Studying biosphere-atmosphere exchange of CO2 through Carbon-13 stable isotopes
Velde, I.R. van der - \ 2015
Wageningen University. Promotor(en): Maarten Krol; Wouter Peters, co-promotor(en): J.B. Miller. - Wageningen : Wageningen University - ISBN 9789462572935 - 143
kooldioxide - biosfeer - atmosfeer - isotopen - koolstofcyclus - klimaat - voorspellingen - carbon dioxide - biosphere - atmosphere - isotopes - carbon cycle - climate - forecasts
Summary Thesis ‘Studying biosphere-atmosphere exchange of CO2 through
carbon-13 stable isotopes’
Ivar van der Velde
Making predictions of future climate is difficult, mainly due to large uncertainties in the carbon cycle. The rate at which carbon is stored in the oceans and terrestrial biosphere is not keeping pace with the rapid increase in fossil fuel combustion and deforestation, resulting in an increase of atmospheric carbon dioxide (CO2). To gain a better understanding of the global carbon cycle we need to combine multiple sources of data into one consistent analysis, such as, forest and agricultural statistics, satellite data, atmospheric and ecological observations, and mechanistic models. This thesis describes fundamental research on some of the key components of the terrestrial carbon cycle, i.e., gross primary production (GPP) and terrestrial ecosystem respiration (TER) of CO2, which forms the key to improved prediction of net exchange. Droughts have been shown to strongly influence this exchange, and to interpret these responses adequately we have turned to a large collection of new atmospheric observations of CO2, and its 13C isotope (13CO2), to constrain key model components.
In Chapter 2 we studied the global budget of atmospheric CO2 and the ratio of 13CO2/12CO2 (δ13C) and investigated the main terrestrial drivers of interannual variability (IAV) responsible for the observed atmospheric δ13C variations. In this chapter we introduced the SiBCASA biogeochemical model that we provided with a detailed isotopic discrimination scheme (to calculate the natural preference of 12CO2 over 13CO2 in uptake processes), separate 12C and 13C biogeochemical pools, and satellite-observed fire disturbances. This model was able to calculate uptake of 13CO2 and 12CO2 and produced return fluxes from its differently aged carbon pools, contributing to the so-called disequilibrium flux. Our simulated terrestrial isotope processes, plant discrimination and disequilibrium, closely resembled previously published values and similarly suggested that discrimination variations in C3 type plants and year-to-year variations in C3 and C4 productivity are the main drivers of IAV. The year-to-year variability in the terrestrial disequilibrium flux was much lower than required to match variations in atmospheric observations, under the common assumption of low variability in net ocean CO2 exchange, constant discrimination, and a closed CO2 budget. It was unclear how to increase IAV in the terrestrial biosphere, which suggested that SiBCASA missed adequate drought responses resulting in a latent isotope discrimination and variability in C3/C4 plant productivity.
Implementation of carbon isotope cycling, biomass burning, and SiBCASA’s drought response were closely studied in Chapter 3. Our biomass burning emissions were similar as in CASA-GFED; both in magnitude and spatial patterns, and the implementation of isotope exchange gave a global mean discrimination value of approximately 15 ‰, and varied spatially depending on the photosynthetic pathway in the plant. These values compared well (annually and seasonally) with other published results. Similarly, the size of the terrestrial isotopic disequilibrium was close to that of other studies. As plants experience drought stress, they respond by closing their stomata to prevent the loss of water. This process also inhibits the uptake of CO2 and reduces the isotope discrimination against 13CO2 molecules. We found that the amplitude of drought response in SiBCASA was smaller than suggested by the measured isotope signatures. We also found that a slight increase in stomatal closure for large vapor pressure deficits amplified the variations in the respired isotope signature. Finally, we saw the need for modified starch/sugar storage pools to improve the propagation of isotopic discrimination anomalies to respiration on short-term time scales.
In Chapter 4 we developed a multi-tracer inversion system to interpret signals in atmospheric CO2 and δ13C observations simultaneously. We wanted to know whether drought stress in plants can induce changes in atmospheric δ13C and whether they are interpretable. Using inverse modeling we were able to refine the discrimination parameter for plants as it reflected detectable variations in atmospheric δ13C. The results showed that the isotope discrimination values were consistently smaller during large severe droughts in the Northern Hemisphere, exceeding the estimates from SiBCASA (i.e., a larger reduction). Decreased discrimination suggested an increase in the regional intrinsic water use efficiency, which was also recorded at a large number of measurement sites. The IAV in net ecosystem exchange was relatively insensitive as we allowed the variability of the discrimination parameter to increase more than 8-fold, but it also allowed significant correlation between annual net exchange and discrimination. This study suggested a larger effect of droughts on discrimination than previously thought and that the treatment of drought response in biosphere models needs to be improved.
Carbon cycle research is far from complete as many components are still largely uncertain, which prevents us from making better predictions of future climate. This thesis, however, highlights the importance of isotope observations to assess and improve biogeochemical models, especially with regard to the allocation and turnover of carbon, and responses to droughts.
Approaches to defining a planetary boundary for biodiversity
Mace, G.M. ; Reyers, B. ; Alkemade, R. ; Biggs, R. ; Stuart Chapin, F. ; Cornell, S.E. ; Diaz, S. - \ 2014
Global environmental change : human and policy dimensions 28 (2014). - ISSN 0959-3780 - p. 289 - 297.
plant functional traits - global biodiversity - ecosystem services - phylogenetic diversity - tree mortality - tipping points - conservation - extinction - time - biosphere
The idea that there is an identifiable set of boundaries, beyond which anthropogenic change will put the Earth system outside a safe operating space for humanity, is attracting interest in the scientific community and gaining support in the environmental policy world. Rockstrom et al. (2009) identify nine such boundaries and highlight biodiversity loss as being the single boundary where current rates of extinction put the Earth system furthest outside the safe operating space. Here we review the evidence to support a boundary based on extinction rates and identify weaknesses with this metric and its bearing on humanity's needs. While changes to biodiversity are of undisputed importance, we show that both extinction rate and species richness are weak metrics for this purpose, and they do not scale well from local to regional or global levels. We develop alternative approaches to determine biodiversity loss boundaries and extend our analysis to consider large-scale responses in the Earth system that could affect its suitability for complex human societies which in turn are mediated by the biosphere. We suggest three facets of biodiversity on which a boundary could be based: the genetic library of life; functional type diversity; and biome condition and extent. For each of these we explore the science needed to indicate how it might be measured and how changes would affect human societies. In addition to these three facets, we show how biodiversity's role in supporting a safe operating space for humanity may lie primarily in its interactions with other boundaries, suggesting an immediate area of focus for scientists and policymakers.
The contribution of nitrogen deposition to the photosynthetic capacity of forests.
Fleischer, K. ; Rebel, T. ; Molen, M.K. van der; Erisman, J.W. ; Wassen, M.J. ; Loon, E.E. ; Montagnani, L. ; Gough, C.M. ; Herbst, M. - \ 2013
Global Biogeochemical Cycles 27 (2013)1. - ISSN 0886-6236 - p. 187 - 199.
net primary productivity - terrestrial carbon sink - leaf-area index - ecosystem respiration - boreal forests - temperate - co2 - sequestration - biosphere - trends
 Global terrestrial carbon (C) sequestration has increased over the last few decades. The drivers of carbon sequestration, the geographical spread and magnitude of this sink are however hotly debated. Photosynthesis determines the total C uptake of terrestrial ecosystems and is a major flux of the global C balance. We contribute to the discussion on enhanced C sequestration by analyzing the influence of nitrogen (N) deposition on photosynthetic capacity (Amax) of forest canopies. Eddy covariance measurements of net exchange of carbon provide estimates of gross primary production, from which Amax is derived with a novel approach. Canopy Amax is combined with modeled N deposition, environmental variables and stand characteristics to study the relative effects on Amax for a unique global data set of 80 forest FLUXNET sites. Canopy Amax relates positively to N deposition for evergreen needleleaf forests below an observed critical load of¿~¿8¿kg¿N ha–1¿yr–1, with a slope of 2.0¿±¿0.4 (S.E.) µmol CO2 m–2¿s–1 per 1¿kg¿N ha–1¿yr–1. Above this threshold canopy Amax levels off, exhibiting a saturating response in line with the N saturation hypothesis. Climate effects on canopy Amax cannot be separated from the effect of N deposition due to considerable covariation. For deciduous broadleaf forests and forests in the temperate (-continental) climate zones, the analysis shows the N deposition effect to be either small or absent. Leaf area index and foliar N concentration are positively but weakly related to Amax. We conclude that flux tower measurements of C fluxes provide valuable data to study physiological processes at the canopy scale. Future efforts need to be directed toward standardizing measures N cycling and pools within C monitoring networks to gain a better understanding of C and N interactions, and to disentangle the role of climate and N deposition in forest ecosystems.
Simultaneous assimilation of satellite and eddy covariance data for improving terrestrial water and carbon simulations at a semi-arid woodland site in Botswana
Kato, T. ; Knorr, W. ; Scholtze, M. ; Veenendaal, E.M. ; Kaminski, T. ; Kattge, J. ; Gobron, N. - \ 2013
Biogeosciences 10 (2013). - ISSN 1726-4170 - p. 789 - 802.
land-surface model - isba-a-gs - atmospheric co2 - soil-moisture - exchange - photosynthesis - transpiration - uncertainties - variability - biosphere
Terrestrial productivity in semi-arid woodlands is strongly susceptible to changes in precipitation, and semi-arid woodlands constitute an important element of the global water and carbon cycles. Here, we use the Carbon Cycle Data Assimilation System (CCDAS) to investigate the key parameters controlling ecological and hydrological activities for a semi-arid savanna woodland site in Maun, Botswana. Twenty-four eco-hydrological process parameters of a terrestrial ecosystem model are optimized against two data streams separately and simultaneously: daily averaged latent heat flux (LHF) derived from eddy covariance measurements, and decadal fraction of absorbed photosynthetically active radiation (FAPAR) derived from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Assimilation of both data streams LHF and FAPAR for the years 2000 and 2001 leads to improved agreement between measured and simulated quantities not only for LHF and FAPAR, but also for photosynthetic CO2 uptake. The mean uncertainty reduction (relative to the prior) over all parameters is 14.9% for the simultaneous assimilation of LHF and FAPAR, 8.5% for assimilating LHF only, and 6.1% for assimilating FAPAR only. The set of parameters with the highest uncertainty reduction is similar between assimilating only FAPAR or only LHF. The highest uncertainty reduction for all three cases is found for a parameter quantifying maximum plant-available soil moisture. This indicates that not only LHF but also satellite-derived FAPAR data can be used to constrain and indirectly observe hydrological quantities.
Determining robust impacts of land-use induced land-cover changes on surface climate over North America and Eurasia; Results from the first set of LUCID experiments
Noblet-Ducoudré, N. de; Boisier, J.P. ; Pitman, A. ; Bonan, G.B. ; Brovkin, V. ; Cruz, F. ; Delire, C. ; Gayler, V. ; Hurk, B.J.J.M. van den; Lawrence, P.J. ; Molen, M.K. van der; Müller, C. ; Reick, C.H. ; Strengers, B.J. ; Voldoire, A. - \ 2012
Journal of Climate 25 (2012)9. - ISSN 0894-8755 - p. 3261 - 3281.
tropical deforestation - temperature trends - secondary lands - use transitions - use/land cover - system model - wood-harvest - biosphere - database - feedbacks
The project Land-Use and Climate, Identification of Robust Impacts (LUCID) was conceived to address the robustness of biogeophysical impacts of historical land use–land cover change (LULCC). LUCID used seven atmosphere–land models with a common experimental design to explore those impacts of LULCC that are robust and consistent across the climate models. The biogeophysical impacts of LULCC were also compared to the impact of elevated greenhouse gases and resulting changes in sea surface temperatures and sea ice extent (CO2SST). Focusing the analys is on Eurasia and North America, this study shows that for a number of variables LULCC has an impact of similar magnitude but of an opposite sign, to increased greenhouse gases and warmer oceans. However, the variability among the individual models’ response to LULCC is larger than that found from the increase in CO2SST. The results of the study show that although the dispersion among the models’ response to LULCC is large, there are a number of robust common features shared by all models: the amount of available energy used for turbulent fluxes is consistent between the models and the changes in response to LULCC depend almost linearly on the amount of trees removed. However, less encouraging is the conclusion that there is no consistency among the various models regarding how LULCC affects the partitioning of available energy between latent and sensible heat fluxes at a specific time. The results therefore highlight the urgent need to evaluate land surface models more thoroughly, particularly how they respond to a perturbation in addition to how they simulate an observed average state.
Terrestrial gross carbon dioxide uptake: Global distribution and covariation with climate
Beer, C. ; Veenendaal, E.M. - \ 2010
Science 329 (2010)5993. - ISSN 0036-8075 - p. 834 - 838.
atmospheric co2 - vegetation - biosphere - ecosystems - radiation - products - fraction - database - sulfide - network
Terrestrial gross primary production (GPP) is the largest global CO2 flux driving several ecosystem functions. We provide an observation-based estimate of this flux at 123 ± 8 petagrams of carbon per year (Pg C year-1) using eddy covariance flux data and various diagnostic models. Tropical forests and savannahs account for 60%. GPP over 40% of the vegetated land is associated with precipitation. State-of-the-art process-oriented biosphere models used for climate predictions exhibit a large between-model variation of GPP’s latitudinal patterns and show higher spatial correlations between GPP and precipitation, suggesting the existence of missing processes or feedback mechanisms which attenuate the vegetation response to climate. Our estimates of spatially distributed GPP and its covariation with climate can help improve coupled climate–carbon cycle process models.
The terrestrial carbon cycle on the regional and global scale : modeling, uncertainties and policy relevance
Minnen, J.G. van - \ 2008
Wageningen University. Promotor(en): Rik Leemans, co-promotor(en): R. Swart. - [S.l.] : S.n. - ISBN 9789085048107 - 237
koolstofcyclus - klimaatverandering - landgebruik - beoordeling - milieubeleid - simulatiemodellen - biosfeer - terrestrische ecosystemen - carbon cycle - climatic change - land use - assessment - environmental policy - simulation models - biosphere - terrestrial ecosystems
Contains the chapters: The importance of three centuries of climate and land-use change for the global and regional terrestrial carbon cycle; and The terrestrial C cycle and its role in the climate change policy
Coupled models for the hydrological cycle; integrating atmosphere, biosphere, and pedosphere
Bronstert, A. ; Carrera, J. ; Kabat, P. ; Lütkemeier, S. - \ 2005
Berlin (Germany) [etc.] : Springer - ISBN 9783540223719 - 345
hydrologie - milieu - geïntegreerde systemen - atmosfeer - pedologie - wiskundige modellen - koppelstukken - hydrologische cyclus - biosfeer - hydrology - environment - integrated systems - atmosphere - pedology - mathematical models - couplings - hydrological cycle - biosphere
Hydrologists, climatologists, soil scientists and environmental engineers are frequently asked to analyse complex environmental problems. It is becoming increasingly apparent that these problems usually involve feedbacks between atmospheric, ecological, and hydrological systems, as well as human society. It is often the feedbacks between systems that are of greatest interest because they may produce unanticipated responses. That is why coupling of different compartments of the Earth system has emerged as a general challenge to the modelling community. This book considers an array of state-of-the-art coupling and modelling concepts. First the relevant Earth system cycles are presented, followed by a discussion on scale issues and multiple equilibria. Inter- and intra-compartmental coupling is addressed, along with a debate on non-linearities and questions of parameterisation. Several applications are presented, where a focus is on cases where the hydrological cycle plays a central role.
|Vegetation, water, humans and the climate; a new perspective on an interactive system
Kabat, P. ; Claussen, M. ; Dirmeyer, P.A. ; Gash, J.H.C. ; Bravo de Guenni, L. ; Meybeck, M. ; Pielke sr., R.A. ; Vörösmarty, C.J. ; Hutjes, R.W.A. ; Lütkemeier, S. - \ 2004
Berlin (Germany) [etc.] : Springer (Global change : the IGBP series ) - ISBN 9783540424000 - 566
geologie - hydrologie - klimaat - bodem - vegetatie - menselijke activiteit - milieutoets - interacties - aardwetenschappen - terrestrische ecosystemen - hydrologische cyclus - biosfeer - geology - hydrology - climate - soil - vegetation - human activity - environmental assessment - interactions - earth sciences - terrestrial ecosystems - hydrological cycle - biosphere
10 Year trend of levels of organochlorine pollutants in Antarctic seabirds
Brink, N.W. van den - \ 2003
earth science - human dimensions - environmental impacts - contaminant level/spills - biological classification - animals - vertebrates - birds - biosphere - ecological dynamics - ecotoxicology - toxicity levels
Contaminants like PCBs and DDE have hardly been used Antarctica. Hence, this is an excellent place to monitor global background levels of these organochlorines. In this project concentrations in penguins and petrels will be compared to 10 years ago, which will show time trends of global background contamination levels. Data set description From several birds from Hop Island, Rauer Islands near Davis, samples were collected from preenoil (oil that birds excrete to preen their feathers. This preenoil was then analysed for organochlorine pollutants like polychlorinated biphenyls, (PCBs), hexachlorobenzene (HCB), DDE and dieldrin. The species under investigation were the Adelie penguin (Pygoscelis adeliae) and the Southern Fulmar (Fulmarus glacialoides). The samples were collected from adult breeding birds, and stored in -20 degrees C as soon as possible. The analysis was done with relatively standard but very optimised methods, using a gas-chromatograph and mass-selective detection.
|Biospheric Aspects of the Hydrological Cycle : (Dutch National Research Programme on Global Air Pollution and Climate Change
Kabat, P. ; Claussen, M. ; Dirmeyer, P.A. ; Gash, J.H.C. ; Bravo de Guenni, L. ; Meybeck, M. ; Pielke Sr., R.A. ; Vörösmarty, C.J. ; Hall, F. ; Hutjes, R.W.A. ; Lütkemeier, S. ; Feddes, R.A. ; Veraart, J.A. - \ 2002
Bilthoven : RIVM - ISBN 9789058510990 - 88
vegetatie - bodem - hydrologie - hydrologische cyclus - biosfeer - vegetation - soil - hydrology - hydrological cycle - biosphere
A briefly review on the current knowledge of the influence of the terrestrial vegetation and soils within the climate system, especially the interactions between the terrestrial biosphere and atmosphere via the hydrological cycle
Wegverlichting en natuur : III : lokale invloed van wegverlichting op een gruttopopulatie
Molenaar, J.G. de; Jonkers, D.A. ; Sanders, M.E. - \ 2000
Wageningen : Alterra (DWW-rapport P-DWW-2000-024 / Alterra-rapport 64) - 96
wegen - verlichting - wegbeplantingen - wegbermplanten - ecologie - diergedrag - habitats - milieu - biota - kunstlicht - fauna - vogels - wetenschap - biosfeer - natuur - roads - lighting - roadside plantations - roadside plants - ecology - animal behaviour - habitats - environment - biota - artificial light - fauna - birds - science - biosphere - nature
Invloed van lichtvervuiling op vogels
Biospheric aspects of the hydrological cycle; preface
Hutjes, R.W.A. ; Kabat, P. ; Running, S.W. ; Shuttleworth, W.J. ; Field, C. ; Bass, B. ; Silva Dias, M.A.F. da; Avissar, R. ; Becker, A. ; Claussen, M. ; Dolman, A.J. ; Feddes, R.A. ; Fosberg, M. ; Fukushima, Y. ; Gash, J.H.C. ; Guenni, L. ; Hoff, H. ; Jarvis, P.G. ; Kayane, I. ; Kaarenke, A.N. ; Changming Liu, ; Meybeck, M. ; Nobre, C.A. ; Oyebande, L. ; Pitman, A. ; Pielke, R.A. ; Raupach, M. ; Saugier, B. ; Schulze, E.D. - \ 1998
Journal of Hydrology 212/213 (1998)1/4. - ISSN 0022-1694 - p. 1 - 21.
hydrologie - biogeochemie - atmosfeer - koolstofcyclus - klimaat - hydrologische cyclus - biosfeer - hydrology - biogeochemistry - atmosphere - carbon cycle - climate - hydrological cycle - biosphere
|Milieuverkenningen en fauna; op weg naar multiple-stress modellen
Verboom, J. ; Faber, J.H. ; Kalkhoven, J.T.R. ; Latour, J.B. ; Opdam, P.F.M. ; Posthuma, L. - \ 1995
Wageningen : IBN-DLO [etc.] - 86
milieu - biota - kwaliteit - controle - verontreinigingsbeheersing - milieubeheer - biogeografie - fauna - nadelige gevolgen - milieueffect - menselijke activiteit - computersimulatie - simulatie - simulatiemodellen - nederland - biosfeer - environment - quality - control - pollution control - environmental management - biogeography - adverse effects - environmental impact - human activity - computer simulation - simulation - simulation models - netherlands - biosphere
Studie naar de mogelijke effecten op flora en fauna als gevolg van de inrichting van de noordpunt Oost - Abtspolder als definitieve opslagplaats voor verontreinigde grond
Elbers, M. ; Doelman, P. - \ 1990
Arnhem : RIN (RIN-rapport 90/11) - 128
luchtverontreiniging - dieren - biota - schade - milieu - milieueffect - milieueffectrapportage - fauna - gezondheidsbescherming - industrieel afval - stortterreinen - bodemverontreiniging - ondergrondse toepassing - afvalverwijdering - afvalstortplaatsen - Nederland - biosfeer - menselijke invloed - rotterdam - zuid-holland - air pollution - animals - biota - damage - environment - environmental impact - environmental impact reporting - fauna - health protection - industrial wastes - landfills - soil pollution - subsurface application - waste disposal - waste disposal sites - Netherlands - biosphere - human impact - rotterdam - zuid-holland