their shorter life cycle enables early harvest.

Figure 3: Medicinal shrubs, herbs and climbers in Shirgunji area. A. Salacia chinensis  B. Ravolfia serpentina  C. Curculigo  orchioides D. Andrographis paniculata  E. Gloriosa superba  F. Abrus precatorius

Views of local stakeholders of medicinal plants cultivation in Shirgunji
Suggestions during group discussion with local stakeholder regarding cultivation of medicinal plants are:

• Majority are interested and take active part in cultivation of medicinal plants.
• Requires assurance such as “buy back” scheme for cultivated medicinal plants.
• Protocol of cultivation methods for specific medicinal plants.
• Favor mostly biennial or annual medicinal plants or which yield early.
• Some requires initial support for cultivating long term medicinal plants such as Cassia fistula, Myristica malabarica, Phyllanthus emblica, Terminalia spp., etc.
• Requirement of medicinal plant cultivation knowledge and awareness.