Theses and Dissertations
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Item Effects of Land Use Practices on Diversity and Abundance of Honey Bee Forage Plants in Senapati District, Manipur(Wildlife Institute of India, Dehradun, 2015) Ziipoa, Benjamin; Rawat, G.S.; Talukdar, G,S.; Gopi, G.V.North-east India, a global biodiversity hotspot, ·is also known for diverse socio-cultural and land use practices. One of the important cultural practices in a few pocket-s is bee keeping and honey production as a means of livelihood. However, there is a growing concern that with shortening of shifting cultivation cycle and frequent forest fire the diversity of bee forage plants· as well as honey production is declining in the region. Therefore, a study on the diversity of bee forage plants and bee keeping practices was conducted across various land use practices in Purul subdivision of Manipur, North-east India. The objectives of the study were: (i) To quantify the diversity and abundance bee forage plants in different land use land cover types, (ii) To document the honey bee abundance with respect to forage plant availability, bee keeping practices and traditional knowledge among the local bee keepers pertaining to bee keeping. The study was conducted during December April 2015 in Purul and Paomata subdivision of senapati, district, Manipur. The study area was stratified into five land use and land cover (LULC) types: (i) Semi-evergreen (primary) Forests above 1800 m asl; (ii) Moist Deciduous (Open Mixed) Forests between 1200- 1800 m asl; (iii) Secondary forests (Old Thurn Fallows between 1000 - 170q m; (iv) Secondary scrub (Young Thurn Fallows); and (v) Home Gardens and Agricultural Fields. Six trails of 2 km each were laid in various strata. AIthough each trail ten m radius plots were laid to quantify tree species abundance; concentric 5 m radius plots for shrubs and climbers; and four 0.5 m radius circular plots for herbaceous species. Direct and indirect signs of bee nests and locations of bee boxes were recorded. 30 professional bee keepers were interviewed for their knowledge on bee keeping and bee forage plants. Data were analysed following standard phytosociological techniques. Relationship between bee forage plants and bee abundance were established using R3.02 Generalized Linear Model (GLM). A total of 272 species of bee forage plants belonging to 105 genera and 92 families were recorded in the study area. Of these, 84 species were flowering during winter season. The number of flowering bee forage plants increased to 112 during spring season. It was noted that at least 25 species of flowering plants flower almost during all the seasons providing either nectar or pollens to the bees and other insect pollinators. Asteraceae, Rosaceae, Fabaceae, Brassicaceae and Malvaceae were the most dominant species available as bee forage plants, especially in and ar01md home gardens, backyards and cultivable waste. These species were very low in abundance in natural forests. However, Rosaceae and Fabaceae were more Common in Secondary Forests and Old Jhum Fields. Very few species of bee forage plants were flowering in Semi-evergreen Forests during winter seasons. Highest diversity of trees was recorded in semi-evergreen forests followed by Moist Deciduous Forest, Old Jhum Fallow and Young Jhum Fallow. However, overall density was highest in Moist Deciduous Forest. Budleja asiatica, Rubus ellipticus, Pyrlls pahsia, Engelhardtia spicata, Prunus cerasioides, Docynai india were the most widely available flowering species during winter and spring. These species were mostly found in open (Moist Deciduous), Old Jhum Fallows and closer to human habitation. Their frequency, density and distribution pattern has been compared across various land uses. The results revealed that settled agriculture with adequate cover of primary and secondary forests in vicinity coupled with plenty of ornamental plants and vegetables are best land use practices for honey production as well as enriching the pollinator diversity in the area. Short Jhum cycles and resultant frequent fires are detrimental to bees as well as bee forage plants. Pattern of bee distribution, local knowledge on bee keeping and conservation practices in relation to land use practices have been presented and discussed.Item Determinants of Butterfly Species Diversity : Plant Diversity, Foliage Height Diversity and Resource Richness Across Vegetation Types(Wildlife Institute of India, Dehradun, 1999) Kunte, Krushnamegh J. ; Rawat, G.S.MacArthur and MacArthur's (1961) theory of foliage height diversity, which was originally discussed as a determinant of bird species diversity, has been a strong concept describing the possible role of vegetation structure in deciding resource use, habitat selection and diversity of organisms. They measured foliage profile, and calculated foliage height diversity using information theory. Their results showed increase in foliage height diversity from simple to complex vegetation types, and bird species diversity was positively correlated with it. They then proposed an evolutionary mechanism to explain this correlation. A continuous flow of studies on vegetation structure and species diversity or habitat use of organisms followed after MacArthur and MacArthur (1961), but mostly they focused on birds. Subsequently, vegetation parameters other than foliage height diversity, such as horizontal vegetation heterogeneity or patchiness, also proved equally useful or better predictors of bird species diversity. Moreover, some studies revealed that foliage height diversity and bird species diversity were not correlated in a few cases. This brought forth a question whether or not foliage height diversity is a strong determinant of bird species diversity, or a frequent correlate of some other factor that has a strong influence on species diversity. To find out why in some cases MacArthur and MacArthur's (1961) theory did notexplain species diversity, I identified following assumptions in their theory, which were unstated in their paper: i)resources for a species are evenly dispersed within a horizontal vegetation layer, ii)resources are unevenly dispersed across the horizontal layers, iii)even for generalist species, the cost of switching over between layers is high, which would preclude switching over between layers, and iv)if the first three assumptions are true, then each horizontal layer of vegetation would have a different set of species, each layer adding a similar magnitude of diversity in more complex habitats. If these assumptions do not hold true for real biological communities, one would expect that foliage height diversity would not be a good predictor of species diversity in all situations. To test MacArthurs' assumptions and explore patterns of butterfly diversity across vegetation types, I studied butterflies at the Anamalais, southern Western Ghats, in southern India. I sampled foliage height diversity in vegetation plots and butterflies on count lines as well as all-aut-walks (opportunistic sampling), recorded body measurements of the butterflies, floral parameters of the plants on which the butterflies fed, and compiled information on larval and adult feeding plant resources. Using these data, I tested three possible degeminates of butterfly species diversity namely, foliage height diversity, 2.plant species diversity, and 3.resource richness in different vegetation types. This was probably the first attempt to analyse growth form-wise resource richness and utilisation by butterflies across vegetation types, in the light of foliage height diversity theory. Although the correlations between butterfly species diversity, plant species diversity and foliage height diversity were statistically significant, the butterfly species diversity was not perfectly correlated with these two determinants. Butterfly species diversity increased from grassland to deciduous forest, through shrub savannah and teak plantation, but was less in the mid-elevation evergreen forest as compared to the deciduous forest. Plant species diversity and foliage height diversity, on the other hand, increased from the grassland to the evergreen forest, with the deciduous forest falling before the evergreen forest. The resources for butterflies were not distributed in the vegetation types as assumed by MacArthur, and butterflies were not observed following the pattern of habitat or resource utilisation as predicted by the theory. As a result, foliage height and plant species diversity did not satisfactorily explain the butterfly species diversity. However, larval host plant and total plant resource richness correlated significantly and appropriately with the butterfly species diversity. Therefore resource richness seems to be an appropriate and better predictor, or at least a correlate, of butterfly species diversity in situations when other predictors may not be correlated with it. This study suggests that butterfly species diversity is dependent more on the resource diversity. However, foliage height diversity and plant species diversity need not be satisfactory surrogates for resource diversity in all situations. Therefore butterfly species diversity may vary independently of plant species and foliage height diversity. Another important result of this study was that even for butterflies, which are directly dependent on plants, the resource richness is not necessarily correlated with the plant species diversity. It means that butterflies selectively use certain plant resources more than other plant resources. I speculate that it would be underlying utilizable chemical diversity and "sociability" of plant resources used that would ultimately decide butterfly species diversity within a vegetation type. I define a "sociable host plant" as the one that supports many insect "guests". The butterfly assemblages using plant resources with maximum utilizable chemical diversity and sociability would be most diverse in the vegetation type supporting these sociable host plants. However, sociability of the utilizable plant species, and resultant butterfly diversity, may be independent of total plant species diversity or foliage height diversity in the vegetation type.