Excellent posts introducing creating plots by ggplot2

http://t-redactyl.io/blog/2016/03/creating-plots-in-r-using-ggplot2-part-9-function-plots.html

Labeling plot in gglot2

            This post is going to introduce tips on how to add text on a plot with ggplot2. Background is that we usually have to label or make notes for elements in a plot to make it more clear to the reader.

http://docs.ggplot2.org/current/geom_text.html

Road to Revive American Chestnut

American chestnut distribution before chestnut blight. From nature.com.

A good synthesis of American Chestnut biology, ecology, and genetics:
http://foresthealthinitiative.org/resources/chestnutdossier.pdf


http://www.citizen-times.com/story/news/local/2014/11/14/american-chestnut-tree-life-follows-death/19052995/

Nature News:
http://www.nature.com/news/plant-science-the-chestnut-resurrection-1.11504