Category :
                    
                    Special section
                                    
                            
                    
        
            
            article id 290,
                            category
                        Special section
                    
        
        
                            Mikko Peltoniemi,
                            Esther Thürig,
                            Stephen Ogle,
                            Taru Palosuo,
                            Marion Schrumpf,
                            Thomas Wutzler,
                            Klaus Butterbach-Bahl,
                            Oleg Chertov,
                            Alexander Komarov,
                            Aleksey Mikhailov,
                            Annemieke Gärdenäs,
                            Charles Perry,
                            Jari Liski,
                            Pete Smith,
                            Raisa Mäkipää.
                    
                    
                (2007).
            
                            
                                    Models in country scale carbon accounting of forest soils.
                            
                            
                Silva Fennica
                                                            vol.
                                        41
                                                                            no.
                                        3
                                article id 290.
            
                            
                https://doi.org/10.14214/sf.290
            
             
        
                                    
                                    
                            Abstract |
                        
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                            Countries need to assess changes in the carbon stocks of forest soils as  a part of national greenhouse gas (GHG) inventories under the United  Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto  Protocol (KP). Since measuring these changes is expensive, it is likely  that many countries will use alternative methods to prepare these  estimates. We reviewed seven well-known soil carbon models from the  point of view of preparing country-scale soil C change estimates. We  first introduced the models and explained how they incorporated the most  important input variables. Second, we evaluated their applicability at  regional scale considering commonly available data sources. Third, we  compiled references to data that exist for evaluation of model  performance in forest soils. A range of process-based soil carbon models  differing in input data requirements exist, allowing some flexibility  to forest soil C accounting. Simple models may be the only reasonable  option to estimate soil C changes if available resources are limited.  More complex models may be used as integral parts of sophisticated  inventories assimilating several data sources. Currently, measurement  data for model evaluation are common for agricultural soils, but less  data have been collected in forest soils. Definitions of model and  measured soil pools often differ, ancillary model inputs require scaling  of data, and soil C measurements are uncertain. These issues complicate  the preparation of model estimates and their evaluation with empirical  data, at large scale. Assessment of uncertainties that accounts for the  effect of model choice is important part of inventories estimating  large-scale soil C changes. Joint development of models and large-scale  soil measurement campaigns could reduce the inconsistencies between  models and empirical data, and eventually also the uncertainties of  model predictions.
                        
                
                                            - 
                            Peltoniemi,
                            Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland
                                                        E-mail:
                                                            mikko.peltoniemi@metla.fi
                                                                                          
- 
                            Thürig,
                            Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland; European Forest Institute, Joensuu, Finland
                                                        E-mail:
                                                            et@nn.ch
                                                                                
- 
                            Ogle,
                            Natural Resources Ecology Laboratory, Colorado State University, Fort Collins, USA
                                                        E-mail:
                                                            so@nn.us
                                                                                
- 
                            Palosuo,
                            European Forest Institute, Joensuu, Finland
                                                        E-mail:
                                                            tp@nn.fi
                                                                                
- 
                            Schrumpf,
                            Max-Planck-Institute for Biogeochemistry, Jena, Germany
                                                        E-mail:
                                                            ms@nn.de
                                                                                
- 
                            Wutzler,
                            Max-Planck-Institute for Biogeochemistry, Jena, Germany
                                                        E-mail:
                                                            tw@nn.de
                                                                                
- 
                            Butterbach-Bahl,
                            Institute for Meteorology and Climate Research, Forschungszentrum Karlsruhe GmbH, Garmisch-Partenkirchen, Germany
                                                        E-mail:
                                                            kbb@nn.de
                                                                                
- 
                            Chertov,
                            St. Petersburg State University, St. Petersburg-Peterhof, Russia
                                                        E-mail:
                                                            oc@nn.ru
                                                                                
- 
                            Komarov,
                            Institute of Physicochemical and Biological Problems in Soil Science of Russian Academy of Sciences, Pushchino, Russia
                                                        E-mail:
                                                            ak@nn.ru
                                                                                
- 
                            Mikhailov,
                            Institute of Physicochemical and Biological Problems in Soil Science of Russian Academy of Sciences, Pushchino, Russia
                                                        E-mail:
                                                            am@nn.ru
                                                                                
- 
                            Gärdenäs,
                            Dept. of Soil Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
                                                        E-mail:
                                                            ag@nn.se
                                                                                
- 
                            Perry,
                            USDA Forest Service, Northern Research Station, St. Paul, MN USA
                                                        E-mail:
                                                            cp@nn.us
                                                                                
- 
                            Liski,
                            Finnish Environment Institute, Helsinki, Finland
                                                        E-mail:
                                                            jl@nn.fi
                                                                                
- 
                            Smith,
                            School of Biological Sciences, University of Aberdeen, Aberdeen, UK
                                                        E-mail:
                                                            ps@nn.uk
                                                                                
- 
                            Mäkipää,
                            Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland
                                                        E-mail:
                                                            raisa.makipaa@metla.fi
                                                                                
 
         
     
 
            
        
            
            article id 289,
                            category
                        Special section
                    
        
        
                            Thomas Wutzler,
                            Martina Mund.
                    
                    
                (2007).
            
                            
                                    Modelling mean above and below ground litter production based on yield tables.
                            
                            
                Silva Fennica
                                                            vol.
                                        41
                                                                            no.
                                        3
                                article id 289.
            
                            
                https://doi.org/10.14214/sf.289
            
             
        
                                    
                                    
                            Abstract |
                        
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                            Estimates of litter production are a prerequisite for modeling soil  carbon stocks and its changes at regional to national scale. However,  the required data on biomass removal is often available only for the  recent past. In this study we used yield tables as a source of probable  past forest management to drive a single tree based stand growth model.  Next, simulated growth and timber volume was converted to tree  compartment carbon stocks and biomass turnover. The study explicitly  accounted for differences in site quality between stands. In addition we  performed a Monte Carlo uncertainty and sensitivity analysis. We  exemplify the approach by calculating long-term means of past litter  production for 10 species by using yield tables that have been applied  in Central Germany during the last century. We found that litter  production resulting from harvest residues was almost as large as the  one from biomass turnover. Differences in site quality caused large  differences in litter production. At a given site quality, the  uncertainty in soil carbon inputs were 14%, 17%, and 25% for beech,  spruce, and pine stands, respectively. The sensitivity analysis showed  that the most influential parameters were associated with foliage  biomass and turnover. We conclude that rates of mean past litter  production and their uncertainties can reliably be modeled on the basis  of yield tables if the model accounts for 1) full rotation length  including thinning and final harvest, 2) differences in site quality,  and 3) environmental dependency of foliage biomass and foliage turnover.
                        
                
                                            - 
                            Wutzler,
                            Max Planck Institute for Biogeochemistry, Jena, Germany
                                                        E-mail:
                                                            tm@nn.de
                                                                                          
- 
                            Mund,
                            Max Planck Institute for Biogeochemistry, Jena, Germany
                                                        E-mail:
                                                            mm@nn.de
                                                                                
 
         
     
 
                        
                
                
                                            Category :
                    
                    Research article
                                    
                            
                    
        
            
            article id 449,
                            category
                        Research article
                    
        
        
                            Thomas Wutzler,
                            Ingolf Profft,
                            Martina Mund.
                    
                    
                (2011).
            
                            
                                    Quantifying tree biomass carbon stocks, their changes and uncertainties using routine stand taxation inventory data.
                            
                            
                Silva Fennica
                                                            vol.
                                        45
                                                                            no.
                                        3
                                article id 449.
            
                            
                https://doi.org/10.14214/sf.449
            
             
        
                                    
                                    
                            Abstract |
                        
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Author Info
            
                            For carbon (C) trading or any other verifiable C reports, it would be  reasonable to identify and quantify continuous changes in carbon stocks  at regional scales without high investments into additional C-specific,  time- and labor-intensive inventories. Our study demonstrates the  potential of using routine stand taxation data from large scale forestry  inventories for verifiable quantification of tree biomass C stocks, C  stock change rates, and associated uncertainties. Empirical models,  parameters, and equations of uncertainty propagation have been assembled  and applied to data from a forest management unit in Central Germany  (550 000 ha), using stand taxation inventories collected between 1993  and 2006. The study showed: 1) The use of stand taxation data resulted  in a verifiable and sufficiently precise (cv = 7%) quantification of  tree biomass carbon stocks and their changes at the level of  growth-regions (1700 to 140 000 ha). 2) The forest of the test region  accumulated carbon in tree biomass at a mean annual rate of 1.8 (–0.9 to  4.5) tC/ha/yr over the studied period. 3) The taxation inventory data  can reveal spatial patterns of rates of C stock changes, specifically  low rates of 0.4 tC/ha/yr in the northwest and high rates of 3.0  tC/ha/yr in the south of the study region.
                        
                
                                            - 
                            Wutzler,
                            Max Planck Institute for Biogeochemistry, Hans-Knöll-Strasse 10, 07745 Jena, Germany
                                                        E-mail:
                                                            twutz@bgc-jena.mpg.de
                                                                                          
- 
                            Profft,
                            Max Planck Institute for Biogeochemistry, Hans-Knöll-Stra§e 10, 07745 Jena, Germany
                                                        E-mail:
                                                            ip@nn.de
                                                                                
- 
                            Mund,
                            Max Planck Institute for Biogeochemistry, Hans-Knöll-Stra§e 10, 07745 Jena, Germany
                                                        E-mail:
                                                            mm@nn.de
                                                                                
 
         
     
 
            
        
            
            article id 232,
                            category
                        Research article
                    
        
        
                            Thomas Wutzler.
                    
                    
                (2008).
            
                            
                                    Effect of the aggregation of multi-cohort mixed stands on modeling forest ecosystem carbon stocks.
                            
                            
                Silva Fennica
                                                            vol.
                                        42
                                                                            no.
                                        4
                                article id 232.
            
                            
                https://doi.org/10.14214/sf.232
            
             
        
                                    
                                    
                            Abstract |
                        
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                            Studies of the carbon sink of forest ecosystems often stratify the  studied stands by the dominating species and thereby abstract from  differences in the mixed-species, multi-cohort structure of many  forests. This case study infers whether the aggregation of forestry data  introduces a bias in the estimates of carbon stocks and their changes  at the scale of individual stands and the scale of a forest district.  The empirical TreeGrOSS-C model was applied to 1616 plots of a forest  district in Central Germany to simulate carbon dynamics in biomass,  woody debris, and soil. In a first approach each stand was explicitly  simulated with all cohorts. In three other approaches the forest  inventory data were aggregated in several ways, including a  stratification of the stands to 110 classes according to the dominating  species, age class, and site conditions. A small but significant bias  was confirmed. At stand scale the initial ecosystem carbon stocks by the  aggregated approach differed from that of the detailed approach by  2.3%, but at the district scale only by 0.05%. The differences in age  between interspersed and dominant cohorts as well as differences in  litter production were important for the differences in initial carbon  stocks. The amounts of wood extracted by thinning operations were  important for the differences in the projection of the carbon stocks  over 100 years. Because of the smallness of bias, this case study  collects evidence that the approaches, that represent stands or stratums  by a single cohort, are valid at the scale of a forest district or  larger.
                        
                
                                            - 
                            Wutzler,
                            Max Planck Institute for Biogeochemistry, Hans Knöll Str. 10, DE-07745, Jena, Germany
                                                        E-mail:
                                                            thomas.wutzler@bgc-jena.mpg.de
                                                                                        