Shola Forests Research Articles

Crude and Ecological Densities of Certain Variants of the Medicinal Shrub, Gaultheria fragrantissima Wallich in Shola Forests of Nilgiris, the Western Ghats

The crude and ecological densities of four leaf type variants of the medicinal plant, Gaultheria fragrantissima such as ovate, lanceolate, elliptic-lanceolate and oblanceolate leaf type variants were determined in four major shola forests of Nilgiris, the Western Ghats such as Ebbenadu shola, Honnathalai shola, Kodappamand shola and Kothagiri terrace shola for a period of one year from January 2004 to December 2004. The study revealed that the ecological densities of all the four variants of G. fragrantissima were higher than that of the respective crude densities at all times of sampling. The annual mean crude density determined for the whole habitat was varying between 0.31/m 2 (oblanceolate leaf type variant in Kothagiri terrace) and 0.84/m 2 (ovate leaf type variant in Ebbenadu shola). The mean annual ecological density of the four variants was varying between 1.33m 2 (elliptic lanceolate leaf type variant in Kodappamand) and 4.22/m 2 (ovate leaf type variant in Ebbenadu shola). The present study revealed that Ebbenadu shola margins have suitable microclimate for the growth and perpetuation of the study species, G. fragrantissima in Nilgiris.

Status of the Red-Listed Plant Species, Smilax wightii A. DC. in Nilgiri Biosphere Reserve, the Western Ghats, India

The rare endemic plant, Smilax wightii, is generally distributed in shola forests at high altitudes in Nilgiri Biosphere Reserve, the Western Ghats, southern India. To determine the ecological status of the species, we surveyed 11 major shola forests in that region. S. wightii has a limited distribution in all sholas (frequency value of < 13%). The density of the species is generally around <TEX>$15/100\;m^2$</TEX> in the sholas except in Thiashola where it occurred at a density of 40 individuals/<TEX>$100\;m^2$</TEX>. The density of S. wightii was generally greater in the margins of the shoals, while the interior forests contained fewer individuals per unit area. The basal cover occupied by this species ranged between 2246 and <TEX>$3144\;mm^2/100\;m^2$</TEX>. The importance value index for S. wightii was >2 in all shoals, which indicates that the species occupies an important position in the lower stratum of shola forests of Nilgiri Biosphere Reserve.

A new species of Nyctibatrachus Boulenger (Amphibia: Anura: Nyctibatrachidae) from the surroundings of Bhadra Wildlife Sanctuary, Western Ghats, India

A new species of Indian nyctibatrachid frog, Nyctibatrachus dattatreyaensis sp. nov. (Amphibia: Anura), is described from the montane Shola forests of Dattatreya Peeta, Bhadra Wildlife sanctuary, Karnataka, southwestern India, on the basis of unique combination of characters: head wider than long; skin on the dorsum highly wrinkled with transverse corrugated folds; three discontinuous longitudinal folds, one dorsolaterally and two laterally; webbing on toes medium (3/ 4 th ); two yellowish bands on the dorsolateral area, prominent from sub-adult to adult stage; femoral glands present. The largest specimen in the type series has a snout-vent length of 41.0 mm. A revised key to the species of Nyctibatrachus is provided.

Gastroprotective effect of Dodonaea viscosa on various experimental ulcer models

Aim of the study Dodonaea viscosa Linn. (Sapindaceae) is used as a medicinal herb by the tribes of Shola forest regions of Western Ghats. It is used for headaches, backaches, stomach pain, piles and simple ulcers. The present study was performed to evaluate the gastroprotective effect and acute toxicity of this plant in various experimental models. Materials and methods Studies were performed in two different models (ethanol and indomethacin induced gastric ulcer) in wistar rats. Gastric protection was evaluated by measuring the ulcer index, gastric glutathione assay, alkaline phosphate assay and histopathological studies. Gastric secretion studies were done by pyloric ligation experiment. Results and conclusions Water and ethanol extract (500 mg/kg body weight) showed moderate activity compared to hexane extract. Hexane extract of Dodonaea viscosa dose dependently inhibited ethanol induced gastric lesions, causing 90% protection at 500 mg/kg, 81% protection at 250 mg/kg, and 70% protection at 125 mg/kg and it also dose dependently inhibited indomethacin induced gastric lesions, causing 92% protection at 500 mg/kg, 77% protection at 250 mg/kg, and 52% protection at 125 mg/kg. The various degrees of inhibition were statistically significant ( p ≤ 0.05). Further in our gastric secretion studies, we found that hexane extract of Dodonaea viscosa (500 mg/kg) decreased the amount of total acid in gastric juice. Dodonaea viscosa hexane extract thus inhibits acid secretion to prevent ulcer aggravation. Acute toxicity study with a higher dose of 1250 mg/kg did not manifest any toxicological signs in rats. We also performed preliminary phytochemical screening of the crude extract which gave positive results for the presence of flavanoids, saponins, bitter principles and phenols.

The montane grasslands of the Western Ghats, India: Community ecology and conservation

The montane (shola) grasslands of Western Ghats, South India are a component of a landscape mosaic including the better-studied shola forests. The conservation of the grasslands depends upon understanding their ecology. This review compiles available information and aims to evaluate the conservation potential of these grasslands. Most studies on these grasslands are descriptive in nature. There is little information regarding habitat heterogeneity, landscape configuration, natural disturbance, grazing and productivity in maintaining the grasslands. Succession is poorly understood because of the short-term nature of most studies. Human activities have historically influenced these grasslands and will continue to do so in more intensive manner. Threats to these grasslands include habitat loss, fragmentation, fires, and invasive species.

Community structure and functional group classification of litter ants in the montane evergreen and deciduous forests of Wayanad region of Western Ghats, Southern India

Community structure of litter ants based on feeding guilds and the more recent functional group classification, and also the role of abiotic factors in determining the community structure have been analyzed following ‘Ants of Leaf Litter’ protocol in a montane evergreen (shola) and deciduous forests in the Wayanad region of Western Ghats, southern India. Distinct variations in the guild structure of litter ant communities in shola and deciduous forests have been recorded. Predators dominated deciduous and omnivores in the shola forests. Cryptic species was the dominant functional guild in both litter stands, although hot-climate specialists have not been recorded from the shola forests. Rank-abundance plots attributed the difference in diversity between the forests to the dominance of Tapinoma sp. and Myrmicaria brunnea in deciduous forest. Physical characteristics of the habitat critically influenced ant abundance in both forest types. Functional group model classification was found to be a better model for the classification of litter ants than the conventional feeding-guild categorization as it enabled a meaningful comparison in relation to physical factors.

Status and distribution of the White-bellied Shortwing Brachypteryx major in the Western Ghats of Karnataka and Goa, India

The White-bellied Shortwing is a Globally Threatened, endemic bird found in the Western Ghats of southern India. Given the few recent records of the species from its range, its population is thought to have dwindled with increasing habitat fragmentation and disturbance. A previous survey covered the states of Kerala and Tamil Nadu while this survey covers the states of Karnataka and Goa; thus together the two surveys cover the species' entire prospective range. The survey resulted in 11 sightings of White-bellied Shortwing in the unique shola forests. Encounter rates in Karnataka were much lower than in Kerala and Tamil Nadu, while no shortwings were sighted in Goa. Effects of sampling effort and detectability were examined as probable causes of the low encounter rates and one site was re-sampled. Conservation problems are highlighted and suggestions are made.

Preliminary studies on antihepatotoxic effect of Physalis peruviana Linn. (Solanaceae) against carbon tetrachloride induced acute liver injury in rats

Physalis peruviana is a medicinal herb used by Muthuvan tribes and Tamilian native who reside in the shola forest regions of Kerala, India against jaundice. It was evaluated for its antihepatotoxic, phytochemical analysis and the acute toxicity of the most promising extract in rats. Water, ethanol and hexane extracts of Physalis peruviana (500 mg/kg body weight) showed antihepatotoxic activities against CCl 4 induced hepatotoxicity. The ethanol and hexane extracts showed moderate activity compared to water extract, which showed activity at a low dose of 125 mg/kg. The results were judged from the serum marker enzymes. Histopathological changes induced by CCl 4 were also significantly reduced by the extract. Further, the extract administration to rats resulted in an increase in hepatic GSH and decrease in MDA. Preliminary phytochemical analysis revealed the presence of various components in the crude aqueous extract. The extract was found to be devoid of any conspicuous acute toxicity in rats.

Logs and snags in a shola forest of Kerala, India

In a tropical wet montane evergreen forest in the southern peninsular India, the estimated stocking of dead wood is 90 ± 3 stems·ha−1 and the total dead wood volume is 70.7 m3·ha−1. When the logs (downed dead trees more than 10.1 cm in diameter) constitute about 80% of the total deadwood stocking and volume, the rest is by snags (sound and rotting standing dead trees). Since the shola forest trees are characterized by their short stature with low to medium girth, about 89% of the total number of deadwood is of the size ranging from 10.1 cm to 40.0 cm in diameter. The estimated standing dead wood/standing live tree ratio is 0.16 indicating that the forest represents an old stand. Variations observed between logs and snags to change from a given decay class to the higher decay classes in two year period could be attributed to the facts that the logs would be in contact with soil for a relatively longer time and in turn would be in more contact with microorganisms and other decomposing agents.

Anthropogenic pressure on structure and composition of a shola forest in Kerala, India

The montane closed evergreen forests found at altitudes above 1,800 m in the Western Ghats of India possess a distinct vegetation type and are called shola forests. Despite the fact that these forests are located in relatively inaccessible areas, they are still under anthropogenic pressure leading to continued habitat degradation and loss of biomass and biodiversity. A case study was conducted in Mananvan shola, the largest shola forest in Kerala of Western Ghats, to recognize the impact of disturbance on vegetation structure, composition and regeneration pattern, to identify the socio-economic reasons for disturbance and to evolve strategies for its management. In the disturbed part of the forest, dominance of light demanding species in tree, shrub and herb communities has been recorded. Here even the dominance of exotic species in tree seedling, shrub and herb communities is prominent. Skewed girth class distribution of tree community with poor representation by the individuals of girth class 30.1 to 90.0 cm, is also an indication of the collection of small wood and poles from the forest. The RISQ (Ramakrishnan Index of Stand Quality) in the disturbed area of the forest is above 2.0 as against near to 1.0 in relatively undisturbed forest stands suggesting that the disturbance is intensive and thus natural recovery process would be slow. Socioeconomic analysis in villages located near the shola forest revealed the fact that the people depended heavily on this forest for their livelihood. Thus, the crux and the success of future management and conservation strategy depend on how one can reduce the dependency of people on the shola vegetation. Enrichment planting in disturbed parts of shola, enhancement of firewood by raising energy plantations, as well as development of lemongrass and firewood based agroforestry systems and reduction of grazing pressure by developing silvopastoral systems are the major strategies for the conservation of these shola forests.

Restoration of southern Indian Shola Forests: Realising community-based forest conservation in the Palni Hills of the Western Ghats

Restoration of southern Indian Shola Forests: Realising community-based forest conservation in the Palni Hills of the Western Ghats

Status and habitat preference of White-bellied Shortwing Brachypteryx major in the Western Ghats (Kerala and Tamilnadu), India

White-bellied Shortwing is a globally threatened species found in the Western Ghats of India. There have been few records of this species over the past 119 years and its population is thought to have fallen due to habitat loss and fragmentation. The present study was conducted to assess the habitat preferences and distribution of this species in the Western Ghats of Kerala and Tamilnadu states as a prelude to a long-term study on the biology and causes of decline of this species. Several areas across varying vegetation type and altitude were surveyed after an intensive reconnaissance. There were 214 sightings from evergreen and shola forests during the study. They were found to prefer shola forests to other vegetation types. The species was also found in pine, wattle and tea plantations near shola forests. Although it was found to prefer an altitude above 1,500 m, it was also found in shola forests between 1,000 and 1,500 m elevations. White-bellied Shortwing was found to occupy an elevation range from 1,000 m to 2,200 m. Encounter rates in shola forests fragmented by human interference were four times higher than those in natural shola forests. Most encounters of shortwings were near streams that were wet (running or damp). Emphasis is laid on the need for long-term studies to unravel the basic biology of the species in order to aid active conservation efforts.

Checklist of orchids from a mid elevation evergreen forest at Kakachi-Kodayar, Kalakkad-Mundanthurai Tiger Reserve, Agasthyamalai, southern Western Ghats

The forests at Kakachi-Kodayar (77o 24’N & 8o 32’E, 1200-1550m), in Kalakad-Mundanthurai Tiger Reserve, part of Agasthyamalai range in the southern part of the Western Ghats (see map) support one of the species-rich forest site (Ganesh et al., 1996).Though some part of the forest is lost to the dam, plantations, logging and Ochlandra spp. (reed bamboo) extraction, it still supports dense contiguous forest of subtropical wet evergreen, subtropical montane and shola forest types surrounded by grasslands.

Vegetation responses along edge-to-interior gradients in a high altitude tropical forest in peninsular India

A study was conducted in a high altitude tropical forest (shola forest) in peninsular India to examine the changes in floristic composition (mainly woody species regeneration) along an edge to interior gradient in relation to changes in edaphic and microenvironmental factors. Species inventory was taken in 25 m 2 plots, established at 10 m intervals along edge to interior transects. The measured soil variables included pH, organic carbon, total nitrogen, available phosphorus, and soil moisture. Microenvironmental factors including light transmittance, relative humidity, and air and soil temperatures also were monitored. Both edaphic and microenvironmental factors exhibited strong patterns along the edge to interior gradient. Forest edges were characterized by higher light transmittance, higher air and soil temperatures, and lower relative humidity. Soil variables including pH, organic carbon, total nitrogen, available phosphorus, and moisture increased toward the forest interior. Significant increases in organic carbon (53.9%), total nitrogen (47%), and soil moisture (55%) indicated a relatively fertile forest interior compared with the forest edge. A definite floristic compositional pattern also was observed along the edge to interior gradient which was correlated to the edaphic and microenvironmental variables as revealed by canonical correspondence analysis. It appears that edge effects in these high altitude forests penetrate to a distance of 15–30 m. Further, edaphic factors have an important influence on woody species regeneration, perhaps much more than microenvironmental factors. This indicates that any disturbance that significantly exposes theforest floor, thus lowering soil moisture and altering soil nutrient status, can adversely affect the regeneration of many of the shola species.

Structural, floristic and edaphic attributes of the grassland-shola forests of Eravikulam in peninsular India

The high elevation shola-grassland vegetation types of the Western Ghats apparently remained in a stable equilibrium for many decades, implying that both vegetational types are highly developed and attained stability under the same climatic regime. Several authors considered these two distinct vegetation formations occurring in juxta-position, as climax formations. According to the Clementsian view of climatic climax, however, two distinctly different vegetation types cannot form climatic climaxes under the same regional climate. Possibly some edaphic or biotic factors are responsible for rendering stability to the grassland in this system. We tested the following three hypotheses in this context. (1) The physico-chemical properties of the soil such as depth, organic matter, nutrient status and water holding capacity are more favourable in the depressions than in the exposed surfaces, which in turn might be responsible for the development of the woody vegetation in the depressions. (2) The shola forests exhibits similar structural attributes and a higher floristic diversity compared with the medium and low elevation wet evergreen forests of the Western Ghats region. (3) The shola trees are characterized by a low regeneration capacity, thus probably making it a shrinking resource base. With its characteristic deep fertile soil and high moisture holding capacity, the shola forests may remain in the same steady climax state, provided anthropogenic and other catastrophic disturbances do not destroy them. The grasslands were, however, characterised by generally shallow soils, low water holding capacity and low site nutrient capital. Hence, the assumption that grasslands are steady state vegetations maintained by edaphic factors, holds good. Structural and floristic elements of the shola forest revealed a very high floristic richness and diversity, probably the highest in the Western Ghats region. A total of 942 stems of at least 10 cm girth at breast height (GBH) and belonging to 53 species were encountered in the 5000 m 2 sampling area (basal area 48 m 2 ha −1). Contrary to the widely held dogma that shola forest does not possess adequate regeneration potential, the present study reveals that under the forest cover, profuse regeneration of almost all of the overstorey species occur. However, regeneration characteristics were different along the margins and in open grasslands, possibly as a result of differences in ecological conditions.

Sholas in south Indian montane: Past, present and future

The forest, short to medium-boled attaining a height between 15 to 20 m, constitutes the only tropical montane forest in pockets in the montane region of Nilgiris, Anamalai, Palni and silent Valley, southern India. Palynological studies have revealed that these shola forest communities had been wide spread in the past. They originated through gradual invasion of shrubs, and under trees into the grassland, about 35,000 years BP corresponding in time to the last glaciation in the north and were established about 24,000 years BP. The progressive recession of sholas had started around 7,000 years BP. Both biotic and climatic factors have not only reduced the sholas to its present-day minimal size but have also created conditions under which the community has almost completely stopped regeneration outside the sholas. Degeneration and fast receding trend in the shola communities and expanding grasslands and massive plantation of exotic trees reduced the soil as well as above surface moisture which is not conducive for the sholas. If preventive measures are not taken the sholas in near future would ultimately perish.

Ecology of the Asian elephant in southern India. I. Movement and habitat utilization patterns

ABSTRACTThe movement and habitat utilization patterns were studied in an Asian elephant population during 1981–83 within a 1130 km2 area in southern India (11° 30′ N to 12° 0′ N and 76° 50′ E to 77° 15′ E). The study area encompasses a diversity of vegetation types from dry thorn forest (250–400 m) through deciduous forest (400–1400 m) to stunted evergreen shola forest and grassland (1400–1800 m).Home range sizes of some identified elephants were between 105 and 320 km2. Based on the dry season distribution, five different elephant clans, each consisting of between 50 and 200 individuals and having overlapping home ranges, could be defined within the study area. Seasonal habitat preferences were related to the availability of water and the palatability of food plants. During the dry months (January-April) elephants congregated at high densities of up to five individuals km-2 in river valleys where browse plants had a much higher protein content than the coarse tall grasses on hill slopes. With the onset of rains of the first wet season (May-August) they dispersed over a wider area at lower densities, largely into the tall grass forests, to feed on the fresh grasses, which then had a high protein value. During the second wet season (September-December), when the tall grasses became fibrous, they moved into lower elevation short grass open forests.The normal movement pattern could be upset during years of adverse environmental conditions. However, the movement pattern of elephants in this region has not basically changed for over a century, as inferred from descriptions recorded during the nineteenth century.

Pollen analysis of late quaternary sediments: Evolution of upland savanna in Sandynallah (Nilgiris, South India)

The evolution of upland swampy savanna with luxuriant herbaceous cover in Sandynallah, in the Nilgiri hills of southern India, from the initial swampy or per-humid stage through humid, semi-humid and arid phases of dense, sparse to poor herbaceous vegetation respectively, is inferred from the pollen analytical data. The present study does not support the view that the swampy grass formations were a secondary development of degraded shola forests. The evidence presented in this paper supports a view that montane grasslands persisted in the area since ca. 30,000 yr B.P. It is probable that frost and soil factors have been the important determinants in maintaining and stabilizing the swampy upland savanna of Sandynallah since ca. 2500 yr B.P.

Quaternary vegetational history of ootacamund, Nilgiris, South India, 1. Kakathope and rees corner

The paper incorporates the results of pollen analytical investigations of profiles collected from Kakathope and Rees Comer, Ootacamund in the Nilgiris, South India. The study of these lake sediments has not only brought about the interesting features of the changes in the plant communities but has also reflected upon the climatic cycles during the past. The important aspect of this study concerns the formation and regeneration of shola forest. The grasslands, as revealed by the pollen diagram from Kakathope, are the pioneer communities. The formation of shola forest commenced through gradual invasion of grasslands about 35-40,000 years B.P., and it gained optimum during 14,000 B.P. The sholas afterward declined giving pace to the grasslands. The present day patchy distribution of sholas throughout the Nilgiris is due to the destruction of forests. The major and foremost reason affecting regeneration of sholas is climatic factor, although edaphic and biotic factors have also played a considerable role in not permitting the sholas to regenerate.

The origin of Shola Forest in the Nilgiris, South India

The formation of Shola forest, the closed evergreen woods in the vicinity of Ootacamund in the Nilgiris in south India, commenced about 35,000 years ago through gradual invasion of the grasslands under a regime of low precipitation, absence of frost and high speed winds. The present disjunct distribution of the Shola forest is due to destruction of the forest probably by Man and much of the grasslands today seem due to anthropogenous activity.