About: http://webisa.webdatacommons.org/23990306

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Of 30 or more species of birches found only in the northern hemisphere, 12 are native in North America and 3 of those are dwarfs such as the one upon which caribou and reindeer browse in Alaska.
http://www.w3.org/ns/prov#wasQuotedFrom	osti.gov