Cluster B: Ecology, economy, and service exchanges

I-B01.2: Plant and insect diversity in agro ecosystems along the rural-urban interface: Patterns, functions and economic value of the agro- biodiversity

Project summary.

The project aims to assess the patterns of change in different components of agrobiodiversity in the rural-urban interface. We will look into the possible influence of urbanization on agricultural ecosystems in the periphery of rural areas by recording the change in diversity of crop species and varieties in particular and the diversity of plants in general. Observations will also record the diversity of insects including pests, parasitoids, predators, soil macro-arthropods and pollinator species. Intensive collection will also be made of pollinators and soil macroarthropods.

The study area will include three zones – urban, semi-urban and rural. For plant diversity, at each of the three identified zones along the changing rural-urban gradient observations will be recorded in six plots or fields of one ha area and the diversity of varieties in each crop, diversity of cultivated crop species and their area covered would be assessed. Along with these the frequency of crop cultivation through the year and seasons would be assessed. The overall diversity of crops and their varieties (DCV) would be analysed using the Simpson’s Diversity Index except that instead of the proportion of the individuals of a species (pi), we shall use the proportion of the area occupied by the species or variety.

For insect diversity in each zone, there will be 30 sampling sites and at each sampling site five samples will be taken as follows: insects associated with plants including parasites and predators by sweep net sampling; additional five samples for pollinators by sweep nets, visual counts and bee bowls; and soil macroarthropods from five soil samples. Samples will be collected at forthnighly or monthly intervals by sampling in two directions of the Bangalore city, commencing from the city into the rural areas.

Obsevation records will include the species of insects, their abundance and distribution. Diversity indices will be worked out to compare between sites. These results will help to understand the effects of changing cropping pattern in the three zones on the abundance and diversity of insect pests, their natural enemies, and on the pollinator and soil macroarthropod populations.

The results will be related to other projects proposed as parts of a collaborative research initiative, such as an assessment of the effects of changing cultivation practices on the patterns of soil and water quality including variations in soil nutrition status and fertility, pollutants, in the soil and water samples, and the quality of irrigation and potable water along the rural-urban interface.