Transcript Quercus - Prairie Ecosystems

To Be or Not to be a Quercus
Bur Oak
Quercus macrocarpa
St Paul
California Blue Oak
Justin Quercus Borevitz
Prairie Ecosystems
4/19/07
• Wood/lignin evolved 3 times in angiosperms
– Asters, grasses (bamboo), legumes
• Oaks Hard wood, slow growing
• Old growth, 400 years! 2 stories high..
• Obligate hosts (fungal, insect/ant farming)
– Edwards hairstreaks
• Sudden Oak Death
• Syndrome (SODS)
– California?
Looks like a hybrid…
Limited hybridization between Quercus lobata and Quercus
douglasii (Fagaceae) in a mixed stand in central coastal California
Kathleen J. Craft2, Mary V. Ashley2,4 and Walter D. Koenig3 American
Journal of Botany. 2002;89:1792-1798.)
We conclude that adult hybrids of Q. douglasii x Q.
lobata are rare at this site and plasticity in morphological
characters may lead to overestimates of hybridization
among Quercus species (Cali - valley oak, blue oak)
Mary V. Ashley Professor UIC Biological Sciences
..found that over half of the acorns from isolated stands are pollinated
by trees outside the stand, at great distances. Within the stand,
pollinations occurred nearly at random. We have clearly
demonstrated that the mating system of the bur oak ..
Model for Speciation, catch it in the act..
Hmm easy to catch since they done go anywhere fast
Quercus rubra, Red Oak,
Quercus muhlenbergii, Chinkapin oak,
chinquapin oak, yellow chestnut oak
Tree of Life
• Dycotiledonae:Hamamelididae:Fagales:Fagaceae
• Taxonomy browser
• Genome Project! English oak 1439 ESTs
• http://www.genome.clemson.edu/projects/fagaceae/
• Quercus robur is one of between 300 and 600 species of oak
distributed over the entire northern hemisphere. The physical size of
the genome is larger than many other woody angiosperms while
being among the lower values of plants. Study of Quercus robur is
one of the entry points for study of the Fagaceae and allows
comparative genomics to become a field of study in woody
angiosperms.
• Research Paper
Plant biol (Stuttg) 2007; 9: 116-126
DOI: 10.1055/s-2006-924542
Genetic Variation and Differentiation Within a Natural Community of
Five Oak Species (Quercus spp.) A. L. Curtu1, O. Gailing1,
L. Leinemann1, R. Finkeldey1
• Oaks (genus Quercus - Fagaceae) are amongst the most common
tree species in the temperate and Mediterranean parts of the
Northern hemisphere ([Nixon, 1993]). Because of their high
ecological and economical importance, but also due to their
propensity to hybridize (e.g., [Burger, 1975]), oaks have been the
focus of intensive research and have become long-standing models
in evolutionary genetics.
• Only the very rare chloroplast variants are species-specific, and
consequently there is a nearly complete lack of differentiation
between the two species, Q. robur and Q. petraea
Chesnuts in their bur
Bur Oak
• evergreen (Q. ilex, Q. coccifera, Q. suber),
• semi-deciduous (Q. trojana, Q. frainetto),
• deciduous habits (Q. cerris, Q. pubescens,
Q. robur, Q. petraea)
• all in Italy!
WHAT ARE GOVERNMENTAL
BODIES DOING?
• City of Los Angeles protects larger Oaks on
large properties
• County of Los Angeles protects large Oak trees
• Pasadena protects larger “native trees”
• City of Bakersfield has no tree protection
ordinances
• State of California has pending Oak tree
conservation legislation
• City of Visalia protects Valley Oaks
OAK TREE REMOVAL
MITIGATION
• Attempt to replace the “value” of what is
lost
• Minimum by law 2:1 15 gallon replacement
• Minimum in practice, 2:1 36” box size
replacement
• No limit on the amount of replacement
mitigation
Nutrition
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Heterotrophic
Secrete extracellular enzymes
Absorptive nutrition
Saprobes: decay dead organic matter
pathogens: biotroph, necrotroph
symbionts: parasites - commensals mutualists
A Cooperative Research:
USDA Forest
The Israel
Service International
Forest Authority
Programs
(KKL)
Curtis Flather,
Ronen Kadmon,
Rocky Mountain Research
Center, USDA Forest
Service
Department of
Ecology,
The Hebrew University
of Jerusalem
Denis Dean, Department
of Forest Sciences,
Colorado State University
Adult oaks (Quercus calliprinos) in Mt. Meron
Herbaceous vegetation in the front, recovering trees in the back, Mt
Earlier stages of recovery following land abandonment
dwarf shrubs, tall shrubs, and low trees in Mt. Meron
30 years after abandonment of
pastoral cultivation in Mt. Meron
Mt. Meron 1945
Mt. Meron 1964
Mt. Meron 1992
Mediterranean type ecosystems
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Br
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Average
annual change
Mediterranean vegetation change in
long-term, landscape-scale studies
2%
1%
0%
Why is there such a difference
between vegetation dynamics
in California and
the Mediterranean basin?
1. Local ecological and
anthropogenic conditions
2. Different soils
3. Different evolutionary history
A transplant
experiment is
currently conducted,
where oaks from
both countries are
grown together in
both sites, in a
controlled
environment
Phylogenetic structure of long-term
experimental communities at Cedar
Creek Natural History Area,
Minnesota
Charles G. Willis
University of Minnesota – Twin Cities
What is phylogenetic structure?
Phylogenetic structure describes the
phylogenetic relationships of species
neighbors within a given community.
In other words, are neighbors closely related
or distantly related evolutionarily?
Pooideae
Chloridoideae
POACEAE
Panicoideae
Areneae
Poeae
Arundioideae
Eragrostideae
Angropogoneae
Paniceae
muhlenbergii
pensylvanicus
sp
triglomerata
sp
capillare
oligosanthes
perlongum
praecocious
sp
virgatum
Carex
Carex
Carex
Scleria
Juncus
Panicum
Panicum
Panicum
Panicum
Panicum
Panicum
lutescens
sp
viridis
ischaemum
sanguinalis
sp
Setaria
Setaria
Setaria
Digitaria
Digitaria
Digitaria
dactyloides
oryzoides
spartea
Leersia
Stipa
cristata
Koeleria
Typha
glauca
Calamagrostis
canadensis
Agrostis scabra
compressa
pratensis
sp
Poa
Poa
Poa
Bromus inermis
Agropyron repens
basiramea
sp
Aristida
Aristida
Calamovilfalongifolia
Calamovilfasp
Sporobolussp
Sporoboluscryptandrus
Muhlenbergia
racemosa
Eragrostis spectabilis
Buchloe
Bouteloua hirsuta
Sorghastrum
nutans
Schizachyrium
scoparium
Andropogongerardi
Paspalum ciliatifolium
italica
Setaria
Cenchrus longispinus
filiculmis
schweinitzii
sp
Cyperus
Cyperus
Cyperus
Phylogenies
A Phylogeny represents the evolutionary
relatedness and history of a given set of species
Patterns of Phylogenetic Structure
communities
communities
Phylogenetic clustering
Phylogenetic overdispersion
Why look at phylogenetic
structure?
Phylogenetic structure can provide insight
into what ecological mechanisms determine
community assembly.
In other words, by looking at the
evolutionary relationships of neighboring
species, we can come to conclusions on
what ecological mechanisms allowed the
species to be neighbors in the first place.
Community Assembly
Modern ecologists tend to define communities between
the contrasting views of Clements and Gleason, with a
stronger inclination toward Gleason.
Although there is interdependence in communities, by
and large communities tend to be better represented as
groups of independent individuals falling out along their
niche dimensions
Gleason Community
Abundance
Abundance
Clements Community
Environmental gradient
Environmental gradient
Community Assembly Rules
Several ecological processes have been put for to explain how
and why communities assemble.
Environmental filtering is the process whereby species are
precluded from a habitat due to biophysical limited of the
species morphology.
•Competitive exclusion is the process whereby species are
precluded from a habitat due to competition with a superior
competitor.
• Neutral theory is the process whereby species occurrence in
a community is driven by species abundance and stochastic
colonization during dispersal
Community Assembly Rules
Environmental Filtering
Competitive Exclusion
Species
Species
ABC DE F GH I
A BC
D E F
Traits
GH I
Communities
Traits
Communities
Phylogenetic Structure and
Community Assembly Rules
Phylogenetic structure can be used to determine
the ecological mechanisms of community
assembly with additional information on the
evolutionary history of species traits
Integration and Explanation:
Phylogenetic Overdispersion
Integration and Explanation:
Phylogenetic Clustering
Determining Phylogenetic
Structure: A Matter of Scale
Scale is the level at which a system is observed. There are
several scales with numerous levels to be studied in
ecology and evolution. Three of the most important ones for
this study include:
Spatial Scale – the physical boundary by which a
community is considered
Temporal Scale – the unit of time over which a community
is considered
Cladistic Scale – the number of branches on a phylogeny
that are considered.
This method of
analysis was
run using
programs
designed by
Jeannine
CavenderBares and
Clarence
Lehman
Pairwise Co-Occurrence
Pooideae
Chloridoideae
POACEAE
Panicoideae
Areneae
Poeae
Arundioideae
Eragrostideae
Angropogoneae
Paniceae
muhlenbergii
pensylvanicus
sp
triglomerata
sp
Carex
Carex
Carex
Scleria
Juncus
lutescens
sp
viridis
ischaemum
sanguinalis
sp
Setaria
Setaria
Setaria
Digitaria
Digitaria
Digitaria
dactyloides
oryzoides
spartea
Leersia
Stipa
cristata
Koeleria
Phylogenetic Distance
Typha
glauca
Calamagrostis
canadensis
Agrostis scabra
compressa
pratensis
sp
Poa
Poa
Poa
Bromus inermis
Agropyron repens
basiramea
sp
Aristida
Aristida
Calamovilfalongifolia
Calamovilfasp
Sporobolussp
Sporoboluscryptandrus
Muhlenbergia
racemosa
Eragrostis spectabilis
Buchloe
Bouteloua hirsuta
Sorghastrum
nutans
Schizachyrium
scoparium
Andropogongerardi
Paspalum ciliatifolium
italica
Setaria
Cenchrus longispinus
Panicum virgatum
Panicum sp
Panicum praecocious
Panicum perlongum
Panicum oligosanthes
Panicum capillare
filiculmis
schweinitzii
sp
Cyperus
Cyperus
Cyperus
Methods
Phylogenetic Distances
Pairwise Co-occurance
Cih =1- 0.5*S|pij - phj|
Correlation Co-efficient
Overdispersion
Clustering
Methods: Null Models
Null Models allow for statistical analyses of data sets that are not
normal distributed as in the case of phylogenetic distances between
species pairs and for statistical analyses of relationships that might
have a weak correlation.
We used null models in our analyses to compare the correlation
co-efficient between phylogenetic distance and co-occurrence
for observed data to the correlation co-efficient of a 1000
randomly generated data sets
These random data sets where generated from existing the
existing data sets, and basically consisted of randomly shifting
species abundances around within plots.
Communities at Cedar Creek
Three large data sets available from Cedar Creek provide an excellent
opportunity to apply these analyses to Minnesota prairie-savanna
communities
Oak-Savanna Burn
Nitrogen Addition Old-Field Succession Experiment – E133
Experiment – E001 Experiment – E014
Oak-Savanna Experiment:
Analysis and Results
Experimental Background
This study examines the effects of long-term prescribed burning treatments on
vegetation structure and composition, productivity, and nutrient cycling in oak
savanna communities. Burning as been occurring on certain plots since 1964.
Plots are prescribed a burn frequency of years along a gradient of “no-burn” to
every 2-3 years.
Vegetation surveys of the savanna burn units began in 1984 and have been carried
out roughly every five years since then.
Previous results:
Fire suppresses shrubs and trees and favors native prairie species. Responses of
plant species to burning, however, are related to season of burning intensity and
frequency of fires. Plant species respond in an individualistic manner.
A tree of Cedar Creek
Poaceae
Asteraceae
Eurosid1
Explanation: Evolutionary
Cedar Creek is an open community. All
species that exist here have evolved ex
situ, colonized the region only after glacial
retreat 12,000 years ago.
Explanation: Evolutionary
Post-glacial colonization is individualistic (Davis
and Shaw 2001). Species advance upward
following the retreating glacier line along their
niche dimensions. Compositional patterns that
existed 10,000, 6,000 or even 1,000 years ago
are not seen today
At large, scales these niches tend to be conserved
through strong stabilizing selection i.e.
environmental filtering. If traits necessary for
colonization are conserved among lineages than
it is likely that communities will be
phylogenetically clustered.
Explanation: Ecological
Oak-Savannas
• Similar explanations could explain the patterns observed
in the oak-savanna analyses. At finer spatial scale,
stochastic ecological processes might ‘muddle’
detectable patterns phylogenetic structure, but at a
larger scale, strong patterns in phylogenetic structure are
detectable.
• As with the N addition fields, the Oak-savanna plots are
often both environmentally and compositionally
heterogeneous thus encouraging ‘random’ events of
colonization and population fluctuations.
Conclusions
At larger scales patterns in phylogenetic
structure are clustered.
This suggests that traits necessary to inhabit
these communities are conserved.
This prediction fits in with the individualist
idea of post-glacial invasion in the area
and the effects of environmental filtering
acting with niche conservatism in the
assembly of open communities.