The Potential Range application can show individual observations -- reports, specimens, and checklists -- indicating where the plant has been seen.

The application can also show the potential habitat of the plant, extrapolated from individual observations, by either watershed or climate model.

• Display
• Potential Habitat Calculations
• Tools
• Shapes and Icons
• Polygon Examples
• Release Notes

Observations

Check Individual observations to display observations in the current map area. This represents the actual known range of the plant. If you zoom out or move the map, press update to re-display observations in the map area.

When you click on an observation point , an info window appears showing a summary of the observation, with a link to see full record details.

Potential habitat:

by Watershed
When the application first comes up, it highlights the watersheds (CalWater super planning watersheds) where the plant has been seen.

If there are two or more observations in the watershed, it is highlighted in yellow. If there is a single observation in the watershed, it is highlighted in orange.

by Climate Model
Check Climate Model to display areas where the plant might grow according to the climate model algorithm. These areas are highlighted in yellow.

It is a challenge to come up with a way to visualize both the known range and the potential habitat of a plant. Ideally the visualization will provide useful information at various scales, from the whole state to very local.

Range is a geographic boundary; potential habitat is made of the biotic and abiotic elements within that range that combine to make some places hospitable to a species, even if not all the apparently suitable habitat is occupied. We generally don't know why it's not occupied. It could be that our understanding of suitable habitat is missing some critical element. It could be a failure of dispersal. It could be local extirpation. All we really know for sure is that habitat is suitable if the plant occurs and survives there. (JK)

This application has two ways of showing potential habitat. Both rely on the availability of adequate observation data.

by Watershed
The application uses CalWater super planning watershed polygons. The application shows where the plant is known to grow, extrapolated to the encompassing watershed. There are 2300 super planning watersheds in California.

by Climate Model
The application shows potential habitat for the plant based on algorithmic prediction. The algorithm utilizes two systems for analyzing the geographical space of California:

1. A grid of 30 arcsecond cells. It takes 599,114 of these cells to cover the land mass of California, including the islands.
2. EPA Level IV Ecoregions. There are 180 level IV ecoregions in California.

Discussion
Both methods involve an extrapolation of where the plant might be from where the plant is known to be. In some situations the watershed method gives the best suggestion of potential habitat; in other situations, the climate model method gives the best suggestion.

Open the TOOLS menu for these functions.

SHARE THIS PAGE
When you click on this link, the current state of the page is added to your browser's URL. After pressing this link, you can:

• use the browser to bookmark the URL;
• copy the URL and email it to someone; or
• use the browser's back button later to return to this state.

LOCATION PROFILE
Check this box to see elevation, climate and soil factors at the current map cursor location .

What Grows Here?
Click this link to bring up the What Grows Here application at this location to see what other plants grow hearby.

Observation Search
Click this link to bring up the Observation Search application at this location to see all nearby observations of the plant.

Download climate model as a GeoTiff
Click this link to download climate model data for this plant as a GeoTiff file, suitable for viewing in QGIS or ArcGIS.
There are three kinds of cell values in this file:

1. If the plant has been observed inside the cell, then the value of the cell is number of observations.
2. If the plant has not been observed inside the cell, but the climate factors of the cell are within the plant's tolerances, then the value of the cell is 0.
3. Otherwise the value of the cell is NaN (not a number).

Polygon data is available for some plants. If data is available, a Polygons checkbox appears. Check this box, and the available shapes will be drawn on the map. Shapes appear as shown on the right. Note that most polygons are tiny, so that you must zoom way in to see them. Switch the map to Satellite to zoom very close.

Polygon observations are indicated by a pink circle.
Point observations are indicated by a purple circle.
Obscured observations are indicated by a blue square. Obscured observations are displayed at the center of the containing quarter quadrangle. A quarter quadrangle is 1/256 of a square degree. The quarter quad itself is displayed as a blue rectangle.
Specimens are indicated by a blue circle.
If surveys or checklists are available for this plant, they are indicated by a green square. If you do not want to see checklists, you can turn them off.
For certain plants (eg. rare plants in the CNPS Inventory), quad data is available. A quad is a USGS quadrangle, or 1/64 of a square degree. A quad record means that the plant has been found somewhere within that quad. Quads are indicated by a yellow square. If you do not want to see quads, you can turn them off.
Records of potential habitat are indicated by an orange circle.
Questionable records are indicated by a red X.

If a record has a medium or low location quality, it is displayed on the map with a white halo around it. In the graphic, the specimen point on left has a high location quality, and the point on the right has a medium location quality.

• Cytisus scoparius (scotch broom)
  Corte Madera
  Marin County Open Space District
• Cytisus scoparius (scotch broom)
  west of Whiskeytown Lake
  National Park Service Exotic Plant Management Team
• Ailanthus altissima (tree of heaven)
  Jackson
  Amador County Agriculture Department
• Carthamus lanatus (wooly distaff thistle)
  east of Olema
  Marin County Open Space District