Plant biomass is a major source of energy for households in eastern Africa. Unfortunately, the he... more Plant biomass is a major source of energy for households in eastern Africa. Unfortunately, the heavy reliance on this form of energy is a threat to forest ecosystems and a recipe for accelerated land resource degradation. Due to the increasing scarcity of traditional fuel wood resources, rural communities have shifted to utilisation of crop residues and cattle dung; which otherwise, are resources for soil fertility improvement. The objective of this study was to assess the supply and consumption patterns of fuel biomass and estimate the amount of nutrients that could be lost from burning non-woody biomass energy sources. A survey was conducted in the Mukehantuta watershed in Ethiopia, using a semi-structured questionnaire. An inventory of woody biomass was also carried out on the existing stock in the watershed. Annually, households in the watershed used 1999, 943, 11, 34 and 229 metric tonnes of wood, dung, charcoal, crop residue and tree residues, respectively. The existing wood b...
Floodplain forests are considered as key forest ecosystems in lowland regions of the European tem... more Floodplain forests are considered as key forest ecosystems in lowland regions of the European temperate zone. Ecosystem services of floodplain forests are essential for maintaining and sustainable management of water resources. The ecological role of floodplain forest ecosystems in the landscape is emphasized in the context of global change because of flood risk management in landscapes along lowland European river. This chapter deals with these important functions of floodplain forests. Authors of the chapter contribute a large amount of their own professional experience and also utilize a large amount from published literature in the field of monitoring, research and management practice of the water regime and its consequences for floodplain forests from an European perspective. The aim of the case study from the Czech Republic is to fill the knowledge gaps related to the monetary evaluation of floodplain forest habitats endangered by the international water management project Dan...
During an investigation on the effects of differing stand densities on biomass distribution, owin... more During an investigation on the effects of differing stand densities on biomass distribution, owing to thinning in 17-year-old Norway spruce stands, specific leaf area (SLA) and 100-needle dry mass were measured for three diameter at breast height (DBH) classes, five canopy sections, and two needle age-classes. Mean SLA was found to be 50 ± 17 cm2/g. High correlation of SLA and 100-needle dry mass with DBH, crown position, and needle age was found. Older needles had a lower mean SLA than the current years needles, while they did not differ significantly in their 100-needles dry mass. Thinning proved to be a minor factor for foliage variability, since DBH, which is dependent upon thinning and the trees competitive status, explained a major part of variation in leaf morphology. A third-degree polynomial regression function could be developed to predict SLA from 100-needle dry mass. This function shows wide validity. It applies to all DBH classes and crown sections. It also shows good f...
Spruce Monocultures in Central Europe: Problems and …, 2000
... Growth of Norway Spruce (Picea abies [L.] Karst.) under Changing Environmental Conditions in ... more ... Growth of Norway Spruce (Picea abies [L.] Karst.) under Changing Environmental Conditions in Europe 15 Finally, in a recent investigation, Untheim ... In recent decades, similar time specific growth fluctuations were observed in Switzerland, France and southwestern ...
Analysis of total S in tree foliage has become widely accepted as a means of assessing S pollutio... more Analysis of total S in tree foliage has become widely accepted as a means of assessing S pollution of forests when air quality data are lacking. An investigation of total S content of mixed needle samples of different age and canopy height from two stands of young Norway spruce with different densities showed that S-content exceeded the maximum natural S-content (i.e. in the absence of SO2-pollution) for spruce. Significantly higher average needle S contents were encountered with decreasing stand density. Changed aerodynamic roughness and physiological status &thinned trees indicated combined action of atmospheric and tree physiological variables on S deposition and uptake in forest ecosystems. A marked increase in S content from 1 yr old to older needles and from the lower to the upper canopy was observed.
The role of agroforestry systems in providing ecosystem services is very crucial. The most signif... more The role of agroforestry systems in providing ecosystem services is very crucial. The most significant increase in carbon (C) storage is often achieved by moving from lower biomass land-use systems to tree-based systems like agroforestry (AF). However, estimation of carbon stocks in indigenous agroforestry systems of South-eastern Rift- valley landscapes, Ethiopia the data are scarce. The study was aimed to investigate the biomass, biomass carbon (BC), and soil organic carbon (SOC) stock of Enset based, Enset-Coffee based, and Coffee-Fruit tree-Enset based agroforestry systems. Comparison of SOC stock of agroforestry systems against their adjacent monocropping farms was also investigated. The study was conducted in three selected sites of the Dilla Zuria district of Gedeo zone. Twenty farms (total of 60) representative of each AF system were randomly selected, inventoried and biomass C stocks estimated. Ten adjacent mono-cropping farms which were related to each AF system were selec...
In Central Europe, where Norway spruce (Picea abies Karst.) was artificially introduced in the 18... more In Central Europe, where Norway spruce (Picea abies Karst.) was artificially introduced in the 1850s, the widespread cultivation of the species outside its natural range has had both positive and negative effects. The original range of Norway spruce in Europe extends, in addition to the boreal zone, to the mountain massifs of the Alps, the Hercynian, Carpathians, Rhodope and Illyrian regions. Historical information proves that spruce has been found frequently also at the lower altitudes on sites with permanent high soil moisture content and even on sites characterized by a high degree of waterlogging or on peat soils. Relict spruce stands of lower altitudes appear to be an exception. The stands are considered to be the remnants of vegetation from the Atlanticum period of postglacial forest vegetation succession, which has remained on certain sites up to the present time. On unsuitable sites, site specific pre-stress is loaded upon the tree species, so that they have only little additional resistance against other harmful abiotic and biotic agents. In the past decades, a new harmful factor has occurred-industrial air pollution. The present conditions of forests in Central Europe, as viewed under the auspices of further negative factors, particularly potential global climatic change, have led towards enhanced efforts to reconstruct forests to more stable and resilient conditions. In many instances such conditions may be achieved by a close-to-nature forest composition, i.e. forests which correspond to the potential natural forest vegetation. In consequence, an all-European discussion on the new orientation of forestry from the viewpoint of its sustainable development and the preservation of a high biodiversity has been accepted as a basic strategic objective. In order to assess the problem on an European scale, an international workshop titled "Spruce monocultures in Central Europe-Problems and Prospects" was organized by the
The name TerrHum is an abbreviation of the words Terrestrial (not hydromorphic, not submerged) an... more The name TerrHum is an abbreviation of the words Terrestrial (not hydromorphic, not submerged) and Humipedon (organic and organic-mineral humus horizons). With this application, it is possible to describe and classify terrestrial forest and grassland topsoils in a system published in Applied Soil Ecology, Special Issue 'Humusica 1-Terrestrial Natural Humipedons'. TerrHum allows the storage of the main content of Humusica 1 on a cellphone. Images, diagrams and simplified tables of classification may be recalled with a few touches on the screen. Humus forms, representing five humus systems, are classified based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing specific figures that are stored in a cloud and can be downloaded the first time the user recalls them. Once all figures have been opened in the device, the application is ready to use, without any further internet connection. The app is in continuous evolution. Core Ideas A common humus classification system improves communication among soil scientists A cellphone application can be used for global soil mapping and monitoring purposes The humus classification can be combined with different soil classification systems
The present paper should be read after the six preceding articles dealing with fundamental concep... more The present paper should be read after the six preceding articles dealing with fundamental concepts, vocabulary, principles and keys of our morpho-functional classification of humus systems and forms, the whole book being conceived as a guide for field studies. It now concerns seven questions which may arise when passing from knowledge to practice or, in other terms, from concepts to real things. In the field, humipedons can differ from reported photographs. Trees, bushes and/or herbs interfere with soil functioning and may generate different humipedons even over a relatively small surface. More generally a researcher must select a few unit plots representative of a given natural floor for defining the frame of his investigation. In this article, authors present some practical and theoretical landmarks and illustrate some solutions for studying humipedons in common natural sites, and replacing them within ecosystem dynamics.
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2008
Structure of diagnostic horizons and humus classification. The classification of the main humus f... more Structure of diagnostic horizons and humus classification. The classification of the main humus forms is generally based on the morpho-genetic characters of the A and OH diagnostic horizons. This is the case in the new European key of classification presented in Freiburg on September 2004 (Eurosoil Congress). Among the morpho-genetic characters, the soil structure covers a very important role. In this work, the structure of the diagnostic A and OH horizons has been analysed in terms of aggregation force, diameter and composition of the soil lumps (peds). In order to study the aggregation force, two disaggregating tools have been conceived and used. The diameter of the lumps has been measured by sieving the soil samples with standardised webs. Observing the samples thanks to a binocular magnifying 10X and 50X, the organic or/and mineral composition of the soil aggregates has been determined, data being investigated with ANOVA and Factorial Analysis. The article examines the argument from two points of view: crashing tools for estimating the soil structure (part 1) and the dimensions of the peds given in European key of humus forms classifica tion (part 2). The categories of soil peds diameter and composition seem to be linked to the main humus forms. For instance, aggregates having a Ø > 1 mm and well amalgamate organo-mineral composition are more present in the A horizons of the Mull forms than in which of the other forms; contrary to the OH hori zon of the Moder or Mor, the OH horizon of the Amphi forms shows an important percent of small organic lumps. Some propositions have been given in order to improve the European key of humus forms classifica tion.
It was time to take stock. We modified the humipedon classification key published in 2018 to make... more It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morpho-functional classification of humipedons (roughly the top 30–40 cm of soil: organic and organomineral surface horizons) would allow for a better understanding of the functioning of the soil ecosystem. This paper provides the founding principles of the classification of humipedon into humus systems and forms. With the recognition of a few diagnostic horizons, all humus systems can be determined. The humus forms that make up these humus systems are revealed by measuring the thicknesses of the diagnostic horizons. In the final part of the article, several figures represent the screenshots of a mobile phone or tablet application that allows for a fast recall of the diagnostic elements of the classification...
RÉSUMÉ Que savons-nous de la productivité naturelle des forêts alluviales des grands fleuves avan... more RÉSUMÉ Que savons-nous de la productivité naturelle des forêts alluviales des grands fleuves avant les travaux de régulation à la fin du 19eme siècle ? Quelle était leur importance en termes de ressources et de source d'énergie ? Ces modèles historiques (pré-aménagements) peuvent-ils être utilisé pour définir des objectifs en termes de gestion durable des forêts alluviales actuelles ? Une équipe interdisciplinaire composée de géomorphologues fluviaux, d'écologues forestiers et d'historien environnementaux a étudié la dynamique des paysages fluviaux dans la région de Vienne (Autriche) au début du 19 ème siècle (1825). L'objectif était de reconstituer la production annuelle potentielle de bois avant les travaux de chenalisation. Nos modèles de reconstitution des forêt alluviales et les sources historiques ont montré que la production naturelle de bois dans ces plaines alluviales était supérieure à celle observée dans des forêt alluviales actuelles quasi-pristine. Cepen...
Plant biomass is a major source of energy for households in eastern Africa. Unfortunately, the he... more Plant biomass is a major source of energy for households in eastern Africa. Unfortunately, the heavy reliance on this form of energy is a threat to forest ecosystems and a recipe for accelerated land resource degradation. Due to the increasing scarcity of traditional fuel wood resources, rural communities have shifted to utilisation of crop residues and cattle dung; which otherwise, are resources for soil fertility improvement. The objective of this study was to assess the supply and consumption patterns of fuel biomass and estimate the amount of nutrients that could be lost from burning non-woody biomass energy sources. A survey was conducted in the Mukehantuta watershed in Ethiopia, using a semi-structured questionnaire. An inventory of woody biomass was also carried out on the existing stock in the watershed. Annually, households in the watershed used 1999, 943, 11, 34 and 229 metric tonnes of wood, dung, charcoal, crop residue and tree residues, respectively. The existing wood b...
Floodplain forests are considered as key forest ecosystems in lowland regions of the European tem... more Floodplain forests are considered as key forest ecosystems in lowland regions of the European temperate zone. Ecosystem services of floodplain forests are essential for maintaining and sustainable management of water resources. The ecological role of floodplain forest ecosystems in the landscape is emphasized in the context of global change because of flood risk management in landscapes along lowland European river. This chapter deals with these important functions of floodplain forests. Authors of the chapter contribute a large amount of their own professional experience and also utilize a large amount from published literature in the field of monitoring, research and management practice of the water regime and its consequences for floodplain forests from an European perspective. The aim of the case study from the Czech Republic is to fill the knowledge gaps related to the monetary evaluation of floodplain forest habitats endangered by the international water management project Dan...
During an investigation on the effects of differing stand densities on biomass distribution, owin... more During an investigation on the effects of differing stand densities on biomass distribution, owing to thinning in 17-year-old Norway spruce stands, specific leaf area (SLA) and 100-needle dry mass were measured for three diameter at breast height (DBH) classes, five canopy sections, and two needle age-classes. Mean SLA was found to be 50 ± 17 cm2/g. High correlation of SLA and 100-needle dry mass with DBH, crown position, and needle age was found. Older needles had a lower mean SLA than the current years needles, while they did not differ significantly in their 100-needles dry mass. Thinning proved to be a minor factor for foliage variability, since DBH, which is dependent upon thinning and the trees competitive status, explained a major part of variation in leaf morphology. A third-degree polynomial regression function could be developed to predict SLA from 100-needle dry mass. This function shows wide validity. It applies to all DBH classes and crown sections. It also shows good f...
Spruce Monocultures in Central Europe: Problems and …, 2000
... Growth of Norway Spruce (Picea abies [L.] Karst.) under Changing Environmental Conditions in ... more ... Growth of Norway Spruce (Picea abies [L.] Karst.) under Changing Environmental Conditions in Europe 15 Finally, in a recent investigation, Untheim ... In recent decades, similar time specific growth fluctuations were observed in Switzerland, France and southwestern ...
Analysis of total S in tree foliage has become widely accepted as a means of assessing S pollutio... more Analysis of total S in tree foliage has become widely accepted as a means of assessing S pollution of forests when air quality data are lacking. An investigation of total S content of mixed needle samples of different age and canopy height from two stands of young Norway spruce with different densities showed that S-content exceeded the maximum natural S-content (i.e. in the absence of SO2-pollution) for spruce. Significantly higher average needle S contents were encountered with decreasing stand density. Changed aerodynamic roughness and physiological status &thinned trees indicated combined action of atmospheric and tree physiological variables on S deposition and uptake in forest ecosystems. A marked increase in S content from 1 yr old to older needles and from the lower to the upper canopy was observed.
The role of agroforestry systems in providing ecosystem services is very crucial. The most signif... more The role of agroforestry systems in providing ecosystem services is very crucial. The most significant increase in carbon (C) storage is often achieved by moving from lower biomass land-use systems to tree-based systems like agroforestry (AF). However, estimation of carbon stocks in indigenous agroforestry systems of South-eastern Rift- valley landscapes, Ethiopia the data are scarce. The study was aimed to investigate the biomass, biomass carbon (BC), and soil organic carbon (SOC) stock of Enset based, Enset-Coffee based, and Coffee-Fruit tree-Enset based agroforestry systems. Comparison of SOC stock of agroforestry systems against their adjacent monocropping farms was also investigated. The study was conducted in three selected sites of the Dilla Zuria district of Gedeo zone. Twenty farms (total of 60) representative of each AF system were randomly selected, inventoried and biomass C stocks estimated. Ten adjacent mono-cropping farms which were related to each AF system were selec...
In Central Europe, where Norway spruce (Picea abies Karst.) was artificially introduced in the 18... more In Central Europe, where Norway spruce (Picea abies Karst.) was artificially introduced in the 1850s, the widespread cultivation of the species outside its natural range has had both positive and negative effects. The original range of Norway spruce in Europe extends, in addition to the boreal zone, to the mountain massifs of the Alps, the Hercynian, Carpathians, Rhodope and Illyrian regions. Historical information proves that spruce has been found frequently also at the lower altitudes on sites with permanent high soil moisture content and even on sites characterized by a high degree of waterlogging or on peat soils. Relict spruce stands of lower altitudes appear to be an exception. The stands are considered to be the remnants of vegetation from the Atlanticum period of postglacial forest vegetation succession, which has remained on certain sites up to the present time. On unsuitable sites, site specific pre-stress is loaded upon the tree species, so that they have only little additional resistance against other harmful abiotic and biotic agents. In the past decades, a new harmful factor has occurred-industrial air pollution. The present conditions of forests in Central Europe, as viewed under the auspices of further negative factors, particularly potential global climatic change, have led towards enhanced efforts to reconstruct forests to more stable and resilient conditions. In many instances such conditions may be achieved by a close-to-nature forest composition, i.e. forests which correspond to the potential natural forest vegetation. In consequence, an all-European discussion on the new orientation of forestry from the viewpoint of its sustainable development and the preservation of a high biodiversity has been accepted as a basic strategic objective. In order to assess the problem on an European scale, an international workshop titled "Spruce monocultures in Central Europe-Problems and Prospects" was organized by the
The name TerrHum is an abbreviation of the words Terrestrial (not hydromorphic, not submerged) an... more The name TerrHum is an abbreviation of the words Terrestrial (not hydromorphic, not submerged) and Humipedon (organic and organic-mineral humus horizons). With this application, it is possible to describe and classify terrestrial forest and grassland topsoils in a system published in Applied Soil Ecology, Special Issue 'Humusica 1-Terrestrial Natural Humipedons'. TerrHum allows the storage of the main content of Humusica 1 on a cellphone. Images, diagrams and simplified tables of classification may be recalled with a few touches on the screen. Humus forms, representing five humus systems, are classified based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing specific figures that are stored in a cloud and can be downloaded the first time the user recalls them. Once all figures have been opened in the device, the application is ready to use, without any further internet connection. The app is in continuous evolution. Core Ideas A common humus classification system improves communication among soil scientists A cellphone application can be used for global soil mapping and monitoring purposes The humus classification can be combined with different soil classification systems
The present paper should be read after the six preceding articles dealing with fundamental concep... more The present paper should be read after the six preceding articles dealing with fundamental concepts, vocabulary, principles and keys of our morpho-functional classification of humus systems and forms, the whole book being conceived as a guide for field studies. It now concerns seven questions which may arise when passing from knowledge to practice or, in other terms, from concepts to real things. In the field, humipedons can differ from reported photographs. Trees, bushes and/or herbs interfere with soil functioning and may generate different humipedons even over a relatively small surface. More generally a researcher must select a few unit plots representative of a given natural floor for defining the frame of his investigation. In this article, authors present some practical and theoretical landmarks and illustrate some solutions for studying humipedons in common natural sites, and replacing them within ecosystem dynamics.
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2008
Structure of diagnostic horizons and humus classification. The classification of the main humus f... more Structure of diagnostic horizons and humus classification. The classification of the main humus forms is generally based on the morpho-genetic characters of the A and OH diagnostic horizons. This is the case in the new European key of classification presented in Freiburg on September 2004 (Eurosoil Congress). Among the morpho-genetic characters, the soil structure covers a very important role. In this work, the structure of the diagnostic A and OH horizons has been analysed in terms of aggregation force, diameter and composition of the soil lumps (peds). In order to study the aggregation force, two disaggregating tools have been conceived and used. The diameter of the lumps has been measured by sieving the soil samples with standardised webs. Observing the samples thanks to a binocular magnifying 10X and 50X, the organic or/and mineral composition of the soil aggregates has been determined, data being investigated with ANOVA and Factorial Analysis. The article examines the argument from two points of view: crashing tools for estimating the soil structure (part 1) and the dimensions of the peds given in European key of humus forms classifica tion (part 2). The categories of soil peds diameter and composition seem to be linked to the main humus forms. For instance, aggregates having a Ø > 1 mm and well amalgamate organo-mineral composition are more present in the A horizons of the Mull forms than in which of the other forms; contrary to the OH hori zon of the Moder or Mor, the OH horizon of the Amphi forms shows an important percent of small organic lumps. Some propositions have been given in order to improve the European key of humus forms classifica tion.
It was time to take stock. We modified the humipedon classification key published in 2018 to make... more It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morpho-functional classification of humipedons (roughly the top 30–40 cm of soil: organic and organomineral surface horizons) would allow for a better understanding of the functioning of the soil ecosystem. This paper provides the founding principles of the classification of humipedon into humus systems and forms. With the recognition of a few diagnostic horizons, all humus systems can be determined. The humus forms that make up these humus systems are revealed by measuring the thicknesses of the diagnostic horizons. In the final part of the article, several figures represent the screenshots of a mobile phone or tablet application that allows for a fast recall of the diagnostic elements of the classification...
RÉSUMÉ Que savons-nous de la productivité naturelle des forêts alluviales des grands fleuves avan... more RÉSUMÉ Que savons-nous de la productivité naturelle des forêts alluviales des grands fleuves avant les travaux de régulation à la fin du 19eme siècle ? Quelle était leur importance en termes de ressources et de source d'énergie ? Ces modèles historiques (pré-aménagements) peuvent-ils être utilisé pour définir des objectifs en termes de gestion durable des forêts alluviales actuelles ? Une équipe interdisciplinaire composée de géomorphologues fluviaux, d'écologues forestiers et d'historien environnementaux a étudié la dynamique des paysages fluviaux dans la région de Vienne (Autriche) au début du 19 ème siècle (1825). L'objectif était de reconstituer la production annuelle potentielle de bois avant les travaux de chenalisation. Nos modèles de reconstitution des forêt alluviales et les sources historiques ont montré que la production naturelle de bois dans ces plaines alluviales était supérieure à celle observée dans des forêt alluviales actuelles quasi-pristine. Cepen...
Humusica 8. The Commission Classification of the Humus Group meet in Paris, by INRA. And decided ... more Humusica 8. The Commission Classification of the Humus Group meet in Paris, by INRA. And decided to publish a first general classification, with diagnostic horizon description. Many scientific Journals refused to publish our work. HAL = Hyper Artiles en Line, a database of the French CNRS accepted to publish it. THANK YOU Frebnch CNRS! The article is still there: https://hal.archives-ouvertes.fr/hal-00541496v1
The name TerrHum is an abbreviation of the words "Terrestrial" (not hydromorphic, not submerged) ... more The name TerrHum is an abbreviation of the words "Terrestrial" (not hydromorphic, not submerged) and "Humipedon" (organic and organic-mineral humus horizons). With this application, it is possible to describe and classify terrestrial forest and grassland topsoils in a system published as a Special Issue entitled "Humusica 1-Terrestrial Natural Humipedons" in the journal Applied Soil Ecology. The iOS application TerrHum allows the storage of the main content of Humusica 1 on a cellular phone. Images, diagrams and simpli ed tables of classi cation may be recalled with a few touches on the screen. Humus forms, representing ve humus systems, are classi ed based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing speci c gures that are stored in a virtual cloud and can be downloaded the rst time the user recalls them. Once all gures have been opened in the device, the application is ready to use, without any further internet connection. The application is in continuous evolution. I n 2003, 26 soil scientists gathered in Trento, Italy to standardize methods and rules for classifying the biologically most active upper part of the soil. For doing so, it was essential to develop a common terminology and to exchange data on soil carbon dynamics and its relation to morphological characteristics of
In Europe an abundance of humus taxonomies exists starting with early approaches in the late 19 t... more In Europe an abundance of humus taxonomies exists starting with early approaches in the late 19 th century. Frequently used in an international context, they do not cover all site conditions in the European area. Although having basic concepts and general lines, the European (and North American, Canadian) classification systems differ in important parameters used for the description and classification of humus forms. These discrepancies result in incongruities, so require adjustments when exchanging partially compatible soil data, even between nearby countries. In 2003, 26 European specialists in humus forms met in Trento (Italy) and decided to formulate rules of classification based on morphogenetic descriptions and diagnostic horizons, adapted to European ecological conditions. Taking into account old and new European and North American systems of humus forms classification, six main references (Anmoor, Mull, Moder, Mor, Amphi and Tangel) were defined, each of them further dividing into detailed categories. This inventory assigned a strong discriminatory power to the action of the pedofauna. Both semiterrestrial (anoxic) and terrestrial (aerated) topsoils were classified. The descriptors of the diagnostic horizons were conceived in accordance with the spirit of recent international soil classifications. Assigning an "ecological value" to each main humus form along a gradient dividing those characterized by accumulation of poorly transformed organic matter, from very biologically active forms degrading and incorporating all organic remains, this European system of classification avoids a hierarchical structure and allows an elastic approach open to additional ecological contributions and renditions.
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Papers by Herbert Hager
Many scientific Journals refused to publish our work.
HAL = Hyper Artiles en Line, a database of the French CNRS accepted to publish it. THANK YOU Frebnch CNRS! The article is still there: https://hal.archives-ouvertes.fr/hal-00541496v1