Auburn University professor co-authors article in Nature, reveals climate change is altering the functions of ecosystems within the Northern Hemisphere

An Auburn University professor says seasonal water deficits may limit the benefits for plant growth of earlier, warmer springs in the Northern Hemisphere, highlighting the impact of lagged effects of spring warmth on plant productivity during the subsequent summer and autumn, reports a paper in the Oct. 4 issue of the scientific journal, Nature. The publication is widely regarded as the world's most highly cited interdisciplinary science journal.

Hanqin Tian, director of the International Center for Climate and Global Change Research in Auburn’s School of Forestry and Wildlife Sciences, is co-author of "Widespread seasonal compensation effects of spring warming on northern plant productivity,” with an international team of 16 scientists led by Wolfgang Buermann, of University of Leeds in the United Kingdom.

According to a statement released by Nature, the authors suggest that the accumulation of seasonal water deficits may result in regional adverse lagged effects in plant growth in response to warmer springs—a key factor to consider when modelling the effects of climate change on plant productivity.

“Climate warming since the early 1970s has caused shifts in plant phenological cycles: earlier spring onset and delayed autumn senescence,” said Tian, who serves as the Solon and Martha Dixon Professor at Auburn. “This study provides evidence for widespread positive and negative lagged plant productivity responses across northern ecosystems associated with warmer springs.”

The research team analyzed a range of data, including satellite measurements of vegetation greenness, and report regional differences in beneficial and adverse lagged effects on plant growth across the Northern Hemisphere.

The study found that the areas in Eurasia above a latitude of 50 degrees north, such as the UK, Scandinavia and parts of Russia, displayed positive correlations between warm springs and plant growth, whereas areas in western North America, Siberia and temperate eastern Asia showed negative correlations.

Altitude and particularly seasonal precipitation seem to strongly influence these regional lagged growth patterns, a finding that contrasts with the idea that temperature and sunlight are key limiters of northern plant growth, said the researchers.