Ecosystems

, Volume 19, Issue 4, pp 601–614

Precipitation Pattern Determines the Inter-annual Variation of Herbaceous Layer and Carbon Fluxes in a Phreatophyte-Dominated Desert Ecosystem

Article

DOI: 10.1007/s10021-015-9954-x

Cite this article as:
Liu, R., Cieraad, E., Li, Y. et al. Ecosystems (2016) 19: 601. doi:10.1007/s10021-015-9954-x

Abstract

Arid and semi-arid ecosystems dominated by shrubby species are an important component in the global carbon cycle but are largely under-represented in studies of the effect of climate change on carbon flux. This study synthesizes data from long-term eddy covariance measurements and experiments to assess how changes in ecosystem composition, driven by precipitation patterns, affect inter-annual variability of carbon flux and their components in a halophyte desert community dominated by deep-rooted shrubs (phreatophytes, which depend on groundwater as their primary water source). Our results demonstrated that the carbon balance of this community responded strongly to precipitation variations. Both pre-growing season precipitation and growing season precipitation frequency significantly affected inter-annual variations in ecosystem carbon flux. Heavy pre-growing season precipitation (November–April, mostly as snow) increased annual net ecosystem carbon exchange, by facilitating the growth and carbon assimilation of shallow-rooted annual plants, which used spring and summer precipitation to increase community productivity. Sufficient pre-growing season precipitation led to more germination and growth of shallow-rooted annual plants. When followed by high-frequency growing season precipitation, community productivity of this desert ecosystem was lifted to the level of grassland or forest ecosystems. The long-term observations and experimental results confirmed that precipitation patterns and the herbaceous component were dominant drivers of the carbon dynamics in this phreatophyte-dominated desert ecosystem. This study illustrates the importance of inter-annual variations in climate and ecosystem composition for the carbon flux in arid and semi-arid ecosystems. It also highlights the important effect of changing frequency and seasonal pattern of precipitation on the regional and global carbon cycle in the coming decades.

Keywords

eddy covariance net ecosystem carbon exchange ecosystem respiration gross ecosystem productivity water-use strategy halophyte desert community 

Supplementary material

10021_2015_9954_MOESM1_ESM.doc (33 kb)
Supplementary material 1 (DOC 33 kb)

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.State Key Lab of Desert and Oasis Ecology, Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqiChina
  2. 2.Landcare ResearchLincolnNew Zealand
  3. 3.Institute of Environmental Sciences CMLLeiden UniversityLeidenThe Netherlands

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