California Rapid Assessment Method (CRAM)

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A summary of one of the Technical Tools used in Environmental Science and Management within California's Central Coast Region created by ENVS 560/L Watershed Systems class at CSUMB.


Summary

California Rapid Assessment Method (CRAM) is a standardized approach to monitor and assess the ecological conditions of wetlands California's wetland resources.[1][2] CRAM is represented as a single score that reflects the wetland's condition and stressors based on metrics of landscape and buffer condition, hydrology, biotic structure, and physical structure.[1]


CRAM was developed by a committee consisting of federal, state, and local agency personnel and scientists, NGO scientists, and consultants.[3] CRAM is considered "rapid" because it can take less than three hours for only two or three practitioners to asses a representative wetland area.[3]

Why use CRAM?

CRAM has been adopted in California because it is consistent, scientifically defensible, and affordable.[4] There are several public and private fund investments aimed at the protection, restoration, and management of California wetlands, but the impact of these investments are difficult to evaluate because there are often inconsistencies in data collections and quality control.[4] With CRAM, wetland health can be compared and monitored under consistent conditions. Additionally, the results of the monitoring are hosted on the EcoAtlas website, making records of CRAM data available to analysts and decision makers.[5][3]

CRAM Procedure

There are eight steps to use CRAM.

Step 1: Assemble Background Information

Background information that is helpful for aiding CRAM assessments are: management objectives, history, known or expected stressors, and general ecological character of the wetland.[4] Useful sources of background information include: USGS topographic quadrangles, National Wetlands Inventory (NWI), State Wetlands Inventory, road maps, maps of geology/soils/vegetation/land use, aerial imagery, data from the California Natural Diversity Database (CNDDB), and reports from water districts, flood control districts, open space districts, federal, state, and local agencies such as Special districts in the Monterey Region.[4]

Step 2: Classify the Wetland

Flow chart to determine which wetland module and sub-type is appropriate for CRAM.[6]


To make CRAM applicable to virtually all of California's diverse range of wetlands, modules or types were created.[4] There are six major types, four of which have sub-types.[4]


Although wetland types can change over time, through either natural or anthropogenic causes, wetlands should be evaluated by their current type.[4] Past or future changes should not be considered when identifying the CRAM type to use.[4] If there is a change in wetland type, it will be documented in the stressor checklist portion of CRAM to identify if the wetland is being stressed by the conversion.[4]


CRAM was originally created to assess vegetated wetlands, so CRAM may not be as effective at describing wetland health if the wetland is non-vegetated.[4] Such non-vegetated wetlands would include tidal flats or mudflats.[4] If CRAM is to be used on a non-vegetated wetland, it should be noted in the Basic Information page and the Plant Community metric.[4]


Each wetland type has its own recommended Assessment Area (AA).[4] For a wetland to be considered as an assessable wetland under CRAM, there must be enough of the wetland area to include one or more AA.[4]

CRAM Wetland Types CRAM Sub-types Recommended AA Size
Riverine Confined Riverine Recommended length is 10x average bankfull channel width; maximum length is 200 m; minimum length is 100 m. AA should extend laterally (landward) from the bankfull contour to encompass all the vegetation (trees, shrubs vines, etc.) that probably provide woody debris, leaves, insects, etc. to the channel and its immediate floodplain; minimum width is 2 m.
Non-confined Riverine
Depressional Individual Vernal Pools There are no size limits.
Vernal Pool Systems Preferred size is <10 ha (about 300m x 300m; shape can vary); there is no minimum size so long as there are between 3 and 6 pools. If the system has between 3 and 6 pools, assess all of them. If there are more than 6 pools, select 6 that represent the range in size of pools present on the site.
Depressional Preferred size is 1.0 ha (a 56 m radius circle or about 100m x 100m, but shape can vary); Maximum size is 2.0 ha (an 80 m radius circle or about 140m x 140m, but shape can vary); There is no minimum size.
Playas No sub-type Preferred size is 2.0 ha (about 140m x 140m, but shape can vary); Minimum size is 0.5 ha (about 75m x 75m).
Estuarine Perennial Saline Estuarine Preferred size and shape for estuarine wetlands is a 1.0 ha circle (radius about 55m), but the shape can be non-circular if necessary to fit the wetland and to meet hydro-geomorphic and other criteria. The minimum size is 0.1 ha (about 30m x 30m).
Perennial Non-saline Estuarine
Bar-Built Estuarine Maximum size is 2.25 ha (about 150 m x 150 m, but shape can vary), The minimum size is 0.1 ha (about 30m x 30m).
Lacustrine No sub-type Preferred size is 2.0 ha (about 140m x 140m, but shape can vary); Minimum size is 0.5 ha (about 75m x 75m).
Slope Seeps and Springs Preferred size is 0.50 ha (about 75m x 75m, but shape can vary); there is no minimum size (least examples can be mapped as dots).
Forested Slope
Wet Meadows Preferred size is 1.0 ha (about 140m x 140m, but shape can vary); Maximum size is 2.0 ha; minimum size is 0.1 ha (about 30m x 30m).
[4]


Links

References

  1. 1.0 1.1 California Creates Rapid Assessment Method for Wetland Protection https://www.epa.gov/wetlands/california-creates-rapid-assessment-method-wetland-protection
  2. California Rapid Assessment Method Website https://www.cramwetlands.org/
  3. 3.0 3.1 3.2 About California Rapid Assessment Method https://www.cramwetlands.org/about
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 California Rapid Assessment Method for Wetlands User’s Manual Version 6.1 https://www.cramwetlands.org/sites/default/files/2013-04-22_CRAM_manual_6.1%20all.pdf
  5. About EcoAtlas https://www.ecoatlas.org/about/
  6. California Rapid Assessment Method Flowchart https://www.cramwetlands.org/sites/default/files/UPDATED%20CRAM%20Flowchart_July2016.pdf

Disclaimer

This page may contain students' work completed as part of assigned coursework. It may not be accurate. It does not necessarily reflect the opinion or policy of CSUMB, its staff, or students...