Forests Of Western Ghats Research Articles

Pollen identification multimedia software: a microtaxonomic palaeobotanical research tool

The utility of the graphically pollen identifiable software as a capacity building, microtaxonomic palaeobotanical research tool is briefly described. The software accompanying a user manual (a booklet) enables many levels of users to learn palynology “at the click of a mouse”. The rationale and operation of the pollen identification system like the parent software IDAO is based on the principle of co-efficient of similarity and character weighting (vide Gower, 1971; Grard, 2000). A total of 145 selected genera belonging to 60 dicot and 2 monocot families have been listed. Out of selected genera, 14 are mangroves and most of the remaining genera come from the evergreen forests of Western Ghats. The vector drawings of weighted 136 pollen character states (in 30 character-interfaces) are also provided. The two major parts of this application, the Graphical Pollen Identification System and the Results are explained. A plate with the pollen digital images of 24 pollen types exemplifies palyno-diversity providing clues for parent-plant determination.

Changes in structural attributes of plant communities along disturbance gradients in a dry deciduous forest of Western Ghats, India

Changes in tree and understory plant diversity and community composition in two sites at different disturbance levels were studied on the Anaikatty hills, Western Ghats. Systematic sampling using small scale permanent quadrates (50 x 20 m for trees, 5 x 5 m for shrubs/saplings, 1 x 1 m for herbs/seedlings) enumerated 3,376 individuals of trees (106 species), 8,599 of individuals shrubs (122 species) and 16,659 individuals of herbs (145 species). Among the two sites, species richness and diversity were highest for low disturbed stand (98 and 3.9, respectively) compared to high disturbed site (45 and 2.71, respectively). Result of cluster analysis showed that two distinct clusters were formed on the basis of disturbance of the area in concordance with our field observation. A total of 37 species were common to both sites, sixty one species exclusively found in low disturbed site and eight species were pertained to highly disturbed site. Mann-Whitney test based on Monte Carlo approximation at 95% confidence levels indicated that both populations were not entirely different. The clear difference was only observed for average basal area of trees, density of seedlings, number of species, density and diversity for shrubs and number of species and diversity for herb. The species composition were different in two stand i.e., Nothopegia racemosa-Albizia amara-Maba neilghrrensis in low disturbed stand and Albizia amara-Pleiospermium alatum-Bauhinia racemosa in high disturbed stand. The major disturbance factors identification using spearman rank correlation indicated that the disturbance in low disturbed habitats were mostly from past logging followed by cutting and illicit felling and grazing, while in high disturbed habitats, it was human presence, past logging and lopping and fuel wood collection.

Density and Diversity of Forest Floor Anurans in the Rain Forests of Southern Western Ghats, India

The structure and composition of forest-floor anuran diversity in the biologically rich rain forests of southern Western Ghats were studied. The study was carried out in the relatively undisturbed rain- forest tract of Kalakad-Mundanthurai Tiger Reserve. A quadrat search method was used to estimate species richness and density of the forest floor anuran community. Sample locations were distributed across three distinct watersheds in the reserve. In total, we captured 509 individuals belonging to 20 species. The density of anurans was 149 individuals ha 21 on the rain-forest floor, and along streams their densities exceeded 300 individuals ha 21 . Total diversity across all watershed locations was partitioned into within and among watershed components, corresponding to alpha and beta diversity. We found high levels of species turnover (high b diversity) among watersheds, a process that may partly explain the high species richness and large number of endemic anuran species known to occur in the rain forests of the Western Ghats. Anurans density was low and comparable to other studies conducted in South-East Asian forests. A re-examination of the reports on anuran densities revealed that Central American anuran densities were an order of magnitude higher than South Asian and South American anuran densities. Existing hypotheses do not adequately explain the differences in anuran densities in different parts of the world.

A Study on Herpetofaunal Assemblages in the Rain Forests of Western Ghats, Karnataka, India

A Study on Herpetofaunal Assemblages in the Rain Forests of Western Ghats, Karnataka, India

Species Composition and Community Structure of Dung Beetles Attracted to Dung of Gaur and Elephant in the Moist Forests of South Western Ghats

The community structure of dung beetles attracted to dung of gaur, Bos gaurus (H. Smith) (Artiodactyla: Bovidae) and Asian elephant, Elephas maximus Linnaeus (Proboscidea: Elephantidae), is reported from the moist forests of Western Ghats, in South India. The dominance of dwellers over rollers, presence of many endemic species, predominance of regional species and higher incidence of the old world roller, Ochicanthon laetum, make the dung beetle community in the moist forests of the region unusual. The dominance of dwellers and the lower presence of rollers make the functional guild structure of the dung beetle community of the region different from assemblages in the moist forests of south East Asia and Neotropics, and more similar to the community found in Ivory Coast forests. The ability of taxonomic diversity indices to relate variation in dung physical quality with phylogenetic structure of dung beetle assemblage is highlighted. Comparatively higher taxonomic diversity and evenness of dung beetle assemblage attracted to elephant dung rather than to gaur dung is attributed to the heterogeneous nature of elephant dung. Further analyses of community structure of dung beetles across the moist forests of Western Ghats are needed to ascertain whether the abundance of dwellers is a regional pattern specific to the transitional Wayanad forests of south Western Ghats.

Evaluation of vegetation greenness metrics for characterizing tropical forest cover types–a case study using NOAA AVHRR datasets

We used vegetation greenness metrics in conjunction with Fourier analysis, a signal detection algorithm to characterize different forest types from NOAA AVHRR datasets. We selected three widely different tropical forest patches in the Indian region, i.e. tropical evergreen forests of the Western Ghats, tropical moist mixed deciduous forests of the Eastern Ghats and tropical wet evergreen forests located in North East India, representing different climatic, physiographic and topographic gradients. In addition to Fourier analysis, we used different vegetation greenness metrics derived from NDVI. These included annual sum of NDVI, maximum, minimum, amplitude, mean, coefficient of variation in NDVI and time integrated NDVI to discriminate the forest types from space. Results suggested relatively high amplitude in vegetation greenness for mixed deciduous forests compared to other forest types. The phase i.e. timing of the peak of vegetation greenness has been found to be quite distinct for different forest types. For mixed deciduous forests (Eastern Ghats), the phase was high during the fourth week of December (phase angle of 322°), compared to the third week of December (phase angle of 312°) for wet evergreen forests of northeast India and early January (phase angle of 6°) for Evergreen forests of Western Ghats. Although, the phase angle for mixed deciduous forests and wet evergreen forests of northeast India were close, differences in amplitude were quite distinct. Evaluation of NDVI metrics for different forest types suggested that wet evergreen forests (northeast India) showed distinct higher values for sum of NDVI, max-NDVI, min-NDVI, integrated NDVI and mean NDVI. Results clearly suggested the potentiality of Fourier analysis and NDVI metrics for characterizing tropical forest types in the Indian region.

Guild structure, diversity and succession of dung beetles associated with Indian elephant dung in South Western Ghats forests

The diversity, guild structure and succession of dung beetles associated with Indian elephant dung is described in a deciduous forest site in Western Ghats, a hot spot of diversity in India. Dung beetles were collected using baited pitfall traps and from exposed dung pats in the forest at intervals of 1, 3, 5, 7, 15 and 21 days. Twenty-one dung beetle species belonging to the 3 major functional guilds were recorded. Abundance of dwellers was high compared to rollers deviating from earlier reports on the high abundance of rollers in the afrotropical regions. Dweller Drepanocerus setosus and tunneler Onthophagus bronzeus were the most abundant species. Dung pats aged 3–5 days attracted the highest abundance of dung beetles. Bray Curtis similarity index indicated low community similarity between different stages of succession. Species richness and abundance of tunnelers increased with dung age and decreasing moisture up to a threshold level, followed by a decrease. Rollers and dwellers did not show any significant relationship with dung moisture content. Further research is needed to estimate the dung beetle community associated with the dung pats of other mega herbivores as well as of elephant dung in other forests of the Western Ghats.

Evaluation of factor patterns of soils in different plantations and natural forests in the Western Ghats, Kerala

An attempt is made in this paper to identify the factor pattern on soil properties in six vegetation types viz., plantations of Eucalypt, Rubber and Teak and natural forests of evergreen, semi-evergreen and moist deciduous types, using the factor analysis. The analysis identified three significant factors viz., aggrading factor (38.81 percent), texture and acidity factor (20.13 percent) and cation exchange capacity (CEC) factor (9.82 percent). They together accounted for 69 percent of the total variation in the eleven selected soil properties. The three factor model explained > 80% of variance in total S; > 75% of the variance in gravel, sand, water holding capacity (WHC) and total P, > 65% of the variance in bulk density (BD), organic carbon (OC), total N and CEC; 60% variance in pH; 32% variance in silt. The inter-factor correlations indicate that this factor model is suitable for assessing the soil status in plantations and natural forests of Western Ghats, Kerala, India.

Impact of Fertility Variation on Gene Diversity and Drift in two Clonal Seed Orchards of Teak (Tectona grandis Linn. f.)

Two 25 year old teak clonal seed orchards comprising 15 (CSO-I) and 20 clones (CSO-II), respectively, selected mostly from moist forests of Western Ghats (latitude 10° N) in southern India, were evaluated for fertility, offspring diversity, and genetic drift. The orchards differed in fertility of clones as well as flower and fruit production per ramet. Fertility was highly skewed in CSO-II, where one clone (originating from higher latitude −17° N, in Eastern Ghats of peninsular India) produced 55% of the fruits and 68% of the flowers in the orchard, in contrast to a similar contribution from four most fertile clones in CSO-I. Fertility variation, measured as `sibling coefficient' (1.7 in CSO-I and 8.3 in CSO-II), was high in CSO-II resulting in high coancestry and low effective population size (3 times lower than CSO-I) in the seed crop. In CSO-I, 58% of the clones contributed effectively to seed production compared to only 12% effective contribution resulting in eight times higher genetic drift in CSO-II. Placing limits on how much seed can be collected per clone might be useful in restricting over representation of highly reproductive clones thereby increasing genetic diversity in the seed crop.

Female courtship calls of the litter frog (Rana curtipes) in the tropical forests of Western Ghats, South India

AbstractWe noticed an uncommon phenomenon of female vocalization in the forest litter frog, Rana curtipes during the breeding season. We digitally recorded the male and female vocalization of the litter frogs in the tropical rain forests of the Western Ghats of South India and analyzed the call characteristics. The female call varied from the male call by being single note in composition. In contrast, the male calls were composed of seven to eight notes and longer in duration. We observed that gravid females, occupying the same location every day, emitted low volume calls when numerous males were found calling at that time. Some females arrived asynchronously and called even in the absence of males possibly to declare their receptive condition. Calling females responded agonistically to receptive conspecifics of the same sex. In addition to declaring receptivity, this calling behavior may be a response to adjacent competing females when the males are few.

Herb layer productivity under different light gaps in the forests of Western Ghats of Karnataka, India

A productivity estimation of tree, shrub and herb layer biomass was undertaken in Uttara Kannada, a Western Ghats district in Karnataka in differentially managed forests. In addition to biomass, light gap in these sample sites was also estimated to understand the relationship between the light interception pattern at different canopy layers and their productivity. The studies indicate that tree biomass productivity decreases and herb productivity increases with increasing light gap. However, the herb biomass productivity attains maximum height at 40-60% light gaps than in plots with no trees or 100% light gap indicating that highest herb biomass is found in forests managed for leaf manure than in grasslands. This further indicates that partial shading enhances herb layer productivity. Thus, a strategy of undertaking agroforestry in villages to enhance the total biomass productivity to meet the needs of the villages was suggested.

Note: Novel acylkaempferol glycoside from the endemic species, Vernonia travancorica Hook. f.

Vernonia travancorica Hook. f. is a taxon, endemic to the evergreen forests of Western Ghats (above 1000 m), India. From the aqueous EtOH extract of the air-dried corymbose inflorescence a novel secondary metabolite, 3-O-β-[β-(6‴-acetyl)-d-glucopyranosyl(1→2)]-d-glucopyranosyl kaempferol (1), has been isolated, together with three other compounds, viz., 4′-methoxykaempferol (2), its 3-O-β-d-glucopyranoside (3) and kaempferol (4). The structure of the new natural product has been established based on chemical analysis, including characteristic colour reactions, rigorous hydrolytic procedures involving acid, alkali and enzyme, as well as spectral (UV, 1H and 13C NMR and FABMS) evidences.

Conservation Threat of Increasing Fire Frequencies in the Western Ghats, India

Abstract: The acceleration of processes such as forest fragmentation and forest fires in landscapes under intense human pressures makes it imperative to quantify and understand the effects of these processes on the conservation of biodiversity in these landscapes. We combined information from remote‐sensing imagery and ground maps of all fires in the Mudumalai Wildlife Sanctuary (MWLS) in the Western Ghats of India over 14 years (1989–2002). These spatial data on fire occurrence were integrated with maps of vegetation types found in the MWLS to examine fire conditions in each. We calculated the average fire‐return interval for each of the vegetation types individually and for the MWLS as a whole. Using vegetation data from the larger Nilgiri Biosphere Reserve and the entire Western Ghats region, we conservatively estimated fire‐frequency information for these larger regions. Because the MWLS does not contain tropical evergreen or montane forests, we were unable to estimate fire conditions in these forest types, which represent 31% of all Western Ghats vegetation cover. For the MWLS, all vegetation types had average fire‐return intervals of <7 years, and the sanctuary as a whole had a fire‐return interval of 3.3 years. Compared with a 13‐year MWLS fire data set from 1909–1921, this represents a threefold increase in fire frequency over the last 80 years. We estimated average fire‐return intervals of roughly 5 years for both the larger Nilgiri Biosphere Reserve and the entire Western Ghats region. Given other recent reports, the estimated fire frequencies for the Western Ghats forests outside protected reserves are conservative. We conclude that the current fire regime of the Western Ghats poses a severe and persistent conservation threat to forests both within and outside protected reserves.

Patterns in abundance and seasonality of insects in the siruvani forest of Western ghats, nilgiri biosphere reserve, southern India.

The seasonal abundance patterns of insects inhabiting the understory vegetation of a mixed deciduous forest were examined with the help of the sweep-net sampling method. During the study period of 2 years, insects were sampled regularly from the understory vegetation of the three selected habitats (moist-deciduous, riverine, and teak plantation) of the mixed deciduous forest. Insect abundance was maximum in the moist-deciduous habitat and minimum in the teak plantation. Generally, insect abundance was the highest during the southwest monsoon in all habitats. The temporal pattern of fluctuations in the insect abundance followed more or less the same pattern in all the three habitats studied. The insect abundance of the understory vegetation varied among the habitats studied, while the pattern of seasonal fluctuations in insect abundance was comparable among habitats. Composition of the insect community also indicated prominent seasonal changes within habitats than interhabitat changes within a season.

Butterflies of Siruvani Forests of Western Ghats, with notes on their seasonality

1003 Received 8 August 2002; Revised received 28 September 2002; Finally accepted 12 November 2002 Abstract The seasonal pattern in the abundance of butterflies belonging to the families, Papilionidae, Pieridae and Nymphalidae was monitored during the period of September 1994 to August 1996 in the moist deciduous forest of Siruvani, using the transect counting method. Seventy-five species of butterflies belonging to 49 genera were recorded from the area during the study. Of these 53 were encountered along the transect. The present paper also provides an account of their seasonality pattern.

Notes on Marsdenia raziana Yogan. & Subram., a Karnataka and Kerala Western Ghats endemic

Marsdenia raziana Yogan. & Subram. (Asclepiadaceae), is endemic to the Western Ghats of Karnataka and Kerala. It was first collected in 1970 from Yelnir Forests of Western Ghats, Samse Range, Chikmagalur District and described during 1976. Present collections from Agumbe and Kannur (Cannanore) form the first report for Shimoga District and extended distribution from southern region of Kerala State respectively.

Didymobotryum spirillum, a New Synnematous Hyphomycete from India

A new synnematous hyphomycete, Didymobotryum spirillum D'Souza & Bhat, collected from decaying culms of bamboo, Dendrocalamus strictus, is described and illustrated from the forests of Western Ghats in Goa, India. The fungus produces monotretic, catenate didymoconidia on spirally twisted synnemata.

Didymobotryum spirillum, a new synnematous hyphomycete from India

A new synnematous hyphomycete, Didymobotryum spirillum D'Souza & Bhat, collected from decaying culms of bamboo, Dendrocalamus strictus, is described and illustrated from the forests of Western Ghats in Goa, India. The fungus produces monotretic, catenate didymoconidia on spirally twisted synnemata.

Plant regeneration through somatic embryogenesis and rapd analysis of regenerated plants in Tylophora indica (Burm. F. Merrill.)

A procedure for the regeneration of complete plantlets of Tylophora indica from cultured leaf callus via somatic embryogenesis is described. Callus induction from leaf explants was on Murashige and Skoog (MS) medium with different concentrations of 2,4-dichlorophenoxyacetic acid (2.4-D; 0.03–3 mg l−1; 0.0–13.56 μM) and kinetin (Kn; 0.01 mg l−1; 0.05 μM). The best response for callus induction was obtained on MS medium containing 2 mg l−1 (9.04 μM) 2.4-D and 0.01 mg l−1 (0.05 μM) Kn. After two subeultures on the same medium the embryogenic callus was transferred to MS medium with different concentrations of the cytokinin, 6-benzyladenine (0.5–3 mg l−1; 2.22–13.32 μM) and 2-isopentenyladenine (2ip; 0.53 mg l−1; 2.46–14.76 μM) along with 0.01 mg l−1 (0.05 μM) indole-3-butyric acid (IBA) for somatic embryo development and maturation. MS medium with 2 mg l−1 (9.84 μM) 2ip produced the maximum number of mature somatic embryos. The mature embryos were bipolar and on transfer to MS basal medium produced complete plantlets. After hardening the regenerants were planted in the Gudalur forests of Western Ghats. Total DNA was extracted from 14 regenerants and the mother plant. Random amplified polymorphic, DNA (RAPD) analysis was carried out using 20 arbitrary oligonucleotides. The amplification products were monomorphic among all the plants revealing the genetic homogeneity and true-to-type nature of the regenerants.

Assessment of livestock grazing pressure in and around the elephant corridors in Mudumalai Wildlife Sanctuary, south India.

Mudumalai Wildlife Sanctuary in southern India plays an important role in biodiversity conservation, especially of large mammals, by offering habitat contiguity of about 3300 km2 with three other protected areas in the region, namely Nagarahole and Bandipur National Parks and Wynaad Wildlife Sanctuary through forest corridors between the Western Ghats and Eastern Ghats forests. The habitat linkage is crucial for large ranging animals such as elephants, which use these forest corridors for migration. Livestock grazing, a major biotic interference in forest corridors, originates from seven settlements of the Masinagudi group of villages on the eastern and the southeastern fringes of the sanctuary. Construction of a series of hydroelectric power stations, numbering about three at Singara, Marvakandy (Masinagudi) and Moyar, around the Masinagudi villages caused a rapid growth in human population (143% between 1961 and 1991), particularly the landless labourers and livestock. Free grazing by about 15 000–17 000 resident as well as migratory livestock every year in and around the forest corridors, coupled with removal of cattle dung from the forest floor, have adversely affected the forest regeneration and helped proliferation of weed species such as Lantana camara, Casia tora, C. occidentalis, Opuntia dillenii, and Ageratum conyzoides. The annual fodder production from the corridor forest could meet the demand of about two-thirds of the resident population, while the crop residues from the marginal agriculture could not support the remaining one-third livestock population. In view of such a situation, measures have been suggested to reduce livestock population and implement the ecodevelopment packages in order to ensure the corridor connectivity for the long-term conservation of the elephant population.