Supplementary material to “Evolving Plans for the USA National Phenology Network (NPN)”

Julio L. Betancourt, U.S. Geological Survey and University of Arizona, Tucson; Mark D. Schwartz, Department of Geography, University of Wisconsin, Milwaukee; David D. Breshears, School of Natural Resources, University of Arizona, Tucson; Carol A. Brewer, Division of Biological Sciences, University of Montana, Missoula; Gary Frazer, U.S. Fish and Wildlife Service, Reston, Virginia; John E. Gross, Inventory and Monitoring Program, U.S. National Park Service, Fort Collins, Colorado; Susan J. Mazer, Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara; Bradley C. Reed, U.S. Geological Survey, Flagstaff, Arizona; Bruce E. Wilson, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee

Citation:
Betancourt, J. L., M. D. Schwartz, D. D. Breshears, C. A. Brewer, G. Frazer, J. E. Gross, S. J. Mazer, B. C. Reed, and B. E. Wilson (2007), Evolving plans for the USA National Phenology Network, Eos Trans. AGU, 88(19), 211. [ Full Article (pdf)]

Phenology is the study of periodic plant and animal life cycle events, and how these are influenced by environmental changes, especially seasonal variations in temperature and precipitation driven by weather and climate. Examples include the timing of leafing and flowering, agricultural crop stages, insect emergence, and bird, fish, and mammal migration. All of these events are sensitive integrators of both weather and climate, are relatively simple to record and understand, and are vital to both the scientific and public interest. Critical scientific questions include how environmental factors affect the phenology of different organisms, and how those factors vary in importance on different spatial and temporal scales. Moreover, we need to know how variations in phenology affect the abundance and diversity of organisms, their inter-specific interactions, their ecological functions, and their effects on fluxes in water, energy, and chemical elements at various scales.

Phenology can be used as a predictor for other processes and variables of importance at local to global scales, and could drive a variety of ecological forecast models with both scientific and practical applications. Phenological data and models are useful in agricultural production, drought monitoring, wildfire risk assessment, and in the management of invasive species, pests, and infectious diseases. The predictive potential of phenological data requires a new data resource—a national network of integrated phenological observations and the tools to analyze them at multiple scales.

A USA-National Phenology Network (NPN) is being organized to engage multiple federal agencies, numerous environmental networks and field stations, educational institutions at every level, and mass participation by citizen scientists. The initial phase will establish a functional continental-scale phenological monitoring network of stations observing selected regionally appropriate native plant species and/or a nationally appropriate indicator plant (e.g., lilacs), with new data collection beginning in Spring 2007.

Progress since 1st NPN Planning Workshop in 2005

The first NPN planning workshop, held in Tucson, AZ on Aug. 23–25, 2005, agreed on a framework of four expandable components or tiers, each representing a different level of spatial coverage and quality/quantity of phenological and environmental information (Figure 1). An Implementation Team of 28 members was tasked with securing funding for a central office and for additional workshops to plan and implement core aspects of the network (Betancourt et al., 2005; see also http://www.uwm.edu/Dept/Geography/npn/).

Figure 1

Figure 1. The tiered system adopted by NPN follows the “Framework for Environmental Monitoring and Related Research” proposed by the Committee on Environmental and Natural Resources (CENR) of the National Science and Technology Council. NPN will consist of four components or tiers: 1) Networks of locally intensive sites focused on process studies (e.g., Long-Term Ecological Research Sites, AmeriFlux, Organization of Field Biological Stations); 2) Spatially extensive environmental networks focused on standardized observations (e.g., National Weather Service Cooperative Observer Network, National Park Service Inventory & Monitoring sites); 3) Volunteer and Education Networks (e.g., garden clubs, plant-, bird- and butterfly-monitoring networks, college campuses); and 4) remote sensing products (e.g., MODIS) that can be ground-truthed and assimilated to extend surface phenological observations to the continental scale.

In summer 2006, a cooperative agreement between USGS and the University of Arizona was established to fund a National Coordinating Office in Tucson. USGS is conducting a formal search for an Executive Director, who will be a permanent USGS employee (www.usajobs.opm.gov, Announcement Number WR-2007-0160, applications due Feb. 9, 2007). The University of Arizona has hired Mark Losleben, formerly a staff scientist at the University of Colorado’s Niwot Ridge LTER station, to serve as Assistant Director. In fall 2006, NSF awarded NPN a 5-year Research Coordination Network grant to promote and sustain scientific planning and collaboration across the network.

Results of 2nd Planning Workshop in 2006

Sponsored by NSF, USGS, U.S. Fish and Wildlife Service (USFWS), and the National Air and Space Administration (NASA), a 2nd Planning Workshop of 44 participants was convened at the University of Wisconsin-Milwaukee on Oct. 10–12, 2006. Working groups labored to

  1. Develop lists of target species and appropriate observation protocols;
  2. Leverage existing networks to build a backbone network of nationwide observations in 2007;
  3. Identify and launch new opportunities for education, citizen science and outreach;
  4. Develop strategies for implementing the remote sensing component of NPN; and
  5. Draft a data management plan for use in 2007 and design the necessary cyberinfrastructure to operate NPN over the long term.

1. Species and Protocols

Criteria for selecting target species are varied, and justifications for selection are necessarily nuanced. Some obvious criteria include ease of identification and observation, sensitivity to different temperature and precipitation thresholds; overlap with species being measured by phenology networks in other countries; breadth of distribution in U.S.A.; ecological amplitude; local and regional dominance; functional, reproductive and dispersal characteristics; economic, social or conservation value; and importance for calibrating remote sensing products and detecting climate change/variability. Groups interested in large-scale process (e.g., biogeochemical cycling, primary productivity, disturbance ecology, ecohydrology, vegetation modeling, and ground-truthing of remote sensing) will naturally focus on widespread and dominant plant species. Conservation biologists studying alpine floras will want to target at risk plants or host plants for at-risk organisms, while phenology of non-native species is essential to most efforts to manage plant invasions via herbicides or biocontrol. At least initially, the list of target species is also constrained by specific interests and species distributions within participating networks and programs.

The Species and Protocols Group (S&P) applied a combination of desired criteria and applications to a comprehensive plant database ( http://www.natureserve.org/explorer/) in selecting prioritized lists of 25, 50, and 100 species, which will be vetted by participating networks and programs. The primary goal of this selection is to establish a baseline of phenological patterns for plants and animals across the Nation, help monitor and detect phenological responses to climate change, immediately prove up on the national scope of network, and engage the largest possible number of participants within a backbone network.

In developing protocols for phenological observations, the S&P group considered siting criteria. Monitoring sites should have convenient access, be secure through time, experience minimum disturbance, and have well defined metadata. For lilacs and other cloned indicator species, near proximity to a met station is mandatory. For native species, the location should be representative of the vegetation type in a larger area (~ 1ha for sites where remote sensing observations are also being obtained). Phenophases will be based on the general BBCH scale used by European Phenology Network or other available protocols, modified to accommodate target species. Ideally, there should be a small number of individuals evaluated per species for a given phenophase. The time commitment at each site should less than 1 hour for observations, 3 times per week (for a sampling interval of 3 days maximum, spanning at least 5 days from the 1st to the 3rd observation), with <15 minutes of data for each observation day. The above should be conducted around the time of the relevant phenophases, and time commitments can be reduced in the well-defined “off-season.” Protocols also are being developed in collaboration with the Remote Sensing Group to provide surface observations of community greenness on a relative scale.

2. Leveraging a Backbone Network of Phenological Observations

The focus for 2007 will be on establishing phenological observations across both spatially-extensive and locally-intensive networks that already have weather or biological monitoring as part of their mission or operational activities. In 2007, NPN will leverage cooperation from five existing ecological/weather networks—the National Weather Service Cooperator Observer (COOP) and other weather networks, the National Park Service (NPS) Inventory & Monitoring Program, the Long Term Ecological Research (LTER) Network, the Organization of Biological Field Stations (OBFS), and AmeriFlux. This backbone network will be expanded in subsequent years as new cooperators become involved. For example, partnerships with LTER/OBS/Ameriflux will lay the groundwork for collaborations already envisioned between NPN and the planned National Ecological Observatory Network (NEON) ( http://www.neoninc.org/documents/ISEP_2006Oct23.pdf).

COOP and other weather networks offer the best opportunity to co-locate daily weather and phenological observations of lilacs and other native species at more than 1000 sites distributed evenly across the country and along seasonal gradients for observers interested in traveling along with the “green wave.” To facilitate participation in NPN, a “doorway” for weather observers to report phenological observations can be accommodated in the latest generation of the NWS web-based data entry system, WxCoder III (Web Xmitted Cooperative Observer Data Encoded Report).

Through its Inventory and Monitoring Program, NPS also is well positioned to contribute to and benefit from NPN by integrating phenological monitoring across more than 275 parks located from American Samoa to Gates of the Arctic. Phenology is an important indicator of status and trends in park resources, particularly the effects of climate change, and is directly related to core operational issues with the parks, including evaluation and management of wildlife, water resources, invasive species, visitor use patterns and interpretation/education.

Developing emphasis on cross-site synthesis within LTER/OBFS/AmeriFlux makes the timing of the proposed partnerships with networks of locally-intensive biological field stations extremely propitious. Partnership with NPN will benefit these networks by providing observation protocols, data management infrastructure, and linkage to the larger network of observations to establish a context for individual sites. Participation can range from the establishment of common indicator species to full-fledged research partnerships focusing establishing root causes of similarities and anomalies in continental patterns, phenology’s role in regulating population abundance and species interactions, as well as more functional aspects of phenology. At AmeriFlux sites, for example, relationships will be established between traditional phenological events and community-level indices of productivity that are intermediate between population-level studies and remote sensing. At these sties, automated measurements taken at half hourly time steps can describing the transient changes in plant states between individual phenological events.

3. Education, Citizen Science and Outreach

The primary goal of the Education, Citizen Science, and Outreach (ECSO) component of NPN is to bring together professional and citizen scientists, students, stewards of public and private lands, amateur naturalists, and outdoor enthusiasts to compile basic information on phenological responses to climate change; to study its nature, pace and the effects of ecosystem function; and to understand connectivity and synchrony among species. The ECSO working group is designing a range of programs and products through which the public and scientific professionals throughout the U.S. can work independently and together to observe and to interpret the phenological world on an unprecedented scale. Each program is designed to achieve one or more of the following objectives:

  1. Engage the public in long-term phenological data collection and analysis through both formal and informal science education programs;
  2. Engender self-directed, voluntary learning using inquiry-based approaches;
  3. Engage currently active land stewards, networks, and master naturalist programs in the collection and contribution of phenological data;
  4. Provide training in the tools and applications of phenological studies to citizens and to scientists at all stages in their careers;
  5. Enhance opportunities for the public to interact with professional scientists;
  6. Promote novel tool development and collaboration among scientists representing historically distinct disciplines.

Several programs with different timelines are under planning, but two are already partially funded, close to implementation, and convey our excitement about the wide range of education and outreach opportunities available to NPN. Project Bud Burst will use 5,000–10,000 public observers to validate protocols for leafing and flowering of 18 common and showy plant species with the intent of disseminating to a wider audience in future data collection. Floral Report Card will create a national experiment in which clones from different ecotypes of four native species will be grown across 16 botanical gardens representing different climatic conditions nationwide. With genetic variation held constant, the clones will act like a network of climate sensors or “phytometers.” Responses in julian dates of first anthesis, peak flowering, first fruit ripened, last fruit ripened, total flowering period and fecundity across the different climatic zones will allow us to infer how these species might respond to future climate change.

4. Remote Sensing of Land Surface Phenology (LSP)

The working group on remote sensing of land surface phenology (LSP) revisited the complexities of characterizing the phenology of a given pixel size (30 m, 250 m, 1 km), due to heterogeneous pixel composition and offsets in timing of phenology for species within a pixel. Standard species-level observations across NPN need to be supplemented with community level observations that are better linked to the LSP scale. With these issues in mind, the group constructed short- and medium-term strategies for implementing the remote sensing component of the NPN. The short-term strategy includes plans for both in situ validation/characterization studies of LSP at intensive observation sites and an observation protocol for cooperating extensive observation sites that will make broader-scale observations. The intensive experiment will collect weekly measurements of community greenness at fixed transect sites that can be directly compared to Landsat and MODIS observed fractional greenness. The extensive observations will provide information on the spatial patterns of stages of vegetation community phenology that can be compared to both remote sensing and species-level observations to forge a stronger link between the two approaches. Mid-term goals include development initiation of a field validation study of the intensive observation sites, and development of proposals involving validation techniques, algorithm intercomparison studies, and forecast model development. Development of a data management strategy for remote sensing data will involve discussions with the Distributed Active Archive Centers (DAACs) at EROS and Oak Ridge National Laboratories.

5. Informatics and Cyberinfrastructure

The NPN requires a data model and infrastructure for the acquisition, management and dissemination of existing and newly collected phenology observation data. The overarching goals of the USA–NPN cyberinfrastructure (NPNCI) will be to ensure that phenological data are

  1. Available — that computing systems in the NPNCI employ appropriate best practice and operate continuously, and that location and content of data can be readily identified.
  2. Usable — data are stored in a stable, reliable, and interpretable data retrieval system;
  3. Reliable — The NPNCI includes a process for QA/QC of data, ensures that data are not inadvertently changed, that all changes are logged, and that users have tools to verify the integrity of data which they have entered;
  4. Shareable — data products are complete, subjected to quality assurance, formatted for use and documented for interpretation by others;
  5. Easily integrated — data and products are consistent with data exchange standards and mechanisms are in place to ensure interoperable with related data sets and information systems; and
  6. Interpretable — the data are routinely summarized, transformed into useful information, and reported in formats designed for specific clients.

The Informatics group has drafted a strategic overview of the requirements, design, and implementation schedule to guide the systematic development of the NPNCI. Full implementation will include tools for data input, an underlying database structure (the “back end”), reporting tools that provide raw data, visualization tools, and more advanced functions that permit linkages to remote data and both automated and streamlined processing (i.e., accommodate scientific workflows). The implementation plan will be developed in three phases, defined largely by available resources. The first phase, likely through spring, 2007, is intended to provide minimal functionality for a central USA-NPN database, web-based data entry and access, and a few basic tools, in a way that facilitates later expansion. Following development of these basics, analytical and visualization tools, as well as connections to related climatological and ecological databases will be added in subsequent phases, building towards a comprehensive NPNCI.

Although the NPNCI will receive general oversight from the National Coordinating Office and the NPN Board of Directors, responsibility for CI construction and operation will be assumed by multiple organizations, including the Environmental Sciences Division of Oak Ridge National Laboratories Environmental Sciences Division, the USGS Center for Earth Resources Observation and Science (EROS), the USGS National Biological Infrastructure Institute (NBII), the San Diego Supercomputing Center, (USGS), NatureServe, the University of Wisconsin-Milwaukee, and the University of Arizona. The main objective of this collaboration will be to develop an information infrastructure appropriate for a national system, capable of distributing information across the web in a perpetually updated format, and with the appropriate content management and user services to serve scientific and practical applications vital to the national interest.

Reference:

Betancourt, J.L., Schwartz, M.D., Breshears, D.D., Cayan, D.R., Dettinger, M.D., Inouye, D.W., Post, E., and Reed, B.C., 2005. Implementing a U.S.A.-National Phenology Network. Eos Transactions American Geophysical Union, Vol. 86, p. 539.

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