Atmospheric deposition, CO2, and change in the land carbon sink
Fernández-Martínez, M. ; Vicca, S. ; Janssens, I.A. ; Ciais, P. ; Obersteiner, M. ; Bartrons, M. ; Sardans, Jordi ; Verger, Aleixandre ; Canadell, J.G. ; Chevallier, F. ; Wang, X. ; Bernhofer, C. ; Curtis, P.S. ; Gianelle, D. ; Grünwald, T. ; Heinesch, B. ; Ibrom, A. ; Knohl, A. ; Laurila, T. ; Law, Beverly E. ; Limousin, J.M. ; Longdoz, B. ; Loustau, D. ; Mammarella, I. ; Matteucci, G. ; Monson, R.K. ; Montagnani, L. ; Moors, E.J. ; Munger, J.W. ; Papale, D. ; Piao, S.L. ; Peñuelas, J. - \ 2017
Scientific Reports 7 (2017). - ISSN 2045-2322 - 13 p.
Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling.
The NUCOMBog R package for simulating vegetation, water, carbon and nitrogen dynamics in peatlands
Pullens, J.W.M. ; Bagnara, M. ; Silveyra González, R. ; Gianelle, D. ; Sottocornola, M. ; Heijmans, M.M.P.D. ; Kiely, G. ; Hartig, F. - \ 2017
Ecological Informatics 40 (2017). - ISSN 1574-9541 - p. 35 - 39.
Competition - Net ecosystem exchange - NUCOMBOG - Peatland - R package - Vegetation
Since peatlands store up to 30% of the global soil organic carbon, it is important to understand how these ecosystems will react to a change in climate and management. Process-based ecosystem models have emerged as important tools for predicting long-term peatland dynamics, but their application is often challenging because they require programming skills. In this paper, we present NUCOMBog, an R package of the NUCOM-Bog model (Heijmans et al. 2008), which simulates the vegetation, carbon, nitrogen and water dynamics of peatlands in monthly time steps. The package complements the model with appropriate functions, such as the calculation of net ecosystem exchange, as well as parallel functionality. As a result, the NUCOMBog R package provides a user-friendly tool for simulating vegetation and biogeochemical cycles/fluxes in peatlands over years/decades, under different management strategies and climate change scenarios, with the option to use all the in-built model analysis capabilities of R, such as plotting, sensitivity analysis or optimization.
Positive biodiversity-productivity relationship predominant in global forests
Liang, J. ; Crowther, T.W. ; Picard, N. ; Wiser, S. ; Zhou, M. ; Alberti, G. ; Schulze, E.D. ; Mcguire, A.D. ; Bozzato, F. ; Pretzsch, H. ; Miguel, S. de; Paquette, A. ; Herault, B. ; Scherer-lorenzen, M. ; Barrett, C.B. ; Glick, H.B. ; Hengeveld, G.M. ; Nabuurs, Gert-Jan ; Pfautsch, S. ; Viana, H. ; Vibrans, A.C. ; Ammer, C. ; Schall, P. ; Verbyla, D. ; Tchebakova, N. ; Fischer, M. ; Watson, J.V. ; Chen, Han Y.H. ; Lei, X. ; Schelhaas, M.J. ; Lu, Huicui ; Gianelle, D. ; Parfenova, E.I. ; Salas, C. ; Lee, E. ; Lee, B. ; Kim, H.S. ; Bruelheide, H. ; Coomes, D.A. ; Piotto, D. ; Sunderland, T. ; Schmid, B. ; Gourlet-Fleury, S. ; Sonke, B. ; Tavani, R. ; Zhu, J. ; Brandl, S. ; Vayreda, J. ; Kitahara, F. ; Searle, E.B. ; Neldner, V.J. ; Ngugi, M.R. ; Baraloto, C. ; Frizzera, L. ; Ba Azy, R. ; Oleksyn, J. ; Zawila-Niedzwiecki, T. ; Bouriaud, O. ; Bussotti, F. ; Finer, L. ; Jaroszewicz, B. ; Jucker, T. ; Valladares, F. ; Jagodzinski, A.M. ; Peri, P.L. ; Gonmadje, C. ; Marthy, W. ; Obrien, T. ; Martin, E.H. ; Marshall, A.R. ; Rovero, F. ; Bitariho, R. ; Niklaus, P.A. ; Alvarez-Loayza, P. ; Chamuya, N. ; Valencia, R. ; Mortier, F. ; Wortel, V. ; Engone-Obiang, N.L. ; Ferreira, L.V. ; Odeke, D.E. ; Vasquez, R.M. ; Lewis, S.L. ; Reich, P.B. - \ 2016
Science 354 (2016)6309. - ISSN 0036-8075 - 15 p.
The biodiversity-productivity relationship (BPR) is foundational to our understanding of the global extinction crisis and its impacts on ecosystem functioning. Understanding BPR is critical for the accurate valuation and effective conservation of biodiversity. Using ground-sourced data from 777,126 permanent plots, spanning 44 countries and most terrestrial biomes, we reveal a globally consistent positive concave-down BPR, showing that continued biodiversity loss would result in an accelerating decline in forest productivity worldwide. The value of biodiversity in maintaining commercial forest productivity alone—US$166 billion to 490 billion per year according to our estimation—is more than twice what it would cost to implement effective global conservation. This highlights the need for a worldwide reassessment of biodiversity values, forest management strategies, and conservation priorities.
Correction to: Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations
Jung, M. ; Reichstein, M. ; Margolis, H.A. ; Cescatti, A. ; Richardson, A.D. ; Arain, M.A. ; Arneth, A. ; Bernhofer, C. ; Bonal, D. ; Chen, J. ; Gianelle, D. ; Gobron, N. ; Kiely, G. ; Kutsch, W. ; Lasslop, G. ; Law, B.E. ; Lindroth, A. ; Merbold, L. ; Montagnani, L. ; Moors, E.J. ; Papale, D. ; Sottocornola, M. ; Vaccari, F. ; Williams, C. - \ 2012
Journal of Geophysical Research: Biogeosciences 117 (2012)4. - ISSN 2169-8953
Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations
Jung, M. ; Reichstein, M. ; Cescatti, A. ; Richardson, A.D. ; Arain, A. ; Arneth, A. ; Bernhofer, C. ; Bonal, D. ; Chen, J. ; Gianelle, D. ; Gobron, N. ; Lasslop, G. ; Moors, E.J. - \ 2011
Journal of Geophysical Research: Biogeosciences 116 (2011)G3. - ISSN 2169-8953 - 16 p.
net ecosystem exchange - energy-balance closure - co2 flux - primary productivity - vegetation model - climate - uncertainty - respiration - sensitivity - dynamics
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° × 0.5° 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 × 1018 yr-1), H (164 ± 15 J × 1018 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
Temporal and among-site variability of inherent water use efficiency at the ecosystem level
Beer, C. ; Ciais, P. ; Reichstein, M. ; Baldocchi, D. ; Law, B.E. ; Papale, D. ; Soussana, J.F. ; Ammann, C. ; Buchmann, N. ; Frank, D. ; Gianelle, D. ; Janssens, I.A. ; Knohl, A. ; Kostner, B. ; Moors, E.J. ; Roupsard, O. ; Verbeeck, H. ; Vesala, T. ; Williams, C.A. ; Wohlfahrt, G. - \ 2009
Global Biogeochemical Cycles 23 (2009). - ISSN 0886-6236 - 13
watergebruiksrendement - kooldioxide - waterdampbeweging - terrestrische ecosystemen - atmosfeer - koolstofcyclus - water use efficiency - carbon dioxide - water vapour movement - terrestrial ecosystems - atmosphere - carbon cycle - scots pine forest - co2 exchange - carbon-dioxide - eddy covariance - central germany - ponderosa pine - canopy-scale - aspen forest - beech forest - time scales
Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities represents ecosystem water use efficiency. Its multiplication with mean daylight vapor pressure deficit (VPD) leads to a quantity which we call “inherent water use efficiency” (IWUE*). The dependence of IWUE* on environmental conditions indicates possible adaptive adjustment of ecosystem physiology in response to a changing environment. IWUE* is analyzed for 43 sites across a range of plant functional types and climatic conditions. IWUE* increases during short-term moderate drought conditions. Mean annual IWUE* varied by a factor of 3 among all sites. This is partly explained by soil moisture at field capacity, particularly in deciduous broad-leaved forests. Canopy light interception sets the upper limits to canopy photosynthesis, and explains half the variance in annual IWUE* among herbaceous ecosystems and evergreen needle-leaved forests. Knowledge of IWUE* offers valuable improvement to the representation of carbon and water coupling in ecosystem process models