Skip to Main Content
A tale of two springs: using recent climate anomalies to characterize the sensitivity of temperate forest phenology to climate changeAuthor(s): Mark A Friedl; Josh M Gray; Eli K Melaas; Andrew D Richardson; Koen Hufkens; Trevor F Keenan; Amey Bailey; John O'Keefe
Source: Environmental Research Letters. 9(5): 054006.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
View PDF (644.51 KB)
DescriptionBy the end of this century, mean annual temperatures in the Northeastern United States are expected to warm by 3-5 °C, which will have significant impacts on the structure and function of temperate forests in this region. To improve understanding of these impacts, we exploited two recent climate anomalies to explore how the springtime phenology of Northeastern temperate deciduous forests will respond to future climate warming. Specifically, springtime temperatures in 2010 and 2012 were the warmest on record in the Northeastern United States, with temperatures that were roughly equivalent to the lower end of warming scenarios that are projected for this region decades from now. Climate conditions in these two years therefore provide a unique empirical basis, that complements model-based studies, for improving understanding of how northeastern temperate forest phenology will change in the future. To perform our investigation, we analyzed near surface air temperatures from the United States Historical Climatology Network, time series of satellite-derived vegetation indices from NASA's Moderate Resolution Imaging Spectroradiometer, and in situ phenological observations. Our study region encompassed the northern third of the eastern temperate forest ecoregion, extending from Pennsylvania to Canada. Springtime temperatures in 2010 and 2012 were nearly 3 °C warmer than long-term average temperatures from 1971-2000 over the region, leading to median anomalies of more than 100 growing degree days. In response, satellite and ground observations show that leaf emergence occurred up to two weeks earlier than normal, but with significant sensitivity to the specific timing of thermal forcing. These results are important for two reasons. First, they provide an empirical demonstration of the sensitivity of springtime phenology in northeastern temperate forests to future climate change that supports and complements model-based predictions. Second, our results show that subtle differences in the character of thermal forcing can substantially alter the timing of leaf emergence and canopy development. By explicitly comparing and contrasting the timing of thermal forcing and leaf phenology in 2010 and 2012, we show that even though temperatures were warmer in 2012 than in 2010, the nature and timing of thermal forcing in 2010 lead to leaf emergence that was almost a week earlier than 2012.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, firstname.lastname@example.org if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationFriedl, Mark A; Gray, Josh M; Melaas, Eli K; Richardson, Andrew D; Hufkens, Koen; Keenan, Trevor F; Bailey, Amey; O'Keefe, John. 2014. A tale of two springs: using recent climate anomalies to characterize the sensitivity of temperate forest phenology to climate change. Environmental Research Letters. 9(5): 054006.
Keywordsclimate change, temperate forests, phenology
- Warmer temperatures reduce net carbon uptake, but do not affect water use, in a mature southern Appalachian forest
- Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir
- Net carbon uptake has increased through warming-induced changes in temperate forest phenology
XML: View XML