Some vegetation changes occur on a landscape scale, such as an expanding plant community (e.g., advancing pinyon/juniper or invasive weeds) or as cumulative effects (e.g., increased acreage of dominance by annuals). Monitoring these changes helps to identify transitions across thresholds, from one state to another. (See information on state and transition models in Appendix B – Ecological Sites.) Although such changes can be detected or tracked with many individual plots, it is often more efficient to track landscape patterns with photos, or other remotely sensed imagery, or maps. While some landscape-scale issues or changes are easy to observe, others can be detected through the use of pattern analysis techniques. Suitable data are needed for these analyses. It is imperative to include location markers for georeferencing. Appendix F — Scales in Monitoring further discusses this topic.
Photos or Other Remote Sensing
Vegetation changes visible at the landscape scale can be tracked with remote sensing when images are interpreted correctly. GIS software can be used in concert with remotely sensed data to capture, analyze and produce raster data sets that contain metrics of change across landscapes. Stereo coverage is desirable (Appendix G – Remotes Sensing to Monitor Rangelands).