Assessing White-Tailed Deer Impacts to Tree Seedling Growth using Citizen Science Data in Minnesota, USA


 White-tailed deer (Odocoileus virginianus Zimmerman) present numerous challenges for maintaining the health of forests in the US Lake States. Although many sources of data exist that provide coarse estimates of deer-browse impacts on plant survival and abundance (e.g., national forest inventories) or examine areas where deer are excluded (e.g., exclosures), few studies exist that use detailed tree seedling measurements across diverse stand conditions and forest types. This study evaluated four years of citizen science data collected in the Assessing Vegetation Impacts from Deer (AVID) program in Minnesota, USA. Results showed that average annual height growth of seedlings for nine browse-palatable species was 1.9 cm. For four of these tree species, annual height growth was not significantly different from zero. These results point to the challenges for the growth and survival of browse-palatable tree species in Minnesota under current deer population levels. Engaging the public through a citizen science project such as AVID showcases the importance of evaluating browse impacts on trees from white-tailed deer while simultaneously providing information to managers and decision makers about this important conservation concern.
 Study Implications: Citizen scientists can collect data on important conservation issues with ecological implications. This study showcases data provided by volunteers in Minnesota’s Assessing Vegetation Impacts from Deer (AVID) program. These results showed that the growth of nine browse-palatable species grew minimally over a four-year span. Citizen science data like these can be used by state wildlife agencies to better understand forest-wildlife interactions and establish wildlife population harvest goals. Measurements of deer browse can also assist researchers by reducing the costs of data collection and providing a geographically diverse data set with detailed measurements of deer impacts to forest vegetation.