Dr. Jake F. Weltzin is an ecologist with the U.S. Geological Survey and the first executive director of the USA National Phenology Network. Dr. Weltzin has been studying the impacts of global change on natural and managed ecological systems for over two decades. His research subjects include plant and animal populations and communities, from habitats ranging from tropical savannas to temperate woodlands to northern peatlands. In all cases, he investigates the response to many driving factors of global environmental change, including atmospheric chemistry, climate change, and biological invasions.

As a science administrator at the National Science Foundation, he recognized the need to foster large-scale science initiatives, so he left academia to develop and direct the National Phenology Network ( The Network is a new national public-private partnership designed to track the influence of climate on phenology (such as the timing of leafing and flowering of plants, and reproduction and migration of animals) as a barometer of climate change impacts on plants, animals, landscapes and human societies. The Network heralds a new approach to science, in that it encourages people of all ages and backgrounds to observe and record phenology as a way to discover and explore the nature and pace of our dynamic world. Citizen scientists, professional scientist, resource managers, Native American tribes, planners and policy-makers all work together, “Taking the Pulse of Our Planet,” to determine rates, patterns and trends of change in our world around us, and to develop tools to better understand and adapt to climate change.

Websites of Interest:

  • NPN homepage:
  • Landing page for USGS Fact Sheet on NPN:
  • Information sheet on Nature’s Notebook:

Relevant Publications

  • Weltzin, J.F., 2011, The USA National Phenology Network; taking the pulse of our planet: U.S. Geological Survey Fact Sheet 2011-3023, 4 p.
  • Kardol, P., C.E. Campany, L. Souza, R.J. Norby, J.F. Weltzin and A.T. Classen. 2010. Climate change effects on plant biomass alter dominance patterns and community evenness in an experimental oldfield ecosystem. Global Change Biology 16:2676–2687. DOI: 10.1111/j.1365-2486.2010.02162.x
  • Souza, L., R.T. Belote, P. Kardol, J.F. Weltzin and R.J. Norby. 2010. CO2 enrichment accelerates successional development of an understory plant community. Journal of Plant Ecology 3:33-39. DOI: 10.1093/jpe/rtp032
  • Classen, A.T., R.J. Norby, C.E. Campany, K.E. Sides, and J.F. Weltzin. 2010. Climate change alters seedling emergence and establishment in an old-field ecosystem. PLoS ONE 5(10): e13476. doi:10.1371/journal.pone.0013476
  • Jones, K.B., H. Bogena, H. Vereecken, and J.F. Weltzin. 2010. Design and Importance of Multi-tiered Ecological Monitoring Networks. Pages 355-374 in F. Müller et al. (eds.), Long-Term Ecological Research, Springer Science+Business Media B.V. DOI 10.1007/978-90-481-8782-9_25
  • Engel, E.C., J.F. Weltzin, R.J. Norby, and A.T. Classen. 2009. Responses of an old-field plant community to interacting factors of elevated [CO2], warming, and soil moisture. Journal of Plant Ecology 2:1-11. DOI: 10.1093/jpe/rtn026