To Be or Not to be a Quercus. Bur Oak Quercus macrocarpa St Paul. Justin Quercus Borevitz Prairie Ecosystems 4/19/07. California Blue Oak. Wood/lignin evolved 3 times in angiosperms Asters, grasses (bamboo), legumes Oaks Hard wood, slow growing Old growth, 400 years! 2 stories high..
Justin Quercus Borevitz
California Blue Oak
Asters, grasses (bamboo), legumes
Oaks Hard wood, slow growing
Old growth, 400 years! 2 stories high..
Obligate hosts (fungal, insect/ant farming)
Sudden Oak Death
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. Koenig3American 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,
The Israel Forest Authority (KKL)
Ronen Kadmon, Department of Ecology,
The Hebrew University of Jerusalem
Rocky Mountain Research Center, USDA Forest Service
Denis Dean, Department of Forest Sciences,
Colorado State University
Herbaceous vegetation in the front, recovering trees in the back, Mt. Meron
dwarf shrubs, tall shrubs, and low trees in Mt. Meron
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, MinnesotaCharles G. WillisUniversity of Minnesota – Twin Cities
Phylogenetic structuredescribes the phylogenetic relationships of species neighbors within a given community.
In other words, are neighbors closely related or distantly related evolutionarily?
A Phylogenyrepresents the evolutionary relatedness and history of a given set of species
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.
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
Several ecological processes have been put for to explain how and why communities assemble.
Environmental filteringis the process whereby species are precluded from a habitat due to biophysical limited of the species morphology.
Phylogenetic structure can be used to determine the ecological mechanisms of community assembly with additional information on the evolutionary history of species traits
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.
Cih =1- 0.5*S|pij - phj|
This method of analysis was run using programs designed by Jeannine Cavender-Bares and Clarence Lehman
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.
Three large data sets available from Cedar Creek provide an excellent opportunity to apply these analyses to Minnesota prairie-savanna communities
Oak-Savanna Burn Experiment – E133
Nitrogen Addition Experiment – E001
Old-Field Succession Experiment – E014
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.
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.
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.
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.
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.