M Sc Dissertation(WII)

Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/3

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Subject: search.filters.subject.Ecological responses

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    Ecological responses of Intertidal Benthic communities to certain abiotic factors in Nancowry islands, Nicobar
    (Wildlife Institute of India, Dehradun, 2017) Kandregula, Samyukta Rao; Sivakumar, K.; Johnson, J.A.
    The intertidal zone is the amphibious niche between the high and low tides. The invertebrate taxa present here lay bare to several influencing factors and facilitate the flow of energy by participating at each trophic level in the marine ecosystem. This study was carried out in order to assess the community structure of intertidal benthic macro invertebrates. Their associations with various factors known to affect intertidal zones were looked into, in the remote islands of Kamorta and Nancowry in Central Nicobar, Andaman and Nicobar archipelago. Three study sites of varying beach profiles (reflective, intermediate and dissipative) were studied across spatio-temporal scales. Baseline information was drawn 'on the key players of the macrofauna community signals. Replicates need to be studied to confirm the patterns observed. Comprehensive community level analyses (at species) need to be done along with supplementary data through Total Organic Carbon (TOC) analysis and heavy metal analysis (ICP-MS analysis) needs to be done to ascertain the sources and magnitudes of the signals of influencing factors.
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    Responses Shown by Bird Communities to Teak Palatations in Sagar Forest Division, Karnataka
    (Wildlife Institute of India, Dehradun, 2009) Barve, Sahas S.; Mohan, D.; Qureshi, Qamar
    This study was aimed at discerning the responses shown by bird communities to teak plantations of various age classes in Sagar Forest Division, Karnataka within Latitude 13° 36' and 14° 38' North 74° Longitude 38' and 75° 32'East Latitude. Birds were sampled using line transects in three habitat strata, natural plantations, mature teak plantations and young teak plantations. Density, diversity and community similarity were the chief ecological responses that were quantified to bring out differences in the usage of forest plantations by native bird fauna. Habitat (vegetation) correlates, both structural and floristic were quantified to establish the reasons for differences. The sampling period was from December 2008 to April 2009. This period was divided into two seasons, winter and summer. A total of 9 transects were laid, marked and sampled at least 4 times per season. Birds were divided into three feeding guilds and three habitat guilds for analysis. The overall density of birds across the three strata was found to be higher in summer than in winter. However a guild level analysis showed that in winter while insectivorous birds were most abundant in natural forest with decreasing density towards young plantations (F (6.241) , p< 0.05). There was no difference in their density in summer. Phytophagous birds showed the exact reverse trend. Density of this guild was higher in young plantations than natural forests and mature plantations in winter and summer (F(S.689), p< 0.05), (F (14.302), p< 0.01) respectively. Overall diversity of birds showed a trend of decreasing species richness from natural forests to young plantations in both seasons. However this difference was almost non existent in summer at the guild level. The abundance of birds belonging to evergreen and moist deciduous forests shows a consistent· rise in abundance from winter to summer in all the three strata. There is also evidence that there is ingression of individuals of species that were common to both seasons possibly for nesting. The overall community similarity is quite high between the three strata and it increases from winter to summer. Bird diversity was found to be affected by the vertical spread of vegetation and tree height heterogeneity (R=0.871, p