Phenology monitoring protocol: Northeast Temperate Network - Tierney, Geri; Mitchell, Brian; Miller-Rushing, Abraham J.; Katz, Jonathan; Denny, Ellen; Brauer, Corinne; Donovan, Therese; Richardson, Andrew D.; Toomey, Michael; Kozlowski, Adam; Weltzin, Jake F.; Gerst, Kathy; et al. (National Park Service Natural Resource Report, 2013)