Recent Trends in Ungulate Forage Inferred From Remote Sensing Datasets

Abstract

Forage quality, quantity, and phenology play a large role in regulating the habitat use and population dynamics of wildlife populations. Assessing how forage has changed over time can help inform management decisions. Using several freely available remotely sensed and climate-based datasets, we calculated forage-related metrics such as the timing and duration of spring greenup on a pixel-by-pixel basis across Montana. We conducted trend analysis from 2000-2014, identifying areas of consistent change within the state and summarizing trends on a more local scale. We also assessed variability and consistency of estimates within and across datasets. In general, mountainous regions and adjacent lower elevations display somewhat opposing trends, highlighting the importance of understanding the changes for conservation of migratory ungulates which rely on greenscape gradients to optimize nutritional gain.