Dataset Information

Centennial-scale reductions in nitrogen availability in temperate forests of the United States.

ABSTRACT: Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon (C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes-especially climate change and elevated atmospheric carbon dioxide concentrations-are increasing demand for N, the element limiting primary productivity in temperate forests, which could be reducing N availability. To determine the long-term, integrated effects of global changes on forest N cycling, we measured stable N isotopes in wood, a proxy for N supply relative to demand, on large spatial and temporal scales across the continental U.S.A. Here, we show that forest N availability has generally declined across much of the U.S. since at least 1850 C.E. with cool, wet forests demonstrating the greatest declines. Across sites, recent trajectories of N availability were independent of recent atmospheric N deposition rates, implying a minor role for modern N deposition on the trajectory of N status of North American forests. Our results demonstrate that current trends of global changes are likely to be consistent with forest oligotrophication into the foreseeable future, further constraining forest C fixation and potentially storage.

SUBMITTER: McLauchlan KK

PROVIDER: S-EPMC5552780 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

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Centennial-scale reductions in nitrogen availability in temperate forests of the United States.

McLauchlan K K KK Gerhart L M LM Battles J J JJ Craine J M JM Elmore A J AJ Higuera P E PE Mack M C MC McNeil B E BE Nelson D M DM Pederson N N Perakis S S SS

Scientific reports 20170810 1

Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon (C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes-especially climate change and elevated atmospheric carbon dioxide concentrations-are increasing demand for N, the element limiting primary productivity in temperate forests, which could be reducing N availability. To determine the long-term, inte ...[more]

PMID: 28798386

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Dataset Information

Centennial-scale reductions in nitrogen availability in temperate forests of the United States.

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Centennial-scale reductions in nitrogen availability in temperate forests of the United States.

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