SGS-LTER Long-Term Montioring Project: Arthropod Pitfall Trapping on Small Mammal Trapping Webs on the Central Plains Experimental Range, Nunn, Colorado, USA 1998-2006, ARS Study Number 118 (Reformatted to the ecocomDP Design Pattern)

This data package is formatted as an ecocomDP (Ecological Community
Data Pattern). For more information on ecocomDP see
https://github.com/EDIorg/ecocomDP. This Level 1 data package was
derived from the Level 0 data package found here: https://pasta.lternet.edu/package/metadata/eml/knb-lter-sgs/134/17.
The abstract below was extracted from the Level 0 data package and
is included for context: This data package was produced by researchers
working on the Shortgrass Steppe Long Term
Ecological Research (SGS-LTER) Project,
administered at Colorado State University.
Long-term datasets and background information
(proposals, reports, photographs, etc.) on the
SGS-LTER project are contained in a comprehensive
project collection within the Digital Collections
of Colorado
(http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429).
The data table and associated metadata document,
which is generated in Ecological Metadata
Language, may be available through other
repositories serving the ecological research
community and represent components of the larger
SGS-LTER project collection. Additional information and referenced materials can be found:
http://hdl.handle.net/10217/83450. With the exception of heteromyids, eg kangaroo
rats and pocket mice, most small rodents in
shortgrass steppe are omnivorous. Depending on
season, arthropods (insects and arachnids) make up
40-85% of the diet of grasshopper mice and
thirteen-lined ground squirrels, the most
widespread rodents in northern shortgrass steppe.
Small mammals are among the most important
predators of ground-dwelling macroarthropods and
herbivorous insects provide a direct resource link
between weather and plant production.
Understanding temporal variability in the
abundance of arthropods is central to determining
the mechanisms that drive small rodent
populations. At present, there are no long-term
studies of arthropods in shortgrass steppe,
despite the important role that these taxa play in
grassland food webs. Beginning in 1998, we
implemented field protocols to track changes in
relative abundance of terrestrial macroarthropods
in grassland and shrub-dominated habitats of
shortgrass steppe. Sampling was conducted on the
six trapping webs (three upland prairie, three
lowland saltbush) where we studied rodent
populations, and was conducted approximately
monthly from May-September (4-5 sessions/year).
Ground-dwelling macroarthropods were sampled on
each web using pitfall traps, set in one
four-by-five grid, with 10 m between traps. Traps
consisted of plastic cups (90-mm diameter, 120 mm
deep), including a plastic funnel (90-mm
diameter), buried flush with the ground surface.
Traps were shaded with wooden covers held in place
with nails; traps could be closed when not
operational by nailing the cover flush to the
ground. Traps were usually open for 4 consecutive
days (ie 80 trap-days) during a trapping session.
On the 4th day, captured arthropods were removed
from the traps, identified and released. All
arthropods were identified to the ordinal level;
beetles (Coleoptera), crickets (Orthoptera), true
bugs (Hemiptera) and spiders were identified to
the familial level; and a few taxa, eg tenebrionid
beetles, were identified to species. We also
recorded any reptiles and amphibians captured. The
number of individuals of each taxa captured per
100 trap-days was used as an index of relative
abundance, with adjustments made for traps that
were flooded or disturbed by cattle or for changes
to the number of days that traps were open (range
4-7 days). We sampled grasshoppers by counting the
numbers flushed from 0.78-m2 circular plots
(hoops) placed on each web. Hoops were set out on
the day that pitfall traps were opened and were
surveyed on the day that traps were closed. A
technician used a wooden lath to flush and count
all grasshoppers from each hoop. Grasshoppers were
not identified to species. Surveys were conducted
in 1998, then were discontinued until 2002. In
1998 and from 2002-2005, nine hoops were sampled
on each web. Beginning in 2006, we sampled a total
of 20 hoops on each web. The Shortgrass Steppe Long Term Ecological
Research (SGS-LTER) project was funded by National
Science Foundation as one of the first sites in
the US LTER Network in 1982. This collaborative,
interdisciplinary research project was established
in the Natural Resource Ecology Lab at Colorado
State University by ecosystem scientists who
learned novel approaches to study grassland
ecosystems during the International Biome Program
(IBP) (1968-1974). The SGS-LTER project was built
upon the foundation of data and information
obtained during IBP, as scientists sought to
identify and follow, and often manipulate in
experiments, important ecosystem processes over
the long-term. The objectives of the SGS-LTER
project were to investigate what mechanisms
regulate processes in the shortgrass steppe.
Research questions focused on how biotic and
abiotic components of the ecosystem are coupled,
where and when ecosystem components are most
vulnerable to perturbations, disseminating
information that would be helpful for rangeland
management and assessing impacts of climate
change. Scientists explored variations in the
structure and function of the ecosystem over space
and time and sought to understand how these
aspects are governed by climate, natural
disturbance, biota, physiography, and human use.
Scientists at the SGS-LTER integrated long-term
monitoring data, designed experimental studies,
performed and advanced modeling techniques, and
synthesized data to conduct innovative research,
education, and outreach. The core SGS-LTER
research site was established on the Central
Plains Experimental Range (CPER) in Nunn,
Colorado, part of the United States Department of
Agriculture’s Agricultural Research Service. The
research site sits in the rain shadow of the Rocky
Mountains at the western edge of the shortgrass
steppe of North America. The shortgrass steppe
ecosystem evolved with grazing by the American
bison, which has now been replaced by cattle.
Grazing by domestic livestock is the primary land
use of native grassland, which occupies about 60%
of the land area of the shortgrass steppe. Short
grasses dominate the vegetation community, which
have adapted to grazing and less than 400 mm of
annual rainfall. The topography is characterized
by gently rolling hills, broad ephemeral stream
courses and low flat-topped terraces. Aspects of
physiography regulate the shortgrass steppe
ecosystem, including landscape position, soil age,
water holding capacity, soil depth and surface
texture which, in turn, determine such properties
as soil moisture storage, net primary productivity
and the distribution of small mammals such as
prairie dogs and pocket gophers. SGS-LTER
scientists have expanded their research studies
beyond the CPER to identify similar or different
patterns in ecosystem structure and function in
North American grasslands; across the Great Plains
region and along the latitudinal gradient from
Wyoming to Mexico. They also conducted cross-site
collaborative research and compared their results
and tested theories in grasslands located in South
America, Asia and Africa. Funding from NSF for the
SGS-LTER project ends in 2014, but over thirty
years of research has resulted in a scientific
team with diverse expertise, which produced over
1200 journal publications, almost 400 book
chapters and over 200 theses. Data, products and
other information produced from the SGS-LTER are
available through the LTER Network Information
System, Digital Collections of Colorado at CSU or
upon request through [e-mail].