Results and Discussion

Floristic Richness: A total of 116 transects studied along with opportunistic surveys yielded a list of 1068 species of flowering plants (about 25% of Western Ghat species) from 138 families. Of these 278 were trees species (from 59 families), 285 shrubs species (73 families) and 505 herb species (55 families) (Figure 4). Among trees Moraceae had maximum representation (18sp), followed by Euphorbiaceae (16 sp.), Leguminosae (15 sp.), Lauraceae (14 sp.), Anacardiaceae (13 sp.) and Rubiaceae (13 sp.) and so on (Figure 5). The genus  Ficus, members of which are considered as keystone resources for large number of birds and mammals, was the most well represented of Moraceae.

Figure 4: Family and species number for trees, Shrubs and Herbs

In Shrubs Leguminosae (32 sp.), Rubiaceae (24 sp.), Euphorbiaceae (24 sp.) were the leading families in species richness (Figure 6).  Grasses (Poaceae) were most speciose (77 sp.) among herbs, followed by sedges –Cyperaceae- (67 sp.) and orchids –Orchidaceae- (35 sp.) (Figure 7). Grasses occur everywhere, except underneath the dark canopy of evergreen forest.   Most of wetlands and very moist areas were under the dominance of Cyperaceae and to some extent under Scrophulariaceae.

Basal area and height:  Details of transect-wise localities depicting tree species/transect, average height and estimated basal area/ha are given in the Table- 3. Hadgeri-1 had the highest average tree height (21.82m) followed by Halsolli and Ambepal. These areas were characterised by lofty individuals of Dipterocarpus indicus, Syzygium gardenerii etc., the mature trees often attaining over 30 m. Most forests in Honavar and Siddapur taluks had greater heights owing to their predominantly evergreen and semi-evergreen forests.

Figure 5. Richness of families in tree species (families with above 3 species shown)

Figure 6: Richness of families in shrub species (those with 4 or more species only shown)

Figure 7: Richness of families with herb species (only families with 4 or more species given)

Table 3: Transect-wise numbers of tree species, average height and estimated basal area per ha and biomass-carbon sequestration

T.no	Locality name	Taluk	Tree species	Av.ht	Basal area (m2/ha)	Above ground biomass (t/ha)	Below ground biomass (t/ha)	Total biomass (t/ha)	Carbon sequestration (t/ha)
1	Asolli-1	Ankola	23	17.1	38.28	256.70	66.74	323.44	161.72
2	Asolli-2	Ankola	33	17.4	38.73	259.75	67.53	327.28	163.64
3	Hosakere	Ankola	30	16.0	37.62	252.28	65.59	317.87	158.94
4	S1-Katangadde-Agasur	Ankola	40	9.6	9.08	58.75	15.28	74.03	37.01
5	S2-Balikoppa-Badgon	Ankola	31	13.6	20.39	135.43	35.21	170.65	85.32
6	S3-Hegdekoppa-Kasinmakki	Ankola	35	14.6	30.41	203.37	52.88	256.25	128.12
7	S4-Vajralli-Ramanguli	Ankola	31	13.9	18.8	124.65	32.41	157.06	78.53
8	Kachinabatti	Ankola	13	15.5	18.39	121.90	31.69	153.60	76.80
9	Maabagi	Ankola	33	16.4	40.78	273.67	71.15	344.82	172.41
10	Dakshinakoppa	Bhatkal	12	16.1	34.83	233.35	60.67	294.02	147.01
11	Gujmavu (semi evergreen)	Bhatkal	33	15.8	32.97	220.75	57.40	278.15	139.07
12	Hudil (evergreen)	Bhatkal	14	17.3	35.82	240.02	62.40	302.42	151.21
13	Hudil (semi evergreen)	Bhatkal	27	15.8	46.11	309.81	80.55	390.36	195.18
14	Golehalli	Haliyal	16	9.54	15.64	103.20	26.83	130.03	65.02
15	Kudalgi-Tatigeri	Haliyal	12	10.98	17.79	117.84	30.64	148.48	74.24
16	Magvad	Haliyal	19	14.9	23.90	159.21	41.39	200.60	100.30
17	Sambrani	Haliyal	11	12.59	31.91	213.54	55.52	269.06	134.53
18	Yadoga	Haliyal	13	14.3	26.30	175.53	45.64	221.17	110.58
19	Ambepal-1	Honavar	25	19.2	31.49	210.66	54.77	265.43	132.72
20	Ambepal-2	Honavar	32	19.6	48.80	328.07	85.30	413.36	206.68
21	Chaturmukhabasti	Honavar	23	15.0	27.76	185.38	48.20	233.58	116.79
22	Gersoppa	Honavar	31	18.2	30.13	201.47	52.38	253.85	126.93
23	Gundabala	Honavar	32	15.4	29.05	194.16	50.48	244.65	122.32
24	Hadageri-1	Honavar	23	21.8	53.69	361.20	93.91	455.11	227.56
25	Hadageri-2	Honavar	19	19.3	45.53	305.85	79.52	385.38	192.69
26	Halsolli	Honavar	9	20.5	30.64	204.93	53.28	258.21	129.11
27	Hessige-1	Honavar	28	18.1	44.25	297.21	77.27	374.48	187.24
28	Hessige-2	Honavar	27	16.6	48.87	328.52	85.42	413.94	206.97
29	Hessige-3	Honavar	25	16.9	31.46	210.47	54.72	265.19	132.60
30	Hessige-4	Honavar	30	17.4	51.56	346.77	90.16	436.93	218.46
31	Kadnir	Honavar	24	16.0	38.17	255.96	66.55	322.51	161.25
32	Karikan-lower slope	Honavar	28	13.6	41.87	281.10	73.09	354.19	177.09
33	Karikan-semievergreen	Honavar	23	14.4	33.98	227.57	59.17	286.74	143.37
34	Karikan-temple side-diptero patch	Honavar	21	17.9	85.41	576.29	149.83	726.12	363.06
35	Mahime	Honavar	18	16.8	30.44	203.57	52.93	256.50	128.25
36	Sharavathy-viewpoint	Honavar	28	17.7	34.70	232.47	60.44	292.92	146.46
37	Tulsani-1	Honavar	27	17.3	36.44	244.26	63.51	307.77	153.89
38	Tulsani-2	Honavar	23	17.1	30.86	206.44	53.68	260.12	130.06
39	Castlerock IB	Joida	28	16.0	55.68	374.67	97.41	472.09	236.04
40	Castlerock-moist-dec.	Joida	22	9.4	12.16	79.64	20.71	100.34	50.17
41	Castlerock-semi everg	Joida	24	15.4	26.27	175.31	45.58	220.89	110.44
42	Desaivada-Nandgadde	Joida	12	16.87	36.96	247.81	64.43	312.24	156.12
43	Gavni-Kangihole-Joida	Joida	35	15.2	48.70	327.37	85.12	412.49	206.25
44	Ivolli-Castlerock	Joida	19	13.7	33.99	227.62	59.18	286.80	143.40
45	Joida-deciduous	Joida	21	16.9	39.44	264.62	68.80	333.42	166.71
46	Kushavali	Joida	30	16.4	75.04	505.93	131.54	637.48	318.74
47	Shivpura	Joida	12	15.90	33.79	226.26	58.83	285.09	142.55
48	Gopishetta	Karwar	23	15.1	32.21	215.58	56.05	271.63	135.82
49	Goyar-moist dec	Karwar	18	15.0	37.99	254.77	66.24	321.01	160.50
50	Kalni-goyar	Karwar	32	17.3	45.05	302.66	78.69	381.35	190.67
51	Karwar-moist dec	Karwar	17	10.8	13.48	88.61	23.04	111.65	55.82
52	Devimane-Campsite	Kumta	36	16.7	42.99	288.63	75.04	363.67	181.84
53	Devimane-Sirsi side	Kumta	30	14.4	40.28	270.31	70.28	340.59	170.30
54	Devimane-temple	Kumta	29	14.8	39.54	265.30	68.98	334.27	167.14
55	Devimane-with myristicas	Kumta	30	15.0	45.86	308.15	80.12	388.27	194.14
56	Hulidevarakodlu	Kumta	34	18.2	43.53	292.35	76.01	368.36	184.18
57	Kalve	Kumta	28	16.2	27.38	182.82	47.53	230.35	115.17

58	Kalve-moist dec.	Kumta	22	14.3	28.76	192.18	49.97	242.14	121.07
59	Kandalli-Devimane	Kumta	28	16.14	41.54	278.84	72.50	351.33	175.67
60	Mastihalla-Devimane arch	Kumta	26	15.27	48.04	322.92	83.96	406.87	203.44
61	Mathali-Kandalli-Devimane	Kumta	29	15.6	41.61	279.34	72.63	351.96	175.98
62	Soppinahosalli	Kumta	15	14.5	25.43	169.60	44.09	213.69	106.85
63	Surjaddi	Kumta	28	17.3	35.75	239.58	62.29	301.88	150.94
64	Surjaddi-Morse	Kumta	30	17.2	29.40	196.53	51.10	247.63	123.82
65	Attiveri-teakmixed-drydec	Mundgod	20	10.1	11.85	77.54	20.16	97.70	48.85
66	Godnal	Mundgod	13	15.6	43.09	289.36	75.23	364.59	182.30
67	Gunjavathi	Mundgod	9	14.3	20.44	135.78	35.30	171.08	85.54
68	Karekoppa-Gunjavathi	Mundgod	11	17.0	36.72	246.15	64.00	310.15	155.08
69	Katur	Mundgod	15	16.69	28.05	187.35	48.71	236.06	118.03
70	Katur to Gunjavati	Mundgod	17	9.07	29.08	194.37	50.54	244.91	122.46
71	G1-Kathalekan-nonswamp	Siddapur	41	14.4	32.31	216.25	56.23	272.48	136.24
72	G2-Kathalekan-nonswamp	Siddapur	39	16.2	39.14	262.58	68.27	330.86	165.43
73	G3-Kathalekan-nonswamp	Siddapur	37	15.6	45.41	305.09	79.32	384.42	192.21
74	G4-Kathalekan –nonswamp	Siddapur	38	16.7	35.87	240.42	62.51	302.93	151.46
75	G5-Kathalekan-nonswamp	Siddapur	39	14.1	39.84	267.28	69.49	336.77	168.39
76	Kathalekan-savanna	Siddapur	5	6.1	1.59	7.98	2.08	10.06	5.03
77	G6-Kathalekan-nonswamp	Siddapur	23	17.8	50.86	342.04	88.93	430.97	215.48
78	G7-Kathalekan-nonswamp	Siddapur	44	16.8	28.22	188.52	49.02	237.54	118.77
79	G8-Kathalekan- nonswamp	Siddapur	34	16.1	41.24	276.80	71.97	348.77	174.38
80	G9-Kathalekan-nonswamp	Siddapur	18	16.0	39.63	265.88	69.13	335.01	167.51
81	Hartebailu-soppinabetta	Siddapur	23	11.5	17.80	117.87	30.65	148.51	74.26
82	Hutgar	Siddapur	25	15.9	30.54	204.22	53.10	257.32	128.66
83	Joginmath-1	Siddapur	35	17.1	31.48	210.65	54.77	265.42	132.71
84	Joginmath_2-semievergreen	Siddapur	25	17.7	42.12	282.74	73.51	356.25	178.12
85	Kathalekan-1	Siddapur	44	16.8	28.22	188.49	49.01	237.50	118.75
86	Kathalekan-2	Siddapur	39	16.7	30.67	205.10	53.33	258.43	129.21
87	Kathalekan –swamp-1	Siddapur	37	16.7	43.16	289.85	75.36	365.21	182.60
88	Kathalekan –swamp-2	Siddapur	27	15.1	40.02	268.53	69.82	338.34	169.17
89	Kathalekan –swamp-3	Siddapur	32	16.0	70.57	475.65	123.67	599.32	299.66
90	Kathalekan –swamp-4	Siddapur	29	17.0	61.10	411.45	106.98	518.43	259.21
91	Kathalekan –swamp-5	Siddapur	21	15.4	43.47	291.92	75.90	367.81	183.91
92	Kathalekan –swamp-6	Siddapur	30	15.8	40.15	269.43	70.05	339.49	169.74
93	Kathalekan –swamp-7	Siddapur	37	15.4	31.80	212.78	55.32	268.10	134.05
94	Kathalekan –swamp-8	Siddapur	29	18.2	55.05	370.41	96.31	466.71	233.36
95	Kathalekan –swamp-9	Siddapur	33	18.4	64.84	436.80	113.57	550.37	275.18
96	Kathalekan-3	Siddapura	45	16.1	29.13	194.71	50.62	245.33	122.67
97	Malemane-1	Sidddapur	33	16.6	37.54	251.70	65.44	317.15	158.57
98	Malemane-2	Siddapur	33	18.5	38.41	257.63	66.98	324.62	162.31
99	Malemane-3	Siddapura	28	17.6	42.63	286.24	74.42	360.66	180.33
100	Siddapur evergreen	Siddapur	26	18.0	30.20	201.95	52.51	254.46	127.23
101	Talekere	Siddapur	14	10.6	10.12	65.82	17.11	82.94	41.47
102	Bugadi-Bennehole	Sirsi	36	15.21	56.15	377.90	98.25	476.15	238.08
103	Gondsor-sampekattu	Sirsi	10	8.7	3.74	22.52	5.86	28.37	14.19
104	Hulekal-Sampegadde-Hebre	Sirsi	40	15.40	50.93	342.47	89.04	431.51	215.75
105	Kanmaski-Vanalli	Sirsi	26	15.2	57.17	384.82	100.05	484.87	242.43
106	Khurse	Sirsi	26	11.2	22.39	149.01	38.74	187.75	93.87
107	Masrukuli	Sirsi	15	14.9	42.36	284.41	73.95	358.36	179.18
108	Hiresara-bettaland	Yellapur	14	11.9	41.73	280.12	72.83	352.95	176.47
109	S5-Gidgar-Yemmalli	Yellapur	39	19.1	43.54	292.39	76.02	368.41	184.21
110	S6-Tarukunte-Birgadde	Yellapur	41	19.5	84.15	567.73	147.61	715.34	357.67
111	S7-Arlihonda-Nandvalli	Yellapur	48	15.5	30.55	204.32	53.12	257.44	128.72
112	S8-Yellapur-Mavalli	Yellapur	39	17.3	35.59	238.49	62.01	300.50	150.25
113	S9-Kiruvatti	Yellapur	16	16.6	11.99	78.48	20.41	98.89	49.44
114	Hasrapal-evergreen	Yellapur	24	19.1	34.79	233.05	60.59	293.65	146.82
115	Hulimundgi-semievergreen	Yellapur	27	17.3	33.63	225.23	58.56	283.79	141.89
116	Lalguli-moist-dec	Yellapur	15	16.9	42.32	284.10	73.87	357.96	178.98

 

Evergreenness and Endemism: More the evergreenness of a forest greater are the endemics contained in them (Table 5 and Figure 11). Seven transects had 100% evergreeness (all the tree individuals being evergreen) and in 60 transects evergreenness was above 90 %. 16 transects where only 50-90% of trees were evergreen are considered here as semi-evergreen forests. Remaining transects with evergreeness below 50% are considered moist to dry deciduous, the latter practically without any evergreen species or poor in evergreens (Figure 12). The southern forests (of Bhatkal, Honavar, Siddapur and Kumta) tend to have more evergreenness than central (of Sirsi, Ankola and Yellapur) and of northern forests (Karwar, Supa taluks). Mundgod and Haliyal in the north-east are dominated by deciduous forests. Eastern parts of Sirsi and Yellapur tend to to be of deciduous nature (Figure 12). The high endemism areas for trees are towards the Ghat areas of Bhatkal, Honavar, Siddapur and Kumta coinciding with higher occurrence of evergreen forests (Figure 13)

Figure 11. Correlation between forest stand evergreenness and Western Ghat endemism

Table 5: Percentage of Western Ghat endemism and evergreenness in the forest samples

A total of 76 Western Ghat endemic tree species were found in the study areas. Altogether 127 endemic trees were endemic to Western Ghat-Sri Lanka  biodiversity hot spot (45.6% endemism). Western Ghat endemic shrub species numbered to 39 and together with Sri Lanka the shrub species were 82.  Herb layer had 76 Western Ghat endemics and together with Sri Lanka endemics rise to 137 species. Highest evergreen forests (100 %) were found in Dipterocarpus forests of Asolli 1 (Ankola), Ambepal-2 (Honnavar), Kathalekan Swamp grid 8-T3 (Siddapur)and non-Dipterocarpus forests of Gujmaav of Bhatkal, Gundabala (Honnavar), Halsolli (Honnavar) and Castlerock IB (Joida). These were either Kans or less disturbed areas in areas with difficult access. Most of the Kathlekan, Karikan, Malemane, Gersoppa and Devimane area forests were higher evergreen forests as fire was absent and protected due to reserved status.  All Mundgod taluk transects along with Goyar (Karwar), Magvad (Haliyal), etc., which were moist to dry deciduous had very negligible to  zero endemism. Endemism is seen as a factor closely correlated to forest evergreenness. Nearly 50 % of total transects were having 50% and above tree endemism; such forests had evergreenness of 90 % and above. The deciduous forests had hardly any Western Ghat endemics. Endemism is the first casualty even in high rainfall areas under heavy human disturbances. The endemics tend  to decline in the wake of fire, logging, grazing and such disturbances leading to endemic poor secondary evergreen forests and finally into deciduous ones devoid of any endemics. Even in endemic rich forests the more sensitive ones such as Syzygium travancoricum, Dipterocarpus indicus, Pallaquium ellipticum, Madhuca bourdilloni, Myristica spp., vanish early with disturbances. The habitats of these species are rich watershed areas giving rise to perennial streams.

Important Value Index (IVI): Important value index is an important parameter to estimate the dominant species in an area taking into account its basal area, density and frequency. Higher the IVI greater is the dominance of that species. Asolli-1 of Ankola has higher IVI for Dipterocarpus indicus (50.15) followed by Knema attenuata (30.77) and Holigarna grahamii (26.25); all of these are Western Ghat endemics. Dipterocarpus indicus is red-listed by IUCN as Endangered. The dominance of evergreen tree species like Olea dioca, Aporosa lindleyana Holigarna arnottiana in a forest indicates secondary nature of the forest. Greater human pressures  in such forests, especially in the form of forest burning, such as at Maabgi of Ankola,  might have increased  deciduous species like Terminalia alata, Vitex altissima and Dillenia pentagyna etc. higher values of biomass/C-stocks are associated with less human or natural disturbances or better site qualities (Lugo and Brown,1992; Brown, 1997). Whereas the undisturbed parts of Kathalekan had high biomass, within the forest interior some hills were savannized in the past, a sample there having least biomass and carbon storage of 10.06 t/ha and 5.03 t/ha respectively). In Gondsor-Sampekattu savanna of Joida the values were higher; with low biomass of 28.37 t/ha and carbon sequestration of 14.19 t/ha this site was only next higher in hierarchy among the 116 transects (Figure 14).

Figure 14. Average basal area, biomass and carbon storage in smaples of different disturbance gradients