Confounded winter and spring phenoclimatology on large herbivore ranges

摘要: Annual variation in winter severity and growing season vegetation dynamics appear to influence the demography of temperate herbivores but parsing from spring effects requires independent metrics environmental conditions specific each season. We tested for independence annual amongst four common used describe early across entire spatial distribution elk (Cervus elaphus) Wyoming 1989 2006. Winter were correlated a way. Winters with snow cover that ended tended be followed by early, slow, rises normalized difference index (NDVI), while long winters extended periods often late rapid NDVI. Across 35 ranges, 0.4–86.8 % rate increase NDVI’s was explained date disappeared SNOTEL stations. Because phenoclimatological are seasons shifting due climate change, identifying constraints on herbivore fitness, particularly migratory species, is more difficult than previously recognized.