Literary and scientific copyrights belong to ECMWF and are reserved in all countries. This public... more Literary and scientific copyrights belong to ECMWF and are reserved in all countries. This publication is not to be reprinted or translated in whole or in part without the written permission of the Director. Appropriate noncommercial use will normally be granted under the condition that reference is made to ECMWF. The information within this publication is given in good faith and considered to be true, but ECMWF accepts no liability for error, omission and for loss or damage arising from its use.
The introduction of rapidly growing trees in so-called short-rotation forestry requires knowledge... more The introduction of rapidly growing trees in so-called short-rotation forestry requires knowledge about their water use in order to select suitable land for plantations and to manage the stands in a proper way. In Sweden, different clones of Salix are usually used in short-rotation forestry today. The diameter of trees in such stands is much smaller compared with trees in traditional forestry. This requires new methods to be developed in order to study water relations at the tree level. The aim of this study was to modify, apply and test the stem tissue heat balance method for long-term sap flow measurements on small size Sulix trees. Sap flows measured on two trees were compared to stand evaporation determined by the Bowen ratio method and to other climatic variables. Diurnal courses of sap flow and evaporation corresponded well to each other but with a pronounced lag of sap flow behind evaporation in the morning. Also, the daily integrals of sap flow, evaporation and global radiation showed good correlation over a two month period. Maximum sap flow rate of 30 mm diameter trees was about 0.2 kg h-' or 2 kg day-I. The size of the pool of easily available water in the trees was estimated to be 0.2 kg. This value constitutes about l/4 of the mean daily transpiration, a value similar to those found for much larger trees. The conclusion of this study was that the stem tissue heat balance method with externally placed heater and internally sensed temperature is an appropriate method for measurement of sap flow and transpiration of individual small size Salix trees.
It is a major challenge in modern science to decrease the uncertainty in predictions of global cl... more It is a major challenge in modern science to decrease the uncertainty in predictions of global climate change. One of the largest uncertainties in present-day global climate models resides with the understanding of processes in the soil±vegetation± atmosphere-transfer (SVAT) system. Continuous, long-term data are needed to correctly quantify balances of water, energy and CO 2 in this system and to correctly model them. It is the objective of this paper to demonstrate how a combined system of existing sensor, computer, and network technologies could be set up to provide continuous and reliable long-term SVATprocess data from an agricultural site under almost all weather conditions. A long-term climate-monitoring system within the framework of NOPEX was set up in 1993±1994 at the Marsta Meteorological Observatory (MMO). It is situated in a¯at agricultural area where annual crops are cultivated on a heavy clay soil. It has successfully monitored relevant states and¯uxes in the system, such as atmospheric¯uxes of momentum, heat, water vapour and CO 2 , atmospheric pro®les of wind speed, direction, and temperature, short-and long-wave radiation, soil temperature, soil-water contents, groundwater levels, and rainfall and snow depth. System uptime has been more than 90% for most of its components during the ®rst 5 years of operation. Results from the ®rst 5 years of operation has proven MMO to be an ideal site for intercomparison and intercalibration of radiometers and fast turbulence sensors, and for evaluation of other sensors, e.g., rain gauges. The long time series of radiation data have been valuable to establish numerical limits for a set of quality-control¯ags. MMO has served as a boundary-layer research station and results from NOPEX campaigns show how the dimensionless wind gradient depends not only on the traditional stability parameter z/L but also on the height of the convective boundary layer. Measurements at the observatory grounds and a neighbouring ®eld show a considerable variability in surface properties, which must be accounted for when assessing budgets of heat and other scalars. Questions concerning long-term calibration plans, maintenance of sensors and Agricultural and Forest Meteorology 98±99 (1999) 75±102
The total stem volume in European forests currently amounts to 35 billion m, of which 84% is avai... more The total stem volume in European forests currently amounts to 35 billion m, of which 84% is available for wood supply. The regions with the largest volumes of growing stock available for wood supply are CentralWest Europe with 8.8 billion m and Central-East Europe with 7.9 billion m. The average density of growing stock in forests in the European region is 163 m/ha. Hence, the average density level of growing stock in forests in Europe is higher than that in the world (133 m/ha); at 205 m/ha, the South America region alone has a higher density level of growing stock in forests than Europe. A little over half of the total growing stock in Europe is made up of coniferous tree species (57%) with broadleaved tree species (43%) making up the remainder. Over the last 25 years, the total growing stock in forests increased by an average of 403 million m each year. This corresponds approximately to a daily increase in the total stem volume of living trees in European forests equivalent to t...
The aim of this study was to evaluate organic carbon content (SOC) in the surface layers of fores... more The aim of this study was to evaluate organic carbon content (SOC) in the surface layers of forest soils in the two Natural Forest Regions situated in Southwest Bohemia, namely Západočeská pahorkatina (NFR 6) and Český les (NFR 11). The study is based upon on two consecutive soil sampling campaigns during autumn 2003 and 2004. While the sampling of 2003 was inadequate to estimate bulk density, the consecutive campaign used a defined sample volume to permit an estimation of bulk density and quantification of soil organic carbon (SOC) for soil organic layers and the upper mineral horizon. The total sampling depth was 30 cm including both organic and mineral layer. SOC of organic horizon was on average 1.99 kg C/m 2. It differed by stand site type ranging from 0.70 to 3.04 kg C/m 2. The organic layer SOC was smallest under beech (1.03 kg C/m 2), whereas it was higher under pine (2.19 kg C/m 2) and spruce (2.09 kg C/m 2). SOC in the mineral layer was in average 7.28 kg C/m 2. SOC differed significantly by the major tree species and reached 10.6; 5.67 and 7.5 kg C/m 2 for beech, pine and spruce sites, respectively. The average SOC for the total soil layer (0-30 cm) reached 9.33 kg C/m 2. The methodological aspects of regional estimation of SOC and the potential of utilization of the national forest inventory program are also discussed.
This study describes parameterization of biomass functions applicable to Scots pine (Pinus sylves... more This study describes parameterization of biomass functions applicable to Scots pine (Pinus sylvestris, L.) in the conditions of Central Europe. Fifty-two sample trees from seven sites in different regions of the Czech Republic were used for destructive measurements. The observed aboveground biomass (B AB) and its individual components were examined by different types of non-linear regression models using one to
as a part of its obligations under the Climate Convention, the Czech republic must annually estim... more as a part of its obligations under the Climate Convention, the Czech republic must annually estimate and report its anthropogenic emissions of greenhouse gases. This also applies for the sector of agriculture, which is one of the greatest producers of methane and nitrous oxide emissions. This paper presents the approaches applied to estimate emissions in agricultural sector during the period 1990-2006. it describes the origin and sources of emissions, applied methodology, parameters and emission estimates for the sector of agriculture in the country. The total greenhouse gas emissions reached 7644 Gg Co 2 eq. in 2006. about 59% (4479 Gg Co 2 eq.) of these emissions has originated from agricultural soils. This quantity ranks agriculture as the third largest sector in the Czech republic representing 5.3% of the total greenhouse gas emissions (GHG). The emissions under the Czech conditions consist mainly of emissions from enteric fermentation, manure management and agricultural soils. During the period 1990-2006, GHG emissions from agriculture decreased by 50%, which was linked to reduced cattle population and amount of applied fertilizers. The study concludes that the GHG emissions in the sector of agriculture remain significant and their proper assessment is required for sound climate change adaptation and mitigation policies.
HAL (Le Centre pour la Communication Scientifique Directe), 2008
• This study describes the scenarios of likely development of carbon pools in managed forest ecos... more • This study describes the scenarios of likely development of carbon pools in managed forest ecosystems of the Czech Republic. The analysis was based on a matrix scenario model (EFISCEN), adopting a novel parameterization based on forest stand site types and forest typology. The model was constrained by practical management rules as prescribed by the Czech Forestry Act and used to assess production potential for the next five decades under three management and three climate scenarios. The analysis provided data on carbon pool development, including both tree biomass and soil compartments. • For the tested scenarios of sustainable forest management (wood removals not exceeding increment) the model indicated a slight increase of soil carbon pool. For the possibly largest removals (maximum sustainable felling scenario), soil carbon stabilized within two or three decades reaching a mean value of about 8.1 kg/m 2 for. At the same time, the mean carbon stock held in biomass reached about 10.2 kg/m 2 including belowground parts. No decline of soil carbon was observed for any of the tested scenarios. • We conclude that it is reasonable to assume that soil carbon is not a source of carbon under the current management constraints as implemented in the Czech forestry practice. forest ecosystem / forest management / soil / climate change / model prediction Résumé-Évolution du stock de carbone forestier et de la production de bois en République Tchèque jusqu'en 2060. • Cette étude décrit les scénarios des évolutions probables des pools de carbone dans les écosystèmes forestiers aménagés de la République Tchèque. L'analyse a été basée sur un modèle de scénario matriciel (EFISCEN), en adoptant une paramétrisation originale basée sur des types de station de peuplements forestiers et sur une typologie forestière. Le modèle était limité par des règles de gestion pratiques comme celles qui sont prescrites par les lois forestières tchèques et était utilisé pour estimer le potentiel de production pour les cinq prochaines décades sous trois types de gestion et scénarios climatiques. L'analyse fournit des données sur l'évolution du pool de carbone, en incluant la biomasse de l'arbre et les compartiments du sol. • Pour les scénarios de gestion forestière durable (enlèvement de bois n'excédant pas l'accroissement) testés, le modèle indique un léger accroissement du pool de carbone du sol. Pour de possibles plus grands enlèvements (scénario d'abattage maximum en gestion durable), le carbone du sol se stabilise dans les deux ou trois décades atteignant une valeur moyenne de 8,1 kg/m 2 for. Dans le même temps, le stock moyen de carbone contenu dans la biomasse atteignait environ 10,2 kg/m 2 en incluant les parties souterraines. Il n'a pas été observé de diminution du carbone du sol pour aucun des scénarios testés.
In the Good Practice Guidance for Land Use, land-Use Change and Forestry-GPG-LULUCF (IPCC 2003) t... more In the Good Practice Guidance for Land Use, land-Use Change and Forestry-GPG-LULUCF (IPCC 2003) the Intergovernmental Panel on Climate Change released comprehensive methodologies and common reporting format tables for reporting emissions and removals from land use, land-use change and forestry (LULUCF). These methodologies and tables provided a more complete reporting approach than in Revised 1996 IPCC Guidelines for National Greenhouse Inventories (IPCC, 1997). The Good Practice Guidance for Land Use, land-Use Change and Forestry is the current standard adopted by most Parties for reporting LULUCF. In 2007, Annex-I parties made their initial submission to the United Nations Framework Convention on Climate Change (UNFCCC) under the Kyoto Protocol. This submission used a common reporting format adopted by the Conference of the Parties (Decision 15/CP.10 Annex 1). These tables are somewhat more convoluted than the new common reporting format adopted in the GPG-LULUCF because of the complicated accounting required because of the negotiations of the Kyoto Protocol. This paper highlights the changes from the Revised 1996 IPCC Guidelines adopted in the GPG-LULUCF and reviews the reporting requirements as part of the Kyoto Protocol. The Kyoto Protocol emissions represent an activity-based subset of the emissions from all lands particularly since only lands that have been converted from non-forest to forests or vice versa since 1990 (afforestation, reforestation and deforestation), management activities on forest land (FM), cropland (CM), grazing land (GM) and activities that increase carbon stocks on non-forest land (RV) since 1990 are considered. Since FM, CM, GM, and RV will only be reported if it is favourable to the Party, the Kyoto Protocol inventory underestimates the emissions from LULUCF. In 2007, the IPCC also released the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC, 2007). These guidelines attempt to account for emissions from all lands within AFOLU, but since use of the new guidelines is not mandatory at this time, a summary of these CRFs is given as an appendix. An Annex-I party is required to report on all Article 3, paragraph 3 emissions. Article 3, Paragraph 4 Activities Specific anthropogenic activities, that have occurred since 1990, but have not caused a conversion of land since 1990, are covered under Article 3, Paragraph 4. These activities are limited to: Forest management (FM): a system of practices for stewardship an use of forest land; Cropland management (CM): as system of practices on land on which agricultural crops are grown or on land that is set aside or temporarily not being used for agricultural production; Grazing land management (GM): a system of practices on land used for livestock production; and Revegetation (RV): an activity that increases carbon stocks on sites but the activity does not create a forest. Since reporting of Article 3, paragraph 3 activities is mandatory, it has precedence over an article 3, paragraph 4 activity. So that if land use change since 1990 was involved then the emissions and removals from this land is reported under Article 3, paragraph 3 even if the land incurred an activity that would be considered under Article 3, paragraph 4. Precedence is also given to the deforested category. Land can theoretically switch from AR to D if the land was subject to AR since 1990 and subsequently deforested, but once land is deforested it remains classified as deforested land during the entire reporting period. A given land area can only be classified under one particular activity, and once included in the KP inventory, it must be accounted for the remainder of the commitment period and subsequent periods 5. Finally, since reporting of Article 3, paragraph 4 is optional, there will be a bias towards using Article 3.4 to a Party's advantage (i.e. the Party will elect to report on Article 3.4 only if it believes that it will create increased emission removals) 6. As a result, only emissions from these activities will appear in the KP inventory. 1.3.2. Carbon pools Unlike the UNFCCC, which requires reporting of stock changes in all pools, under the Kyoto Protocol, a Party may omit any carbon pool with due justification 7. Carbon stock changes in harvested wood products (HWP) are not reported. 4 Though there is a distinction between afforestation and reforestation in the KP, it is not necessary to distinguish between the land use changes that are afforestation and those that are reforestation in the KP common reporting format (CMP.3, Good practice guidance for land use, land-use change and forestry activities under Article 3, paragraphs 3 and 4, of the Kyoto Protocol) 5 Decision 16/CMP.1, Annex, paragraph 19, also GPG-LULUCF page 4.15 6 Canada elected not to report FM under Article 3.4 because the risk of FM being a net source primarily due to losses from forest fire was more than the risk of FM being a net sink. 7 Decision 15/CP.10 Annex 1, paragraph 3.1.2.
Tree water use and growth increment were studied in a north-facing forest edge of a 70-year-old m... more Tree water use and growth increment were studied in a north-facing forest edge of a 70-year-old monospecific Scots pine (Pinus sylvestris L.) stand growing on poor sandy soils in the northern boreal zone of Sweden. The forest edge in this study bordered a 20-year-old clearcut. There were differences in water use and growth increment during the growing season between trees growing at the forest edge and trees growing in the forest interior. These differences were likely related to soil conditions, such as access to soil moisture, soil temperature, and soil frost conditions, whereas an effect of aboveground microclimate was not found. The estimated tree water use and growth increment over one growing season tended to be greater for trees at the edge zone relative to those from the interior. The variability of the measured tree water fluxes was high, especially for the edge-zone trees. There were also structural differences between the two groups of trees, most notably in the radial pr...
Abstract. Tree crown size is a key parameter of tree structure that has a variety of uses, includ... more Abstract. Tree crown size is a key parameter of tree structure that has a variety of uses, including assessment of stand density, tree growth, and amount of timber volume assessment. Remote sensing techniques provide a potentially low-cost alternative to field-based assessments, but require the development of algorithms to easily and accurately extract the required information. This study presents a method for average crown diameter estimation on a plot level based on high-resolution airborne data. The method consists of the combination of a window binarization procedure and a granulometric algorithm. This approach avoids the complicated crown delineation procedure that is currently used to estimate crown size. The method was applied to a spruce mountain forest and was verified on 23 reference plots. The method achieved best results of R2=76% [RMSE=0.37 m (11.2% of the observed mean)] and R2=79% [RMSE=0.49 m (16.7% of the observed mean)]. The study investigates the dependence of the algorithm results on the sun altitude of each image, and determines the optimal combination of spectral bands from hyperspectral airborne images for the application of the method.
We examined the effect of individual environmental factors on the current spruce tree growth asse... more We examined the effect of individual environmental factors on the current spruce tree growth assessed from a repeated country-level statistical landscape (incl. forest) survey in the Czech Republic. An extensive set of variables related to tree size, competition, site characteristics including soil texture, chemistry, N deposition and climate was tested within a random-effect model to explain growth in the conditions of dominantly managed forest ecosystems. The current spruce basal area increment was assessed from two consecutive landscape surveys conducted in 2008/2009 and six years later in 2014/2015. Tree size, age and competition within forest stands were found to be the dominant explanatory variables, whereas the expression of site characteristics, environmental and climatic drives was weaker. The significant site variables affecting growth included soil C/N ratio and soil exchangeable acidity (pH KCl; positive response) reflecting soil chemistry, long-term N-deposition (averaged since 1975) in combination with soil texture (clay content) and Standardized Precipitation Index (SPI), a drought index expressing moisture conditions. Sensitivity of growth to N-deposition was positive, although weak. SPI
Decline or health deterioration of Norway spruce (Picea abies (L.) Karst.) dominated forest stand... more Decline or health deterioration of Norway spruce (Picea abies (L.) Karst.) dominated forest stands has recently been observed mainly in sub-mountainous parts of Central Europe. Forest inventory of 208 randomly distributed circular plots including field observations of spruce tree health and rot symptoms by honey fungus (Armillaria ostoyae) was used for assessing intensity of spruce forest health decline in a managed forest area of 12.7 th. ha located in Beskids Mts., NE Czech Republic. First, principal component analysis was used to separate inventory variables related to environmental stress (reduced apical increment, dry tree top and stem resin exudation due to A. ostoyae infestation) into PC1, and health deterioration symptoms associated with mechanical damage (peeling, crown breaks) into PC2. The first two principal components explained 59% of the total variability in health decline symptoms. Spatial variability of both principal components was explained using spatial lag regression model identified from a set of environmental variables including sulfur and nitrogen deposition, elevation, solar radiation, age of the forest stands and geological properties (geochemical reactivity index). Environmental stress (PC1) was associated with low elevations (sub-optimal for spruce), high level of nitrogen and sulfur deposition (their interaction), low geochemical reactivity and also stand age. On the other hand, mechanical damage (PC2) significantly increased with elevation and stand age. As the forest decline in Beskids Mts. is related to A. ostoyae spreading from local infestation hot spots, both principal components had a significant spatial autocorrelation, partly distorting the signal of environmental conditions. The results indicate that the disturbed forest soils by long-term acid deposition and subsequent nutrient degradation and more pronounced drought stress at low elevations are the most important drivers of the recent spruce health decline in Beskids Mts.
Forest defoliation and discoloration have been monitored extensively in Europe over the past deca... more Forest defoliation and discoloration have been monitored extensively in Europe over the past decade, yet the number of published studies seeking to interpret these data in light of environmental parameters such as lithology and airborne pollution are few. In this study we summarize and compare data on defoliation and discoloration of Norway spruce dominated stands from three regions of the Czech Republic that differ in their lithology. In the Š umava and Krkonoše regions these measures increased over the monitoring period, which is interpreted as an effect of residual soil acidification. At Beskydy, a general stability in forest health parameters was observed. Regional differences are attributed to underlying lithography-the greater calcium carbonate content of the flysch bedrock at Beskydy provides better buffering against acid deposition. These results are supported by evidence of similar trends in atmospheric pollution (ambient air concentrations and deposition) between Beskydy and the Krkonoše region and higher sulphur inputs than at Š umava. Stand elevation and age, collected as explanatory variables, did not affect this interpretation. Additionally, in the Krkonoše region forest health data were examined for four soil type categories (extreme, acidic, enriched and nutritive) specific to forest conditions in the Czech Republic. Simple time series analysis of defoliation and discoloration demonstrated that extreme and acidic soils accounted for the majority of the increasing trend of forest decline in Krkonoše. However, multivariate non-linear regression analysis using elevation and stand age revealed that defoliation was not significantly different between acidic and nutritive soil type categories; rather, this was an artefact of the experimental design. The implications of the research are that acidic and nutritive soil type categories respond similarly to acid deposition while enriched, the most nutrient rich type category is most resistant. As such our results support the interpretation that lithology is a factor mitigating forest decline in Norway spruce dominated forests in the Czech Republic. Our results have implications for zonation strategies like those being used in Krkonoše National Park which seek to prescribe specific restoration measures based upon abiotic factors for acid-damaged forests.
ABSTRACT Most European countries have signed the United Nations Framework Convention on climate c... more ABSTRACT Most European countries have signed the United Nations Framework Convention on climate change and its Kyoto Protocol. Because the European Union is a party to the convention just like the individual countries, there is a need for harmonizing emissions reporting. This specifically applies to the Land Use, Land-Use Change, and Forestry sector, for which harmonized reporting is complex and generally challenging. For example, parties use a variety of different methods for estimating emissions and removals, ranging from application of default factors to advanced methods adapted to national circumstances, such as ongoing field inventories. In this study, we demonstrate that without harmonization, national definitions and methods lead to inconsistent estimates. Based on case studies in Finland, Germany, Norway, Portugal, Slovenia, and Sweden, we conclude that common reference definitions and country-specific bridges are means to harmonize the estimates and make greenhouse gas reporting from forests comparable across countries. FOR. SCI. 58(3):248-256.
The aim of this paper is to develop biomass models for commonly multi-stemmed Prosopis juliflora/... more The aim of this paper is to develop biomass models for commonly multi-stemmed Prosopis juliflora/ pallida trees. The data were collected on three of the Cape Verde islands (Maio, Santiago and Santo Antao). The dataset covers 240 trees containing 1,882 stems with stem diameter at breast height over 2 cm; of that 255 individual tree stems were sampled destructively. These calibration data were used to construct stem and tree-level models for estimation of total aboveground biomass and its fine and course fractions with diameter threshold of 5 cm. A set of parameterized biomass models for multi-stemmed Prosopis spp. trees suited for biomass estimation at tree and stem levels using appropriate set of independent variables, commonly available in forest inventory programs, was created. The effect of site (island) on tree allometry was not detected. The two-phase construction of tree biomass models based on destructive sampling limited to individual stems combined with a routine field measurement of entire multi-stemmed tree specimen represents a practicable approach leading to biomass and carbon assessment that may be generally suited for tree species with complex multi-stemmed growth form similar to that of Prosopis spp.
Literary and scientific copyrights belong to ECMWF and are reserved in all countries. This public... more Literary and scientific copyrights belong to ECMWF and are reserved in all countries. This publication is not to be reprinted or translated in whole or in part without the written permission of the Director. Appropriate noncommercial use will normally be granted under the condition that reference is made to ECMWF. The information within this publication is given in good faith and considered to be true, but ECMWF accepts no liability for error, omission and for loss or damage arising from its use.
The introduction of rapidly growing trees in so-called short-rotation forestry requires knowledge... more The introduction of rapidly growing trees in so-called short-rotation forestry requires knowledge about their water use in order to select suitable land for plantations and to manage the stands in a proper way. In Sweden, different clones of Salix are usually used in short-rotation forestry today. The diameter of trees in such stands is much smaller compared with trees in traditional forestry. This requires new methods to be developed in order to study water relations at the tree level. The aim of this study was to modify, apply and test the stem tissue heat balance method for long-term sap flow measurements on small size Sulix trees. Sap flows measured on two trees were compared to stand evaporation determined by the Bowen ratio method and to other climatic variables. Diurnal courses of sap flow and evaporation corresponded well to each other but with a pronounced lag of sap flow behind evaporation in the morning. Also, the daily integrals of sap flow, evaporation and global radiation showed good correlation over a two month period. Maximum sap flow rate of 30 mm diameter trees was about 0.2 kg h-' or 2 kg day-I. The size of the pool of easily available water in the trees was estimated to be 0.2 kg. This value constitutes about l/4 of the mean daily transpiration, a value similar to those found for much larger trees. The conclusion of this study was that the stem tissue heat balance method with externally placed heater and internally sensed temperature is an appropriate method for measurement of sap flow and transpiration of individual small size Salix trees.
It is a major challenge in modern science to decrease the uncertainty in predictions of global cl... more It is a major challenge in modern science to decrease the uncertainty in predictions of global climate change. One of the largest uncertainties in present-day global climate models resides with the understanding of processes in the soil±vegetation± atmosphere-transfer (SVAT) system. Continuous, long-term data are needed to correctly quantify balances of water, energy and CO 2 in this system and to correctly model them. It is the objective of this paper to demonstrate how a combined system of existing sensor, computer, and network technologies could be set up to provide continuous and reliable long-term SVATprocess data from an agricultural site under almost all weather conditions. A long-term climate-monitoring system within the framework of NOPEX was set up in 1993±1994 at the Marsta Meteorological Observatory (MMO). It is situated in a¯at agricultural area where annual crops are cultivated on a heavy clay soil. It has successfully monitored relevant states and¯uxes in the system, such as atmospheric¯uxes of momentum, heat, water vapour and CO 2 , atmospheric pro®les of wind speed, direction, and temperature, short-and long-wave radiation, soil temperature, soil-water contents, groundwater levels, and rainfall and snow depth. System uptime has been more than 90% for most of its components during the ®rst 5 years of operation. Results from the ®rst 5 years of operation has proven MMO to be an ideal site for intercomparison and intercalibration of radiometers and fast turbulence sensors, and for evaluation of other sensors, e.g., rain gauges. The long time series of radiation data have been valuable to establish numerical limits for a set of quality-control¯ags. MMO has served as a boundary-layer research station and results from NOPEX campaigns show how the dimensionless wind gradient depends not only on the traditional stability parameter z/L but also on the height of the convective boundary layer. Measurements at the observatory grounds and a neighbouring ®eld show a considerable variability in surface properties, which must be accounted for when assessing budgets of heat and other scalars. Questions concerning long-term calibration plans, maintenance of sensors and Agricultural and Forest Meteorology 98±99 (1999) 75±102
The total stem volume in European forests currently amounts to 35 billion m, of which 84% is avai... more The total stem volume in European forests currently amounts to 35 billion m, of which 84% is available for wood supply. The regions with the largest volumes of growing stock available for wood supply are CentralWest Europe with 8.8 billion m and Central-East Europe with 7.9 billion m. The average density of growing stock in forests in the European region is 163 m/ha. Hence, the average density level of growing stock in forests in Europe is higher than that in the world (133 m/ha); at 205 m/ha, the South America region alone has a higher density level of growing stock in forests than Europe. A little over half of the total growing stock in Europe is made up of coniferous tree species (57%) with broadleaved tree species (43%) making up the remainder. Over the last 25 years, the total growing stock in forests increased by an average of 403 million m each year. This corresponds approximately to a daily increase in the total stem volume of living trees in European forests equivalent to t...
The aim of this study was to evaluate organic carbon content (SOC) in the surface layers of fores... more The aim of this study was to evaluate organic carbon content (SOC) in the surface layers of forest soils in the two Natural Forest Regions situated in Southwest Bohemia, namely Západočeská pahorkatina (NFR 6) and Český les (NFR 11). The study is based upon on two consecutive soil sampling campaigns during autumn 2003 and 2004. While the sampling of 2003 was inadequate to estimate bulk density, the consecutive campaign used a defined sample volume to permit an estimation of bulk density and quantification of soil organic carbon (SOC) for soil organic layers and the upper mineral horizon. The total sampling depth was 30 cm including both organic and mineral layer. SOC of organic horizon was on average 1.99 kg C/m 2. It differed by stand site type ranging from 0.70 to 3.04 kg C/m 2. The organic layer SOC was smallest under beech (1.03 kg C/m 2), whereas it was higher under pine (2.19 kg C/m 2) and spruce (2.09 kg C/m 2). SOC in the mineral layer was in average 7.28 kg C/m 2. SOC differed significantly by the major tree species and reached 10.6; 5.67 and 7.5 kg C/m 2 for beech, pine and spruce sites, respectively. The average SOC for the total soil layer (0-30 cm) reached 9.33 kg C/m 2. The methodological aspects of regional estimation of SOC and the potential of utilization of the national forest inventory program are also discussed.
This study describes parameterization of biomass functions applicable to Scots pine (Pinus sylves... more This study describes parameterization of biomass functions applicable to Scots pine (Pinus sylvestris, L.) in the conditions of Central Europe. Fifty-two sample trees from seven sites in different regions of the Czech Republic were used for destructive measurements. The observed aboveground biomass (B AB) and its individual components were examined by different types of non-linear regression models using one to
as a part of its obligations under the Climate Convention, the Czech republic must annually estim... more as a part of its obligations under the Climate Convention, the Czech republic must annually estimate and report its anthropogenic emissions of greenhouse gases. This also applies for the sector of agriculture, which is one of the greatest producers of methane and nitrous oxide emissions. This paper presents the approaches applied to estimate emissions in agricultural sector during the period 1990-2006. it describes the origin and sources of emissions, applied methodology, parameters and emission estimates for the sector of agriculture in the country. The total greenhouse gas emissions reached 7644 Gg Co 2 eq. in 2006. about 59% (4479 Gg Co 2 eq.) of these emissions has originated from agricultural soils. This quantity ranks agriculture as the third largest sector in the Czech republic representing 5.3% of the total greenhouse gas emissions (GHG). The emissions under the Czech conditions consist mainly of emissions from enteric fermentation, manure management and agricultural soils. During the period 1990-2006, GHG emissions from agriculture decreased by 50%, which was linked to reduced cattle population and amount of applied fertilizers. The study concludes that the GHG emissions in the sector of agriculture remain significant and their proper assessment is required for sound climate change adaptation and mitigation policies.
HAL (Le Centre pour la Communication Scientifique Directe), 2008
• This study describes the scenarios of likely development of carbon pools in managed forest ecos... more • This study describes the scenarios of likely development of carbon pools in managed forest ecosystems of the Czech Republic. The analysis was based on a matrix scenario model (EFISCEN), adopting a novel parameterization based on forest stand site types and forest typology. The model was constrained by practical management rules as prescribed by the Czech Forestry Act and used to assess production potential for the next five decades under three management and three climate scenarios. The analysis provided data on carbon pool development, including both tree biomass and soil compartments. • For the tested scenarios of sustainable forest management (wood removals not exceeding increment) the model indicated a slight increase of soil carbon pool. For the possibly largest removals (maximum sustainable felling scenario), soil carbon stabilized within two or three decades reaching a mean value of about 8.1 kg/m 2 for. At the same time, the mean carbon stock held in biomass reached about 10.2 kg/m 2 including belowground parts. No decline of soil carbon was observed for any of the tested scenarios. • We conclude that it is reasonable to assume that soil carbon is not a source of carbon under the current management constraints as implemented in the Czech forestry practice. forest ecosystem / forest management / soil / climate change / model prediction Résumé-Évolution du stock de carbone forestier et de la production de bois en République Tchèque jusqu'en 2060. • Cette étude décrit les scénarios des évolutions probables des pools de carbone dans les écosystèmes forestiers aménagés de la République Tchèque. L'analyse a été basée sur un modèle de scénario matriciel (EFISCEN), en adoptant une paramétrisation originale basée sur des types de station de peuplements forestiers et sur une typologie forestière. Le modèle était limité par des règles de gestion pratiques comme celles qui sont prescrites par les lois forestières tchèques et était utilisé pour estimer le potentiel de production pour les cinq prochaines décades sous trois types de gestion et scénarios climatiques. L'analyse fournit des données sur l'évolution du pool de carbone, en incluant la biomasse de l'arbre et les compartiments du sol. • Pour les scénarios de gestion forestière durable (enlèvement de bois n'excédant pas l'accroissement) testés, le modèle indique un léger accroissement du pool de carbone du sol. Pour de possibles plus grands enlèvements (scénario d'abattage maximum en gestion durable), le carbone du sol se stabilise dans les deux ou trois décades atteignant une valeur moyenne de 8,1 kg/m 2 for. Dans le même temps, le stock moyen de carbone contenu dans la biomasse atteignait environ 10,2 kg/m 2 en incluant les parties souterraines. Il n'a pas été observé de diminution du carbone du sol pour aucun des scénarios testés.
In the Good Practice Guidance for Land Use, land-Use Change and Forestry-GPG-LULUCF (IPCC 2003) t... more In the Good Practice Guidance for Land Use, land-Use Change and Forestry-GPG-LULUCF (IPCC 2003) the Intergovernmental Panel on Climate Change released comprehensive methodologies and common reporting format tables for reporting emissions and removals from land use, land-use change and forestry (LULUCF). These methodologies and tables provided a more complete reporting approach than in Revised 1996 IPCC Guidelines for National Greenhouse Inventories (IPCC, 1997). The Good Practice Guidance for Land Use, land-Use Change and Forestry is the current standard adopted by most Parties for reporting LULUCF. In 2007, Annex-I parties made their initial submission to the United Nations Framework Convention on Climate Change (UNFCCC) under the Kyoto Protocol. This submission used a common reporting format adopted by the Conference of the Parties (Decision 15/CP.10 Annex 1). These tables are somewhat more convoluted than the new common reporting format adopted in the GPG-LULUCF because of the complicated accounting required because of the negotiations of the Kyoto Protocol. This paper highlights the changes from the Revised 1996 IPCC Guidelines adopted in the GPG-LULUCF and reviews the reporting requirements as part of the Kyoto Protocol. The Kyoto Protocol emissions represent an activity-based subset of the emissions from all lands particularly since only lands that have been converted from non-forest to forests or vice versa since 1990 (afforestation, reforestation and deforestation), management activities on forest land (FM), cropland (CM), grazing land (GM) and activities that increase carbon stocks on non-forest land (RV) since 1990 are considered. Since FM, CM, GM, and RV will only be reported if it is favourable to the Party, the Kyoto Protocol inventory underestimates the emissions from LULUCF. In 2007, the IPCC also released the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC, 2007). These guidelines attempt to account for emissions from all lands within AFOLU, but since use of the new guidelines is not mandatory at this time, a summary of these CRFs is given as an appendix. An Annex-I party is required to report on all Article 3, paragraph 3 emissions. Article 3, Paragraph 4 Activities Specific anthropogenic activities, that have occurred since 1990, but have not caused a conversion of land since 1990, are covered under Article 3, Paragraph 4. These activities are limited to: Forest management (FM): a system of practices for stewardship an use of forest land; Cropland management (CM): as system of practices on land on which agricultural crops are grown or on land that is set aside or temporarily not being used for agricultural production; Grazing land management (GM): a system of practices on land used for livestock production; and Revegetation (RV): an activity that increases carbon stocks on sites but the activity does not create a forest. Since reporting of Article 3, paragraph 3 activities is mandatory, it has precedence over an article 3, paragraph 4 activity. So that if land use change since 1990 was involved then the emissions and removals from this land is reported under Article 3, paragraph 3 even if the land incurred an activity that would be considered under Article 3, paragraph 4. Precedence is also given to the deforested category. Land can theoretically switch from AR to D if the land was subject to AR since 1990 and subsequently deforested, but once land is deforested it remains classified as deforested land during the entire reporting period. A given land area can only be classified under one particular activity, and once included in the KP inventory, it must be accounted for the remainder of the commitment period and subsequent periods 5. Finally, since reporting of Article 3, paragraph 4 is optional, there will be a bias towards using Article 3.4 to a Party's advantage (i.e. the Party will elect to report on Article 3.4 only if it believes that it will create increased emission removals) 6. As a result, only emissions from these activities will appear in the KP inventory. 1.3.2. Carbon pools Unlike the UNFCCC, which requires reporting of stock changes in all pools, under the Kyoto Protocol, a Party may omit any carbon pool with due justification 7. Carbon stock changes in harvested wood products (HWP) are not reported. 4 Though there is a distinction between afforestation and reforestation in the KP, it is not necessary to distinguish between the land use changes that are afforestation and those that are reforestation in the KP common reporting format (CMP.3, Good practice guidance for land use, land-use change and forestry activities under Article 3, paragraphs 3 and 4, of the Kyoto Protocol) 5 Decision 16/CMP.1, Annex, paragraph 19, also GPG-LULUCF page 4.15 6 Canada elected not to report FM under Article 3.4 because the risk of FM being a net source primarily due to losses from forest fire was more than the risk of FM being a net sink. 7 Decision 15/CP.10 Annex 1, paragraph 3.1.2.
Tree water use and growth increment were studied in a north-facing forest edge of a 70-year-old m... more Tree water use and growth increment were studied in a north-facing forest edge of a 70-year-old monospecific Scots pine (Pinus sylvestris L.) stand growing on poor sandy soils in the northern boreal zone of Sweden. The forest edge in this study bordered a 20-year-old clearcut. There were differences in water use and growth increment during the growing season between trees growing at the forest edge and trees growing in the forest interior. These differences were likely related to soil conditions, such as access to soil moisture, soil temperature, and soil frost conditions, whereas an effect of aboveground microclimate was not found. The estimated tree water use and growth increment over one growing season tended to be greater for trees at the edge zone relative to those from the interior. The variability of the measured tree water fluxes was high, especially for the edge-zone trees. There were also structural differences between the two groups of trees, most notably in the radial pr...
Abstract. Tree crown size is a key parameter of tree structure that has a variety of uses, includ... more Abstract. Tree crown size is a key parameter of tree structure that has a variety of uses, including assessment of stand density, tree growth, and amount of timber volume assessment. Remote sensing techniques provide a potentially low-cost alternative to field-based assessments, but require the development of algorithms to easily and accurately extract the required information. This study presents a method for average crown diameter estimation on a plot level based on high-resolution airborne data. The method consists of the combination of a window binarization procedure and a granulometric algorithm. This approach avoids the complicated crown delineation procedure that is currently used to estimate crown size. The method was applied to a spruce mountain forest and was verified on 23 reference plots. The method achieved best results of R2=76% [RMSE=0.37 m (11.2% of the observed mean)] and R2=79% [RMSE=0.49 m (16.7% of the observed mean)]. The study investigates the dependence of the algorithm results on the sun altitude of each image, and determines the optimal combination of spectral bands from hyperspectral airborne images for the application of the method.
We examined the effect of individual environmental factors on the current spruce tree growth asse... more We examined the effect of individual environmental factors on the current spruce tree growth assessed from a repeated country-level statistical landscape (incl. forest) survey in the Czech Republic. An extensive set of variables related to tree size, competition, site characteristics including soil texture, chemistry, N deposition and climate was tested within a random-effect model to explain growth in the conditions of dominantly managed forest ecosystems. The current spruce basal area increment was assessed from two consecutive landscape surveys conducted in 2008/2009 and six years later in 2014/2015. Tree size, age and competition within forest stands were found to be the dominant explanatory variables, whereas the expression of site characteristics, environmental and climatic drives was weaker. The significant site variables affecting growth included soil C/N ratio and soil exchangeable acidity (pH KCl; positive response) reflecting soil chemistry, long-term N-deposition (averaged since 1975) in combination with soil texture (clay content) and Standardized Precipitation Index (SPI), a drought index expressing moisture conditions. Sensitivity of growth to N-deposition was positive, although weak. SPI
Decline or health deterioration of Norway spruce (Picea abies (L.) Karst.) dominated forest stand... more Decline or health deterioration of Norway spruce (Picea abies (L.) Karst.) dominated forest stands has recently been observed mainly in sub-mountainous parts of Central Europe. Forest inventory of 208 randomly distributed circular plots including field observations of spruce tree health and rot symptoms by honey fungus (Armillaria ostoyae) was used for assessing intensity of spruce forest health decline in a managed forest area of 12.7 th. ha located in Beskids Mts., NE Czech Republic. First, principal component analysis was used to separate inventory variables related to environmental stress (reduced apical increment, dry tree top and stem resin exudation due to A. ostoyae infestation) into PC1, and health deterioration symptoms associated with mechanical damage (peeling, crown breaks) into PC2. The first two principal components explained 59% of the total variability in health decline symptoms. Spatial variability of both principal components was explained using spatial lag regression model identified from a set of environmental variables including sulfur and nitrogen deposition, elevation, solar radiation, age of the forest stands and geological properties (geochemical reactivity index). Environmental stress (PC1) was associated with low elevations (sub-optimal for spruce), high level of nitrogen and sulfur deposition (their interaction), low geochemical reactivity and also stand age. On the other hand, mechanical damage (PC2) significantly increased with elevation and stand age. As the forest decline in Beskids Mts. is related to A. ostoyae spreading from local infestation hot spots, both principal components had a significant spatial autocorrelation, partly distorting the signal of environmental conditions. The results indicate that the disturbed forest soils by long-term acid deposition and subsequent nutrient degradation and more pronounced drought stress at low elevations are the most important drivers of the recent spruce health decline in Beskids Mts.
Forest defoliation and discoloration have been monitored extensively in Europe over the past deca... more Forest defoliation and discoloration have been monitored extensively in Europe over the past decade, yet the number of published studies seeking to interpret these data in light of environmental parameters such as lithology and airborne pollution are few. In this study we summarize and compare data on defoliation and discoloration of Norway spruce dominated stands from three regions of the Czech Republic that differ in their lithology. In the Š umava and Krkonoše regions these measures increased over the monitoring period, which is interpreted as an effect of residual soil acidification. At Beskydy, a general stability in forest health parameters was observed. Regional differences are attributed to underlying lithography-the greater calcium carbonate content of the flysch bedrock at Beskydy provides better buffering against acid deposition. These results are supported by evidence of similar trends in atmospheric pollution (ambient air concentrations and deposition) between Beskydy and the Krkonoše region and higher sulphur inputs than at Š umava. Stand elevation and age, collected as explanatory variables, did not affect this interpretation. Additionally, in the Krkonoše region forest health data were examined for four soil type categories (extreme, acidic, enriched and nutritive) specific to forest conditions in the Czech Republic. Simple time series analysis of defoliation and discoloration demonstrated that extreme and acidic soils accounted for the majority of the increasing trend of forest decline in Krkonoše. However, multivariate non-linear regression analysis using elevation and stand age revealed that defoliation was not significantly different between acidic and nutritive soil type categories; rather, this was an artefact of the experimental design. The implications of the research are that acidic and nutritive soil type categories respond similarly to acid deposition while enriched, the most nutrient rich type category is most resistant. As such our results support the interpretation that lithology is a factor mitigating forest decline in Norway spruce dominated forests in the Czech Republic. Our results have implications for zonation strategies like those being used in Krkonoše National Park which seek to prescribe specific restoration measures based upon abiotic factors for acid-damaged forests.
ABSTRACT Most European countries have signed the United Nations Framework Convention on climate c... more ABSTRACT Most European countries have signed the United Nations Framework Convention on climate change and its Kyoto Protocol. Because the European Union is a party to the convention just like the individual countries, there is a need for harmonizing emissions reporting. This specifically applies to the Land Use, Land-Use Change, and Forestry sector, for which harmonized reporting is complex and generally challenging. For example, parties use a variety of different methods for estimating emissions and removals, ranging from application of default factors to advanced methods adapted to national circumstances, such as ongoing field inventories. In this study, we demonstrate that without harmonization, national definitions and methods lead to inconsistent estimates. Based on case studies in Finland, Germany, Norway, Portugal, Slovenia, and Sweden, we conclude that common reference definitions and country-specific bridges are means to harmonize the estimates and make greenhouse gas reporting from forests comparable across countries. FOR. SCI. 58(3):248-256.
The aim of this paper is to develop biomass models for commonly multi-stemmed Prosopis juliflora/... more The aim of this paper is to develop biomass models for commonly multi-stemmed Prosopis juliflora/ pallida trees. The data were collected on three of the Cape Verde islands (Maio, Santiago and Santo Antao). The dataset covers 240 trees containing 1,882 stems with stem diameter at breast height over 2 cm; of that 255 individual tree stems were sampled destructively. These calibration data were used to construct stem and tree-level models for estimation of total aboveground biomass and its fine and course fractions with diameter threshold of 5 cm. A set of parameterized biomass models for multi-stemmed Prosopis spp. trees suited for biomass estimation at tree and stem levels using appropriate set of independent variables, commonly available in forest inventory programs, was created. The effect of site (island) on tree allometry was not detected. The two-phase construction of tree biomass models based on destructive sampling limited to individual stems combined with a routine field measurement of entire multi-stemmed tree specimen represents a practicable approach leading to biomass and carbon assessment that may be generally suited for tree species with complex multi-stemmed growth form similar to that of Prosopis spp.
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