National Park Service

North Coast and Cascades Network (NCCN)

Prairie Vegetation Monitoring

Sand dune prairie habitat at San Juan Island NHP
Sand dune prairie habitat at San Juan Island NHP

Resource Briefs

Monitoring Reports - coming soon

Prairie Vegetation Monitoring Protocol

For more information contact:
Regina Rochefort or Mignonne Bivin

Importance & Issues

Prairies and Garry oak woodlands were once extensive in the lowlands of Washington and Oregon. Today, it is estimated that less than 3% of these areas still exist and many are severely degraded. The goal of the prairie monitoring program is to detect and describe changes in the extent and quality of prairie (herbaceous) communities in San Juan Island National Historical Park, in both the American Camp and English Camp units. The extent and distribution of prairies, oak woodlands, and forests is an important attribute of the park's cultural landscape.

Parks Monitored


Monitoring Objectives

  • Detect change in the extent of physiognomic cover types within American Camp and English Camp.
  • Detect change in the proportion of areas dominated by exotic and native species within American Camp and English Camp.
  • Detect change in the quality of herbaceous cover types within American Camp and English Camp.
  • Detect changes in composition and diversity of herbaceous cover types at American Camp and English Camp.

Potential Measures

Prairie monitoring has two design stages; the first stage is designed to detect changes in physiognomic cover classes, and the second stage focuses on composition of herbaceous communities. Sampling is conducted along parallel transects drawn at random using a general random tessellation stratified sample (GRTS). Physiognomic cover types and origin of predominant species (i.e. exotic or native) are recorded along the transects. Species composition, within herbaceous cover types, is monitored using 1-m square quadrats located systematically along the transects.

Status & Trends

Status and trends of cover types are assessed through changes in origin of predominant species, species richness, the floristic quality index (FQI), and changes in species composition. Ecological integrity of cover types is classified as good, caution, or significant concern based on status of the cover types. Trends in predominant species, floristic quality, and extent of cover types are used to describe whether the status of the cover type (% native) is stable, improving, or declining.

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Last Updated: December 30, 2016 Contact Webmaster