The diversity
of forbs in a restored oak savanna is very high, generally
higher than in either a prairie or woodland. The reason
for this is that the savanna offers both prairie-like
and woodland-like areas as well as “true” savanna areas.
Thus, in addition to prairie and woodland plants, plants
which thrive in intermediate light regimes, savanna
specialists, are present. See the
work of Stephen Packard.
Savanna
Indicator Species
Some of these unique savanna specialists have been called
“savanna indicator species.” The list in the table below
was developed by a group of experts for the 1995 Midwest
Oak Savanna Conference and was collated by Brian
Pruka, an ecologist at the University of Wisconsin-Madison.
According
to Pruka: “The presence of these light-dependent understory
species indicates a recent closure of the canopy. Wooded
sites containing sufficient populations of these species,
therefore, have the highest potential for recovery if
properly managed through the use of prescribed burns,
mechanical canopy thinning, and other techniques….[These]
are the best indicators of former savannas and open
woodlands because they tend to be limited to partial
canopy conditions. In more densely-wooded sites, these
species are usually in a state of declining vigor due
to the ever-increasing canopy closure. They typically
persist in densely-wooded sites only near canopy openings
such as woodlot edges, roadsides, or brushed utility
corridors.” |
|
Oak
savanna "indicator" species (Pruka's
list #1 ) |
Latin
name |
Common
name |
Agastache
nepetoides |
Yellow
giant hyssop |
Agastache
scrophularieaefolia |
Purple
giant hyssop |
Anemone
virginiana |
Tall
anemone |
Asclepias
purpurascens |
Purple
milkweed |
Aster
linariifolias |
Flax-leaved
aster |
Astragalus
Canadensis |
Canadian
milkvetch |
Aureolaria
grandiflora |
Yellow
false foxglove |
Aureolaria
pedicularia |
Clammy
false foxglove |
Baptisia
leucantha |
White
wild indigo |
Baptisia
leucophaea |
Cream
wild indigo |
Besseya
bullii |
Kitten
tails |
Blephilia
ciliata |
Ohio
horse-mint |
Bromus
kalmii |
Prairie
brome |
Cacalia
atriplicifolia |
Pale
Indian plantain |
Cacalia
muhlenbergii |
Great
Indian plantain |
Camassia
scilloides |
Wild
hyacinth |
Castilleja
occinea |
Indian
paintbrush |
Ceanothus
americana |
New
Jersey tea |
Ceanothus
ovatus |
Prairie
redroot |
Cirsium
altissimum |
Woodland
thistle |
Convolvulus
spithamaeus |
Low
bindweed |
Cypripedium
pubescens |
Large
yellow lady-slipper |
Desmodium
canadense |
Showy
tick-trefoil |
Dodecatheon
meadia |
Shooting
star |
Elymus
villosus |
Silky
wild rye |
Elymus
virginicus |
Virginia
wild rye |
Erigeron
pulchellus |
Robin's
plantain |
Eupatorium
sessilifolium |
Woodland
boneset |
Gentiana
alba |
Cream
gentian |
Heuchera
americana |
Prairie
alum-root |
Hieracium
candense |
Canada
hawkweed |
Hypoxis
hirsuta |
Yellow
star-grass |
Krigia
biflora |
False
dandelion |
Lilium
philadelphicum |
Prairie
lily |
Lysimachia
lanceolata |
Lance-leaved
loosestrife |
Lysimachia
quadrifolia |
Whorled
loosestrife |
Oenothera
perennis |
Small
sundrops |
Oxalis
violacea |
Violet
wood-sorrel |
Pedicularis
canadensis |
Wood
betony |
Penstemon
gracilis |
Slender
beard-tongue |
Phlox
pilosa |
Prairie
phlox |
Polemonium
reptans |
Jacob's
ladder |
Polygala
senega |
Seneca
snakeroot |
Polytaenia
nutallii |
Prairie
parsley |
Prenanthes
alba |
Lion's
foot |
Ranunculus
fascicularis |
Early
buttercup |
Ranunculus
rhomboideus |
Prairie
buttercup |
Silene
stellata |
Starry
campion |
Solidago
hispida |
Hairy
goldenrod |
Taenidia
integerrima |
Yellow
pimpernel |
Tephrosia
virginiana |
Goat's
rue |
Thaspium
trifoliatum |
Meadow
parsnip |
Tomanthera
auriculata |
Eared
false foxglove |
Triosteum
aurantiacum |
Late
horse gentian |
Triosteum
perfoliatum |
Early
horse gentian |
Veronicastrum
virginicum |
Culver's
root |
Zigadenus
elegans |
White
camas |
Zizia
aurea |
Golden
Alexander |
|
|
|
|
Photos
of some savanna "indicator" species |
|
|
|
|
|
|
Giant
yellow hyssop |
Purple
milkweed |
Canada
milk vetch |
|
|
|
Yellow
false foxglove |
New
Jersey tea |
Canada
tick trefoil |
|
|
|
Shooting
star |
Cream
gentian |
Jacob's
ladder |
|
|
|
Lion's
foot |
Culver's
root |
Golden
Alexander |
|
|
|
|
|
|
Henderson
list of Wisconsin Savanna Specialists
In
his review of oak savanna communities of Wisconsin,
Richard Henderson presented a smaller of characteristic
savanna specialists for Wisconsin, some of which are
also listed above.
|
Latin
name |
Common
name |
Arnoglossum
atriplicifolium |
Pale
Indian plantain |
Asclepias
purpurascens |
Purple
milkweed |
Besseya
bullii |
Kitten
tails |
Camassia
scillioides |
Wild
hyacinth |
Ceanothus
americanum |
New
Jersey tea |
Cirsium
altissimum |
Woodland
thistle |
Elymus
villosus |
Silky
rye |
Eupatorium
sessilifolium |
Upland
boneset |
Gentiana
alba |
Cream
gentian |
Lespedeza
virginica |
Slender
bush clover |
Solidago
ulmifolium |
Elm-leaved
goldenrod |
Taenidia
integrifolium |
Yellow
pimpernel |
Triosteum
perfoliatum |
Tinker's
weed |
|
|
|
|
The
John Curtis Savanna List of Prevalent Savanna Species
In his extensive
research on the vegetation of Wisconsin, John
Curtis measured the relatively frequency of the groundlayer
forbs and grasses in a number of oak savannas. These data
are given in the table below, sorted by average frequency.
The Curtis list gives the average data for a number of southern
Wisconsin oak savannas, whereas the Pruka list is based on
knowledge by a group of experts.
|
|
Latin
name |
Common
name |
Average
frequency % |
Presence
% |
Amphicarpaea
bracteata |
Hog
peanut |
41.1 |
79 |
Euphorbia
corollata |
Flowering
spurge |
34.3 |
89 |
Amorpha
canescens |
Lead-plant |
33.8 |
79 |
Galium
boreale |
Northern
bedstraw |
33.2 |
79 |
Poa
pratensis |
Blue
grass |
27.9 |
53 |
Monarda
fistulosa |
Wild
bergamot |
23.1 |
84 |
Rosa
sp. |
Rose |
22.5 |
84 |
Heliopsis
helianthoides |
Ox-eye
sunflower |
22.1 |
42 |
Cornus
racemosa |
Gray
dogwood |
21.8 |
79 |
Corylus
americana |
American
hazelnut |
20.8 |
68 |
Apocynum
androsaemifolium |
Spreading
dogbane |
19.5 |
68 |
Andropogon
gerardii |
Big
bluestem |
19.4 |
68 |
Desmodium
glutinosum |
Pointed
tick-trefoil |
18.7 |
58 |
Geranium
maculatum |
Wild
geranium |
15.5 |
68 |
Lithospermum
canescens |
Hoary
puccoon |
14.6 |
68 |
Coreopsis
palmata |
Prairie
tickseed |
14.4 |
63 |
Fragaria
virginiana |
Wild
strawberry |
13.5 |
68 |
Helianthus
strumosus |
Pale-leaved
woodland sunflower |
13.3 |
47 |
Dalea
purpureum |
Purple
prairie clover |
12.7 |
63 |
Rhus
radicans |
Staghorn
sumac |
12.5 |
58 |
Helianthus
pauciflorus |
Prairie
sunflower |
12.3 |
32 |
Schizachyrium
scoparium |
Little
bluestem |
12.2 |
58 |
Galium
concinnum |
Shining
bedstraw |
12.1 |
42 |
Smilacina
racemosa |
False
Solomon's seal |
12.1 |
79 |
Vitis
riparius |
Riverbank
grape |
11.6 |
79 |
Comandra
umbellata |
False
toadflax |
11 |
84 |
Panicum
leibergii |
Prairie
panic grass |
10.9 |
58 |
Ceanothus
americanus |
New
Jersey tea |
10.3 |
63 |
Viola
pedata |
Bird's
foot violet |
8.6 |
63 |
Stipa
sp |
Needle
grass |
8.5 |
58 |
Carex
pensylvanica |
Pennsylvania
sedge |
8.4 |
32 |
Rhus
glabra |
Smooth
sumac |
8.4 |
53 |
Aralia
nudicaulis |
Wild
sarsaparilla |
8 |
42 |
Lespedeza
capitata |
Round-headed
bush clover |
7.9 |
47 |
Antennaria
neglecta |
Field
pussytoes |
7.8 |
53 |
Parthenocissus
vitacea |
Virginia
creeper |
7.6 |
53 |
Anemone
cylindrica |
Prairie
thimbleweed |
7.5 |
58 |
Viola
cucullata |
Common
violet |
5.8 |
42 |
Smilax
herbacea |
Carrion
flower |
5.6 |
37 |
Helianthus
occidentalis |
Western
sunflower |
5.3 |
37 |
Aquilegia
canadensis |
Wild
columbine |
4 |
37 |
Polygonatum
biflorum |
Smooth
Solomon's seal |
3.8 |
53 |
Physalis
virginiana |
Lance-leaved
ground-cherry |
3.2 |
37 |
Prenanthes
alba |
Lion's
foot |
3.2 |
47 |
Phlox
pilosa |
Prairie
phlox |
3 |
42 |
Asclepias
syriaca |
Common
milkweed |
1.3 |
37 |
|
From
Curtis Table XVI-2. The data have been
sorted by average frequency, with the most frequent at the
top. Presence means
the percentage of sites where the species was found.
|
|
Brian
Bader’s species lists
A much more extensive set of species lists has been developed
by Brian Bader, based on observations from the University of
Wisconsin-Madison Arboretum. This list is very extensive and
includes shrubs as well as forbs and grasses. Also, the species
are categorized as far as preferences for full sunlight, partial
sunlight, partial shade, or full shade.
Bader’s lists are very useful for detailed restoration work,
and can be downloaded
here as a PDF version.
|
|
Ecology
of savanna understory plants |
|
A major activity
in any savanna restoration is the recovery of the understory
vegetation. Depending upon the history of a site, its understory
may be rich in species, impoverished, or absent. The next
section will deal with the ecology of savanna forbs and grasses,
and the significance of this knowledge for managing a savanna
restoration.
|
|
Packard,
S. 1988a. Just a few oddball species: restoration and rediscovery
of the tallgrass savanna. Restoration & Management
Notes 6:130-24.
Pruka,
Brian. 1995. Midwest Oak Savanna Conference.
Curtis,
John T. 1959. The Vegetation of Wisconsin. University
of Wisconsin Press, Madison
|
|