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Spatial patterns of tree and shrub species diversity in Savanadurga State Forest, Karnataka
Get PDFA study conducted in Savanadurga State Forest in Karnataka indicates that the spatial variation of trees
was high and similarity among the species in the adjacent
plots was low, suggesting that the spatial heterogeneity
is influencing the pattern of diversity of tree species. The degraded forest, which is considered as shrub and tree savanna of the Anogeissus–Chloroxylon–Acacia series is highly diverse, recording over 59 tree and 119 shrub species. Tree species similarity index among quadrats in the forest is less than 0.02, indicating high diversity in tree species within a limited area of the sample. Conversely, the shrub species are far more similar than the tree species when the two plots are compared. The number of stems > 1 cm DBH observed in the sampled plot (7844/ha) is high, further reinforcing that the area is rich in species and stems. Correlation between species diversity of mean and standard deviations of adjacent plots of the focal plot was high, indicating that the species-rich patches in the forests are likely to associate with other speciesrich patches. The study is based on 30 quadrats of 25 m ´ 25 m laid at 1 km interval over the state forest
Reproductive Biology of Butea monosperma (Fabaceae)
No full textThe reproductive biology encompassing phenology, ¯oral biology, pollination and breeding systems, of Butea monosperma, a beautiful tree of the Indian subcontinent, was investigated in a protected dry, deciduous forest
located in New Delhi. Phenological studies indicated that although the species shows a regular ¯owering season,
all trees do not ¯ower every year. Flowers are typically papilionaceous; the stigma is wet papillate and the style
is hollow. The ¯owers show characteristics of bird pollination being large and bright orange-red in colour with copious amounts of nectar, and exhibiting diurnal anthesis. Although the ¯owers are frequented by as many as seven species of birds belonging to six families, only one species, the purple sunbird (Nectarinia asiatica), is theeffective pollinator. The ¯owers are also pollinated by the three-striped squirrel (Funambulus tristiatus). Unlike other ¯ower visitors, these two pollinators forage the nectar from the open side of the keel (legitimate path) during which pollen grains are deposited on their body parts. After the ®rst visit of a sunbird or a squirrel, virgin ¯owers showed pollen load on the stigma and developed into fruits. B. monosperma shows a weak form of selfincompatibility. Fruit set following manual self-pollination (5´25 %) was comparable with open-pollination (approx. 5 %) but was signi®cantly lower than manual cross-pollination (22´51 %). This indicates that there is a high degree of geitonogamous pollination in this species, which may lead to a weakening of self-incompatibility as a means of reproductive assurance. The results are analysed in the light of prevailing discussions on specialized vs. generalized pollination systems
Pollination systems of trees in kakachi, a mid-elevation wet evergreen in Western Ghats, India
No full textTropical wet forests support a diverse assemblage of tree
species, which are dependent on an equally wide array of animals for their pollination (Baker et al., 1983; Bawa, 1990). This has resulted in a highly complex set of interactions among them (Gilbert, 1980). Identifying pollination guilds or tree species assemblages with common pollination modes can delineate this complexity to some extent (Ibarra-Manrı´quez and Oyama, 1992). Further, comparisons of pollination modes in the different wet forest sites in the tropics can provide insights into the broad coevolutionary patterns between plants and their animal vectors (Howe, 1984) or perhaps cast light on such issues as the role of pollinators on angiosperm diversification (Bawa, 1995). Broad-scale community-level pollination studies also have wide application in ecosystem restoration (Johnson and Steiner, 2000; Kremen and Rickett, 2000). There is an increasing concern that human alterations of the ecosystem affect pollination systems, especially those that are relatively more specialized and dependent on a few pollinators (Bond, 1994). Specialized systems cannot be identified unless
we conduct community-wide surveys of pollination systems.
Complete community-level characterization of pollination
of any tropical forest site has not been successfully executed so far (Shatz, 1990). This kind of study could not be completed because much of the diversity of the plant species is contributed by the tall canopy trees in tropical forests that have remained inaccessible (Lowman and Nadkarni, 1995)
Identification, distribution and conservation of Phyllanthus indofischeri, another source of Indian gooseberry
Get PDFNon-timber forest products (NTFP) such as fruits, seeds, roots, etc. are an important source of income for the indigenous people living in and around forests1,2.The pressure on forests for the collection of NTFPs has motivated conservation biologists and forest managers to find ways to harvest NTFPs in a sustainable manner3,4.
Identification of plant species is the first and foremost criterion in planning for sustainable utilization of resources, especially if an NTFP comes from two closely related plant species or when the identity of plant species is doubtful. Proper identification of the plant species of commercial importance can shed more light on its distribution, population status in the wild, and its resource generation capability. Lack of knowledge on distribution or population status may make the species vulnerable to extinction due to over-exploitation,
especially when the population is small or has restricted distribution. Thus, proper identity of the species, from which the resource of commercial interest is collected,
is very important for conservation biologists and forest managers to protect the plant species from over exploitation and extinction. Proper identity of species
also enables traders and consumers to avoid adulteration of products, and aids officials concerned to prevent smuggling or bio-piracy
A new species and a new record of the genus Australomymar Girault (Hymenoptera: Mymaridae) from the Oriental Region
No full textThe genus Australomymar was raised by Girault in 1929 on the
type species Australomymar aurigerum from Victoria, Australia. New (1974) redesribed the genus since the original description of Girault was inadequate for its easy recognition. Noyes and Valentine (1989) noted that there are several undescribed species of Australomymar in New Zealand, Neotropical region and in various parts of South East Asia. In this paper we describe a new species from India
Important nesting habitats of olive ridley turtles Lepidochelys olivacea along the Andhra Pradesh coast of eastern India
No full textOlive ridley turtles Lepidochelys olivacea nest along the east and west coasts of India, with major mass nesting beaches in the state of Orissa. The coast of Andhra Pradesh, the state immediately south of Orissa, has sporadic nesting of olive ridley turtles and is believed to form part of the migratory route of the turtles that nest in Orissa. A survey of nesting beaches and offshore waters of the Andhra Pradesh coast was carried out from November 2000 to April 2001. Preliminary interviews and secondary data were used to determine potential nesting beaches. During January–March 2001 intensive surveys of seven beaches and monthly surveys of the rest of the coast provided a lower bound of c. 4,000 nests along the Andhra Pradesh coast. Nesting densities were higher at beaches near river mouths, at 60–100 nests km−1 in northern and central Andhra Pradesh, and 15–20 nests km−1 in southern Andhra Pradesh. Sightings and incidental catch in experimental trawls indicated the presence of olive ridley turtles in offshore waters. Fisheries related mortality is the major threat to the species, with nearly 1,000 dead turtles being washed ashore during January–March, but depredation of eggs by humans and feral animals was also widespread. Conservation efforts need to address these issues, and also the effects of coastal development and artificial illumination, especially at beaches that support relatively high densities of nesting olive ridley turtles
Ethanol in ponderosa pine as an indicator of physiological injury from fire and its relationship to secondary beetles
No full textSixteen days after a September wildfire, ethanol and water were measured in phloem and sapwood at breast height and the base of Pinus ponderosa Dougl. ex P. & C. Laws. with zero (control), moderate, heavy, and severe crown scorch. The quantity of ethanol increased with each level of injury, resulting in trees with severe scorch containing 15 and 53 times more phloem and sapwood ethanol, respectively, than controls. Ethanol concentrations in the sapwood and adjacent phloem were related, probably as a result of diffusion. Upward movement in xylem sap was most likely responsible for the relationship between sapwood ethanol concentrations at breast height and the stem base. As trees recovered from their heat injuries, the ethanol concentrations declined. In contrast, ethanol accumulated in dead trees that lost their entire crowns in the fire. Various bark and xylophagous beetles landed in greater numbers on fire-damaged trees than on controls the following spring and summer, suggesting that ethanol was being released to the atmosphere and influencing beetle behavior. Beetle landing was more strongly related to sapwood ethanol concentrations the previous September than in May. Sapwood ethanol measured 16 days after the fire was the best predictor of second-year mortality for trees with heavy and severe crown scorch
Effect of logging on the structure and regeneration of important fruit bearing trees in a wet evergreen forest, southern Western Ghats, India.
No full textGANESAN, R. & DAVIDAR, P. 2003. Effect of logging on the structure and regeneration of important fruit bearing trees in a wet evergreen forest, southern Western Ghats,
India. The effect of selective and clearcut logging on stem density and regeneration of six important resource trees, namely, Cullenia exarillata, Aglaia bourdillonii, Artocarpus heterophyUus, Myrislica dactyloides, Gomphandra coriacea and Palaquium eUipticum, were
studied. Forests logged 24 years ago were compared with an unlogged forest. Belt transects (10 x 100 m) were established to enumerate adult trees (>10 cm dbh). Subplots (10 x 10 m) along the belt transects at 0-10,40-50 and 90-100 m were enumerated for saplings (1-10 cm dbh). Adult stem density was significantly lower in both selectively logged and clearcut logged sites for all species except A. heterophyUus. Palaquium ellipticum-was missing in clearcut logged sites. The higher dbh class (>50 cm) remained missing in the logged forests after 24 years. Sapling densities of A. heterophyUus and P. ellipticumviere significantly reduced in the selectively logged forests. In the clearcut logged forest, other species had significantly reduced sapling density except
A. bourdillonii. Palaquium eUipticum had no saplings in the clearcut logged forest. The adult:sapling ratios were generally high in the unlogged forest. Low adult density and reduced regeneration potential of these species in the logged sites suggest that the medium elevation evergreen forest at Kalakad-Mundanthurai Tiger Reserve, Agasthyamalai Range, is degraded by logging
Predicting the potential geographical distribution of the sugarcane woolly aphid using GARP and DIVA-GIS
Get PDFManagement of newly emerging pests and diseases has often been limited by the lack of forecasting systems that could predict the route(s) of spread and potential geographical distribution of the species. While the importance of the patterns of spread of invasive organisms has always been realized, the necessary analytical tools for making reasonably robust predictions are limited. In recent years however, availability of ecological and climatologic data,computational abilities to process huge data sets, and development of suitable
algorithms have helped in a better understanding of the patterns of spread of the invasive species. For instance, algorithms such as Genetic Algorithm for Rule Set Prediction (GARP) and DIVA-GIS, are being successfully employed in a wide range of situations for predicting the
spread of invasive species1–4. Here, we explore these two modelling approaches to predict the potential geographical distribution of a newly emerging insect
pest, the sugarcane woolly aphid that has played havoc with crops in parts of Maharashtra and Karnataka5
Nontimber Forest Products in the Rural Household Economy
No full textAmong the multiple outputs of forests, the category labeled nontimber forest products, or NTFPs, has drawn increased policy and research attention during the past 20 years. NTFPs have become recognized for their importance in the livelihoods of the many relatively poor households who live in or near forests, especially in the tropics. Policy concern about NTFPs takes two forms. On the one hand, collection of relatively high-volume, low-value NTFPs, such as fuelwood, fodder, and mulch, has raised concerns about degradation of the forest resource, potentially resulting in hardships for households and negative environmental externalities. On the other hand, collection of relatively high-value, low-volume NTFPs, such as specialty food products, inputs to cosmetics and crafts, and medicinal plants, has drawn interest as an activity that could raise standards of living while being compatible with forest conservation. Addressing these policy concerns requires an improved "understanding of how households interact with natural resources and how one can affect household behavior in desired ways" (Ferraro and Kramer 1997: 20