Recent applications of continental-scale phenology data for science and resource management

The USA National Phenology Network (USA-NPN; www.usanpn.org) serves science and society by promoting a broad understanding of plant and animal phenology and the relationships among phenological patterns and all aspects of environmental change. The National Phenology Database, maintained by the USA-NPN, is experiencing steady growth in the number of data records it houses; these data are now being used in a number of applications for science, conservation and resource management. The majority of the data in the database has been provided by participants in the USA-NPN national-scale, multi-taxa phenology observation program Nature's Notebook. Participants, including both professional scientists and volunteers, follow vetted protocols that employ phenological “status” monitoring. On each repeated visit to a site, observers indicate the status of each phenophase (e.g., “breaking leaf buds” or “open flowers”) for individual plants or for animal species with a ‘yes' if the phenophase is occurring or a ‘no' if it is not. Additionally, an estimate of the intensity of the phenophase can also be reported (e.g. “less than 3 leaf buds breaking” or ”25-49% of flowers open”). This approach has a number of advantages (e.g., estimation of uncertainty in dates of phenophase onset and end, measure of phenophase duration and magnitude, measure of within-season gaps in the presence of a phenophase due to periodic activity or repeat events) and is especially well-suited for integrated multi-taxa monitoring to create a robust ecological dataset.

Between 2008 and June 2014, the 3580 active participants registered with Nature's Notebook have contributed over 3.5 million observation records for plants and animals, including historical lilac and honeysuckle data that go back to 1956. Customizable data downloads are freely available from www.usanpn.org/results/data. Data are accompanied by FGDC-compliant metadata, data-use and data-attribution policies, vetted and documented methodologies and protocols, and version control. Quality assurance and quality control, and metadata associated with field observations are also documented. Data are also available for exploration, visualization and preliminary analysis at www.usanpn.org/results/visualizations.

We demonstrate several types of questions that can be addressed with this observing system and the resultant data, and highlight several ongoing local- to national-scale projects as well as some recently published studies. Projects include national-level bioclimatic indices, regional assessments of historical and potential future trends in phenology, sub-regional assessments of temperate deciduous forest response to recent variability in spring-time heat accumulation, and local monitoring for invasive species detection across platforms from ground to satellite. Additional data-mining and exploration by interested researchers and/or resource managers will likely further demonstrate the value of these data.