Influence of human land use and invasive species on beta diversity of tropical ant assemblages

New paper from my PhD research is published in Royal Entomological Society's Insect Conservation and Diversity. 

Link to Full Paper: CLICK

Graphical Summary:

Plain Summary: 

1. 18 NEW additions to ants of Goa. 

2. Asian Weaver Ant is the most common and an important species in Goa, maintaining several important ecological functions. 

3. Human conversion of natural habitats will disrupt diversity and distribution of ants and will cause harm to ecosystem functions like nutrient cycling, decomposition, pest control and seed dispersion. 

4. Lateritic plateaus of Goa have diverse and unique ant fauna that perform several important ecosystem functions. Further conversion of lateritic plateaus for human use without proper management plans will affect human wellbeing. 

5. Five invasive species of ants are inching towards decimating local ant populations and affecting several critical ecosystem functions like decomposition and seed dispersal. Management of invasive ants, especially Yellow Crazy Ant, which is a globally important invasive, is going to become an important challenge for India.

Acadmic Abstract:

1. Understanding how biodiversity is distributed is increasingly becoming important under ongoing and projected human land use. Measures of beta diversity, and its partitions, can offer insights for conservation and restoration of biodiversity. 

2. We ask how different species, functional groups, and land use contribute to beta diversity, and whether invasive species have a negative influence on beta diversity. We address these questions using ant assemblages (Hymenoptera: Formicidae) at 277 sites distributed across five geomorphic land use types in Goa, India. 

3. We recorded 68 species (35 genera, 7 subfamilies) of which 5 were invasive. We classified them into eight functional groups. Oecophylla smaragdina—a common tropical arboreal species, and Anoplolepis gracilepis—a globally significant invasive, contributed the most to beta diversity. Large-bodied omnivores which may influence soil functions contributed more to beta diversity than small-bodied predators. Lateritic plateaus contributed most to beta diversity, whereas human-influenced plantations contributed the least. Beta diversity across sites was related to species turnover, whereas nestedness was more prominent for functional groups. This indicates how species replace one another with change in land use, but functional roles are lost despite such turnover. Sites with human land use had higher incidence of invasive species, and invaded sites contributed less to beta diversity than non-invaded sites. 

4. Human land use strongly influences diversity and distribution of ant assemblages. Land use may spare local species richness, but not functional groups. A small number of invasive species exert negative influence even in very speciose communities.