General floristic composition: Transect cum quadrat data and opportunistic survey revealed a total of 219 species coming under 75 families and 125 genera.  Habit-wise 113 species of trees, 33 of shrubs, 41 of herbs and 32 climbers were recorded. Families with highest number of species were Fabaceae (13), and Rubiaceae (13), followed by Euphorbiaceae (9), Anacardiaceae (8), Lauraceae (7), Meliaceae (7) and Myrtaceae (7). Other families were having less than 7 species (Figure 2.1). Details of most specious genera are given in Figure 2.2. Evergreen tree genera Diospyros (6 sp) was followed by Syzygium (5) and Holigarna (4) and others had lesser number.

Floristic diversity and forest structure: Except Jankadkal 2 and Jankadkal 3 patches which were semi-evergreen type all the five transects sampled were evergreen forests (Table 2.1).  This shows their relatively lesser disturbance compared to more coastal facing areas which were very disturbed and some changed into moist deciduous types to barren hills due to land use pressures, especially in the past. Species area curve plotted for the seven transects showed flattened saturated curve (Figure 2.3) implying sufficiency of the sampling efforts. Jankadkal-Ammanabetta-T5 with 174 trees was the highest followed by Jankadkal-T4 with 167 individuals.  Lowest was found in Jankadkal-T3 with 100 individuals (Figure 2.4). This particular transect passed through a dry, narrow streamlet, which on either side was covered with high entanglement of climbers with lesser trees showing probable earlier disturbances.

Jankadkal-T2 with 34 species and Jankadkal-Darbejaddi-T7 having 30 species were among transects with highest species number. Height of the forest constitutes one of the important parameter to characterize the forest stature. I general undisturbed old forests had bigger heights compared to crooked stunted trees in severely disturbed forest. Jankadkal-T1 (16.6m) had the highest average canopy height, followed by Jankadkal-T4 (16.5m). Jankadkal-T2 (13.4) had the least height which reflects its disturbed condition.

Fig. 2.1. Family-wise species richness in Jankadkal MPCA

Fig. 2.2.  Genera-wise species richness among trees in Jankadkal MPCA

Table 2.1. Jankadkal transects forest composition (trees) and basal area details.

Fig. 2.3. Species area curve for trees in Jankadkal MPCA

Fig. 2.4. Jankadkal-Transect 3 -entanglement of climbers and lesser density of trees

Forest diversity: South East Asia has long been recognised as a centre of plant biodiversity. Being situated in the tropics, with areas of high rainfall and a year round hot humid climate, South East Asia boasts some of the largest numbers of vascular plants species in the world (Mittermeier et al. 1999). However Western Ghats, higher in latitude (8 degrees N to 20 degrees N), with its more seasonal climate and high anthropogenic pressure such high diversity as of more equatorial Amazonia or Malaysia cannot be expected.  The anthropogenic causes disruption of forest structure and alters the species composition, leading towards reduction in tree species and density and finally drive the forest to extremely degraded stage (Baithalu et. al. 2013). Such is the case in most of the coastal area forest in Uttara Kannada. However Jankadkal forest which has escaped severe degradation has higher Shannon diversity in some semi-evergreen transects such as Jankadkal T2 (3.1) and Jankadkal-T3 (3.0). This increase in diversity in these two transects is due to addition of deciduous species (Table 2.2), indicators of past disturbances, mixing with the evergreens. Others have lower values with lowest in Jankadkal-Ammanabetta-T5 (2.5) due to mainly dominance of evergreens like Strombosia ceylanica and Diospyros sylvaticus. Lower diversity is also due to dominance of evergreens D. sylvaticus, along with Knema attenuata, S. ceylanica and Hopea ponga.
Basal area and population dynamics: Jankadkal-Darbejaddi-T7 (76.5 sq.m/ha) had the highest basal area contributed mainly by lofty trees of Strombosia ceylanica and Diospyros sylvatica, followed by Knema attenuata and Holigarna ferruginea. Myristica malabarica was also found in good number here. Huge trees with immense buttresses of Tetrameles nudiflora also contributed to the higher basal area of this transect (Figure 2.5). Lowest basal area was found in Jankadkal-T2 which had lesser number of trees and more of lower girths. This transect also had higher number of deciduous species such as Lagerstroemia microcarpa and secondary evergreen Aporosa lindleyana probably revealing past disturbance, especially shifting cultivation history.

Table 2.2. Species richness, Shannon diversity, Simpson dominance, Simpson diversity, and Pielou’s evenness in Jankadkal MPCA.

Important value index: Most of the trees having higher IVI are evergreen species. Strombosia ceylanica and Diospyros sylvatica, followed by Knema attenuata and Holigarna ferruginea are leading  trees in most of the transects (Table 2.3 -2.5). These, except S. ceylanica, are endemic to Western Ghats. Jankadkal MPCA is dominated by endemic tree species. Non-endemics are more towards western side foothills closer to human habitations. Deciduous trees of larger size, especially Lagerstroemia microcarpa had higher presence.  It would have established in the past due to the use of fire for forest clearance during shifting cultivation history.  Some smaller girth classes of this tree occurs indicating also recent disturbance. Hardy evergreens such as Olea dioica and Aporosa lindleyana were also seen in higher IVI values in many transects, indicating ongoing forest disturbances, or recovery process from such disturbances.

Fig. 2.5. Tetrameles nudiflora, a  buttressed tree. In the background are talipot palm Corypha umbraculifera

Table 2.3. Transect-wise IVI of leading 10 trees in Jankadkal T1 to T3

Table 2.4. Transect-wise IVI of leading 10 trees in Jankadkal T4 and T5

Table 2.5. Transect-wise IVI of leading 10 trees in Jankadkal T6 and T7

Evergreenness and Endemism: Evergreenness (% of evergreen tree individuals in the total tree population) was high in most transects, Jankadkal-T2 and Jankadkal-T3 which were semi-evergreen, being exceptions. Nearly 43% of tree individuals were endemic to Western Ghats alone, and in combination (Western Ghats-Sri Lanka biodiversity hotspot) endemism is even more. Highest tree endemism was found in Jankadkal-T1 (60.8%) followed by Jankadkal -T4 (50.9%). Lesser endemism was found in Jankadkal-Ammanabetta-T5 (37.5%) and by Jankadkal-Darbejaddi-T7 (38.2%). As most of this MPCA has over 40% endemism it is important to have such a conservation centre for endemic medicinal species (Figure 2.6).

Fig. 2.6. Percentage of evergreenness and Western Ghat endemism in the tree community of Jankadkal MPCA

Medicinal plant diversity: A total of 178 medicinal plants were noted in Jankadkal forest study including also opportunistic surveys, outside the sample plots. Out of them 93 species were trees, 31 climbers, 23 shrubs, and 31 herb species. Habitat wise 74 medicinal plants came from evergreen to semi-evergreen forest, 28 from both evergreen and moist deciduous, 20 from moist deciduous and scrub-savanna, 8 occurred in evergreen-semi-evergreen, moist deciduous, and scrub savannah combination; 7 were exclusiv to moist deciduous, 7 exclusive to stream sides, and remaining 34 species were found in other habitats such as grassy areas, marsh, plantations etc. (Annexure 1 for details). Within in any major habitat type microhabitat conditions, such as shade intensity, canopy opening, steepness, rockiness, soil, water and litter richness etc. influenced species distribution.  From conservation angle more detailed studies need to be initiated on micro-habitat conditions and medicinal plant regeneration potential.

Transect wise medicinal plant composition: Transect wise Jankadkal-T1 had the highest number of medicinal trees in the transect (80) followed by Jankadkal-ammanabetta-T5 (76). Highest number of medicinal tree species per transect was found in Jankadkal-T2 (21 sp) followed by Jankadkal-Darbejaddi-T6 (19 sp) (Table 2.4). Jankadkal-Darbejaddi-T6 (76 %) had the highest percentage of medicinal plants, followed by Jankadkal-ammanabetta-T5 (68 %) (Figure 2.7).

Table 2.4: Total medicinal plant individuals and species among total individuals and species/transect in Jankadkal MPCA

Fig. 2.7. Percentage of medicinal tree individuals in the total tree population and percentage of medicinal tree species per transect

Girth distribution in trees: Girth classes of individuals of important medicinal and some emergent tree species pooled together from Jankadkal shows an inverted “J” curve (Figure 2.8), indicating overall healthy recruitment in lower girth classes.  Higher girth classes, though lesser, comparatively, are likely to increase under MPCA protection. Artocarpus hirsutus, Lophopetalum wightianum, Syzygium gardnerii etc. were among the trees having highest girth classes. Myristica malabarica, Olea dioica, Cinnamomum malabatrum, Syzygium hemispericum, and Polyalthia fragrans were also having many trees with girth classes above 200 cm. However Olea dioica in more numbers in higher girth classes indicates past disturbances. Presence of Lagerstroemia microcarpa in lower girth classes in some transects indicates recent disturbances due to fire.

Medicinal tree Knema attenuata and another climax evergreen species Strombosia ceylanica had highest regenerating seedlings per hectare of more than 5000/ha (Table 5). This indicates that the forest is in the process of turning into high evergreen. Other medicinal trees species such as Aporosa lindleyana, Ervatamia heyneana, Mallotus phillipensis, Nothopegia  castaneaefolia, Olea dioica,  Garcinia gummigutta, Pterospemum diversifolium etc., had medium to high regeneration of more than 500 seedlings /ha.  Medicinal tree species including Myristica malabarica, Artocarpus hirsutus, Calophyllum apetalum, Dysoxylum sp, Garcinia morella, G. indica, Mangifera indica, Mimusops elengi, Neolitsea scrobiculata, Persea macrantha, Saraca asoca etc., were not having regeneration in seedling stage in herb layer, which is a matter of some concern. Many medicinal deciduous trees such as Terminalia’s, Careya arborea and Stereospermum colais had poor regeneration as the forest is turning into evergreen to semi-evergreen type giving little scope for regeneration of deciduous trees. Many medicinal plants from the forest is used mainly for local consumption. As per National Medicinal Plants Board (NMPB) and FRLHT assessment of Indian traded medicinal species the study area has nearly 44 plants in herb, shrub and tree species which are traded (not necessarily from the area under study) and some very highly traded requiring stringent protection (Annexure 1, 2)

Fig. 2.8: Girth distribution of important trees in Jankadkal (all transects together)

Many shrubs and palms from the study site are also known for medicinal uses. Palms with some medicinal value, such as Corypha umbraculifera (Talemara) and Arenga wightii had the highest regeneration per hectare (Figure 2.9).  Medicinally important shrubs Psychotria flavida, Calamus thwaitsii, Ardisia solanaceae etc. also had higher regeneration compared to other shrub species. Many shrubs such as Apama siliqosa (Chakrani) which need more special habitats were having less regenerating saplings compared to widely growing species such as Psychotria. Overall some dominant trees like Knema and Strombosia had higher regeneration compared to others. Many medicinal endemics such as Myristica malabarica (Rampatri), endemic climbers such Salacia sp. (Ekanayaka), and Embelia ribes (Vayuvilang) etc., also had lesser regeneration due to their sparser distribution requiring more specialised habitat needs. Hence more studies need to be conducted to understand the ecology medicinal such medicinal plants which are in high market demand.

Fig. 2.9. Regeneration in medicinal shrubs and palms showing their population per hectare in shrub layer (<30 cm gbh and >1m)

Table 2.5: Estimated numbers of notable trees/ha girth classes & in seedling and sapling stages (regeneration profile)