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Bonell M.,University of Dundee | Purandara B.K.,National Institute of Hydrology | Venkatesh B.,National Institute of Hydrology | Krishnaswamy J.,Suri Sehgal Center for Biodiversity and Conservation | And 3 more authors.
Journal of Hydrology | Year: 2010

There is comparatively limited information in the humid tropics on the surface and sub-surface permeability of: (i) forests which have been impacted by multi-decades of human occupancy and (ii) forestation of land in various states of degradation. Even less is known about the dominant stormflow pathways for these respective scenarios. We sampled field saturated hydraulic conductivity, K* at 23 sites at four depths (0m, n=166), (0.10m, n=139), 0.45-0.60m, n=117, (1.35-1.50m, n=117) under less disturbed forest (Forest), disturbed production forest of various local species (Degraded Forest) and tree-plantations (Acacia auriculiformes, 7-10years old, Tectona grandis, ∼25-30years old, Casuarina equisetifolia, 12years old) in the Uttar Kannada district, Karnataka, India, in the Western Ghats. The sampling strategy was also undertaken across three physiographic blocks and under three main soil types. Subsequently the determined K* were then linked with rainfall intensity-duration-frequency (IDF) characteristics to infer the dominant stormflow pathways.The Degraded Forest shows an order of magnitude decline in K* at the surface as result of human impacts at decadal to century time scales. The lowest surface permeability is associated with the Degraded Forests over the Laterite (Eutric Nitosols and Acrisols) and Red soils (Eutric Nitosols) and infiltration-excess overland flow, IOF probably occurs. Further there is a progressive decline in K* with depth in these soils supporting Degraded Forests. The A. auriculiformes plantations over the Red and Lateritic soils are progressively restoring the near-surface K*, but their K* still remain quite low when compared to the less disturbed forest permeability. Consequently these plantations still retain the 'memory' from the previous degraded state. In contrast the permeability of the Black soils (Vertisols) are relatively insensitive to T. grandis plantations and this soil group has a very low K*, irrespective of land cover, so that IOF likely prevails. Overall, the Laterites are the most variable in K* when compared to the other soil groups. Thus when compared to other studies, IOF is probably more prevalent in this region. More especially so, when taking into account the marked reduction in surface K* during the wet season when compared to dry season measurements. In addition, we have demonstrated the potential for the 'infiltration - trade-off' hypothesis to be realized in this landscape under certain conditions of land degradation and restoration. It is most relevant to the combination of degraded sites and A. auriculiformes plantations on Red or Laterite soils using the less disturbed forests as the baseline. The intensity of forest use and effects of monoculture plantations on soil ecology (relative to native, mixed forests) is likely to be the critical factor in affecting surface K* over time. Predicted changes in the intensity of rain events in the future is likely to enhance overland flow on degraded sites on all soils and especially on Black soils, and restoration efforts by all stake-holders, preferably using native or non-invasive species, are needed to address this concern. © 2010 Elsevier B.V. Source

Ganesan R.,Suri Sehgal Center for Biodiversity and Conservation
Rheedea | Year: 2011

Litsea kakkachensis R. Ganesan, a new species of Lauraceae from Agasthyamalai hills, southern Western Ghats is described with illustration. It differs from its allied species L. venulosa (Meisn.) Hook.f. in number of lateral nerves, fl oral characters and shape of the fruit. The habitat, phenology, abundance and threat status are also discussed. Source

Ghosal S.,Norwegian University of Life Sciences | Skogen K.,Norwegian Institute for Nature Research | Krishnan S.,Suri Sehgal Center for Biodiversity and Conservation
Conservation and Society | Year: 2015

People's reactions to large carnivores take many forms, ranging from support and coexistence to resistance and conflict. While these reactions are the outcome of many different factors, in this paper we specifically explore the link between social constructions of landscapes and divergent responses to large carnivore presence. We compare case studies from four different landscapes shared by people and large carnivores, in India and Norway. We use social construction of landscapes as a key concept to explore responses to large carnivores in the context of ecological, economic, social, and cultural changes in these areas. Based on this comparison, we argue that the process of change is complex, with a plurality of responses from the groups affected by it. The response to large carnivore presence is influenced by many different factors, of which the interpretation of change-particularly landscape change-plays a significant role.Copyright: © Khumalo and Yung 2015. Source

Crone E.E.,Harvard University | Ellis M.M.,University of Montana | Morris W.F.,Duke University | Stanley A.,Institute for Applied Ecology | And 16 more authors.
Conservation Biology | Year: 2013

Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models. © 2013 Society for Conservation Biology. Source

Seshadri K.S.,Suri Sehgal Center for Biodiversity and Conservation | Gururaja K.V.,Indian Institute of Science | Aravind N.A.,Suri Sehgal Center for Biodiversity and Conservation
Zootaxa | Year: 2012

A new species of the shrub frog genus Raorchestes Biju, Souche, Dubois, Dutta and Bossuyt is described as Raorchestes kakachi sp. nov. from Agastyamalai hill region in the southern Western Ghats, India. The small sized Raorchestes (male: 24.7-25.8 mm, n = 3 and female: 24.3-34.1 mm, n = 3) is distinguished from all other known congeners by the following suite of characters. Snout oval in dorsal view; tympanum indistinct; head wider than long; moderate webbing in feet; colour on dorsum varying from ivory to brown, blotches of dark brown on flanks, brown mottling on throat reducing towards vent; inner and outer surface of thigh, inner surface of shank and inner surface of tarsus with a distinct dark brown horizontal band which extends upto first three toes on upper surface. A detailed description, advertisement call features, ecology, natural history notes and comparison with closely related species are provided for the new species. Copyright © 2012 · Magnolia Press. Source

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