Friday, June 17, 2011

16000 western North American Herbarium Specimen Records - DWTaylor

I have posted a tabulation of 16,000 of my 21,000 vascular plant herbarium specimen records on Google Fusion. Search on 16000 western North American Herbarium Specimen and DWTaylor to pull up the dataset. There are a few records that are mapping screwy. About 1,000 records are of sufficiently poor quality for label information that they are as yet not georeferenced. For about half of these records, a known accession number is given. A sizable number of accessions at DAV are not yet posted on the Consortium of California Herbaria database.

An approximate tabulation by location is:
Alaska 19
Alberta 18
Arizona 58
Baja California Norte 142
Baja California Sur 93
British Columbia 64
California 12,845
Colorado 445
Hawaii 3
Idaho 318
Montana 55
Nevada 443
New Mexico 186
Oregon 830
Texas 49
Utah 52
Washington 179

Monday, June 6, 2011

Current 2011 Herbarium Specimen Density for California

A key took to understanding the California flora is the availability of observation and specimen records. The CCH web portal shows statistics for specimen density for each of the 58 California counties. Here, I summarize these data by county. With 1.2 million specimens databased, the mean collection density state wide is 3.2 specimens/square kilometer. The striking pattern obtained by mapping specimen density within quartiles on a county basis is the inequality pattern: slightly over half of counties fall below the mean. but a sizable number of counties (San Benito, Fresno, Shasta, Glenn, Stanislaus, Imperial, Madera, Lassen, Merced, San Joaquin and Kings) fall in the lower quartile (that is, below 1.6 specimens/km2). The undercollected nature of Kings County can be attributed to little remaining natural habitat, as might be argued for Madera and Fresno Counties. However, if we discount the ag portions of these counties (at roughly half their area), their specimen density still falls below the median. Understandably, the lower herbarium specimen density for Shasta and Lassen counties is owing to remoteness.

as Jepson's bookplate admonished "something is still lost beyond the ranges, over yonder go ye' there"

But go ye to the lower quartile counties.