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Wieser G.,Federal Office and Research Center for Forests | Oberhuber W.,University of Innsbruck | Walder L.,University of Innsbruck | Spieler D.,University of Innsbruck | Gruber A.,University of Innsbruck
Annals of Forest Science | Year: 2010

Temperature is suggested to determine the upper limit of tree life. Therefore, future climate warming may be of importance for tree distribution within the European Alps, where low temperatures limit carbon metabolism. We focused on the effects of air and soil temperature on net photosynthesis (P n) of Pinus cembra an evergreen climax species of the timberline ecotone of the Central Austrian Alps. Light response and temperature response curves were estimated along an altitudinal gradient ranging from the forest limit up to the krummholz limit in both summer and fall. In general, P n was significantly lower in fall as compared to summer. Nevertheless, independent from season mean Pn values tended to increase with elevation and were positively correlated with root zone temperatures. The specific leaf area by contrast declined with increasing elevation. Furthermore, the temperature optimum of net photosynthesis declined with increasing elevation and was positively correlated with the mean maximum air temperature of the 10 days prior the date of measurement. Thus, our findings appear to reflect a long-term adaptation of the photosynthetic apparatus of Pinus cembra to the general temperature conditions with respect to elevation combined with a short term acclimation to the prevailing temperature regime. © INRA, EDP Sciences, 2010.


Matyssek R.,TU Munich | Wieser G.,Federal Office and Research Center for Forests | Calfapietra C.,National Research Council Italy | De Vries W.,Wageningen University | And 9 more authors.
Environmental Pollution | Year: 2012

Forests in Europe face significant changes in climate, which in interaction with air quality changes, may significantly affect forest productivity, stand composition and carbon sequestration in both vegetation and soils. Identified knowledge gaps and research needs include: (i) interaction between changes in air quality (trace gas concentrations), climate and other site factors on forest ecosystem response, (ii) significance of biotic processes in system response, (iii) tools for mechanistic and diagnostic understanding and upscaling, and (iv) the need for unifying modelling and empirical research for synthesis. This position paper highlights the above focuses, including the global dimension of air pollution as part of climate change and the need for knowledge transfer to enable reliable risk assessment. A new type of research site in forest ecosystems ("supersites") will be conducive to addressing these gaps by enabling integration of experimentation and modelling within the soil-plant-atmosphere interface, as well as further model development. © 2011 Elsevier Ltd. All rights reserved.


Cieslik S.,European Commission - Joint Research Center Ispra | Tuovinen J.-P.,Finnish Meteorological Institute | Baumgarten M.,TU Munich | Matyssek R.,TU Munich | And 2 more authors.
Developments in Environmental Science | Year: 2013

Climate change is expected to affect the exchange of gases between forest ecosystems and the atmosphere. In this review, we focus on a few related topics, including the emission of greenhouse gases from the forest floor, and vegetation fires and their impact on air quality and soil CO2 efflux. In particular, we summarise the current state of knowledge on O3 deposition in forest ecosystems, both for stomatal uptake and non-stomatal sinks. Based on such summaries, we discuss interactions between forests, atmospheric composition and climate, and finally outline directions for multi- and interdisciplinary research required for mechanistically understanding such interrelationships. © 2013 Elsevier Ltd.


Schindlbacher A.,Federal Office and Research Center for Forests | De Gonzalo C.,Polytechnic University of Mozambique | Diaz-Pines E.,Polytechnic University of Mozambique | Giorra P.,Polytechnic University of Mozambique | And 5 more authors.
Journal of Geophysical Research: Biogeosciences | Year: 2010

The temperature sensitivity of the soil organic matter (SOM) decomposition along the slopes of mountain forests in Austria and Spain was analyzed. High-altitude forest soils store large quantities of organic carbon (C) and are particularly vulnerable to global warming if the decomposition of the SOM is more temperature sensitive than at lower altitude. Mineral soil and O-layer material was incubated in the laboratory at temperatures increasing from 5C to (20C) 25C. The temperature sensitivity (Q10) was determined by fitting different temperature response functions to the measured CO2 efflux. Bulk soil and density fractions were analyzed for organic C and nitrogen (N) contents. C and N stocks along the elevation gradients were estimated. Q10 over the whole incubation temperature range varied between 1.5 and 2.5 but did not show any altitudinal trends for O-layer material and mineral soils along both gradients. Besides that, Q10 generally increased with decreasing soil temperatures. SOM decomposition at higher elevation forests will be more responsive to global warming because it will be affected in a more sensitive (cooler) temperature range compared to lower elevation sites. This effect was modeled by the Lloyd and Taylor function and Gaussian but not by the frequently used exponential temperature function. Both soil C and N contents increased with increasing altitude. Density fractionation showed deviating altitudinal C and N patterns of labile and recalcitrant SOM pools along the Spanish gradient. Soil C stocks along both gradients did not resemble the trend in C contents and were determined by other site-specific factors. This, and significantly low C and N contents and stocks of a site that was used as a forest pasture, indicates that both forest management and land use can play equally important roles in the development of soil C as climatic factors. Copyright 2010 by the American Geophysical Union.


Inclan R.,CIEMAT | Uribe C.,CIEMAT | Sanchez L.,Polytechnic University of Mozambique | Sanchez D.M.,CIEMAT | And 5 more authors.
Biogeochemistry | Year: 2012

We investigated N 2O and CH 4 fluxes from soils of Quercus ilex,Quercus pyrenaica and Pinus sylvestris stands located in the surrounding area of Madrid (Spain). The fluxes were measured for 18 months from both mature stands and post fire stands using the static chamber technique. Simultaneously with gas fluxes, soil temperature, soil water content, soil C and soil N were measured in the stands. Nitrous oxide fluxes ranged from -11. 43 to 8. 34 μg N 2O-N m -2 h -1 in Q. ilex, -7. 74 to 13. 52 μg N 2O-N m -2 h -1 in Q. pyrenaica and -28. 17 to 21. 89 μg N 2O-N m -2 h -1 in P. sylvestris. Fluxes of CH 4 ranged from -8. 12 to 4. 11 μg CH 4-C m -2 h -1 in Q. ilex, -7. 74 to 3. 0 μg CH 4-C m -2 h -1 in Q. pyrenaica and -24. 46 to 6. 07 μg CH 4-C m -2 h -1 in P. sylvestris. Seasonal differences were detected; N 2O fluxes being higher in wet months whereas N 2O fluxes declined in dry months. Net consumption of N 2O was related to low N availability, high soil C contents, high soil temperatures and low moisture content. Fire decreased N 2O fluxes in spring. N 2O emissions were closely correlated with previous day's rainfall and soil moisture. Our ecosystems generally were a sink for methane in the dry season and a source of CH 4 during wet months. The available water in the soil influenced the observed seasonal trend. The burned sites showed higher CH 4 oxidation rates in Q. ilex, and lower rates in P. sylvestris. Overall, the data suggest that fire alters both N 2O and CH 4 fluxes. However, the magnitude of such variation depends on the site, soil characteristics and seasonal climatic conditions. © 2010 Springer Science+Business Media B.V.


Diaz-Pines E.,Polytechnic University of Mozambique | Schindlbacher A.,Federal office and Research Center for Forests | Pfever M.,Federal office and Research Center for Forests | Jandl R.,Federal office and Research Center for Forests | And 2 more authors.
European Journal of Forest Research | Year: 2010

We conducted a trenching experiment in a mountain forest in order to assess the contribution of the autotrophic respiration to total soil respiration and evaluate trenching as a technique to achieve it. We hypothesised that the trenching experiment would alter both microbial biomass and microbial community structure and that fine roots (less than 2 mm diameter) would be decomposed within one growing season. Soil CO2 efflux was measured roughly biweekly over two growing seasons. Root presence and morphology parameters, as well as the soil microbial community were measured prior to trenching, 5 and 15 months after trenching. The trenched plots emitted about 20 and 30% less CO2 than the control plots in the first and second growing season, respectively. Roots died in trenched plots, but root decay was slow. After 5 and 15 months, fine root biomass was decreased by 9% (not statistically different) and 30%, (statistically different) respectively. When we corrected for the additional trenched-plot CO2 efflux due to fine root decomposition, the autotrophic soil respiration rose to »26% of the total soil respiration for the first growing season, and to »44% for the second growing season. Soil microbial biomass and community structure was not altered by the end of the second growing season. We con-clude that trenching can give accurate estimates of the autotrophic and heterotrophic components of soil respiration, if methodological side effects are accounted for, only. © Springer-Verlag 2008.


Matyssek R.,TU Munich | Knoke T.,TU Munich | Clarke N.,Norwegian Forest And Landscape Institute | Cudlin P.,Academy of Sciences of the Czech Republic | And 4 more authors.
Developments in Environmental Science | Year: 2013

Conclusions from the individual chapters are integrated into a synopsis, covering achievements and perspectives, and linking challenges for natural and social sciences, provisioning ecosystem services (ESs) under environmental change. The required research and policy making are facilitated by novel understanding of ecosystem functioning and internal factorial interactions with the atmosphere. A basis is provided through methodological progress for establishing forest research 'supersites' within global research networks, possessing capacities for creating generic mechanistic knowledge of ecological relevance. On such grounds, provisioning versus regulating ESs must accommodate diversification in the joint production of agricultural and forestry goods, backed by integrative bioeconomic land-use modelling. Advancement requires forest ecosystem-level unification of air pollution and climate change research while strengthening communication between experimentalists, monitoring experts, modellers, policy makers and stakeholders towards tool development for reliable risk assessment. A critical and appreciative view of forest functions and services is demanded in relation to the (post-)Kyoto debate. © 2013 Elsevier Ltd.


Matyssek R.,TU Munich | Clarke N.,Norwegian Forest And Landscape Institute | Cudlin P.,Academy of Sciences of the Czech Republic | Mikkelsen T.N.,Technical University of Denmark | And 3 more authors.
Developments in Environmental Science | Year: 2013

This chapter outlines the aims and scope of the book. An introduction is given to the current status of knowledge which is presented on the topic of the book. Arguments are presented for writing the book, in view of continued, long-term and process-based research needed for mitigating ecological and socio-economic risks to forests under global change. The book will conclude on suggestions for decision making and reasons for continued funding of related research. © 2013 Elsevier Ltd.


Uddling J.,Gothenburg University | Matyssek R.,TU Munich | Pettersson J.B.C.,Gothenburg University | Wieser G.,Federal Office and Research Center for Forests
Environmental Pollution | Year: 2012

Pre-requisite for reliable O 3 risk assessment for plants is determination of stomatal O 3 uptake. One unaddressed uncertainty in this context relates to transpiration-induced molecular collisions impeding stomatal O 3 influx. This study quantifies, through physical modelling, the error made when estimating stomatal O 3 flux without accounting for molecular collisions arising from transpiratory mass flow of gas out of the leaf. The analysis demonstrates that the error increases with increasing leaf-to-air water vapour mole fraction difference (Δw), being zero in water vapour saturated air and 4.2% overestimation at Δw of 0.05. Overestimation is approximately twice as large in empirical studies quantifying stomatal O 3 flux from measured leaf or canopy water flux, if neglecting both water vapour-dry air collisions (causing overestimation of leaf conductance) and collisions involving O 3. Correction for transpiration-induced molecular collisions is thus relevant for both empirical research and for large-scale modelling of stomatal O 3 flux across strong spatial Δw gradients. © 2012 Elsevier Ltd. All rights reserved.


Matyssek R.,TU Munich | Wieser G.,Federal Office and Research Center for Forests | Fleischmann F.,TU Munich | Grunhage L.,Justus Liebig University
Developments in Environmental Science | Year: 2013

Empirical evidence underlines enhanced ground-level O3 regimes as components of global change, although interaction responses of forest trees and ecosystems have only recently been addressed by research. One case study is the tree-level Kranzberg Forest Experiment, having been resumed for envisioning "next-generation" ecosystem-level O3 research. Quantifying enhanced O3 impact is highlighted as part of a multi-factorial, abiotic-biotic interaction network of experiments and monitoring sites, which challenge the required quantitative predictability of the plasticity, and hence, extent and risk in system response, given the significance of forests as global determinants of carbon storage and sequestration. Here, we outline such integrated research concepts, cross-linking experimentation, monitoring and modelling to scale up O3 responses from internal tree processes towards zonobiomic spatio-temporal scales. The availability of conceptual and methodological means as pre-requisites is emphasized. The relevance of respective research for providing spin-offs within socio-economic contexts related to biogenic energy production and CO2 emission trading is examined. © 2013 Elsevier Ltd.

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