Dataset: Population Genomic Calls for green ash, Fraxinus pennsylvanica, collected in eastern North America 2015

Fossil pollen records from eastern North America were downloaded from the Neotoma Paleoecology Database. There were 465 pollen records within our study region with at least one pollen count sample in the considered time period (LGM to present). Each pollen record includes pollen taxon counts at a set of depths. Most records include reliable sample age estimates derived from an age-depth model. Occurrence data were downloaded from the Botantical Information and ecology network (BIEN version 4.1.1). Using specimen and plot data for F. pennsylvanica from across its native range, we calibrated 24 different species distribution models (SDM) using present-day climate reconstructions from two paleoclimate models (CCSM, the Community Climate System Model, and ECBilt). 

We collected leaf or twig samples from adult trees (> 10 cm DBH) in 48 naturally regenerated sites. Leaf DNA was extracted using a modified CTAB protocol. For each individual tree sampled, 100ng of genomic DNA was cut using two restriction enzymes, EcoRI and MseI.  Subsequently, adaptors were ligated on each end of fragments that resulted from restriction enzyme digestion. Adaptors complementary to the EcoRI cut site also included a 8-base sequence unique to each individual included in the library to serve as a barcode to identify sequences from that individual during bioinformatic processing. Two rounds of PCR followed the ligations in parallel (each reaction started with the same product from ligation reactions). Finally all reaction products were pooled. This pooled library was size-selected to include fragments from 300-500bp in size and then sequenced on two lanes of the Illumina HiSeq 2000 platform.

Organism identifiers:
green ash, Fraxinus pennsylvanica, Fraxinus pennsylvanica Marshall, urn:lsid:dyntaxa.se:Taxon:221644, https://www.checklistbank.org/dataset/315834/taxon/6JMHT