Abstracts
0006
Native revegetation of previously cultivated land in the dry
mixedgrass natural subregion of Alberta, Canada.
Jennifer Richman1, Brad Downey2, Kevin France1, Paul Jones2,
Brandy Downey1, Francois Blouin31Alberta Environment and
Sustainable Resource Development, Lethbridge, Alberta, Canada,
2Alberta Conservation Association, Lethbridge, Alberta, Canada,
3Prairie Conservation Forum, Lethbridge, Alberta, Canada
MULTISAR is a multiple species conservation strategy that aims
to conserve multiple species of wildlife, including Species at
Risk, at the landscape level, through a process that integrates
range management with fish and wildlife management principles. In
the early 1900's a significant amount of native dry Mixedgrass
range was ploughed to make way for intensive agriculture.
Currently, only 43% of the dry mixedgrass natural subregion remains
native and continues to be fragmented by human development. In
2008, the MULTISAR program partnered with a landowner to convert
57ha of marginal cropland back to native grassland. A seed mix for
the site was determined by assessing the ecological characteristics
of the native grasslands immediately adjacent and identifying the
composition of the plant community. Seed was broadcast at 10kg/ha
followed by a light harrow in the spring of 2008. In the spring of
2009 the site was sprayed with a broadleaf herbicide to combat
weeds and 150 silver sagebrush plugs were planted in low lying
areas. In 2010 after the third growing season, species composition
equaled 13.4% blue grama (Boutelua gracilis), 13% northern
wheatgrass (Agropyron dasystachyum), 10.9% June grass (Koeleria
macrantha), 6.7% western wheatgrass (Agropyron smithii), and 4.7%
needle and thread grass (Stipa comata). Wildlife present on the
site shifted from a community dominated by horned larks (Eremophila
alpestris) in 2007, to thirteen species identified in 2010
including species at risk like Sprague's pipit and
chestnut-collared longspur. Further research is needed to determine
their nesting and rearing success on reseeded native
grasslands.
0015
Perennial Grass Establishment Following Cheatgrass Control Using
Herbicides
Charlie D Clements, Daniel N HarmonUSDA-ARS, Reno, NV, USA
The introduction and subsequent invasion of Cheatgrass (Bromus
tectorum) onto Intermountain rangelands has resulted in increased
frequencies of wildfires and severely altered native plant
communities.The objective of this study was to test the
effectiveness of herbicides [Imazapic (Plateau), Rimsulfuron
(Matrix), Sulfometuron Methyl (Landmark)] on controlling cheatgrass
and allowing for the establishment of seeded species. Twelve plots,
25m x 50m, were established in fall 2010 and treated with 1)
Imazapic @ 6oz/ac, 2) Rimsulfuron @ 4oz/ac, and 3) Sulfometuron
Methyl @ 1.75oz/ac rates and replicated 3 times in a completely
randomized block design with controls. The treated plots were
fallowed for one year and then seeded to Siberian wheatgrass
(Agropyron fragilla ssp. sibiricum) at 7 lbs/ac rate.Sulfometuron
Methyl yielded the highest control of cheatgrass above ground
densities from 24.7/ft down to 0.4/ft (98.7%) followed by Imazapic,
17.6/ft down to 0.8/ft (95.6%) and Rimsulfuron 13.1/ft down to
1.1/ft (91.9%). The control plots averaged 39 cheatgrass plants/ft.
Siberian wheatgrass seedlings emerged in March 2012 at fairly high
densities (22.5/ft in the Sulfometuron Methyl treated plots) and by
mid-June 2012 still yielded excellent results in some of the
treatments. Sulfometuron Methyl treated plots yielded 6.5/ft,
followed by Imazapic, 4.1/ft and Rimsulfuron, 1.5/ft. Control plots
yielded 1.1/ft despite only receiving 6.2" of annual precipitation.
These numbers are expected to decline over the hot dry summer
months, yet the Sulfometuron Methyl and Imazapic treated plots
should result in sufficient long-lived perennial grass
establishment to suppress cheatgrass densities in the near
future.
0016
Combustion dynamics of cattle fecal pats
John Derek Scasta, Dave M. Engle, John R. WeirOklahoma State
University, Stillwater, OK, USA
The combustion of cattle fecal pats could have implications on
focal micro-disturbances and production issues associated with
cattle parasites. In 2011 and 2012, we geospatially identified
fifty cow pats in six pastures (n = 300) and assessed combustion of
each pat in relation to multiple variables, including: fire weather
(relative humidity, temperature, hours since precipitation); fecal
pat characteristic (index of age, volume); four time-lag fuel
classes (1 hr, 10 hr, 100 hr and 1000 hr) and fuel load (at each
pat). Multiple linear regression using AIC was applied to determine
the best combustion models, and stepwise selection was used to
select the best multiple regression model. Combustion of pats
ranged from 3% to 62%. None of the fire weather variables were
significant. Of the fecal pat characteristics, only the age score
index was significant, and of the fuel variables, only 100-hr fuel
moisture and fuel load were significant. The suggested regression
model (r2 = 0.4266; p < 0.0001) was comprised of a three way
interaction (100-hr fuel moisture age score index fuel load).
Simple linear regression of pat combustion averaged for each
pasture (n = 6) and 100-hr fuel moisture was highly correlated (r2
= 0.9587). These data suggest that grazing and fuel characteristics
could be managed to optimize combustion of pats for a variety of
ecological or production oriented goals.
0017
Perceptions of Drought: How Ranchers in Arizona Prepare for and
Respond to Drought
Greg Butler, George Ruyle, Mitch McClaran, Diane
AustinUniversity of Arizona, Tucson, Arizona, USA
Ranchers and land managers in Arizona must respond quickly to
drought in order to employ the most effective management practices
for maintaining forage utilization without degrading livestock or
range conditions. I determined relationships between rancher
perceptions of drought, practices used in preparation for and
response to drought, drought preparedness and sources of drought
management information. In order to evaluate these relationships, I
sent a mail survey to ranchers and land managers in eastern and
southeastern Arizona. Respondents consider the most important
practices used both to prepare for and respond to drought to be
rotational grazing, reducing herd size, adding more drinking water
sources and purchasing additional feed. Sixty eight percent of
respondents believe they are more prepared for drought now than
they were 10 years ago in spite of worsening drought conditions.
They understand they cannot control the weather, but they can
control how they manage their operation in response to changing
weather conditions.
0036
Development of South Texas Germplasm sideoats grama and
comparison to previous releases
Keith Pawelek1, Forrest Smith1, Anthony Falk1, John
Lloyd-Reilley2, Shelly Maher2, William Ocumpaugh11South Texas
Natives, Caesar Kleberg Wildlife Research Institute, Texas A&M
University-Kingsville, Kingsville, TX, USA, 2United States
Department of Agriculture (USDA), Natural Resources Conservation
Service (NRCS), E. Kika de la Garza Plant Materials Center,
Kingsville, TX, USA
Sideoats grama is a widespread native bunchgrass in North
America, which is often used in reclamation plantings. Eleven seed
releases of Bouteloua curtipendula have been made through the work
of the USDA NRCS Plant Materials Program and their collaborators.
In addition to these tested materials, a number of wild-harvested
seed sources of sideoats grama are offered for sale by commercial
seed companies, however, no regionally adapted or locally
originating (e.g. ecotypic) seed source of sideoats grama has been
available for restoration projects in the region known as south
Texas. As a result, we began work to collect, evaluate, and develop
a seed release of a blend of ecotypic populations for use in the
area.
South Texas Germplasm sideoats grama (Bouteloua curtipendula
[Michx.] Torr. Var. caespitosa Gould&Kapadia) was cooperatively
released in 2012 as a Texas Selected Native Plant Germplasm. This
germplasm is a blend of six selected native populations originating
from the Rio Grande Plains and Edwards Plateau Ecoregions of south
Texas. Following initial evaluation, selection, and isolated seed
increase of each component, South Texas Germplasm was compared to
sideoats grama cultivars originating from nearest the area of
intended use of the germplasm: Haskell', Premier' and Vaughn', in a
6-site variety trial utilizing transplanted and seeded experimental
plots. South Texas Germplasm exhibited significantly higher 90-day
seedling emergence than available cultivars at planting sites
within the area of intended use, as well as superior performance in
the transplant experiment at 2 of 3 experimental sites in south
Texas.
0038
Who can take the heat: Caespitose grass response to increasing
fuel loads
Ryan LimbOregon State University, Corvallis, Oregon, USA
Fire is a natural disturbance that frequents most landscapes
globally and produces varying disturbance intensities depending on
several factors. Likely the most easily understood and manipulated
factor affecting fire intensity on rangelands is the herbaceous
fuel load. Alterations in plant community composition and structure
in addition to decreased grazing intensities have led to relatively
high fuel loads on many western North America caespitose grass
rangelands. Increased fuel loads directly increase fire intensity,
but also increase other factors that may be more critical to plant
survival including residual flame time, burn duration and total
heat transfer. Numerous reports suggest that increased fire
intensity reduces bunchgrass survival, but often these studies were
conducted in wildfire situations where exact fuel loads and fire
conditions were not knows. We planted four bunchgrasses native to
western North America (Achnatherum thurberianum, Elymus elymoides,
Festuca idahoensis, Psuedoroegneria spicata) in 2.5 L pots and
maintained them in a climate controlled greenhouse. At 20 weeks
old, we burned individual plants under controlled conditions with
herbaceous fuel loads ranging between 2000 kgha-1 to 4000 kgha-1.
An additional cohort of plants was clipped to 2-cm height to
simulate a grazing event. We compared survival of individual plants
among the different fuel load and clipping treatments and a
non-treated control 21 days post-treatment and tracked the length
of time to produce green biomass among the surviving
individuals.
0039
Impact of High Stocking Density Grazing on Livestock Walking and
Resting Behavior
Alexander Smart, George Perry, Julie Walker, Cody Wright, Megan
Mortellaro, Kevin Vander WalSDSU, Brookings, SD, USA
High stocking density "mob" grazing is a recent phenomenon that
is being promoted by a few practitioners, but has not undergone
rigorous scientific testing. The objective of this study was to
determine the walking and resting behavior of cattle grazing at
high and low stocking densities. The study was conducted in 2012 on
smooth bromegrass (Bromus inermus L.) pasture near Brookings, South
Dakota. Two replicate treatments consisting of livestock grazing at
a high stocking density (200,000 kg of live weight per ha moved
three times per day) or a low stocking density (3,600 kg of live
weight per ha moved once per week) were compared. Pedometers were
put on three heifers for each replication of the high stocking
density treatment and two heifers in each replication of the low
stocking density treatment. Pedometers recorded number of steps,
the number of laying bouts, and time laying down in one second
intervals. Number of steps taken per day in the high stocking
density treatment (3103 steps) was 40% more (P=0.02) than the low
stocking density treatment (2218 steps). Daily laying bouts was 50%
fewer (P=0.01) for high stocking density (10) than for low stocking
density (15). Daily resting time was 10.5 hours for heifers in the
high stocking density treatment compared with 11.1 hours in the low
stocking density treatment (P=0.03). It would appear that high
stocking density grazing might cause cattle to do more walking and
expend more energy compared with low stocking density rotational
grazing.
0054
Long-term alfalfa and clover recovery dynamics in northern
temperate pastures sprayed with residual broadleaf herbicide.
Amanda Miller1, Edward Bork1, Linda Hall1, Patrick Forsythe2,
Bill Summers01University of Alberta, Edmonton, Alberta, Canada,
2DuPont, Wetaskawin, Alberta, Canada
Beneficial legumes such as alfalfa (Medicago sativa) and white
clover (Trifolium repens) increase the productivity of pastures and
quality of forage, and are important features of northern temperate
pastures. When pastures are sprayed for the control of broadleaf
weeds existing legumes are removed from the plant community.
Although prompt re-establishment of legumes in sprayed pastures is
a goal of many land managers, this process depends on a number of
different factors. Current re-cropping guidelines for many
herbicide bioactives are based on data from areas with different
soil and climatic conditions relative to western Canada. This study
used long-term plots to track the degradation of herbicide
bioactives (aminopyralid and aminocyclopyrachlor) via the
performance of key forage legumes: alfalfa and white clover. Five
long-term field sites were established to assess the ongoing
recovery of legumes by investigating changes in legume biomass for
3 years following herbicide application. Each experimental site was
organized into 4 replicate blocks of a randomized strip-split plot
design. Mowing main plots were randomly assigned to of each block,
herbicide subplots assigned to each plot, and seeding sub-subplots
(alfalfa, clover, or non-seeded) repeated between the mowed and
non-mowed portions of herbicide sub-plots. Herbicide bioactives
were applied at two rates (0x or 1x) to herbicide subplots. Legume
performance differed modestly between plots sprayed with the two
different bioactives, and more markedly between mowing regimes. As
re-establishment of legumes is an important goal, this information
provides insight into the expected return of legumes under field
conditions.
0057
Impact of High Stocking Density Grazing on Litter
Decomposition
Megan Mortellaro, Alexander Smart, Jiyul Chang, Michelle
Ohrtman, Sharon Clay, David ClaySouth Dakota State University,
Brookings, SD, USA
High Stocking density mob grazing is a recent phenomenon that is
being promoted by a few practitioners, but has not undergone
rigorous scientific testing. The objective of this study was to
determine the decomposition of litter from cattle grazing at high
and low stocking densities. The study was conducted in 2011-2012 on
smooth bromegrass (Bromus inermus L.) pasture near Brookings, South
Dakota. Two replicate treatments consisting livestock grazing at a
high stocking density (200,000 kg of live weight per ha moved two
times per day) or a low stocking density (5,800 kg of live weight
per ha moved once per week) for 2consecutive years were compared. A
2x2x2x2 factorial treatment design was used to examine litter
decomposition by stocking density treatment (high or low), liter
type (fresh or old), placement (surface or buried at 7.5 cm), and
origin (high or low stocking litter) in-situ from August 2011 until
mid-May 2012. After collection, samples were washed, dried and
weighed. Fresh litter decomposed 17% more than old litter (55% vs.
47%; P