Purpose
This provisional Biogeographic Analysis Package provides an analysis of an annual Spring Index, First Leaf, within the user-selected area of interest.
Change in the timing of seasonal biological events (phenology – e.g., leaf-out, migration, and reproduction) is one of the most proximate responses to climate change. Information on phenological changes supports managers in adjusting the timing of activities such as treating invasive species, operating visitor facilities, and scheduling climate-related events (e.g., flower festivals, autumn leaf-viewing). Recent work shows that 53% of natural resource parks managed by the United States National Park Service are experiencing extremely early springs (that is, earlier than 95% of historic springs, Monahan et al 2016). As interannual variability also tends to increase under climate change, understanding these patterns on a local scale becomes more important. Using this interface, protected area managers can explore interannual patterns in spring arrival since 1981.
Methods
Analyses use modeled estimates of spring onset based on predicted dates of first leaf and first bloom derived from early spring shrubs (lilacs and honeysuckles) (Schwartz et al 2013).
Constraints
These provisional data were compiled with regard to the following standards and appropriate uses. Please be aware of the limitations of the data.
Appropriate Uses
Users should consider management conditions and challenges on the ground in recent years, using the First Leaf and First Bloom date as a framework for contextualizing early and late springs.
Inappropriate Uses
Users should be aware of uncertainty in these estimates of spring arising from the use multiple input sources, including error propagated forward from the interpolation of station data to create the underlying gridded climate data. In addition, uncertainty is introduced by the Spring Index models, which are approximations of reality, based on linear relationships between phenological events and meteorological variables.
USGS Provisional Software
This software is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The software has not received final approval by the U.S. Geological Survey (USGS). No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. The software is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the software.
