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Monitoring Ecological Conditions

Can we devise efficient, accurate, and reliable methods to monitor changes in vegetation over time? How can we use monitoring to infer the effects of climate change, deer, and landscape conditions on native plants?

Ecological monitoring of terrestrial vegetation and white-tailed deer impacts in National Parks of the Great Lakes Region

To make sound management decisions, National Park Service managers need to know how natural systems change over time and what kinds and rates of change fall within the natural range of historic variability. The Great Lakes Inventory and Monitoring Network (GLKN) of National Parks has identified terrestrial vegetation as a high priority ‘Vital Sign’ of ecosystem health. In collaboration with GLKN ecologists, we are developing a protocol for long-term vegetation monitoring to detect the status of and shifts in species dynamics, community composition and structure in nine National Parks across the region. We are evaluating sampling methods to propose an efficient and reliable method that will be sensitive to selected indicator variable changes. The GLKN has identified several factors that may contribute to vegetation changes in the region, and the over-abundance of white-tailed deer ranks among the top threats in parks within the Great Lakes network. In addition to summarizing information on the past and current status of deer populations in the region, we are developing a protocol for monitoring deer browse effects that will function in concert with the vegetation monitoring protocol. These long-term data will provide information on changing deer densities and impacts on vegetation that may assist resource managers in identifying thresholds necessary for management action.

Don, JoshSarah Johnson, Don Waller and Erica Mudrak work out a monitoring protocol at Pictured Rocks National Lakeshore, UP MIchigan.

The nine national parks in the great lakes region are developing a plan for evaluating vital signs of ecosystem health monitoring. We are partnering with them in these efforts through developing monitoring protocols for (1) terrestrial vegetation and (2) white-tailed deer impacts.


The GLKN ranked terrestrial vegetation 3rd among all the vital signs they evaluated with good reason. When combined with other vital signs, vegetation monitoring provides key data on ecosystem health. Such data are important for several reasons including:

  • Vegetation integrates and expresses information about geology, hydrology, soils, disturbance, and climate.

  • Vegetation represents the trophic base for ecosystem processes and primary habitat for all animal species.

  • Vegetation data capture information about ecosystems (productivity, C storage, etc.), communities (structure and function), and plant guild and species composition.

  • Plant communities can be sampled directly in the field, providing many sample points on many species (dozens to hundreds). Such data provide sensitive metrics for tracking many types of ecological change over time at particular spatial scales.

Terrestrial Vegetation Monitoring

Goals and Objectives:
To make sound management decisions, National Park Service (NPS) managers need to know how natural systems change over time and what kinds and rates of change fall within the natural range of historic variability.

Dan, JoshJosh Sulman and Dan Olson collect diversity data from a 1x1 m herb quad at PIRO.

The vegetation monitoring protocols and networks we propose to develop should provide key data that will grow increasingly valuable with long-term monitoring. These efforts should also identify key ‘vital signs’ capable of providing early warning signs of impending declines in ecosystem integrity. Such early detection of potential problems should allow park managers to take timely action before solutions become ecologically, economically, socially, or politically intractable. We focus on three broad questions central to the vegetation monitoring program:

  • How is plant community composition changing over time?

  • How is the structure of terrestrial plant communities changing over time?

  • How are plant communities responding to anthropogenic and natural disturbances?

The latter include widespread increases in weedy invasive plants and levels of deer herbivory.

White-tailed Deer Monitoring


  • To bring together state of knowledge on white-tailed deer browsing impacts in the Great Lakes Network.

  • To determine effective white-tailed deer monitoring of vegetation impacts through examining browse damage and identifying herbaceous species that are the most effective indicators of the level of deer impacts.

Related Publications

Johnson, S.E, E.L. Mudrak, E.A. Beever, S. Sanders, and D.M. Waller. 2008. Comparing power among three sampling methods for monitoring forest vegetation. Can. J. For. Res. 38(1): 143-156. doi:10.1139/X07-121.

Waller, D.M., S. Johnson, R. Collins, E. Williams. 2009. Threats posed by ungulate herbivory to forest structure and plant diversity in the Upper Great Lakes Region with a review of methods to assess those threats. National Resource Report NPS/GLKN/NRR-2009/102. National Park Service, Fort Collins, CO. ‘Vital Signs’ program. March, 2009. 57 pp

Mudrak, E.L., S.E. Johnson, and D.M. Waller. 2009. Forty-seven year changes in vegetation at the Apostle Islands: Effects of deer on the forest understory Nat. Areas J. 29: 167-176.

Waller, D. M., and T. P. Rooney. 2004. Nature is changing in more ways than one. Trends in Ecology & Evolution 19:6-7.

PIROSand dune landscape at PIRO.