DOI: 10.5061/dryad.wstqjq2zp
title: Common buckthorn (Rhamnus cathartica) invasion exacerbates white-tailed deer (Odocoileus virginianus) browsing on native woody plants

description: Selective feeding by overabundant herbivores can considerably alter plant
 community composition and structure, often benefiting non-native species.
 White-tailed deer (Odocoileus virginianus) are a dominant herbivore in
 North America, known for their preference for native plants over
 unpalatable invasive species. Common buckthorn (Rhamnus cathartica), a
 widely invasive shrub, is largely avoided by deer, potentially
 facilitating its competitive advantage against native plants. This study
 investigates the interactive effects of buckthorn invasion and deer
 browsing on native woody plants within a post-industrial urban forest
 undergoing restoration. Specifically, we employed both a long-term
 observational tree survey and an experimental shrub study to assess
 buckthorn impacts on native trees and shrubs, and to investigate whether
 buckthorn presence intensifies deer browsing. For the tree study, we
 surveyed ten native tree species planted in areas with varying levels of
 buckthorn invasion to assess tree health as a function of buckthorn and
 canopy tree cover. For the shrub study, we examined deer and insect
 herbivory on five deer-resistant native shrubs with and without deer
 exclusion and buckthorn removal. We found that increased buckthorn cover
 correlated with reduced health in native tree species, a relationship not
 found between the trees and native canopy tree cover. We also found that
 all five planted native shrub species experienced considerable browsing,
 with deer and insect damage intensifying in the presence of buckthorn.
 This study highlights the complex interplay between non-native plant
 invasions and native herbivore activity, demonstrating that buckthorn
 indirectly facilitates increased deer herbivory on native species. These
 findings emphasize the need for integrated forest restoration strategies
 that address both invasive plant removal and herbivore management to
 support native species recovery.
description: # Common buckthorn (*Rhamnus cathartica*) invasion exacerbates
 white-tailed deer (*Odocoileus virginianus*) browsing on native woody
 plants Dataset DOI: [10.5061/dryad.wstqjq2zp](10.5061/dryad.wstqjq2zp) ##
 Description of the data and file structure ### Tree survey  #### File:
 Tree.Dryad.csv Ident = individual line number Spp = tree species * ACRU =
 *Acer rubrum* * ACSA = *Acer saccharinum* * CAOV = *Carya ovata* * CEOC =
 *Celtis occidentalis* * JUCI = *Juglans cinerea* * PODE = *Populus
 deltoides* * PLOC = *Platanus occidentalis* * QUBI = *Quercus bicolor* *
 SANI = *Salix nigra* * TIAM = *Tilia americana* Unit = Tifft area where
 planted Shelter = sapling protection type Survey data = when the survey
 was conducted Status = alive (1) or dead (0) Rating = ordinal health
 rating * 0 = dead * 1 = least healthy * 2 = less than average health * 3 =
 average * 4 = more than average * 5 = most healthy Buckthorn_Cover =
 percent cover 1 m2 circle surrounding target tree Canopy_Cover = percent
 cover 1 m2 circle surrounding target tree ### Shrub experiment #### File:
 Shrub.Dryad.csv Ident = individual line number Date = data collection
 dates Month = data collection months Cluster = clustering of shrubs, 5
 clusters per plot Buckthorn - Regrowth = present; Removed = absent Deer -
 Fenced = deer exclusion; Open = no exclusion) Species = shrub species *
 S.canadensis = *Sambucus canadensis* * I.verticillata = *Ilex
 verticillata* * C.sercea = *Cornus sericea* * C.occidentalis = *Celtic
 occidentalis* * L.benzoin = *Lindera benzoin* Damage = overall damage bins
 (0, 20, 40, 60, 80, 100) Deer.damage = deer damage bins Insect.damage =
 insect damage bins ## Code/software R 4.5.0