Upland Vegetation Monitoring Data for Bighorn Canyon National Recreation Area

This Microsoft Excel file contains sample data from recent years for a long term program to monitor specific upland vegetation species in Bighorn Canyon National Recreation Area. Please read worksheet ‘Data Description & Notes’. Complete documentation for sampling and data collection is found in the NPS Greater Yellowstone Network’s Upland Vegetation Monitoring Protocol and Procedures - see worksheet 'References'. These sample data are designed primarily for landscape-scale statistical inference about the overall status and trends of target species. Please see related annual reports.

These data are from a protocol for monitoring indicators of ecological condition within upland plant communities of Bighorn Canyon National Recreation Area (Bighorn Canyon). Upland vegetation and soils at Bighorn Canyon were identified as a vital sign in the Greater Yellowstone Network‘s (GRYN) monitoring plan (Jean et al. 2005) and as an important indicator of ecological response to climate change in the National Park Service‘s (NPS) climate change response strategy for high elevation parks (Bingham et al. 2010). The upland plant community types of interest for monitoring in this protocol are sagebrush (Artemisia tridentata), juniper (Juniperus spp.), and juniper-mountain mahogany (Cercocarpus ledifolius).

Sagebrush and woodland communities are among the most dominant and common vegetation types in Bighorn Canyon, occurring over 60% of the land area inside the park (Knight et al. 1987). These vegetation communities provide important habitat for wildlife and are used by the Pryor Mountain wild horse herd (Komp et al. 2012). The quality and abundance of key plant species and soil cover in these communities are considered indicators of overall rangeland health and the focus of our monitoring objectives which are to determine the status (current condition) and trends (change in condition over time) in composition and abundance of key plant species and soil cover attributes. The selected monitoring metrics include ocular estimation of canopy and ground cover by Daubenmire (1959) cover class and stem counts of juniper and mountain mahogany trees <10 cm tall.

The sample design for this protocol uses temporary quadrats that are randomly assigned each year. The quadrats are distributed within each sample frame by the Generalized Random-Tessellation Stratified (GRTS) algorithm. The number of sample quadrats (50, 75, 100) assigned per sample frame depends on the size of the sample frame.  There are a total of 925 sample quadrats across the 15 permanent sample frames. Seven of the sample frames are visited annually while the other eight are visited on a 3 year rotation.  Approximately 500 sample quadrats are visited annually.

Field methods for this protocol are designed to be readily learned by individuals with some field experience identifying plants but do not depend on advanced expertise in plant taxonomy. A week of field training includes calibration exercises for ocular cover estimation and plant identification for each target species. Observed and measured data values are entered directly into a database on a field computer. At the end of the field season, the database and all physical project materials are quality-control checked and then filed with the project records archived in the GRYN office. Status results are summarized and reported after each year of data collection; analysis will primarily focus on estimating the proportion of sampling plots within each Daubenmire cover class. Differences in plant cover (%) measured during two different years (a step-change) will be assessed with a proportion test (Sheskin 2007) The significance of linear trends in plant cover will be tested using a Proportional Odds Model, following the methods of Irvine and Rodhouse (2010).

Tags: biota, data, ecological-framework-biological-integrity-focal-species-or-communities-forest-woodland-communit, ecological-framework-biological-integrity-focal-species-or-communities-shrubland-communities, juniper, monitoring, plants, sage-steppe, sagebrush, vegetation
Organization: Department of the Interior