Earlier springs decrease peak summer productivity in North American boreal forests
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In this paper, the authors analyzed nearly three decades (1982?2008) of observational records and derived products, including satellite microwave and optical imagery as well as upscaled ecosystem flux observations, to better understand how shifts in seasonality impact hydrology and productivity in the North American boreal forests.Abstract:
In the northern high latitudes, alternative hypotheses with regards to how warming-related shifts in seasonality influence ecosystem productivity exist. Increased plant growth associated with a longer growing season may enhance ecosystem productivity, but shifts to earlier springs may also negatively influence soil moisture status and productivity during the peak of the growing season. Here, we analyzed nearly three decades (1982?2008) of observational records and derived products, including satellite microwave and optical imagery as well as upscaled ecosystem flux observations, to better understand how shifts in seasonality impact hydrology and productivity in the North American boreal forests. We identified a dominant adverse influence of earlier springs on peak summer forest greenness, actual evapotranspiration and productivity at interannual time scales across the drier western and central sections of the North American boreal forests. In the vast regions where this spring onset mechanism operates, ecosystem productivity gains from earlier springs during the early portion of the growing season are effectively cancelled through corresponding losses in the later portion. Our results also indicate that recent decadal shifts towards earlier springs and associated drying in the midst of the growing season over western North American boreal forests may have contributed to the reported declines in summer productivity and increases in tree mortality and fire activity. With projections of accelerated northern high-latitude warming and associated shifts to earlier springs, persistent soil moisture deficits in peak summer may be an effective mechanism for regional-scale boreal forest dieback through their strong influence on productivity, tree mortality and disturbance dynamics.read more
Citations
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Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations
Abstract: We upscaled FLUXNET observations of carbon dioxide, water, and energy fluxes to the global scale using the machine learning technique, model tree ensembles (MTE). We trained MTE to predict site-level gross primary productivity (GPP), terrestrial ecosystem respiration (TER), net ecosystem exchange (NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climate and meteorological data, and information on land use. We applied the trained MTEs to generate global flux fields at a 0.5 degrees x 0.5 degrees spatial resolution and a monthly temporal resolution from 1982 to 2008. Cross-validation analyses revealed good performance of MTE in predicting among-site flux variability with modeling efficiencies (MEf) between 0.64 and 0.84, except for NEE (MEf = 0.32). Performance was also good for predicting seasonal patterns (MEf between 0.84 and 0.89, except for NEE (0.64)). By comparison, predictions of monthly anomalies were not as strong (MEf between 0.29 and 0.52). Improved accounting of disturbance and lagged environmental effects, along with improved characterization of errors in the training data set, would contribute most to further reducing uncertainties. Our global estimates of LE (158 +/- 7 J x 10(18) yr(-1)), H (164 +/- 15 J x 10(18) yr(-1)), and GPP (119 +/- 6 Pg C yr(-1)) were similar to independent estimates. Our global TER estimate (96 +/- 6 Pg C yr(-1)) was likely underestimated by 5-10%. Hot spot regions of interannual variability in carbon fluxes occurred in semiarid to semihumid regions and were controlled by moisture supply. Overall, GPP was more important to interannual variability in NEE than TER. Our empirically derived fluxes may be used for calibration and evaluation of land surface process models and for exploratory and diagnostic assessments of the biosphere.
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References
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Journal ArticleDOI
The Association Between Circulation Anomaliesin the Mid-Troposphere and Area Burnedby Wildland Fire in Canada
TL;DR: In this article, the authors examined the physical links between anomalous mid-tropospheric circulation over various regions of Canada and wildland fire severity and found statistically significant correlations between regional total area burned and clusters of anomalous 500 hPa geopotential height values immediately over, and immediately upstream of the affected region.
Journal ArticleDOI
Summer Drought Patterns in Canada and the Relationship toGlobal Sea Surface Temperatures
Amir Shabbar,Walter Skinner +1 more
TL;DR: In this article, large-scale relationships between summer PDSI patterns in Canada and previous winter global sea surface temperature (SST) patterns are analyzed using singular value decomposition (SVD) analysis.
Journal ArticleDOI
Interannual covariability in Northern Hemisphere air temperatures and greenness associated with El Niño‐Southern Oscillation and the Arctic Oscillation
Wolfgang Buermann,Wolfgang Buermann,Bruce T. Anderson,Compton J. Tucker,Robert E. Dickinson,Wolfgang Lucht,Christopher S. Potter,Ranga B. Myneni +7 more
TL;DR: In this paper, the year-to-year variations in northern vegetation greenness as they relate to the dominant modes of climate variability were estimated, and it was found that during spring, large-scale modes of interannual vegetation variability are strongly correlated with spatiotemporal modes of variability in the overlying temperature field.
Journal ArticleDOI
Coupling between carbon cycling and climate in a high-elevation, subalpine forest: a model-data fusion analysis.
TL;DR: The model-data fusion showed that most of the interannual variability in NEE was due to variability in GEE, and not RE, and it was found that longer growing seasons at Niwot Ridge were correlated with less net CO2 uptake, due to a decrease of available snow-melt water during the late springtime photosynthetic period.
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Change in snow phenology and its potential feedback to temperature in the Northern Hemisphere over the last three decades
Shushi Peng,Shilong Piao,Shilong Piao,Philippe Ciais,Pierre Friedlingstein,Liming Zhou,Tao Wang +6 more
TL;DR: In this paper, the authors analyzed trends in dates of onset and termination of snow cover in relation to temperature over the past 27 years (1980-2006) from over 636 meteorological stations in the Northern Hemisphere.
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