About Observation Data |
Objectives
Sources of Observation Data
Observation data in Calflora comes from many sources:
records contributed by individuals from smart phone applications,
records from land management agencies,
herbarium specimen records, checklists compiled by
botanists for known locations,
plant lists made by environmental consulting companies
for development projects,
rare plant occurrences documented by the
California Department of Fish and Wildlife (CDFW)
Natural Diversity Database,
survey data from the CDFW Vegetation Mapping Project, et al.
Herbarium specimen records are contributed by the member herbaria of the Consortium of California Herbaria (CCH). Specimen data can additionally be viewed and downloaded directly from here. A list of all data sources is available here. By providing ready access to all these types of occurrence data, Calflora seeks to facilitate research on questions related to biodiversity, ecology, and conservation, and help researchers get the full benefit of geographic analysis and modeling tools.
How Data is Assimilated
The intent is to provide a core set of data about each
observation and enough information for the user to select only those records
that are suitable for their purpose.
When possible, links are provided to the
data source for additional information.
When we receive bulk data sets, we examine them to extract:
Quality Control
When you see an observation of a plant at a certain
location on Calflora, does it mean that the
plant is (was) really there?
Because Calflora collects data from diverse sources,
each with their own strengths and weaknesses,
there is some filtering of the data which you, the user, must do
to make the best use of it.
Here are some error conditions to watch out for:
Whenever possible, we try to identify such records and to label them as suspect. This is an ongoing task as new data continues to come in. Meanwhile, here are several strategies for determining the level of evidence for a plant at a location:
2. Pay attention to the individual observers and collectors responsible for a record. Some are more reliable at plant identification than others.
Scientific Name Changes
Calflora preserves the scientific name chosen by the contributor.
A contributor can change the scientific name on a record
at any time, but Calflora does not automatically change
scientific names.
If a scientific name changes, and the change in unambiguous
(for instance, from Rhamnus californica to
Frangula californica in 2012),
Calflora will keep the old name, but make it resolve to
the new name.
As an example, here is the DETAIL PAGE for a record that Michael O'Brien contributed in 2010. He chose the scientific name Rhamnus californica. When the record was first entered, Rhamnus californica was an accepted name, and so clicking on the Rhamnus californica link went to the Taxon Report page for Rhamnus californica. Currently, clicking on the Rhamnus californica link goes to the Taxon Report page for Frangula californica (which shows Rhamnus californica as a synonym or alternate name).
Location Quality
When GPS enhanced devices
are used to make observations, the device typically produces
an error radius understood as the accuracy of the
device at the moment the observation was made.
If an observation arrives with an error radius of 2 meters,
it indicates that the plant was growing somewhere in an
area of 12.5 square meters around the given coordinates.
Some specimen records from the Consortium of California Herbaria were georeferenced after the fact (eg. from written location descriptions), and are assigned a large error radius. If an observation arrives with an error radius of 2 miles, it indicates that the plant was growing somewhere in an area of 12.5 square miles (8,000 acres) around the given coordinates. In order to integrate these diverse record types, Calflora classifies the quality of location data in several levels as follows.
Internally, Calflora uses these quality levels for various purposes. One purpose is to select which points are appropriate for making climate and soil profiles, according to the resolution of the available climate and soil map layers. (If the accuracy is better than 15 acres (60,000 square meters), the point is usable for a soil profile. If the accuracy is better than 185 acres (750,000 square meters), the point is usable for a climate profile.)
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