Transcript poster

Community Classification of the Pawnee National Grasslands, Shortgrass Steppe, USA
Scott B. Franklin
1
1,
Michael Schiebout
2,
& Amber Brandt
1
School of Biological Sciences, University of Northern Colorado, Greeley, CO USA; 2 Department of Biology, Union University, Jackson, TN USA
But from these immense prairies may arise one great advantage to the United States, viz., the restriction of our population to some
certain limits, and thereby a continuation of the union. Our citizens being so prone to rambling, and extending themselves on the
frontiers, will, through necessity, be constrained to limit their extent on the west to the borders of the Missouri and the Mississippi,
while they leave the prairies, incapable of cultivation, to the wandering and uncivilized Aborigines of the country.
Zebulon Pike
Purpose
Results
Classification of vegetation provides an inventory to assess change, a common
language to compare communities among regions, and a baseline for land
stewardship decisions. Several initial efforts toward mapping and vegetation data
collection are available for the Pawnee National Grasslands, but not a structured
community analysis and subsequent mapping for the entire area. The goal of this
study is to provide such a local community analysis and relate community types to
environmental conditions. Subsequently, local types will be related to The National
Vegetation Classification (USNVC) developed as a standard for the United States.
NMS ordination revealed clear significant patterns of community types, and
subsequent discriminant analyses differentiated community types mainly by
Bouteloua-Yucca
percent
cover
and
site
type
(an
index
Bouteloua-Opuntia
Pascopyrum smithii
of the moisture gradient).
Bouteloua Ridgetop
The Pawnee National Grasslands is located in
northeastern Colorado with the Shortgrass
Steppe Ecoregion, and part of the Colorado
Piedmont and High Plains physiographic regions.
The fragmented area is gently rolling with few
outcrops; 78,128 ha.
Physiography
2.0
NMS Axis 2
Study Area
2.5
Mixed
Carex-Eleocharis
Sporobolus-Glycyrrhiza
Bouteloua gracilis
Bouteloua dactyloides
decreasing
cover
1.5
The mixed community included
everything from dry riparian to rock
outcrops harboring mixed prairie
species, Pinus flexilis, and shrubs.
1.0
0.5
0.0
increasing
moisture
-0.5
Site 1
-1.0
-2
-1
0
1
2
NMS Axis 1
Euclidean Distance Clustering using Ward’s Method
Site 5
Sedimentary cycles
Climate
Mean Max Daily Temp in
Summer = 31°C
Bouteloua-Yucca Small Rock Outcrop Community
Bouteloua-Opuntia Slope Community
Site 7
Mean PPT = 305-380 mm
Pascopyrum smithii Community
Bouteloua Open [low cover] Community
Slightly increasing moisture
from west to east
Remnant
Buffalo
Wallow
Cottonwood
riparian
Mixed Community
Geology includes shale, sandstone, sand dunes, and gravel; soils
include badlands, mollisols, entisols, and alfisols.
Site 2
Carex-Eleocharis Wet Community
Sprobolis airoides-Glycyrrhiza lepidota Community
Methods
Bouteloua gracilis Community
The initial phase of this project used GIS map layers to develop an
ecological land type classification that was used to stratify field
plots, including geology, soils, elevation, and landscape location
(Kupfer & Franklin 2000; see Figures below).
Site 97
Bouteloua dactyloides Community
Site 4
Site 11
Site 44
Site 33
Discriminant Analysis accuracy table; values are percent of plots correctly classified
Plot sampling utilized the Carolina Vegetation
Sampling method modular plots (Peet et al.
1998); ten 10X10 modules = 20X50 m plots.
A total of 102 plots were collected. Cover of
taxa was recorded in four of the ten modules
using a modified Daubenmire cover scale.
Trees were measured in all ten modules.
Community Type
Bouteloua-Yucca
Bouteloua-Opuntia
Pascopyrum smithii
Bouteloua Ridgetop
Mixed
Carex-Eleocharis
Sprobolus- Glycyrrhiza
Bouteloua gracilis
Bouteloua dactyloides
Various multivariate techniques were used to
classify the local community types and relate
those types to abiotic parameters.
t
t
0.1
1.1
0.5
0.5
t
0.1
0.3
0.1
0.1
Community Types
Bouteloua- Bouteloua Boutelousa Pascopyrum
SporobolisOpuntia
gracilis dactyloides
smithii
Mixed Glycrrhiza
10.9
41.7
12.9
13.2
3.2
2.7
1.3
1.8
2.2
0.2
3.6
15.6
9.2
40.5
7.2
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1.3
1.9
1.5
0.3
0.2
0.2
0.2
t
t
t
4.7
8.8
6.1
7.6
0.5
t
5.2
2.6
2.6
37.5
0.9
8.2
1.5
0.3
0.2
0.2
0.5
t
1.8
t
t
0.5
t
1.5
2
1.3
1.4
t
0.5
t
3.3
1.7
0.3
t
t
39.2
0.2
12.5
t
t
1.9
2.5
0.4
5.8
0.1
5.8
t
t
0.2
0.1
0.2
0.3
2.9
t
1.5
0.8
0.2
0.5
t
t
t
41.7
Pascopyrum
smithii
12.5
8.33
100
5.9
8.3
4.8
94.1
16.7
16.7
14.3
8.3
4.8
33.3
SporobolusGlycyrrhiza
25.0
25.0
100
8.3
Bouteloua
gracilis
Bouteloua
dactyloides
12.5
8.3
16.7
100
8.3
23.8
50.0
14.3
8.3
38.1
The local Community types provided above are just that, local, and represent
variations on concepts of wider distribution. However, it is important to place our
local community types into the national classification concepts to fully describe the
types. Most of the communities are part of the Great Plains Shortgrass Prairie Group.
A total of 299 species (~430 known) were witnessed in the 102 plots scattered
throughout the Pawnee National Grasslands. Eights distinct (one mixed)
community types were distinguished through clustering analysis.
Species
Bouteloua gracilis
Yucca glauca
Bouteloua dactyloides
Aristida purpurea
Elymus elymoides
Rhus trilobata
Opuntia polyacantha
Pascopyrum smithii
Artemesia frigida
Artemesia filifolia
Atriplex canescens
Schizochirium scoparium
Toxicodendron rydbergii
Sporobolus airoides
Glycyrrhiza lepidota
Distichlis spicata
Elymus canadensis
Juncus balticus
Taraxacum officinale
Poa spp
Carex spp
Juncus spp
Eleocharis spp
Circium arvense
BoutelouaOpuntia
Fitting the Local Community Types to the USNVC
Results
Bouteloua BoutelouaOpen
Yucca
2.3
15
0.7
6.8
1.1
4.8
0.2
4.5
0.1
2.5
0.7
1.9
0.2
1.6
2.2
1.1
0.3
0.7
t
0.3
0.1
0.3
1.1
0.3
0.1
0.1
0.2
BoutelouaYucca
62.5
8.33
Community Type
Bouteloua Mixed
CarexOpen
Eleocharis
12.5
8.3
t
t
Community Types
BoutelouaYucca
CarexEleocharis
0.1
t
0.1
1.7
0.1
0.9
1.1
3.1
26
13.5
7.4
1.7
BoutelouaOpuntia
Bouteloua
Boutelousa
Pascopyrum SporobolisCarexUSNVC
Bouteloua Open
gracilis
dactyloides
smithii
Glycyrrhiza Eleocharis
Bouteloua
Bouteloua
Bouteloua gracilisArtemesia gracilis-Buchloe gracilis-Buchloe
Great Plains Shortgrass Prairie & Shrubland Buchloe dactyloides Gutierrezia
frigidadactyloides
dactyloides
MG
Xeric Soil
sarothrae –
Boutleloua
Herbaceous
Herbaceous
Great Plains Shortgrass Prairie Group
Herbaceous
Yucca glauca gracilis Dwarf- Vegetation
Vegetation
Vegetation
Dwarf-shrub
shrub
?
?
Pascopyrum
Great Plains Mixedgrass Prairie & Shrubland
smithiiMG
Bouteloua
Central Great Plains Mixed Grass Prairie
gracilis
Group
Artemesia
filifoliaBouteloua
Great Plains Sand Grassland & Shrubland
gracilis
http://usnvc.org/explore-classification/
MG
Shrubland
Take-home Messages
 A vegetation gradient was found from open rock communities to
wet prairies.
 Local communities were related to environmental factors, but also
typical disturbances (i.e., prairie dogs, grazing).
 The relation of these local types to the USNVC is clear for most of
the area and common vegetation, but the USNVC is lacking mesic
prairie association descriptions.