My ecological address: the shortgrass steppe biome
Information for the Instructor:
GOAL OF THE LAB: The goal of this lab is to get students out in the field and guide them in
their discovery and understanding of the shortgrass steppe biome (their local biome in Fort
Collins). To achieve this goal, the lab is divided into the following components:
1. A short reading assignment
2. A self-guided visit to the Shortgrass Steppe LTER site to collect data on
a. Interactions among plants and their physical environment
b. Interactions among different species of plants
c. Interactions among plants and animals
3. Climate diagram construction and assessment
4. Synthesis Questions
5. Construction of a model that demonstrates INTERACTIONS among plants, animals,
and the environment.
Two optional assignments have been included and can be incorporated at the instructor’s
discretion.
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5. Quiz on assigned reading
6. An internet link to a listening piece on The Nature Conservancy’s hands-on exchange
program between the US and Mongolia. This program encourages information
exchange on the sustainable use of grassland ecosystems (and shortgrass steppe, in
particular). For the student, this demonstrates that many biome types are found in
several locations across the globe.
READING ASSIGNMENT: Before going out into the field, students will be asked to read an
article about Great Plains grasslands.
Samson FB, Knopf FL, Ostlie WR. 2004. Great Plains ecosystems: past, present, and future.
Wildlife Society Bulletin 32:6-15.
There is an optional True/False quiz and answer sheet available for the instructor to use.
TECHNICAL LOGISTICS: This lab exercise is intended for students to complete in groups.
The instructor may want to remind students that some basic sampling equipment is required
and that a digital camera should be brought along in the field to document sampling and the
visit. Detailed questions throughout the lab exercise will effectively guide students in their
sampling efforts.
The exact location of sampling is to be determined by the instructor. Directions to the
Shortgrass Steppe LTER (north of Nunn, CO) are included in the student’s packet.
FINAL ASSIGNMENT: The lab is currently set up to have students conduct the field visit and
data collection in groups, followed by a 5-10 minute PowerPoint presentation of their findings.
At the end of the assignment, students are given a list of “things to include” in their presentation.
ADDITIONAL INSTRUCTOR INFORMATION: To tie all this information together, students are
instructed to create a box model that demonstrates interactions between plants, animals, and
the environment. If box models have not been used in the course previously, the instructor may
need to guide the students in this exercise (as this box model is essential for their presentation).
My ecological address: the shortgrass steppe biome
Student’s Name:___________________________
Date:__________________
Group Members Names:__________________________________________________
Introduction
Today you will be exploring the ecosystem type that characterizes Fort Collins and the Colorado
Front Range – the shortgrass steppe. Scattered throughout Fort Collins are native remnants of
this ecosystem, which you may be familiar with if you’ve hiked the Kathie Fromme Prairie or
ridden your mountain bike in the Pine Ridge Natural Area. This lab exercise will encourage you
to become an ecologist for a day as you visit the Shortgrass Steppe Long-Term Ecological
Research (LTER) site in northeastern Colorado.
As a final project, and a way to assess how much you’ve learned in this lab, you will be asked to
create a PowerPoint presentation that you will share with your classmates. The topic of this
presentation will be “My experience in the shortgrass steppe” and it should emphasize the three
types of interactions highlighted below.
Use the questions throughout this lab exercise to guide you in your collection of data at the field
site. Additionally, feel free to take notes and digital photographs of anything that catches your
eye or may aid the rest of the class in understanding this biome.
Objectives
In this learning module, you will:
1. Observe the physical factors, plant dominance, and interactions among organisms in the
shortgrass steppe ecosystem.
2. Identify the main plant species, describe some of their key structural features, and
consider how these features enable them to be successful in this ecosystem.
3. Develop some hypotheses that explain why the vegetation in the shortgrass steppe is so
very different than in the Rocky Mountains and foothills, which are fewer than 100 miles
to the west.
4. Learn about another location on earth that is similar in structure and function to
shortgrass steppe of Colorado.
Ecological History of the Shortgrass Steppe & Great Plains of the United States
Ecological communities are extraordinarily complex. The assemblage of plants that you
observe at any time results from (1) interactions among plants and their physical environment,
(2) interactions among different species of plants, and (3) interactions among plants and
animals. All of these interactions are driven by a flow of energy from the sun that is captured by
green plants and passed to herbivores, predators, and decomposers.
The shortgrass steppe is a grassland ecosystem that is part of the Great Plains of North
America. It is the westernmost grassland type in this region.
Initial Reading Assignment
Before leaving for the shortgrass steppe field site, please read the following article:
Samson FB, Knopf FL, Ostlie WR. 2004. Great Plains ecosystems: past, present, and future.
Wildlife Society Bulletin 32:6-15.
Why are grasslands of conservation interest? Why are they important economically?
List five words (scientific or non-scientific) that come to mind when you think of grasslands
and/or the shortgrass steppe ecosystem.
Equipment/Materials you will need for fieldwork/data collection
IR Thermometer
Flags (4)
Measuring tape (at least 5m in length)
This lab handout
Pencil
Digital Camera
The Central Plains Experimental Range: How do I get there?
The Central Plains Experimental Range (CPER) is ca. 40 miles from the CSU campus. Allow
ca. 1 hour for travel time.
From CSU: Head west on Mulberry Road (5 miles), which becomes CO-14 after passing over I25. You will continue west on CO-14 for 13 miles until you enter the town of Ault. Once you
pass through the tall of Ault, turn north onto CO-85. You will need to drive ca. 16 miles before
keeping your eyes out for a sign for the CPER, which will be on the right-hand (or east) side of
the road. Make a right (east) turn onto CO-114 (gravel road). Your instructor will provide
detailed directions as to the specific place in which you should stop and collect your data.
At the Central Plains Experimental Range
PART 1 – Observe and assess the ecological characteristics of the shortgrass
steppe
Imagine you are a plant or an animal. Take some time to look around, listen, and think about
what it takes to survive in this environment.
List at least 2 major challenges associated with survival and reproduction in this environment?
Abiotic factors
Abiotic factors are non-living chemical or physical aspects of the environment. In
characterizing an organism’s environment, ecologists may describe abiotic factors such as
water availability, sunlight intensity, temperature, soil structure, and climate.
1. Is the sunlight intense? Can you find any way to escape it if you are a plant? Animal?
Insect? (In other words, can you find any shade in which to hide?)
2. What is the temperature 2 m aboveground? What is the temperature at the soil surface? Is
the wind blowing or is it still? Use the IR thermometer to document the temperature in at
least 4 different locations.
3. Describe the color and texture of the soil. Does it feel moist or dry? Is it sandy or does it
feel like clay?
4. Describe the ground cover. Is it mostly covered by plants or this there abundant bare soil?
5. Is there a layer of plant litter (old, dried, dead material) on the ground?
Biotic factors
Biotic factors are living factors (plants, animals, etc.) that surround and potentially influence
an organism. In characterizing an organism’s environment, ecologist may describe biotic
factors such as food acquisition, predator-prey relationships, competition of plants for
resources, or plant-pollinator relationships.
Plant Abundance & Dominance
Biomes are frequently characterized based on the type and abundance of plants that inhabit
them. In ecology, the term “biodiversity” is most often used to describe the number of species
in a given area. It can also be used to describe a plant community in terms of the variety of
functional groups that are present. There are 3 functional groups that you will encounter at the
shortgrass steppe: grasses, forbs (non-graminoid herbs or “wildflowers”), and shrubs.
Why do you think ecologists bother to separate plants into functional groups? Is it arbitrary, or
does each group interact with its environment in a different way?
For this section of the lab, you will need to use a meter tape and some flags to create a 5m x
5m study area for vegetation sampling. In order to identify the plants in your square, use the
pictures of common shortgrass steppe plants that are included at the end of the lab handout. If
you encounter a plant that is not pictured, just call it “unknown plant 1,” “unknown plant 2”, etc.
Remember to take some pictures of the plants that you find!
1. List the plant species that are present in the 5m x 5m area.
2. Is there a single species that is most abundant in cover or are several species equally
abundant?
3. What general categories of plant types (shrubs, grasses, forbs) are present?
4. Describe the physical features of 3 different plant species that you see. Some things to
consider are a) the size and shape of leaves, b) plant height, c) the presence or absence of
woody stems, and d) the presence of spines or other mechanisms to deter herbivores. It
may help to compare the plants to those from another ecosystem (i.e. forest).
Interactions among organisms
There are many types of plant-animal interactions that take place within the shortgrass
steppe—pollination and grazing are just two examples. The following questions will ask you to
think about how the animals you see “fit” into this ecosystem. Take some time to observe
animal behavior.
1. What are some of the vertebrates (i.e. rodents, mammals, birds) you have seen at the study
site or on your drive around the field site? How do they influence this ecosystem? What do
they eat? Are they predators or prey for other animals?
2. What are some of the invertebrates (i.e. insects)? What is their role in this ecosystem?
What do they eat? Are they predators or prey for other animals?
3.
Did you observe any prairie dog colonies? List some ways in which prairie dogs modify the
shortgrass steppe ecosystem.
Back at CSU: post-fieldtrip exercise
Climate diagrams
Climate diagrams are special graphs that display monthly average temperature and precipitation
in a region over the course of a year. In plotting these data together on a single graph, it is
much easier to view the relationship between temperature and the quantity and distribution of
precipitation in different months/seasons of the year. Ecologists and geographers use climate
diagrams in order to understand and describe why certain types of vegetation are found in
different climates.
In this lab exercise, you are going to construct and compare climate diagrams for 2 different
ecosystems – shortgrass steppe and sub-alpine forest.
Directions for constructing a climate diagram:
The x-axis (independent variable) will consist of the months of the year – January through
December. Using vertical bars to indicate amounts (mm), plot precipitation data for each month
using the normal left y-axis (remember to label units!). Next, plot the temperature data (with a
dot for each month) using the x-axis (month) and a right y-axis. The 12 data points should then
be connected by a line.
The data that you will need to construct your data is included in a table below. A climate
diagram for the Fraser Experimental Forest (sub-alpine forest) has already been constructed for
you as an example (see below).
30
30
120
Sub-alpine forest
10
60
0
40
Precipitation (mm)
80
20
100
Temperature (C)
Precipitation (mm)
Shortgrass steppe
20
100
80
10
60
0
40
-10
20
20
-10
0
-20
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug Sep
Oct
Nov
Dec
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug Sep
Oct
Nov
Dec
Temperature (C)
120
Table 1. Monthly precipitation and temperature data for the shortgrass steppe and sub-alpine
forest. Data are mean values.
shortgrass steppe
Month Precip. (mm) Temp. (°C)
Jan
9.2
-1.8
Feb
10.3
-1.1
Mar
17.4
2.4
Apr
25.5
7.5
May
51.9
13.1
Jun
48.4
17.9
Jul
43.8
21.8
Aug
34.0
20.6
Sep
29.4
15.7
Oct
16.4
9.0
Nov
7.0
2.0
Dec
3.9
-2.2
Mean
25.1
8.9
Total
287.7
--
sub-alpine forest
Precip. (mm) Temp. (°C)
45.5
-10.2
44.4
-7.9
57.3
-4.5
68.4
-0.6
65.5
4.0
35.9
9.7
56.6
12.4
46.7
11.0
41.4
6.8
39.6
0.2
50.2
-6.1
46.8
-10.1
49.9
0.3
598.3
--
For each ecosystem, list the month of the year in which the most precipitation is received? Is it
the same for both ecosystems?
For each ecosystem, which time of year is the majority of precipitation received (spring, winter,
fall, or summer)?
Is precipitation distributed uniformly throughout the course of the year?
Using the climate information (above), your data from the CPER, and your experience in subalpine forest, develop 2 hypotheses that explain the difference in vegetation between the
shortgrass steppe and sub-alpine forest.
Synthesis Questions
What adaptations help plants to survive in the shortgrass steppe ecosystem?
Which resource (light, nitrogen, water) do you think is the most limiting in the shortgrass
steppe?
How does climate influence the type of plants and animals that are native to the shortgrass
steppe? Why are there not more trees in this ecosystem?
Using your knowledge about plant strategies and competition, do you think that an introduced
plant species would have an easy or hard time becoming established in this ecosystem? Why?
What structural and functional aspects of the shortgrass steppe has man exploited in making
this ecosystem economically profitable?
INTERACTIONS. In the shortgrass steppe (and in all ecosystems), organisms interact with
both each other and the environment. In the space below:
1) make a list of five organisms
2) indicate how each organism interacts with the environment and 1-2 other organisms.
Next, construct a box model for the ecosystem that depicts energy flow through this ecosystem.
Choose one organism and describe (in words) the impact of removing it from the ecosystem.
PowerPoint Presentation
As part of your assessment, each group will put together a 5-10 minute PowerPoint
presentation using pictures and data from the field visit. You may also wish to include
information from the reading. Your presentation should begin with a explanation of the
shortgrass steppe ecosystem through a box model. Use pictures and data to support the
interactions between organisms that you observed in the field and are important aspects of
ecosystem structure and function.
Common Plants of the Shortgrass Steppe Ecosystem
Scientific Name: Bouteloua gracilis
Common Name: blue grama
Reference: USDA Plants Database
(http://plants.usda.gov/)
Key Characteristics: Plant is short (10-20 inches)
with narrow basal leaves of 3-6 inches. It grows in
definite bunches. Mature seed heads are curved
and resemble a human eyelash.
Scientific Name: Stipa comata
Common Name: needleandthread grass
Reference: Northern State University – The Nature
Source:http://www.northern.edu/natsource/GRASS
ES/ng1.jpg
Key Characteristics: Plant ranges in height from 1-4
feet and has narrow basal leaves that are usually
rolled inward (3-12 inches long). If present, the
seed head contains a long awn that resembles a 49 inch strand of thread.
Scientific Name: Elymus hystrix
Common Name: bottlebrush squirreltail
Reference: KSU Agronomy Station
(http://spuds.agron.ksu.edu/ksgrasskey/images/Sita
nionhystrix.jpg)
Key Characteristics: Plant ranges in height from 8180 cm and has leaves distributed throughout the
stem. Leaves often rough and/or hairy. If present,
the seed head resembles a bottlebrush.
Scientific Name: Vulpia octoflora
Common Name: sixweeks fescue
Reference: Digital Flora of Texas, Vascular Plant
Library
(http://www.csdl.tamu.edu/FLORA/imaxxpoa.htm)
Key Characteristics: This plant is usually found in
solitary or small clumps. Leaf blades are very
narrow (1-2 mm) and occur in tufts that are 1-4
inches long. If in flower, many flowers will be
arranged along the stem (or spike).
Scientific Name: Carex eleocharis
Common Name: needleleaf sedge
Reference: Texas A&M Digital Libraries
(http://www.csdl.tamu.edu/FLORA/carex/k2332560.ht
m)
Key Characteristics: This plant may be 10-25 cm in
height. Plant Leaves originate basally and are often
contained in brown to dark brown papery sheaths.
Seed heads are small and typically appear as one
per stem.
Scientific Name: Buchloe dactyloides
Common Name: buffalograss
Reference: USDA Plants Database
(http://plants.usda.gov)
Soft, grey-green grass that grows 3-12 inches in
height. Leaves originate along the stem and
rhizomes may be observed on the soil surface
connecting individual plants.
Scientific Name: Sphaeralcea coccinea
Common Name: scarlet globemallow
Reference: National Park Service
(http://www.nps.gov/plants)
Key Characteristics: If in flower, flowers will
be a brilliant orange color. Leaves are
deeply palmate, arranged alternately on
stems, and grey-hairy on the undersides.
Scientific Name: Opuntia polycantha
Common Name: plains pricklypear
Reference: http://www.elicriso.it/index.htm
Cactus (it’s the only one in this list!)
Scientific Name: Chrysopsis villosa
Common Name: hairy goldenaster
Reference: USDA Plants
Database(http://plants.usda.gov/)
Key Characteristics: The narrow grey-green leaves
of this plants are covered by hairs. Numerous
many-petaled sunflower-like flowers occur atop the
branched stems.
Scientific Name: Artemisia frigida
Common Name: fringed sagewort
Reference: USGS Northern Plains
Wildlife Research Center
(http://npwrc.usgs.gov)
Key Characteristics: A low matforming shrub with silver leaves
and little yellow flowers. This plant
is typically 10-40 cm in height.
Many leaves grow from the stems,
each of which is finely cut.
Scientific Name: Chrysothamnus nauseosus
Common Name: rubber rabbitbrush
Reference: Digital Flora of Texas, Vascular Plant
Library
(http://www.csdl.tamu.edu/FLORA/imaxxpoa.htm)
Key Characteristics: A low, shrubby, much
branched perennial with average heigh of 0.5-1
m. This shrub is woody at the base and stems
have a dense cover of white, felty hair that creates
a wooly cover. Flowers are yellow.
Scientific Name: Oenothera albicaulis
Common Name: prairie evening primrose
Reference: Oklahoma Panhandle State
University Plants Database
(http://www.opsu.edu/)
Key Characteristics: This plant is
generally very low to the ground, but can
grow to 0.3 m. It flowers in early summer
with white petals and yellow
pistils/stamens. Leaves are highly
dissected.
Listening assignment: the shortgrass steppe in Mongolia
The Nature Conservancy in Colorado is currently involved in a hands-on exchange program
with ecologists and pastoralists in Mongolia. The purpose of this research and outreach
program is to share information and learn about the sustainable use of grassland ecosystems
worldwide. Read about this program on their website:
http://www.nature.org/wherewework/northamerica/states/colorado/travel/art16575.html
Listen to the Voice of America Newsclip about research connections between shortgrass steppe
in Colorado and the Mongolian Plateau.
Read the section entitled Colorado’s Grassland Work.
In a single paragraph, write a short reflection or response to the Nature Conservancy’s
Exchange Program.
Instructor Copy
QUIZ ON ASSIGNED READING – SAMSON ET AL. 2004
For each of the statements below, identify whether it is “True” or “False.” Next, correct
statements that you identify as false.
1. TRUE or FALSE The key ecological drivers in Great Plains grasslands are fire,
drought, and grazing.
2. TRUE or FALSE Great Plains grasslands include shortgrass steppe, mixed grass
prairie, and tallgrass prairie. The extent of these grasslands has been reduced by 40%,
largely due to conversion for agriculture and development.
3. TRUE or FALSE Prior to European settlement, grasslands in the United States were
grazed by bison, which are now extinct.
4. TRUE or FALSE The movement of bison across the Great Plains and their grazing
patterns was historically influenced by both rainfall and fire frequency.
5. TRUE or FALSE Some conservation efforts for Great Plains grasslands have focused
on identifying and establishing MDAs. MDAs are land areas that should contain key
ecological drivers and be of sufficient size to support native biodiversity.
6. TRUE or FALSE Short- and mixed grass prairie in Colorado, Wyoming, and Kansas
offer the best chance for action to conserve the full array of biodiversity within
grasslands. These states still contain large areas of native grasslands.
7. TRUE or FALSE A key aspect of grassland conservation is the need to conserve
underlying processes that create biodiversity. In grasslands, these processes include
fire and grazing.
8. TRUE or FALSE Restoration efforts should focus on re-establishing dominant plant
species because these species have an important influence on ecosystem structure and
function. Additionally, dominant species are an important source of food and habitat for
species of higher trophic levels.
9. TRUE or FALSE Prairie dogs are keystone herbivores in shortgrass steppe.
10. TRUE or FALSE Restoration of grasslands will take 10-20 years because of the time
involved in restoring soil organic matter, soil carbon, and soil nitrogen.
QUIZ ON ASSIGNED READING – SAMSON ET AL. 2004
For each of the statements below, identify whether it is “True” or “False.” Next, correct
statements that you identify as false.
1. The key ecological drivers in Great Plains grasslands are fire, drought, and grazing.
TRUE
2. Great Plains grasslands include shortgrass steppe, mixed grass prairie, and tallgrass
prairie. The extent of these grasslands has been reduced by 40%, largely due to
conversion for agriculture and development.
FALSE. 70%
3. Prior to European settlement, grasslands in the United States were grazed by bison,
which are now extinct.
FALSE. Bisons are not extinct and still graze in limited areas within the United States.
4. The movement of bison across the Great Plains and their grazing patterns was
historically influenced by both rainfall and fire frequency.
TRUE.
5. Some conservation efforts for Great Plains grasslands have focused on identifying and
establishing MDAs. MDAs are land areas that should contain key ecological drivers and
be of sufficient size to support native biodiversity.
TRUE
6. Short- and mixed grass prairie in Colorado, Wyoming, and Kansas offer the best chance
for action to conserve the full array of biodiversity within grasslands. These states still
contain large areas of native grasslands.
FALSE. Kansas does not contain large amounts of native grassland relative to other
states.
7. A key aspect of grassland conservation is the need to conserve underlying processes
that create biodiversity. In grasslands, these processes include fire and grazing.
TRUE.
8. Restoration efforts should focus on re-establishing dominant plant species because
these species have an important influence on ecosystem structure and function.
Additionally, dominant species are an important source of food and habitat for species of
higher trophic levels.
TRUE.
9. Prairie dogs are keystone herbivores in shortgrass steppe.
TRUE.
10. Restoration of grasslands will take 10-20 years because of the time involved in restoring
soil organic matter, soil carbon, and soil nitrogen.
FALSE. 30-50 years