Abstract Detail

Ecology

Kaur, Sukhraj [1], Shrotri, Saket [2], Gowda, Vinita [3].

Using floral trait-based pollination networks to understand community assembly in tropical laterite grasslands.

The assemblage of species in a community is often attributed to various abiotic (environmental filtering) and biotic factors (ecological interactions). Seasonal plant communities are unique since they are restricted to a short window of favourable environmental conditions, wherein, the pollination success determines the reproductive fitness of annual species. Such annually flowering herbaceous species dominate our study site, which are the lateritic plateaus that form ‘sky-islands’ in the northern Western Ghats, India. These plateaus are a major biodiversity hotspot and host a wide variety of endemic plant species. These species exhibit ‘mass-flowering’ as multiple individuals flower simultaneously. We noted an interesting pattern in the flowering phenology on one of these plateaus where the landscape changes colour as the most abundant floral colour-group shifts from one to another.
Surprisingly, floral traits selection has long been the focus in population biology and evolutionary ecology with trait/species-specific approach, but remains neglected in functional trait-based studies that focus on community assembly. Therefore, we proposed to use plant-pollinator networks as an ecological model to understand the assembly of plant communities, and sharing of resources i.e. pollinators. In order to address the objective stated above, we asked: i) do flowering species show convergent or divergent floral colour distributions in their flowering phenology, and ii) does pollinator preference change with the changing abundance of floral colour-groups?
We sampled four communities during the flowering season that are also spatially isolated and experience similar environmental conditions. We recorded their flowering phenology using the transect method, measured the floral traits such as, floral colour, size, shape and display, and quantified the number of fruits per flowering species. We observed the floral visitors for all flowering species throughout the season to build the pollination networks to capture the temporal shift in plant-pollinator interactions.
The communities which supported more diverse types of microhabitats had higher species diversity. Each community varied in the proportion of the total abundance of floral colour-groups, whereas, the two geographically closer sites displayed similar proportions of floral colour abundance. The month of peak flowering for each colour-group is the same across plateaus. Therefore, even if the overall abundance of floral colour-groups varies across sites, the flowering phenology pattern does not show much variation. The number of active pollinator types are low during the beginning of the season and the diversity of pollinator-type increases as the number of species gradually increases. Although plant species composition varies between study sites, bees remain the most generalist and dominant pollinator in all communities. Our study contributes to the understanding of the role of native pollinators in maintaining the grassland communities that are vulnerable to anthropogenic disturbance.

1 - Indian Institute Of Science Education And Research Bhopal, Biological Sciences, Lab Number 303, AB3, IISER Bhopal, Bhauri, Bhopal, MP, 462066, India
2 - Indian Institute Of Science Education And Research Bhopal, Department Of Biological Sciences, Tropical Ecology And Evolution (TrEE) Lab, Room 303, AB3, IISER Bhopal, Bhauri Campus, Bhopal By Pass Road, Bhopal, MP, 462066, India
3 - IISER Bhopal, Room 223, AB3, Dept. Of Biological Sciences,, IISER- Bhopal, Bhopal Bypass Road, Bhauri,, Bhopal, MP, 462066, India

Keywords:
visitation network
community ecology
Floral traits
community assembly
tropical grassland
mass flowering.

Presentation Type: Oral Paper
Number: EC03006
Abstract ID:984
Candidate for Awards:Ecological Section Best Graduate Student Paper