I. A. Janssens

University of Antwerp, Antwerpen, Flemish, Belgium

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Publications (235)987.17 Total impact

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    ABSTRACT: The sensitivity of soil organic matter decomposition to global environmental change is a topic of prominent relevance for the global carbon cycle. Decomposition depends on multiple factors that are being altered simultaneously as a result of global environmental change; therefore, it is important to study the sensitivity of the rates of soil organic matter decomposition with respect to multiple and interacting drivers. In this manuscript we present an analysis of the potential response of decomposition rates to simultaneous changes in temperature and moisture. To address this problem, we first present a theoretical framework to study the sensitivity of soil organic matter decomposition when multiple driving factors change simultaneously. We then apply this framework to models and data at different levels of abstraction: 1) to a mechanistic model that addresses the limitation of enzyme activity by simultaneous effects of temperature and soil water content, the latter controlling substrate supply and oxygen concentration for microbial activity; 2) to different mathematical functions used to represent temperature and moisture effects on decomposition in biogeochemical models. To contrast model predictions at these two levels of organization, we compiled different datasets of observed responses in field and laboratory studies. Then we applied our conceptual framework to: 3) observations of heterotrophic respiration at the ecosystem level; 4) laboratory experiments looking at the response of heterotrophic respiration to independent changes in moisture and temperature; and 5) ecosystem-level experiments manipulating soil temperature and water content simultaneously. This article is protected by copyright. All rights reserved.
    Journal of Advances in Modeling Earth Systems 01/2015; DOI:10.1002/2014MS000358 · 5.15 Impact Factor
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    ABSTRACT: Understanding how flowering phenology responds to warming and cooling (i.e., symmetric or asymmetric response) is needed to predict the response of flowering phenology to future climate change that will happen with the occurrence of warm and cold years superimposed upon a long-term trend. A three-year reciprocal translocation experiment was performed along an elevation gradient from 3200 m to 3800 m in the Tibetan Plateau for six alpine plants. Transplanting to lower elevation (warming) advanced the first flowering date (FFD) and transplanting to higher elevation (cooling) had the opposite effect. The FFD of early spring flowering plants (ESF) was four times less sensitive to warming than to cooling (by -2.1 d/degrees C and 8.4 d/degrees C, respectively), while midsummer flowering plants (MSF) were about twice as sensitive to warming than to cooling (-8.0 d/degrees C and 4.9 d/degrees C, respectively). Compared with pooled warming and cooling data, warming alone significantly underpredicted 3.1 d/degrees C for ESF and overestimated 1.7 d/degrees C for MSF. These results suggest that future empirical and experimental studies should consider nonlinear temperature responses that can cause such warming-cooling asymmetries as well as differing life strategies (ESF vs. MSF) among plant species.
    Ecology 12/2014; 95(12). DOI:10.1890/13-2235.1 · 5.00 Impact Factor
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    ABSTRACT: AimPlant elemental composition and stoichiometry are crucial for plant structure and function. We studied to what extent elemental stoichiometry in plants might be strongly related to environmental drivers and competition from coexisting species.LocationEurope.Methods We analysed foliar N, P, K, Ca and Mg concentrations and their ratios among 50 species of European forest trees sampled in 5284 plots across Europe and their relationships with phylogeny, forest type, current climate and N deposition.ResultsPhylogeny is strongly related to overall foliar elemental composition in European tree species. Species identity explained 56.7% of the overall foliar elemental composition and stoichiometry. Forest type and current climatic conditions also partially explained the differences in foliar elemental composition among species. In the same genus co-occurring species had overall higher differences in foliar elemental composition and stoichiometry than the non-co-occurring species.Main conclusionsThe different foliar elemental compositions among species are related to phylogenetic distances, but they are also related to current climatic conditions, forest types, drivers of global change such as atmospheric N deposition, and to differences among co-occurring species as a probable consequence of niche specialization to reduce direct competition for the same resources. Different species have their own ‘fixed’ foliar elemental compositions but retain some degree of plasticity to the current climatic and competitive conditions. A wider set of elements beyond N and P better represent the biogeochemical niche and are highly sensitive to plant function. Foliar elemental composition can thus be useful for representing important aspects of plant species niches.
    11/2014; 24(2). DOI:10.1111/geb.12253
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    ABSTRACT: Combustion of solid and liquid fuels is the largest source of potentially toxic volatile organic compounds (VOCs), which can strongly affect health and the physical and chemical properties of the atmosphere. Among combustion processes, biomass burning is one of the largest at global scale. We used a Proton Transfer Reaction “Time-of-Flight” Mass Spectrometer (PTR-TOF-MS), which couples high sensitivity with high mass resolution, for real-time detection of multiple VOCs emitted by burned hay and straw in a barn located near our measuring station. We detected 132 different organic ions directly attributable to VOCs emitted from the fire. Methanol, acetaldehyde, acetone, methyl vinyl ether (MVE), acetic acid and glycolaldehyde dominated the VOC mixture composition. The time-course of the 25 most abundant VOCs, representing ∼ 85% of the whole mixture of VOCs, was associated with that of carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) emissions. The strong linear relationship between the concentrations of pyrogenic VOC and of a reference species (i.e. CO) allowed us to compile a list of emission ratios (ERs) and emission factors (EFs), but values of ER (and EF) were overestimated due to the limited mixing of the gases under the stable (non-turbulent) nocturnal conditions. In addition to the 25 most abundant VOCs, chemical formula and concentrations of the residual, less abundant VOCs in the emitted mixture were also estimated by PTR-TOF-MS. Furthermore, the evolution of the complex combustion process was described on the basis of the diverse types of pyrogenic gases recorded.
    Atmospheric Environment 11/2014; 97. DOI:10.1016/j.atmosenv.2014.08.007 · 3.06 Impact Factor
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    Seminaris del Departament d'Ecologia de la Universitat de Barcelona, Barcelona; 10/2014
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    ABSTRACT: Clay is generally considered an important stabiliser that reduces the rate of decomposition of organic matter (OM) in soils. However, several recent studies have shown trends contradicting this widely held view, emphasising our poor understanding of the mechanisms underlying the clay effects on OM decomposition. Here, an incubation experiment was conducted using artificial soils differing in clay content (0, 5, and 50%) at different temperatures (5, 15, and 25 °C) to determine the effects of clay content, temperature and their interaction on fresh OM decomposition. CO2 efflux was measured throughout the experiment. Phospholipid fatty acids (PLFAs), enzyme activities, microbial biomass carbon (MBC), and dissolved organic carbon (DOC) were also measured at the end of the pre-incubation and incubation periods in order to follow changes in microbial community structure, functioning, and substrate availability. The results showed that higher clay contents promoted OM decomposition probably by increasing substrate availability and by sustaining a greater microbial biomass, albeit with a different community structure and with higher activities of most of the extracellular enzymes assayed. Higher clay content induced increases in the PLFA contents of all bacterial functional groups relative to fungal PLFA content. However, clay content did not change the temperature sensitivity (Q10) of OM decomposition. The higher substrate availability in the high clay artificial soils sustained more soil microbial biomass, resulting in a different community structure and different functioning. The higher microbial biomass, as well as the changed community structure and functions, accelerated OM decomposition. From these observations, an alternative pathway to understanding the effects of clay on OM decomposition is proposed, in which clay may not only accelerate the decomposition of organic materials in soils but also facilitate the SOM accumulation as microbial products in the long term. Our results highlight the importance of clay content as a control over OM decomposition and greater attention is required to elucidate the underlying mechanisms.
    Soil Biology and Biochemistry 10/2014; 77:100–108. DOI:10.1016/j.soilbio.2014.06.006 · 4.41 Impact Factor
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    ABSTRACT: Fresh plant litter inputs accelerate soil organic matter (SOM) decomposition through a ubiquitous mechanism called priming. Insufficient priming has been suggested as a stabilization mechanism of SOM at depth, as well as the long-term persistence of some highly degradable organic compounds in soils. Priming therefore plays a crucial, albeit unquantified and commonly neglected, role in the global carbon cycle. Because priming intensity is likely to be altered by global change-induced changes in net primary productivity, it casts substantial uncertainty to future projections of the climate-carbon cycle feedback. Using results from a large field litter manipulation experiment in Mongolian steppe, we here show that priming intensifies with increasing litter inputs, but at a decreasing efficiency: the stimulation per unit litter added declines with increasing litter inputs. This non-linear behavior originates from two antagonistic responses to fresh litter inputs: a stimulation of microbial activity versus a shift in microbial community composition (more fungi) associated to substrate shift from SOM to litter. Despite all complexity, however, the priming effect on SOM decomposition scaled linearly with the response of microbial biomass across the entire range of plant litter addition (60–480 g C m−2), suggesting that priming could be modeled effectively as a function of the response of microbial biomass to litter inputs. Incorporating the priming mechanism in Earth System models will improve their estimates of the SOM-climate feedback and appears to be best addressed by explicitly representing microbial biomass in the models.
    Oikos 10/2014; DOI:10.1111/oik.01728 · 3.56 Impact Factor
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    Lise Fivez, Sara Vicca, Ivan A Janssens, Patrick Meire
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    ABSTRACT: Changes in land use, implementation of protective measures and a warming climate have improved the survival rate of geese, resulting in considerable increases in the majority of Western Palaearctic goose populations during recent decades. To the best of our knowledge, this is the first study aiming to understand the impact of goose grazing on carbon cycling in their winter habitat. To this end, the impact of goose grazing pressure on biomass, litter decomposition and CO 2 fluxes (net CO 2 exchange partitioned into photosynthesis and ecosystem respiration) was studied in the coastal polders of Belgium, a wintering habitat for geese of international importance. Experimentally manipulated grazing by Anser anser (Greylag Geese) in grassland mimicked four different grazing pressures, including a control treatment from which geese were excluded. We found that grazing pressure by geese has a significant, but variable effect on carbon fluxes during the entire year. In winter, at the end of the grazing season, both plants' carbon assimilation and total ecosystem respiration were decreased with increasing grazing pressure, resulting in less carbon taken up during day time. Total ecosystem respiration was also reduced due to goose grazing in spring and autumn (i.e., outside the grazing season), while no significant difference in ecosystem CO 2 fluxes was detected in summer. These grazing effects on CO 2 fluxes can partly be explained by the effect of goose grazing on standing biomass. Decomposition rates were significantly reduced by higher grazing pressure during the winter season when geese were present, but on the long term grazing accelerated decomposition rates. Our data suggest that the rising numbers of Western Palaearctic breeding geese can alter the carbon balance of their winter habitat. The differences between short-and long-term effects observed in our study demonstrate the complexity of goose grazing effects on carbon cycling and indicate directions for future studies.
    Ecosphere 10/2014; 5(10):139. DOI:10.1890/ES14-00012.1 · 2.60 Impact Factor
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    ABSTRACT: Forests strongly affect climate through the exchange of large amounts of atmospheric CO2. However, the main drivers of spatial variability in net ecosystem production (NEP) on a global scale are poorly known. We present our synthesis study of 92 forests in different climate zones revealing that nutrient availability indeed plays a crucial role in determining NEP and ecosystem carbon-use efficiency [CUEe, i.e. the ratio of NEP to gross primary production (GPP)]. Forests with high GPP exhibited high NEP only in nutrient-rich forests (CUEe = 33 ± 4%; mean ± SE). In nutrient-poor forests, a much larger proportion of GPP was released through ecosystem respiration, resulting in lower CUEe (6 ± 4%). We have also analyzed C-flux time series to check whether GPP, Re and NEP has increased during the last two decades. Our analysis of 23 temperate and boreal forests revealed a strong increase in GPP and NEP from 1992 to 2013, especially important during the first decade. Instead Re has remained rather constant. These increases in GPP and NEP were mostly attributable to the CO2 fertilization effect. However, increasing temperatures and nutrient limitation can constrain the effect of increasing CO2.
    1st ICOS International Conference on Greenhouse Gases and Biogeochemical Cycles, Brussels; 09/2014
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    ABSTRACT: AimAlthough numerous studies have reported advanced Northern Hemisphere spring phenology since the 1980s, recent studies based on remote sensing have reported a reversal or deceleration of this trend. This study aimed (1) to fully understand recent spring phenology shifts using both in situ observations and satellite-based normalized difference vegetation index (NDVI) datasets, and (2) to test whether the NDVI methods capture the trends observed in situ.LocationWestern Central Europe.Methods Temporal spring phenology trends (leaf unfolding dates) were examined using 1,001,678 in situ observations of 31 plant species at 3984 stations, as well as NDVI-based start-of-season dates, obtained using five different methods, across the pixels that included the phenology stations.ResultsIn situ and NDVI observations both indicated that spring phenology significantly advanced during the period 1982–2011 at an average rate of −0.45 days yr−1. This trend was not uniform across the period and significantly weakened over the period 2000–2011. Furthermore, opposite trends were found between in situ and NDVI observations over the period 2000–2011. Averaged over all species, the in situ observations indicated a slower but still advancing trend for leaf unfolding, whereas the NDVI series showed a delayed spring phenology.Main conclusionsThe recent trend reversal in the advancement of spring phenology in western Central Europe is likely to be related to the response of early spring species to the cooling trend in late winter. In contrast, late spring species continued to exhibit advanced leaf unfolding, which is consistent with the warming trend during spring months. Because remote sensing does not distinguish between species, the signal of growing-season onset may only reflect the phenological dynamics of these earliest species in the pixel, even though most species still exhibit advancing trends.
    08/2014; 23(11):1255–1263. DOI:10.1111/geb.12210
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    ABSTRACT: Over the last century the Northern Hemisphere has experienced rapid climate warming, but this warming has not been evenly distributed seasonally, as well as diurnally. The implications of such seasonal and diurnal heterogeneous warming on regional and global vegetation photosynthetic activity, however, are still poorly understood. Here, we investigated for different seasons how photosynthetic activity of vegetation correlates with changes in seasonal daytime and night-time temperature across the Northern Hemisphere (>30°N), using Normalized Difference Vegetation Index (NDVI) data from 1982 to 2011 obtained from the Advanced Very High Resolution Radiometer (AVHRR). Our analysis revealed some striking seasonal differences in the response of NDVI to changes in day- versus night-time temperatures. For instance, while higher daytime temperature (Tmax) is generally associated with higher NDVI values across the boreal zone, the area exhibiting a statistically significant positive correlation between Tmax and NDVI is much larger in spring (41% of area in boreal zone – total area 12.6×106 km2) than in summer and autumn (14% and 9%, respectively). In contrast to the predominantly positive response of boreal ecosystems to changes in Tmax, increases in Tmax tended to negatively influence vegetation growth in temperate dry regions, particularly during summer. Changes in night-time temperature (Tmin) correlated negatively with autumnal NDVI in most of the Northern Hemisphere, but had a positive effect on spring and summer NDVI in most temperate regions (e.g., Central North America and Central Asia). Such divergent covariance between the photosynthetic activity of Northern Hemispheric vegetation and day- and night-time temperature changes among different seasons and climate zones suggests a changing dominance of ecophysiological processes across time and space. Understanding the seasonally different responses of vegetation photosynthetic activity to diurnal temperature changes, which have not been captured by current land surface models, is important for improving the performance of next generation regional and global coupled vegetation-climate models.This article is protected by copyright. All rights reserved.
    Global Change Biology 08/2014; 21(1). DOI:10.1111/gcb.12724 · 8.22 Impact Factor
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    ABSTRACT: Simulating gross primary productivity (GPP) of terrestrial ecosystems has been a major challenge in quantifying the global carbon cycle. Many different light use efficiency (LUE) models have been developed recently, but our understanding of the relative merits of different models remains limited. Using CO2 flux measurements from multiple eddy covariance sites, we here compared and assessed major algorithms and performance of seven LUE models (CASA, CFix, CFlux, EC-LUE, MODIS, VPM and VPRM). Comparison between simulated GPP and estimated GPP from flux measurements showed that model performance differed substantially among ecosystem types. In general, most models performed better in capturing the temporal changes and magnitude of GPP in deciduous broadleaf forests and mixed forests than in evergreen broadleaf forests and shrublands. Six of the seven LUE models significantly underestimated GPP during cloudy days because the impacts of diffuse radiation on light use efficiency were ignored in the models. CFlux and EC-LUE exhibited the lowest root mean square error among all models at 80% and 75% of the sites, respectively. Moreover, these two models showed better performance than others in simulating interannual variability of GPP. Two pairwise comparisons revealed that the seven models differed substantially in algorithms describing the environmental regulations, particularly water stress, on GPP. This analysis highlights the need to improve representation of the impacts of diffuse radiation and water stress in the LUE models.
    Agricultural and Forest Meteorology 07/2014; s 192–193:108–120. DOI:10.1016/j.agrformet.2014.03.007 · 3.89 Impact Factor
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    C W Xiao, I A Janssens, Y Zhou, J Q Su, Y Liang, B Guenet
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    ABSTRACT: Global climate change has generally increased net primary production which leads to increasing litter inputs. Therefore assessing the impacts of increasing litter inputs on soil nutrients, plant growth and ecological Carbon (C) : nitrogen (N) : phosphorus (P) stoichiometry is critical for an understanding of C, N and P cycling and their feedback 5 processes to climate change. In this study, we added plant litter to the 10–20 cm subsoil layer under a steppe community at rates equivalent to 0, 150, 300, 600 and 1200 g (dry mass) m −2 and measured the resulting C, N and P content of different pools (above and below ground plant biomass, litter, microbial biomass). High litter addition (120 % of the annual litter inputs) significantly increased soil inorganic N and available P, above-10 ground biomass, belowground biomass and litter. Nevertheless small litter additions, which are more realistic compared to the future predictions, had no effect on the vari-ables examined. Our results suggest that while very high litter addition can strongly affect C : N : P stoichiometry, the grassland studied here is quite resilient to more real-istic inputs in terms of stoichiometric functioning. This result highlights the complexity 15 of the ecosystem's response to climate change.
    Biogeosciences Discussions 07/2014; 11(7). DOI:10.5194/bgd-11-10487-2014
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    ABSTRACT: As a key component of the carbon cycle, soil CO2 efflux (SCE) is being increasingly studied to improve our mechanistic understanding of this important carbon flux. Predicting ecosystem responses to climate change often depends on extrapolation of current relationships between ecosystem processes and their climatic drivers to conditions not yet experienced by the ecosystem. This raises the question to what extent these relationships remain unaltered beyond the current climatic window for which observations are available to constrain the relationships. Here, we evaluate whether current responses of SCE to fluctuations in soil temperature and soil water content can be used to predict SCE under altered rainfall patterns. Of the 58 experiments for which we gathered SCE data, 20 were discarded because either too few data were available, or inconsistencies precluded their incorporation in the analyses. The 38 remaining experiments were used to test the hypothesis that a model parameterized with data from the control plots (using soil temperature and water content as predictor variables) could adequately predict SCE measured in the manipulated treatment. Only for seven of these 38 experiments, this hypothesis was rejected. Importantly, these were the experiments with the most reliable datasets, i.e., those providing high-frequency measurements of SCE. Regression tree analysis demonstrated that our hypothesis could be rejected only for experiments with measurement intervals of less than 11 days, and was not rejected for any of the 24 experiments with larger measurement intervals. This highlights the importance of high-frequency measurements when studying effects of altered precipitation on SCE, probably because infrequent measurement schemes have insufficient capacity to detect shifts in the climate-dependencies of SCE. Hence, the most justified answer to the question whether current moisture responses of SCE can be extrapolated to predict SCE under altered precipitation regimes is ‘no’ – as based on the most reliable datasets available. We strongly recommend that future experiments focus more strongly on establishing response functions across a broader range of precipitation regimes and soil moisture conditions. Such experiments should make accurate measurements of water availability, should conduct high-frequency SCE measurements, and should consider both instantaneous responses and the potential legacy effects of climate extremes. This is important, because with the novel approach presented here, we demonstrated that at least for some ecosystems, current moisture responses could not be extrapolated to predict SCE under altered rainfall conditions.
    Biogeosciences 06/2014; 11:2991-3013. DOI:10.5194/bg-11-2991-2014 · 3.75 Impact Factor
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    ABSTRACT: The traditional view of forest dynamics originated by Kira and Shidei [Kira T, Shidei T (1967) Jap J Ecol 17:70-87] and Odum [Odum EP (1969) Science 164(3877):262-270] suggests a decline in net primary productivity (NPP) in aging forests due to stabilized gross primary productivity (GPP) and continuously increased autotrophic respiration (Ra). The validity of these trends in GPP and Ra is, however, very difficult to test because of the lack of long-term ecosystem-scale field observations of both GPP and Ra. Ryan and colleagues [Ryan MG, Binkley D, Fownes JH (1997) Ad Ecol Res 27:213-262] have proposed an alternative hypothesis drawn from site-specific results that aboveground respiration and belowground allocation decreased in aging forests. Here, we analyzed data from a recently assembled global database of carbon fluxes and show that the classical view of the mechanisms underlying the age-driven decline in forest NPP is incorrect and thus support Ryan's alternative hypothesis. Our results substantiate the age-driven decline in NPP, but in contrast to the traditional view, both GPP and Ra decline in aging boreal and temperate forests. We find that the decline in NPP in aging forests is primarily driven by GPP, which decreases more rapidly with increasing age than Ra does, but the ratio of NPP/GPP remains approximately constant within a biome. Our analytical models describing forest succession suggest that dynamic forest ecosystem models that follow the traditional paradigm need to be revisited.
    Proceedings of the National Academy of Sciences 06/2014; 111(24). DOI:10.1073/pnas.1320761111 · 9.81 Impact Factor
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    ABSTRACT: Recent temperature increases have elicited strong phenological shifts in temperate tree species, with subsequent effects on photosynthesis. Here, we assess the impact of advanced leaf flushing in a winter warming experiment on the current year's senescence and next year's leaf flushing dates in two common tree species: Quercus robur L. and Fagus sylvatica L. Results suggest that earlier leaf flushing translated into earlier senescence, thereby partially offsetting the lengthening of the growing season. Moreover, saplings that were warmed in winter-spring 2009-2010 still exhibited earlier leaf flushing in 2011, even though the saplings had been exposed to similar ambient conditions for almost 1 y. Interestingly, for both species similar trends were found in mature trees using a long-term series of phenological records gathered from various locations in Europe. We hypothesize that this long-term legacy effect is related to an advancement of the endormancy phase (chilling phase) in response to the earlier autumnal senescence. Given the importance of phenology in plant and ecosystem functioning, and the prediction of more frequent extremely warm winters, our observations and postulated underlying mechanisms should be tested in other species.
    Proceedings of the National Academy of Sciences 05/2014; 111(20). DOI:10.1073/pnas.1321727111 · 9.81 Impact Factor
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    ABSTRACT: Climate changes increasingly threaten plant growth and productivity. Such changes are complex and involve multiple environmental factors, including rising CO2 levels and climate extreme events. As the molecular and physiological mechanisms underlying plant responses to realistic future climate extreme conditions are still poorly understood, a multiple organizational level-analysis (i.e. eco-physiological, biochemical and transcriptional) was performed, using Arabidopsis exposed to incremental heat wave and water deficit under ambient and elevated CO2. The climate extreme resulted in biomass reduction, photosynthesis inhibition, and considerable increases in stress parameters. Photosynthesis was a major target as demonstrated at the physiological and transcriptional levels. In contrast, the climate extreme treatment induced a protective effect on oxidative membrane damage, most likely as a result of strongly increased lipophilic antioxidants and membrane-protecting enzymes. Elevated CO2 significantly mitigated the negative impact of a combined heat and drought, as apparent in biomass reduction, photosynthesis inhibition, chlorophyll fluorescence decline, H2O2 production and protein oxidation. Analysis of enzymatic and molecular antioxidants revealed that the stress-mitigating CO2 effect operates through up-regulation of antioxidant defense metabolism, as well as by reduced photorespiration resulting in lowered oxidative pressure. Therefore, exposure to future climate extreme episodes will negatively impact plant growth and production, but elevated CO2 is likely to mitigate this effect.This article is protected by copyright. All rights reserved.
    Global Change Biology 05/2014; 20(12). DOI:10.1111/gcb.12626 · 8.22 Impact Factor
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    ABSTRACT: Forests strongly affect climate through the exchange of large amounts of atmospheric CO2. The main drivers of spatial variability in net ecosystem production (NEP) on a global scale are, however, poorly known. As increasing nutrient availability increases the production of biomass per unit of photosynthesis and reduces heterotrophic respiration in forests, we expected nutrients to determine carbon sequestration in forests. Our synthesis study of 92 forests in different climate zones revealed that nutrient availability indeed plays a crucial role in determining NEP and ecosystem carbon-use efficiency (CUEe; that is, the ratio of NEP to gross primary production (GPP)). Forests with high GPP exhibited high NEP only in nutrient-rich forests (CUEe = 33 ± 4%; mean ± s.e.m.). In nutrient-poor forests, a much larger proportion of GPP was released through ecosystem respiration, resulting in lower CUEe (6 ± 4%). Our finding that nutrient availability exerts a stronger control on NEP than on carbon input (GPP) conflicts with assumptions of nearly all global coupled carbon cycle–climate models, which assume that carbon inputs through photosynthesis drive biomass production and carbon sequestration. An improved global understanding of nutrient availability would therefore greatly improve carbon cycle modelling and should become a critical focus for future research.
    Nature Climate Change 04/2014; DOI:10.1038/nclimate2177 · 15.30 Impact Factor

Publication Stats

9k Citations
987.17 Total Impact Points

Institutions

  • 2000–2015
    • University of Antwerp
      • Department of Biology
      Antwerpen, Flemish, Belgium
  • 2012
    • Research Institute for Nature and Forest
      Bruxelles, Brussels Capital Region, Belgium
    • Technical University of Denmark
      • Department of Chemical and Biochemical Engineering
      Copenhagen, Capital Region, Denmark
  • 2011
    • University of Udine
      • Department of Agricultural and Environmental Sciences
      Udine, Friuli Venezia Giulia, Italy
  • 2010
    • University of Innsbruck
      • Institut für Ökologie
      Innsbruck, Tyrol, Austria
  • 2009
    • Catholic University of Louvain
      Лувен-ла-Нев, Walloon, Belgium
  • 2006
    • Woods Hole Research Center
      Falmouth, Massachusetts, United States