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Effects of canopy cover on fruiting intensity and fruit removal of a tropical invasive weed

Cite this dataset

Taneja, Yukti V.; Page, Navendu V.; Kumar, R. Suresh; Naniwadekar, Rohit (2022). Effects of canopy cover on fruiting intensity and fruit removal of a tropical invasive weed [Dataset]. Dryad. https://doi.org/10.5061/dryad.6t1g1jx2j

Abstract

Lantana camara (hereafter, Lantana) is among the worst invasive alien plants spread extensively across Africa, Australia and Asia at an alarming rate, posing significant challenges to conservation of native biodiversity. While, Lantana invasion is widely recognised to be more pronounced in open-canopy habitats (including deciduous forests, forest edges and gaps), the potential role of variation in seed dispersal across habitats varying in overstory canopy cover is poorly understood. Avian frugivores are among primary seed dispersers of the fleshy-fruited Lantana. We monitored 45 Lantana shrubs across a gradient of overstory canopy cover to determine the relationship between fruiting intensity and canopy cover. We watched 80 Lantana shrubs (240 h) across a canopy cover gradient to determine 1) differences in frugivore assemblage visiting Lantana across open- and closed-canopy habitats, 2) drivers of frugivore visitation on Lantana, and 3) relationship between seed disperser visitation rate and overstory canopy cover. We found that Lantana shrubs under low overstory canopy cover had higher fruit abundance than those in high canopy cover. Frugivore assemblage differed between Lantana shrubs in open- versus closed-canopy cover habitats. Drivers of frugivore visitation on Lantana varied across different frugivore species with a greater probability of occurrence of bulbuls (the primary seed dispersers of Lantana) on shrubs under low overstory canopy cover. Visitation rates of the effective seed dispersers were higher on shrubs under low overstory canopy cover. Thus, there was greater chances of dispersal of seeds in habitats with low overstory canopy cover. The study demonstrates variable fruiting intensity and fruit removal rate as a driver of differences in dispersal of seeds across habitats. It highlights greater vulnerability of open habitats to invasion and the need to prioritise Lantana management efforts in open habitats. Anthropogenic activities that lead to canopy openings (e.g. tree lopping and logging) likely facilitate Lantana invasion through greater fruit production and seed dispersal.

Methods

The data was collected at field sites in the Western Himalayan region. We marked Lantana shrubs (n = 45) in a gradient of canopy cover and monitored fruiting phenology fortnightly from Aug 2021- Jan 2022. We watched Focal Lantana shrubs (n = 80), each for a period of 3 hours (total observation hours = 240 hr). The identity, number and fruit handling behaviour of visitors on Lantana was recorded. Habitat (e.g., Tree density, shrub cover, canopy cover, understory height) and focal shrub features ( e.g., fruit crop size, shrub volume) were measured.  

Usage notes

The project contains data on variation in fruiting phenology, frugivore composition, and seed disperser visitation on invasive Lantana camara across open and forest habitats in the Western Himalayan region of India. The data was collected by Ms Yukti V.Taneja for her master's dissertation study in Wildlife Institute of India (WII) under the guidance of Dr. Navendu Page and R. Suresh Kumar of WII and Dr. Rohit Naniwadekar of Nature Conservation Foundation (NCF, India). Data were collected from open shrubland-grassland mosaics and Shorea-robusta dominated moist deciduous forest sites in and around the WII campus. The manuscript related to the study has been accepted in Forest Ecology and Management and will be available shortly. The title of the manuscript is "Effects of Canopy Cover on Fruiting Intensity and Fruit Removal of a Tropical Invasive Weed". The authors of this article are Yukti V. Taneja, Navendu V. Page, R. Suresh Kumar and Rohit Naniwadekar. 

For a description of the columns corresponding to the data, see file: "README_for_datafiles_FEM_Taneja_etal"

Data files (arranged alphabetically) : dat_glm.csv; dat_glmm.csv; dat_hmsc_sxy_pa.csv; dat_hmsc_tp.csv; dat_nmds.csv; dat_sde.csv; dat_spatial_autocorr.csv; dat_species_code.csv. See file " README_info_FEM_Taneja_etal" for project and datafile description summary. 

Funding

NA, Award: NA