If ‘nothing in biology makes sense except in the light of evolution,’ then why model species as if they appeared through spontaneous creation? Now out: our paper on estimating niches while accounting for intra- and interspecific evolution!
Smith, A.B., Godsoe, W., Rodríguez-Sánchez, F., Wang, H-H., and Warren, D. In press. Niche estimation above and below the species level. Trends in Ecology and Evolution 34:260-273 (article page | science daily |Texas A&M)
Just out: a two-volume set on conservation of North American crop wild relatives! Adam had the honor of contributing to a chapter on threat assessment. “This chapter introduces the roles of conservation status and threat assessments in informing conservation priorities for crop wild relatives in North America and provides an overview of the current results for US taxa.” Some key results: Residential development is the most common threat to crop wild relatives in the US, followed by fire/fire suppression, then invasive species.
Frances, A., Smith, A.B., and Khoury, C. 2018. Conservation status and threat assessments for North American crop wild relatives. Pp. 189-208 in North American Crop Wild Relatives: Conservation and Use (Springer, New York). (chapter pre-print | book)
See also Hernández-Yáñez, H., Kos, J.T., Bast, M.D., Griggs, J.L., Hage, P.A., Killian, A.,Whitmore, M.B., Loza, M. L., Smith, A.B. 2016. A systematic assessment of threats affecting the rare plants of the United States. Biological Conservation 203:260-267. (article page | kudos)
We are very excited to host Stephen, who is interested in combining aspects of biogeography and macroecology with his ongoing work in community ecology. Stephen graduated from Ohio State University, and is now supported by a grant from the Institute for Museum and Library Services for developing and testing methods for using vaguely georeferenced and dated herbarium and natural history museum records. Welcome, Stephen!
Adam’s (somewhat abandoned) proposal for chaperoned assisted migration was recently discussed by Smithsonian Magazine in a story on using cities as refugia for endangered and climate-sensitive species!
Feral Ring-Necked Parakeet (Wikimedia)
We are excited to serve as the new intellectual home of Kelley Erickson, a recent graduate of the University of Miami where she studied the demography of the highly invasive shrub Schinus terebinthifolia (Brazilian peppertree). Kelley is working on incorporating issues related to detectability in species distribution models in a project sponsored by the Institute for Museum and Library Services. Welcome, Kelley!
Awesome news! We were just informed that the National Science Foundation will fund our proposal to use pollen, genetic, and distributional data to estimate the spatial dynamics of how trees migrated poleward after the last glacial maximum. This is a collaborative project with Sean Hoban (Morton Arboretum), Andria Dawson (Mount Royal University), John Robinson (Michigan State University), and Allan Strand (College of Charleston). We will be hiring two postdocs over the 3 years of the grant. The first position will be based at The Morton Arboretum near Chicago, Illinois and the second at Michigan State University.
Collectively, biodiversity databases represent over a billion specimens and sightings of species. Unfortunately, quite often 60-90% or more of that data does not meet the standards necessary for biogeographic analysis: coordinates are missing or blatantly wrong, dates are missing, and some identifications can be questionable. Typically this data is discarded before analysis, even though it represents hundreds, perhaps thousands of years of person-work in collection and curation. More importantly, many of the discarded records are probably critical to understanding historical distributions and environmental tolerances of species because they represent the only known collections from a given location or on the edge of the range. Many of these erstwhile “unusable” records are historical and yet very valuable. Indeed, using historical records indicative of pre-anthropogenic range contractions better estimates species’ environmental tolerances.
We are excited to announce Version 1.01 of bayesLopod, a Bayesian modeling framework that can use vaguely-georeferenced specimen records and estimate the probability that a record that falls outside the body of the distribution was incorrectly identified. bayesLopod is an R package that relies on Stan, a Bayesian coding language (which you do not need to know!) that approximates posteriors very fast compared to BUGS or JAGS. The input is either a points file, raster, or a shapefile, with detections and some background estimate of sampling effort. The output is in the same data format and provides an estimate of the probability of occupancy and the probability that a sample unit (e.g., raster cell) contains an incorrectly-identified record. We hope this tool can help conservation biogeographers better address pressing questions about Earth’s biodiversity.
The bayesLopod model juxtaposes records of a species (top left) with sampling intensity (bottom left) to estimate the range (main panel). The model can utilize badly georeferenced specimens (this species has only 90 accurately-referenced records but the model uses 5300 records).
Our long-awaited paper on predicting country-scale biodiversity from small plots is out! Of 19 “upscaling” techniques, the most successful method was able to predict total plant richness in the United Kingdom with <10% error, though few techniques were able to recreate the shape of the actual species-area relationship.
Kunin, W.E., Harte, J., He, Fangliang, Hui, C., Jobe, R.T., Ostling, A., Polce, C., Šizling, A., Smith, A.B., Smith, Krister, Smart, S.M., Storch, D., Tjørve, E., Ugland, K-I., Ulrich, W., and Varma, V. Accepted. Up-scaling biodiversity: Estimating the species-area relationship from small samples. Ecological Monographs. doi: 10.1002/ecm.1284
Our latest paper in Global Change Biology on modeling intraspecific phenotypic variation has gotten great press! Combined, the news outlets covering our research reach ~78 million people and included The San Francisco Chronicle, The Seattle Times, US News and World Report, The Topeka Capital Journal, The Manhattan Mercury, and numerous other regional newspapers, radio stations (e.g., KWMU 90.7), TV stations (e.g., KWCH12), and science news websites (e.g., Science News Online)!
Smith, A.B., Alsdurf, J., Knapp, M. and Johnson, L.C. 2017. Phenotypic distribution models corroborate species distribution models: A shift in the role and prevalence of a dominant prairie grass in response to climate change. Global Change Biology 23:4365-4375. doi: 10.1111/gcb.13666
Change in biomass of Andropogon gerardii due to climate change
Climate path of St. Louis, Missouri, USA
How can we communicate global warming to local audiences (= everybody who lives in a place)? Recently I made a poster showing the locations that climatically currently resemble the future climate of St. Louis.
But how did I know where to locate the “future” St. Louis climatically? By running species distribution models in “reverse”. First, I created a set of 100 points to represent St. Louis (I actually had them have the exact same coordinates–it’s false sample size inflation, but it doesn’t matter much since at first approximation St. Louis is a point–and it does allow me to use more complex fitting features in Maxent).
Second, I associated these points with the climate layers I have for the 2070s (once for each emissions scenario).
I then trained a Maxent model using this future climate data, then projected it back to the present.
Finally, I calculated the geographic center of gravity of all cells using the predicted suitability as weights. The center gravity is the average location of the “future” climate of St. Louis! I found I got slightly better (= intuitive) results by thresholding first, then using suitability values above the threshold as weights. I also found I got better results when using only mean annual temperature and precipitation, rather than all 19 WORLCLIM variables.
This procedure is fairly simple and takes advantage of the fact that 1) “species” distribution models are not just for species, and 2) the output of a SDM (or whatever you want to call them) is really just an index of similarity of a multivariate space (= climate layers) at a set of points (= presences) and another set of points (= all grid cells in the layer to which you’re projecting).
I’ll be trying the poster out at the Missouri Botanical Garden’s upcoming Science Open House–hopefully it will spark some conversation!