DBH (cm)

10 20 30 40 50 60 70

010

2030

Basal Sprouts

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

0.0

0.5

1.0

1.5

2.0

Q. marilandica

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

0.0

0.5

1.0

1.5

2.0

Q. stellata

DBH

# of

Spr

outs

10 20 30 40 50 60 70

010

2030

40

Epicormic Sprouts

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

02

46

8

Q. marilandica

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

02

46

8

Q. stellata

DBH

# of

Spr

outs

Quercus stellata

Nu

mb

er o

f b

asal

sp

rou

ts

10 20 30 40 50 60 70

010

2030

Basal Sprouts

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

0.0

0.5

1.0

1.5

2.0

Q. marilandica

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

0.0

0.5

1.0

1.5

2.0

Q. stellata

DBH

# of

Spr

outs

10 20 30 40 50 60 70

010

2030

40

Epicormic Sprouts

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

02

46

8

Q. marilandica

DBH

# of

Spr

outs

0 10 20 30 40 50 60 70

02

46

8

Q. stellata

DBH

# of

Spr

outs

Quercus marilandica

DBH (cm)

Nu

mb

er o

f b

asal

sp

rou

ts

Poisson regressions demonstrate the relation between number of basal sprouts and Diameter for Q. marilandica and Q. stellata. Both have similar numbers of sprouts when undamaged, but blackjack oak (marilandica) responds more dramatically to destruction.

Research focus: Response to a tornadoResearch focus: Response to a tornado

-0.6 1.0

-0.8

0.8

AMCR

AMGO

AMRO

BEWRBGGN

BHCO

BLGR

NOBOCACH

CARW

DICKDOWO

EAME

EAWP

FISP

GCFL

GRSP

INBU

LASP

MODO

NOCA

PABU

PIWO

RWBL

SOSP

SUTA

TUTI

YBCU

Impacted Forest

Grassland

Non-impacted Forest

pCCA Axis 1

pCC

A A

xis

2

The bird community

In March 2003, a severe tornado (F4 on the Fujita scale) struck a crosstimbers stand, causing substantial damage and mortality. Blackjack oak proved much more susceptible to damage than post oak, but had a much stronger resprouting response. The bird community was strongly affected by tornado damage. Ongoing research will evaluate the long-term effects of the tornado on a permanently marked plot.

Epicormic sprouting on oaks

Torn

ado

path

Research in the Crosstimbers of the Tallgrass Prairie Preserve, Osage County, Oklahoma

Laboratory for Innovative Biodiversity Research and

Analysis

The crosstimbers are forests dominated by Quercus stellata (post oak) and Quercus marilandica (blackjack oak), and are prevalent throughout much of Oklahoma. Research conducted by LIBRA at the Tallgrass Prairie Preserve (managed by The Nature Conservancy) aims to resolve how these enigmatic ecosystems function.

Throughout their ranges, post and blackjack oak share dominance. Thus, they can provide a useful model system for the study of coexistence.

0

20

40

60

80

100

120

140

160

180

200

0 20 40 60 80 100 120 140 160 180 200

X

Y

Quercus stellata Quercus marilandica other

Map of a crosstimbers stand (units are meters) showing highly clumped spatial distribution of both species

Forest cover

Aci

dity

, sa

nd

Sandstone

Limestone or

bottomland

Tallgrass Prairie

mesic forest

savannas

Shortgrass prairie / limestone outcrops

crosstimberscrosstimbers

Crosstimbers dominate the dry, sandstone-derived ridges of the Tallgrass Prairie Preserve. They are more species-poor than other forests of the

preserve, and grade imperceptibly into savannahs and prairies.

Sandstone outcrops

Research focus: Spatial patternsResearch focus: Spatial patterns

Research focus: Gradient AnalysisResearch focus: Gradient Analysis

Research focus: codominanceResearch focus: codominance

Post oakBlackjack

oak

Fire history of the tornado site: summary

There were 47 fire events over 51 years (a higher fire frequency than any documented in the literature). All known fires were recorded by the trees.

Most fires occurred in dormant season since 1973, although a few were in the early and late growing season. Fire years did not correspond with drought years

Research focus: fire historyResearch focus: fire history

Fires seem to have the largest effects on the prairie/forest border

Contrary to popular thought, Contrary to popular thought, oaks effectively record fire oaks effectively record fire eventsevents

Although the effects of fire on grasslands are well-studied, the historic fire regime is largely unknown. Fire scars on trees at the edges of crosstimbers represent an opportunity for understanding fire history of both forests and grasslands.

Preliminary research on the fire history of the tornado site demonstrates the feasibility of research in fire ecology

1800

1850

1900

1950

2000

Osage tribe hunted bison seasonally, using fire to attract bison

First oil wells drilledFirst cattle in Osage CountyGrazing leases for Texas and Kansas cattlemen

Osage Reservation established; tribe relocated thereFirst railroad through Osage County

First white settlers

Dramatic increase in stocking of cattle

Major oil field discovered

Osage tribal members become ranchers

Oklahoma Statehood

Decline in cattle after WW I

Increase in stocking rate due to WW II

Four largest ranches established

Oklahoma Land and Cattle Company purchased these ranches

TNC purchased preserve and implemented bison and fire management

Exis

tin

g f

ire

sca

r re

co

rd f

or

torn

ad

o-d

am

age

d s

ite

De

taile

d d

ocu

men

ted

fire

re

co

rd

Po

ten

tia

l fire

sca

r re

cord

re

su

ltin

g f

rom

th

is s

tud

y

1800

1850

1900

1950

2000

Osage tribe hunted bison seasonally, using fire to attract bison

First oil wells drilledFirst cattle in Osage CountyGrazing leases for Texas and Kansas cattlemen

Osage Reservation established; tribe relocated thereFirst railroad through Osage County

First white settlers

Dramatic increase in stocking of cattle

Major oil field discovered

Osage tribal members become ranchers

Oklahoma Statehood

Decline in cattle after WW I

Increase in stocking rate due to WW II

Four largest ranches established

Oklahoma Land and Cattle Company purchased these ranches

TNC purchased preserve and implemented bison and fire management

1800

1850

1900

1950

2000

1800

1850

1900

1950

2000

Osage tribe hunted bison seasonally, using fire to attract bison

First oil wells drilledFirst cattle in Osage CountyGrazing leases for Texas and Kansas cattlemen

Osage Reservation established; tribe relocated thereFirst railroad through Osage County

First white settlers

Dramatic increase in stocking of cattle

Major oil field discovered

Osage tribal members become ranchers

Oklahoma Statehood

Decline in cattle after WW I

Increase in stocking rate due to WW II

Four largest ranches established

Oklahoma Land and Cattle Company purchased these ranches

TNC purchased preserve and implemented bison and fire management

Exis

tin

g f

ire

sca

r re

co

rd f

or

torn

ad

o-d

am

age

d s

ite

De

taile

d d

ocu

men

ted

fire

re

co

rd

Po

ten

tia

l fire

sca

r re

cord

re

su

ltin

g f

rom

th

is s

tud

y

Recent clearing of old-growth oaks on the border of the preserve has provided an opportunity for expanding the fire history study backwards in time, and over a larger spatial extent.

Fire history is closely tied in with human history, thus its study requires a transdisciplinary approach

Several hundred tree disks have been collected and are currently being cross-dated and evaluated for fire history.

Support for the fire history project is provided by the National Science Foundation’s Small Grants for Exploratory Research

The plant virus biodiversity and ecology (PVBE) group is attempting to inventory the plant viruses of the Tallgrass Prairie Preserve, with a special interest in the crosstimbers. So far, approximately half of crosstimber specimens are positive for RNA viruses, although the majority display no obvious viral symptoms.

Research focus: Plant Viruses of the CrosstimbersResearch focus: Plant Viruses of the Crosstimbers

AcknowledgementsAcknowledgements

David W. Stahle, David W. Stahle, Richard Guyette, Donald A. Falk, Michael Stambaugh Stephen W. Richard Guyette, Donald A. Falk, Michael Stambaugh Stephen W. Hallgren, Ronald Tyrl, Tom Wohlgemuth, Jerad Linneman, Shyam Thomas, Robert Hallgren, Ronald Tyrl, Tom Wohlgemuth, Jerad Linneman, Shyam Thomas, Robert

Hamilton, Miwa Hara, Michael C. Marler, Per Milberg and the Hamilton, Miwa Hara, Michael C. Marler, Per Milberg and the QuercusQuercus group of group of Linköping University, many volunteersLinköping University, many volunteers

Support bySupport by The Nature Conservancy, OSU Botany Department, Payne County Audubon Society, The Nature Conservancy, OSU Botany Department, Payne County Audubon Society, Oklahoma Department of Wildlife Conservation, Oklahoma State Regents for Higher Oklahoma Department of Wildlife Conservation, Oklahoma State Regents for Higher

Education, National Science FoundationEducation, National Science Foundation

Research in the crosstimbers is of international interest, as there are other ancient oak woodlands in the temperate northern hemisphere. This Quercus robur specimen is part of a complex of ancient oak woodlands in Östergötland Province, Sweden. There are many ecological similarities between these woodlands and the crosstimbers.

Fumiko Shirakura1, Matt Allen1, José Ramón Arévalo1,2, Mary Carmen Cobo1,3, Peter Earls1, Daniel McGlinn1, Kiyoshi Sasaki1, Vaskar Thapa1, and Michael W. Palmer1

1Oklahoma State University, 2University of La Laguna, 3Jaén University