Multiscale analysis of temporal variability of soil CO₂ production as influenced by weather and vegetation

• Published in: Global change biology Vol. 16; no. 5; pp. 1589 - 1605
• Main Authors: VARGAS, RODRIGO, DETTO, MATTEO, BALDOCCHI, DENNIS D, ALLEN, MICHAEL F
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.05.2010; Blackwell Publishing Ltd; Wiley-Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Carbon dioxide; Climate change; CO2 sensors; CO₂ sensors; Fundamental and applied biological sciences. Psychology; General aspects; Meteorology; model performance; rain pulse; soil respiration; Soil testing; Spectrum analysis; temperature independent; time series analysis; wavelet analysis; wavelet coherence; wireless sensors; time series analysis; Temperature; Carbon dioxide; Time series; soil respiration; Environmental factor; rain pulse; CO; wavelet coherence; wireless sensors; Weather; Soils; temperature independent; Rain; sensors; wavelet analysis; Vegetation; Models; Atmospheric precipitation; Performance; Respiration; model performance
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/j.1365-2486.2009.02111.x

Ecosystem processes are influenced by weather and climatic perturbations at multiple temporal scales with a large range of amplitudes and phases. Technological advances of automated biometeorological measurements provide the opportunity to apply spectral methods on continuous time series to identify differences in amplitudes and phases and relationships with weather variation. Here we used wavelet coherence analysis to study the temporal covariance between soil CO₂ production and soil temperature, soil moisture, and photosynthetically active radiation (PAR). Continuous (hourly average) data were acquired over 2 years among three vegetation types in a semiarid mixed temperate forest. We showed that soil temperature and soil moisture influence soil CO₂ production differently at multiple periods (e.g. hours, days, weeks, months, years), especially after rain pulse events. Our results provide information about the periodicity of soil CO₂ production among vegetation types, and provide insights about processes controlling CO₂ production through the study of phase relationships between two time series (e.g. soil CO₂ production and PAR). We tested the performance of empirical models of soil CO₂ production using the continuous wavelet transform. These models, built around soil temperature and moisture, failed at multiple periods across the measured dates, suggesting that empirical models should include other factors that regulate soil CO₂ production at different temporal scales. Our results add a new dimension for the analysis of continuous time series of biometeorological measurements and model testing, which will prove useful for analysis of increasing sensor data obtained by environmental networks.