|dc.contributor.author||Radtke, Troy Mark||
|dc.description||A Thesis Submitted to the Faculty of Graduate Studies and Research in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Biology, University of Regina, xv, 160 l.||en_US
|dc.description.abstract||Agropyron cristatum (crested wheatgrass) is a
management concern in the northern Great Plains because of
the low plant biodiversity and high stability in A.
cristatum stands. Small consumers have the potential to
contribute to A. cristatum invasion and stability through
granivory and herbivory. Little is known about ant species
composition in the Northern Great Plains. I quantified seed
removal rates, granivore seed preferences, and ant
communities in paired native grasslands and A. cristatum
I examined temporal variation in vegetation factors
that influence granivory rates. Finally, I determined the
relationship between seed size and vertebrate granivore
preferences in herbaceous and woody communities, and I
sampled ants to determine species composition and how
vegetation parameters influence ant communities.
Granivory rates did not differ between native
grasslands and A. cristatum stands. Forb cover and season
were important predictors of granivory rates in 2009, with
higher granivory later in the growing season and at sites
with greater cover of forbs. In 2010, there were no
important predictors of granivory rates. Granivory rates in
A. cristatum stands were similar to those in native grasslands, possibly because the vegetative cover and
litter depth of A. cristatum stands was similar to that of
native grasslands. Granivores did not prefer native seeds
to exotic ones and showed little seed preference.
A review of vertebrate granivore seed size preferences
revealed that granivores often prefer relatively small
seeds in forests and relatively large seeds in herbaceous
communities. However, the absolute size of preferred seeds
in each community is often similar.
Ant species richness was similar between native
grasslands and A. cristatum stands, while ant species
composition differed between the two vegetation types.
However, there were no differences in total ant abundance
or the abundance of functional groups between native
grasslands and A. cristatum stands. Ant abundance increased
with the covers of bare ground and litter.
Granivory was related to variables such as forb cover
and bare ground, which varied within both vegetation types.
Yet, in spite of differences in plant species dominance and
plant diversity between native grasslands and A. cristatum
stands, there were few differences between the vegetation
types in terms of granivory rates, granivore seed
preferences or total ant abundance.||en_US
|dc.description.uri||A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy *, University of Regina. *, * p.||en
|dc.publisher||Faculty of Graduate Studies and Research, University of Regina||en_US
|dc.subject.lcsh||Crested wheatgrass--Seeds--Predators of--Saskatchewan||
|dc.subject.lcsh||Crested wheatgrass--Seeds--Predators of--Montana||
|dc.title||Granivory and Granivores in Native Grasslands and Agropyron Cristatum Stands in the Northern Great Plains||en_US
|thesis.degree.name||Doctor of Philosophy (PhD)||en_US
|thesis.degree.grantor||University of Regina||en
|thesis.degree.department||Department of Biology||en_US