Ecological memory of daily carbon exchange across the globe and its importance in drylands

Yao Liu, Christopher R Schwalm, Kimberly E. Samuels-Crow, Kiona Ogle

Research output: Contribution to journalLetter

Abstract

How do antecedent (past) conditions influence land-carbon dynamics after those conditions no longer persist? In particular, quantifying such memory effects associated with the influence of past environmental (exogenous) and biological (endogenous) conditions is crucial for understanding and predicting the carbon cycle. Here we show, using data from 42 eddy covariance sites across six major biomes, that ecological memory—decomposed into environmental and biological memory components—of daily net carbon exchange (NEE) is critical for understanding the land-carbon metabolism, especially in drylands for which memory explains ~ 32% of the variation in NEE. The strong environmental memory in drylands was primarily driven by short- and long-term moisture status. Moreover, the strength of environmental memory scales with increasing water stress. This universal scaling relationship, emerging within and among major biomes, suggests a potential adaptive response to water limitation. Our findings underscore the necessity of considering ecological memory in experiments, observations and modelling.

Original languageEnglish (US)
JournalEcology Letters
DOIs
StateAccepted/In press - Jan 1 2019

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Keywords

  • Antecedent conditions
  • carbon exchange
  • carbon flux
  • dryland
  • ecological memory
  • environmental memory
  • hierarchical Bayesian model
  • lag effects
  • scaling relationship

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

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