Open to Invasion Patterns in Fruiting Phenology and Seed Dispersal of Lantana Camara Across Different Habitats in North India

Abstract

Lantana camara (hereafter, Lantana) is a fleshy-fruited alien invasive plant that spreads mainly through seed dispersal mediated by vertebrate frugivores. Lantana has low shade tolerance and is thus more abundant in relatively open habitats. While open habitats may facilitate better germination of seeds and growth of saplings and adults, the role of habitat type on its reproductive output (fruits) and seed dispersal remains largely unknown. Understanding this can help predict differential patterns of invasion in different habitats. In this study, I aimed to understand the influence of canopy cover and other drivers on fruiting phenology, visitation patterns of frugivores on Lantana and fruit removal of Lantana. I carried out this study in Shorea robusta- dominated. moist deciduous forest and grassland-shrubland mosaics in and around the Wildlife Institute of India (WII) campus in the Dehradun valley, Uttarakhand from August 2021 to December 2021. To determine the influence of canopy cover on fruiting phenology, I marked and monitored (every fortnight) 45 Lantana bushes across a gradient of canopy cover from late August. To determine the drivers of visitation patterns of frugivores on Lantana and the fruit removal rates of Lantana across habitats, I earned out focal plant watch on 80 Lantana bushes across a gradient of canopy cover. I used a generalized linear mixed model (GLMM) to test the effect of canopy cover and shrub volume on the fruit crop size of Lantana bushes monitored for phenology.