The Science

Newswise — Warmer climates on mountaintops will alter the activity of plants and soil microbes. These alterations can affect the availability and movement of important nutrients such as nitrogen, phosphorous, and carbon. As a result, these cycles may become out of step with their historic patterns at high elevations. The result? Severe impacts to plants that have evolved under those patterns.

The Impact

In many mountain ecosystems around the world, nitrogen and phosphorus cycles are constrained at higher, cool elevations, while these cycles are becoming decoupled at lower, warmer elevations. Consequently, plants may not be able to “march up the mountainside” when it warms, as many models predict. A study shows how mountain ecosystems may respond to warming in the future. These ecosystems are biodiversity hotspots. They provide numerous human services such as clean drinking water.

Summary

Despite interest in how climate warming affects ecological processes, remarkably little is known about whether similar types of ecosystems respond to warming with changes in elevation. By comparing seven replicated temperate treeline regions worldwide, researchers showed that comparable changes in temperature affect plant community-level nutrient dynamics in remarkably similar ways across contrasting regions. Notably, their study reveals that despite broad differences in regional floras and geologies, declining temperatures at high elevations universally constrained plant nutrient dynamics. This finding has broad global change implications, given the high risk that alpine environments face under global climate change.

Funding

This work was made possible by a Wallenberg Scholars Award to D.A.W.; regional support from Fondecyt 1120171 to A.F.; National Science Foundation Dimensions of Biodiversity grant (NSF-1136703), Carlsberg Fund grant, and the Danish National Research Foundation’s support to the Center for Macroecology, Evolution, and Climate to N.J.S.; U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Terrestrial Ecosystem Science program award (DE-SC0010562) to A.T.C.; support from the United Kingdom’s Natural Environment Research Council to R.D.B.; support from the BiodivERsA project Resilience of Marginal Grasslands and Biodiversity Management Decision Support (REGARDS) (ANR-12-EBID-004-01) to J.C.C., S.L., and K.G. and REGARDS (FWF-I-1056) to M.B.; support from the Netherlands Organization for Scientific Research (VENI 451-14-017) to D.L.O.; and support from the Natural Sciences and Engineering Research Council of Canada to Z.G.

Publication

J. Mayor, N.J. Sanders, A.T. Classen, R.D. Bardgett, J.C. Clément, A. Fajardo, S. Lavorel, M.K. Sundqvist, M. Bahn, C. Chisholm, E. Cieraad, Z. Gedalof, K. Grigulis, G. Kudo, D.L. Oberski, and D.A. Wardle, “Elevation alters ecosystem properties across temperate treelines globally.” Nature 542, 91-95 (2017). [DOI: 10.1038/nature21027]