Do basic QA/QC on plant cover data

[KristinaRiemer]

Checking for outliers, errors, etc.

• [x] Percent cover values between 0 and 100
• [x] Single site + time summed percent cover doesn't exceed 100
• [x] Compare species locations to distributions
• [x] Check for unusual/unique latlons

[KristinaRiemer]

Notes:

• Some individual records have no value for percent cover. Does that mean that plant was in the plot and very tiny, or are those errors that need to be removed?
• Some subplots have summed percent cover that exceeds 100%. Is that because entire plants overhanging plot were included?
• There are only a few lat lon combos that have only one or a few records, which were all mostly at the TEAK site in California, which was mostly only sampled in 2019.
• Compared the 8 most common species against GBIF occurrences, which all looked good.

Pull request