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Infectivity of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) isolates to the arboreal termite Odontotermes sp. (Isoptera: Termitidae)
No full textInfectivity of the entomopathogenic fungus Metarhizium anisopliae against workers of the arboreal termite Odontotermes sp. was assayed under laboratory conditions.
Test isolates were collected from different sources, including soil from varied locations and insect hosts from the orders Lepidoptera, Coleoptera, Hemiptera and Orthoptera. All the 23 isolates tested and the standard (ARSEF 7413) were pathogenic to the workers of Odontotermes sp. at a concentration of 107 conidia/ml, with mean mortality ranging from 57.5 to 100%. Two of the isolates (Ma2, Ma13) and the standard caused 100% mortality in the termite species. A detailed bioassay was subsequently conducted with the five most promising isolates, namely Ma1, Ma2, Ma13, Ma16 and Ma17, at concentrations ranging from 104 to 107 conidia/ml. The lethal concentrations (LC50) of these isolates ranged from 0.01 to 0.46 £ 105 conidia/ml. The average survival time (AST) for the termites treated with the most virulent isolate (Ma2) varied from 4.2 to 5.7 days across the four spore loads, while AST with the standard isolate ranged from 5.3 to 6.3 days. Two of the isolates, Ma2
and Ma13, were found to be significantly more pathogenic to Odontotermes sp. workers than all the others, including the standard
Protectionism and natural history research in India
Get PDFThis paper provides an overview of the status of natural history research in India, and describes how some policies on wildlife protection hamper the conduct of research on insect taxonomy, knowledge of which is mentioned to be vital to wildlife conservation in the region. The opening up of natural history research in India to reputed international scientists is recommended to facilitate the characterization and conservation of biodiversity in the countr
Quantifying and mapping biodiversity and ecosystem services: Utility of a multi-season NDVI based Mahalanobis distance surrogate
No full textThere is an urgent need for techniques to rapidly and periodically measure biodiversity and ecosystem services over large landscapes. Conventional vegetation classification and mapping approaches are based on discrete arbitrary classes which do not capture gradual changes in forest type (and corresponding biodiversity
and ecosystem services values) from site to site. We developed a simple multi-date NDVI based Mahalanobis distance measure (called eco-climatic distance) that quantifies forest type variability across a moisture gradient for complex tropical forested landscapes on a single ecologically interpretable, continuous scale. This Mahalanobis distance, unlike other distance measures takes into account the variability in the reference class and shared information amongst bands as it is based on the covariance matrix, and therefore is most useful to summarize ecological distance of a pixel to a reference class in multi-band remotely sensed space In this study we successfully apply this measure as a surrogate for tree biodiversity and ecosystem services at two nested scales for the Western Ghats Bio-diversity hotspot. Data from over 500 tree-plots and forest type maps was used to test the ability of this remotely sensed distance to be a surrogate for abundance based tree-species compositional turn-over and as a continuous measure of forest type and ecosystem services. Our results suggest a strong but scale dependant relationship between the remotely-sensed distance measure and floristic distance between plots. The multi-date NDVI distance measure emerges as very
good quantitative surrogate for forest type and is a useful complement to existing forest classification
systems. This surrogate quantifies forest type variability on a single, continuous quantitative scale and has important applications in conservation planning and mapping and monitoring of hydrologic and carbon
storage and sequestration services
What can the Forest Rights Act Decentralise: Protection or Conservation?
Get PDFThe Rules for The Scheduled Tribes and Other Forest
Dwellers (Recognition of Forest Rights) Act, 2006 (henceforth RFRA) were finally gazetted in January 2008. The six month wait in gazetting the rules, which first
appeared in draft form in June 2007, is only representative of delays that have beleaguered the Act since its introduction as a Bill in 2005. Conflict prevailed between conservationists and tribal rights groups in the form of protests and lobbying. The very process of writing the provisions of the Act, wherein each lobby at different junctures in the nearly 3-year legislative career of the Act included and excluded favourable and unfavourable clauses and whole sections, reflects this conflict. This essay refers to such conflicts, especially the one that
possibly prevailed in the changes made to the draft rules. It draws implications these changes could potentially have for how the RFRA achieves what is stated in its preamble, namely, to ‘strengthen the conservation regime of forests
Domestication of cardamom (Elettaria cardamomum) in Western Ghats, India: divergence in productive traits and a shift in major pollinators
No full textBackground and Aims Elettaria cardamomum, a highly priced spice, is native to the Western Ghats of South India. Wild populations still occur in isolated patches in their natural habitats; however, much of today’s commercial
product comes from cultivated sources. There is no information on domestication-related traits of this species; the main objective of this study was to compare wild and cultivated populations of cardamom in terms of vegetative and reproductive features in order to identify domestication syndromes and to examine whether the two populations have developed reproductive barriers. Methods Two wild populations and five cultivated plantations were used for the present study. Vegetative and floral traits, flowering phenology, pollination biology and breeding systems of wild and cultivated populations were compared. Effective pollinators amongst floral visitors were identified by confirming pollen transfer as well as by fruit set following their visit to virgin flowers. Manual pollinations were carried out in order to study the breeding systems of the two populations and reproductive barriers, if any, between them. Key Results Several productive traits including the number of branches, number of inflorescences, and total number of flowers per clump, number of flowers that open each day, the duration of flowering, the length of the flower and the amount of nectar per flower are significantly greater in cultivated cardamom. The principal pollinators in wild cardamom are solitary bees, Megachile sp. and two species of Amegilla, whereas those in cultivated cardamom are the social bees Apis dorsata, A. cerana and Trigona iridipennis. Both the wild and cultivated populations are self-compatible and there are no reproductive barriers between the two populations. Conclusions Domestication in cardamom has brought about significant changes in vegetative and reproductive traits and a shift in effective pollinators from native solitary bees to social bees. The shift in pollinators seems to be due to the availability of a large number of flowers for prolonged periods in cultivated cardamom that can attract and sustain social bees, rather than due to co-evolution of the flower and the pollinator
Drivers of regrowth in South Asia’s human impacted forests
Get PDFWhile loss of forest cover continues to represent a serious environmental challenge, significant reforestation is taking place in many parts of the world. This article assesses the institutional factors that impact forest management in developing countries, with a
focus on Nepal and India. Research methods link empirical results obtained from multiple methods in multiple field settings at different temporal and spatial scales to look at the human drivers of forest cover change across a range of social-ecological contexts. The legitimacy of ownership, degree of monitoring, density of forest users, and the flexibility to adapt to changing conditions appear critical factors, although the official designation of a forest tenure regime does not appear to be as important
Decomposition in tropical forests: a pan-tropical study of the effects of litter type, litter placement and mesofaunal exclusion across a precipitation gradient
No full textDecomposition of dead plant material is an important process by which carbon fixed during photosynthesis is returned to the atmosphere (Schlesinger 1977; Singh & Gupta 1977), and is critical for nutrient cycling (Swift et al. 1979, Sayer 2006). As a primarily biotic process, decomposition and concomitant CO2 release and nutrient mineralization depend upon a number of drivers that directly and indirectly affect decomposer activity.
Empirical studies, conducted largely in the temperate zone, have identified three key drivers of decomposition, in order of decreasing importance: climate, litter quality (e.g. chemical composition) and the decomposer community (e.g. bacteria, fungi and soil fauna (Meentemeyer 1978, 1984; Coûteaux et al. 1995). Despite the established importance of the decomposer community (Seastedt 1984; Bradford et al. 2002a), it is typically
assumed that decomposition can be modelled using climate
and litter chemistry data alone, with either no or very minimal information on the decomposer community (e.g. microbial biomass data; but see Moorhead & Sinsabaugh 2006; Wall et al. 2008). Models also typically assume that above- and below-ground decomposition are controlled by the same factors (Moorhead et al. 1999). Several lines of evidence suggest that these assumptions may not always hold, especially in tropical ecosystem
Of land, legislation and litigation: Forest leases, agrarian reform, legal ambiguity and landscape anomaly in the Nilgiris, 1969-2007
No full textThis paper provides a history and sociology of how and why the Janmam Act, an apparently well-intended scheme of agrarian reform in Gudalur, South India, has had unintended social, legal and ecological consequences. The Act sought to abolish a largely forested janmam (Zamindari) estate and reform its tenures. Some of its provisions pertaining to acquisition of forests leased to planters are still operative four decades since. Legal ambiguity, constituted chiefly by litigation and also by long periods of legal incertitude, has rendered ambivalent the revenue and forest departments administration of forests in leases. Planters have expanded and forested portions of leases have been occupied by migrant peasants. Forest leases appear legally and ecologically anomalous to the state. Popular and legal resistance to state efforts in establishing its interests, especially conservation, is rife. Due to sheer denudation and agrarian conversion, Gudalur is ceasing to be a constituency for conservation. This even as a title seeking social constituency has emerged, albeit problematically, because peasant claims are untenable as per the Act. Such local complexities, with distinct agrarian afflictions, have been wrought by the reformatory scheme and contribute to scheme incompletion
Ground insect community responses to habitat restoration efforts in the Attappady hills, Western Ghats, India
Get PDFA reconnaissance survey was undertaken to assess the responses of ground insect communities to habitat restoration efforts in the Attappady hills, Western Ghats.Diversity patterns of various ground insect assemblages such as ants, beetles, etc. were compared across an age trajectory of restored sites. The diversity of these assemblages was correlated with age trajectory
of sites. Also, patterns of recolonization by different
insect trophic guilds and ant functional groups were
comparable with earlier studies from different biogeographic areas
Evaluating the potential role of Eucalyptus plantations in the regeneration of native trees in southern Western Ghats, India
No full textThe potential role of Eucalyptus plantations in recovering the native tree species regeneration was evaluated in south-western Ghats by comparing 25 year-old (25-EP) and 40 year-old Eucalyptus plantations (40-EP) and cleared evergreen forests (CF). Forty noncontiguous quadrats of 10 × 10 m size, totaling 0.4 ha each were randomly established in the ize). Sub-quadrats of 1 × 1 m size at the four corners of 10 × 10 m quadrat were sampled for tree seedlings. The CF had maximum number of native tree species at three states of regeneration (adult, sapling and seedling). Among the Eucalyptus plantations, 25-EP had adult species richness little lower than 40-EP, while the tree sapling and seedling diversity in 25-EP were higher than 40-EP. Of the 45 endemic tree species, the CF harbored more endemics (42%) than 25-EP (38%) and 40-EP (39%). Majority of the endemics were climax species (64%) which were dispersed by birds (40%) or mammals (29%). Unlike earlier belief, the Eucalyptus plantations in the study area seemed to play a significant role in promoting regeneration of the native tree species and facilitated natural forest succession