Complex Effects of Ungulate Browsers on Tree Recruitment and Herbaceous Layers in New England Temperate Forests

Faison, Edward K

Publication:
Complex Effects of Ungulate Browsers on Tree Recruitment and Herbaceous Layers in New England Temperate Forests

dc.contributor.advisor	Stephen DeStefano
dc.contributor.advisor	David Foster
dc.contributor.author	Faison, Edward K
dc.contributor.department	University of Massachusetts Amherst
dc.date	2024-03-27T17:31:23.000
dc.date.accessioned	2024-04-26T16:09:04Z
dc.date.available	2024-04-26T16:09:04Z
dc.date.submitted	September
dc.date.submitted	2015
dc.description.abstract	Browsing by ungulates is a leading biotic disturbance in northern forest ecosystems and an important determinant of habitat, biodiversity, and ecosystem services. A large body of work has revealed that white-tailed deer (Odocoileus virginianus) at high densities alter forest understories in strong and predictable ways; however, less is known about how lower densities of deer and the combined effects of multiple herbivores influence forest understory vegetation, particularly in stands following canopy disturbance. Using fenced exclosures, remote cameras and other field observations, I explored the foraging response and browsing effects of low densities of deer and moose (Alces alces) on tree recruitment and herbaceous layers (low shrubs, herbs, and small trees) in stands disturbed by logging and simulated Hemlock Woolly Adelgid (HWA) attack over 4-7 years in Massachusetts, USA. I also examined the effects of 15 years of deer exclusion on an intact hardwood forest in southwestern Connecticut exposed to decades of high densities of deer. In Massachusetts, large variations in tree densities developed over time in different stand disturbance types (simulated HWA attack, logging), altering the foraging response of herbivores and mitigating browsing effects. Still, moose + deer browsing delayed tree recruitment by about three years in logged stands, whereas deer alone had relatively minor effects. Delayed tree recruitment by browsers corresponded with reduced abundance of forest indicator herbs and shrubs and greater abundance of open/disturbance indicator plant species in plots browsed by deer + moose. Richness of native herbs and low woody plants also increased with the addition of browsers. Among major tree taxa, pin cherry (Prunus pensylvanica) and oak (Quercus spp.) recruitment declined with browsing. In the Connecticut forest, sedge and exotic species abundance and richness generally declined with deer exclusion, whereas forb abundance increased. The direction in which native species richness was altered by deer exclusion depended on the plant functional group (i.e., shrub richness increased, but herb richness declined). My results revealed complex effects of herbivory over time on forest understories, highlighting the importance of examining ungulate-forest interactions across a range of ungulate densities and forest conditions and utilizing ≥3 browser treatments whenever feasible.
dc.description.degree	Doctor of Philosophy (PhD)
dc.description.department	Wildlife & Fisheries Conservation
dc.identifier.doi	https://doi.org/10.7275/7350157.0
dc.identifier.orcid	N/A
dc.identifier.uri	https://hdl.handle.net/20.500.14394/19666
dc.relation.url	https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1462&context=dissertations_2&unstamped=1
dc.source.status	published
dc.subject	Alces alces
dc.subject	Odocoileus virginianus
dc.subject	browsing
dc.subject	forest disturbance
dc.subject	multiple herbivores
dc.subject	species richness
dc.subject	Ecology and Evolutionary Biology
dc.title	Complex Effects of Ungulate Browsers on Tree Recruitment and Herbaceous Layers in New England Temperate Forests
dc.type	openaccess
dc.type	article
dc.type	dissertation
digcom.contributor.author	isAuthorOfPublication\|email:efaison@highstead.net\|institution:University of Massachusetts Amherst\|Faison, Edward K
digcom.identifier	dissertations_2/451
digcom.identifier.contextkey	7350157
digcom.identifier.submissionpath	dissertations_2/451
dspace.entity.type	Publication