Afforestation has been a major cause for the loss of open natural grasslands in India. In the Nilgiri and Anamalai-Palani Hills landscapes, tropical montane (shola) grasslands have been historically converted to exotic tree plantations of Eucalyptus sp. and Acacia mearnsii (black wattle). In the Munnar landscape, the Kerala Forest and Wildlife Department has initiated shola grassland restoration interventions by removing black wattle using different strategies. My study compares two major restoration strategies based on their goals, methods used, costs incurred, the ecological impact in terms of plant species richness, frequency and community composition of native and invasive species, wattle regeneration and faunal activity. I also assessed how the local communities perceive restoration.

I noted that CFP-treated (Cutting, controlled Fire and Planting) sites involved removal of wattle by controlled burning, manual or mechanical felling and planting of grasses and had higher invasion intensity. The CNR treatment (Cutting followed by Natural Regeneration) relied on natural regeneration after manual or mechanical felling of wattle as the invasion intensity was lower. Both treatments included weeding of the regenerated wattle and other invasive species as a maintenance method. I selected two sites for each treatment and used a control (wattle) - treatment (CFP and CNR) - reference (benchmark grassland) sampling design across a total of 40 wattle plots, 20 CFR plots, 22 CNR plots and 12 benchmark grassland plots.

I identified 111 species which included 14 endemic species, 18 exotic species and 15 invasive species. At three years after initiation, CNR-treated sites are more similar to benchmark grasslands in terms of plant species composition compared to CFP-treated sites. The frequency and richness of native grass species and associated herbs is also higher in CNR in comparison to CFP sites. On the other hand, wattle regeneration in CFP is lower than CNR treatment sites and this could be related to the higher efficacy of regular intensive weeding in CFP sites. At the same time, invasive species like Ageratina adenophora, Pteridium aquilinum, Xerochrysum bracteatum and Erigeron karvinskianus are commonly found in both treatment sites and this indicates that methods to target these species also need to be devised to develop successful site-specific restoration strategies.