European Forest Types: definitions, criteria and structure of forest classification. Marco Marchetti

Transcription

1 Workshop on Pan European understanding of forest classification November, Bled,, Slovenia European Forest Types: definitions, criteria and structure of forest classification Marco Marchetti Italian Academy of Forest Sciences, IUFRO & University of Molise UNECE FAO

2 General context

3 Political framework IMPROVED PAN-EUROPEAN INDICATORS FOR SUSTAINABLE FOREST MANAGEMENT to evaluate and report on progress towards implementing SFM in the pan-european region

4 Data provision to MCPFE for the elaboration of periodical reports IMPROVED PAN-EUROPEAN INDICATORS FOR SUSTAINABLE FOREST MANAGEMENT MCPFE indicators reporting format FOREST TYPE SPECIFICATION Data processing to meet MCPFE reporting obligations Data acquisition (NFIs, management plans, etc.)

5 C 1: Maintenance and Appropriate Enhancement of Forest Resources and their Contribution to Global Carbon Cycles C 2: Maintenance of Forest Ecosystem Health and Vitality C 4: Maintenance, Conservation and Appropriate Enhancement of Biological Diversity in Forest Ecosystems 1.1 Forest area 1.2 Growing stock 1.3 Age structure and/or diameter distribution 2.4 Forest damage 4.1 Tree species composition 4.3 Naturalness 4.5 Deadwood Area of forest and other wooded land, classified by forest type and by availability for wood supply, and share of forest and other wooded land in total land area Growing stock on forest and other wooded land, classified by forest type and by availability for wood supply Age structure and/or diameter distribution of forest and other wooded land, classified by forest type and by availability for wood supply Forest and other wooded land with damage, classified by primary damaging agent (abiotic, biotic and human induced) and by forest type Area of forest and other wooded land, classified by number of tree species occurring and by forest type Area of forest and other wooded land, classified by undisturbed by man, by semi-natural or by plantations, each by forest type Volume of standing deadwood and of lying deadwood on forest and other wooded land classified by forest type

6 Although forest types are not yet formally defined by the MCPFE,, they are considered as a key tool for improving the assessment and monitoring of forest biological diversity in Europe Cf. Vienna Resolution 4 (MCPFE, 2005): ( )) need of improving existing international forest classification, through developing a pan-european understanding on forest classification systems including forest types, naturalness and introduced forest species, in line with the Pan-European Criteria and Indicators for Sustainable Forest Management

7 Limitation of present forest types some considerations

8 Today, the forest types adopted for MCPFE reporting are 3 broad classes broadleaved forest, coniferous forest, mixed broadleaved and coniferous forest a very feasible solution to standardize forest information on a global and Pan-European level, but poorly informative

9 European forest area =1004 = million ha Present forest types make flat the variability in natural conditions and anthropogenic influences affecting MCPFE indicators limiting data quality

10 Forest area (indicator( 1.1) In 2003 MCPFE report, figures on recent changes in forest area are reported for ten countries of northern and central Europe by coniferous, broadleaved and mixed forest types relative changes in total forest area range from 0.1 to 5.6% depending on countries relative changes by forest types show a larger range of variation: coniferous forest area from +2,6 to +59,3% broadleaved forest area from -2,2 to +28,3% mixed forest area from -54,7 to +180%

11 Forest area (indicator( 1.1) tricky data interpretation: is this a good sign for SFM? What is the origin of forest expansion? Natural colonisation of abandoned farmland? Afforestation of former agricultural land (forest plantations, sensu MCPFE indicator 4.3)? Both?

12 Apparently encouraging figures becomes deceptive without any reference to the origin of the phenomenon the increase of forest plantations,, though it would make a significant contribution to wood supply in some countries, may produce negative impacts on local biodiversity especially when introduced,, species are used Forest area (indicator( 1.1)

13 Tree species composition (indicator 4.1) The indicator is used as a proxy variable for the species diversity of the forest community Key factors affecting variation in tree species composition are: natural factors (climate, edaphic and hydrological site conditions, stage of stand development) present and past human activity (forestry intensity, agro-forestry, grazing)

14 Tree species composition (indicator 4.1) In high latitudes, altitudes, or under certain ecological limiting conditions (peatland,, poor soils) single-species, species, mainly coniferous,, forests naturally dominate

15 Tree species composition (indicator 4.1) mixed forest is naturally more frequent in central and southern Europe, in broadleaved deciduous and in mixed evergreen forest zones edaphic variation,, from poor to rich soils, and hydrological site conditions from wet to dry soils are further key factors of variation in species composition

16 Interpretation of figures The presence of species mixtures alone does not means, in itself, higher forest naturalness the indicator tree species composition should be used not to assess if the number of tree species is good, bad, adequate rather, to evaluate the progress made by forest management in favouring the establishment of tree species mixtures, given certain ecological conditions and intensity of management regimes

17 Why do we need more specific forest types? Justification

18 To do justice to the state of forests and sustainable forest management in Europe to better reflect this variety the variety the in MCPFE European reporting forests should be requires taken forest into account types more soundly ecologically framed than this the variety, three is broad reflected species by groups the values taken adopted by MCPFE so far indicators in different localities (i.e. under different natural and anthropogenic determinants)

19 Proposal for future MCPFE reporting European Forest Types = 14 classes of European forests growing under relatively homogeneous ecological conditions (climatic, edaphic) ) and levels of anthropogenic modification Increased quality of information provided to policy makers and to the large public

20 Definitions and criteria behind the proposed forest classification

21 DEFINITION Forest types = A A category of forest defined by its composition, and/or site factors (locality), as categorized by each country in a system suitable to its situation (The Montreal Process, 1998) Forest types are a flexible approach to collect and organise forest information in a given region, according to a typology useful for understanding differences which are relevant to a specific application

22 DELINEATION CRITERIA To delineate forest types suitable for MCPFE reporting the primary determinants of variation in MCPFE indicators on a Pan-European scale have been identified ( (key-factors, sensu Larsson et al., 2001)

23 changes of the existing/spontaneous vegetation of a site to an artificial stock of trees (afforestation or reforestation forest plantation) or to self-sown stands of exotic species changes of ecological forest zones influencing the natural tree-species composition, the length of the growing season (i.e. growing stock), decomposition rate and natural disturbance regimes (i.e deadwood type and amount) variation in management systems (silviculture, agroforestry) is considered as further anthropogenic factor affecting forest structure and composition Primary determinants

24 Structure of the forest classification

25 Classification scheme 14 Top level classes for the MCPFE reporting (CATEGORIES) low level classes (TYPES) to describe and document the variety of forest communities that each category comprises Types are intended to stratify national forest data, the 14 categories to report on MCPFE indicators

26 Higher naturalness Lowest naturalness 1. Boreal forest 2. Hemiboreal and nemoral coniferous and mixed broadleaved-coniferous forest 3. Alpine coniferous forest 4. Acidophilous oak and oak-birch forest 5. Mesophytic deciduous forest 6. Beech forest 7. Montane beech forest 8. Thermophilous deciduous forest 9. Broadleaved evergreen forest 10. Coniferous forests of the Mediterranean, Anatolian and Macaronesian regions 11. Mire and swamp forest 12. Floodplain forest 13. Non-riverine alder, birch or aspen forest 14. Plantations and self-sown exotic forest 14 Categories 13 classes of forest of dominated by native tree species Important breaking point of naturalness

27 Categories are defined by a unique interplay of forest ecological conditions and anthropogenic influences that drive the MCPFE indicators variation along a characteristic pattern; ; a pattern that distinguish each category from the others

28 Meaning of category 14 Cat 14 = plantation forests (as defined in MCPFE) + self-sown sown stands of exotic species The low level of naturalness of the class is related to: - simplification of forest structure,, because plantations forest basically consist of even-aged, often monospecific stands, established with regularly spaced trees - relevant modification of site genetic variety of the locality,, as the genetic variability of the plantation is usually lower and different from m that of spontaneous vegetation - relevant modification in site species composition,, when the native vegetation is replaced by forest stands predominantly consisting of non- native (or non-indigenous, exotic, introduced) trees,, e.g. Robinia, Eucalyptus, Picea sitchensis, Pinus contorta, Pseudotsuga menziesii

29 Categories & Boreal forest 2. Hemiboreal and nemoral coniferous and mixed broadleaved-coniferous forest 3. Alpine coniferous forest 4. Acidophilous oak and oak-birch forest 5. Mesophytic deciduous forest 6. Beech forest 7. Montane beech forest 8. Thermophilous deciduous forest 9. Broadleaved evergreen forest 10. Coniferous forests of the Mediterranean, Anatolian and Macaronesian regions 11. Mire and swamp forest 12. Floodplain forest 13. Non-riverine alder, birch or aspen forest Cat & 13 = groups of ecologically distinct forests communities dominated by specific assemblages of native tree species Their physiognomy is mainly determined by the latitudinal/altitudinal zonation of European vegetation and by inner climatic and edaphic variation therein

30 Categories and vegetation zones: influence on MCPFE indicators Vegetation zones have a significant influence on forest productivity (e.g. different length of the growing season); accordingly, a natural gradient in the average stem volume is found along latitude (MCPFE, 2003) More in general, climatic and edaphic variability can be regarded as the natural driver of the pattern of the MCPFE indicators: number of forest occurring species, growing stock, deadwood amount

31 temperature and length of the growing season are the main climatic variables which determine forest productivity the harsh climatic conditions affect forest composition, dominated by two conifers species (PiceaPicea abies, Pinus sylvestris) ) in mature stages of forest succession deciduous trees including birches (Betula spp.), aspen ( (Populus tremula), rowan ( (Sorbus aucuparia) ) and willows ( (Salix spp.) tend to occur as early colonisers of bare ground or in the early stages of forest succession under natural conditions, forest fires repeated with cyclical frequency regulate the dynamic of boreal coniferous forest most of the boreal forest is managed as even-aged forest for commercial forestry 1. Boreal forest

32 2. Hemiboreal and nemoral coniferous and mixed broadleaved-coniferous forest It includes the latitudinal mixed forests located in between the boreal and nemoral forest zones (hemiboreal( forest) and anthropogenic coniferous forest in the nemoral zone the light regime and length of the growing season are the main climatic variables controlling forest productivity the hemiboreal forest is featured by the coexistence of boreal coniferous species with temperate broadleaved tree species (QuercusQuercus robur, Fraxinus excelsior, Ulmus glabra, Tilia cordata) the structure and composition of the category forests is affected by a complex interplay of natural and anthropogenic influences

33 Nemoral coniferous forest: origin Natural features: e.g. significant ingrowth of self- sown trees, mixed tree canopy composition, uneven aged diameter distribution; often managed as conversion forest 2: Nemoral Scots pine forest coniferous forest is very widespread in the nemoral zone (scots pine, spruce, black pine) this «replacement forest» mainly originate from the large reforestation projects initiated in the 18th and 19th in the stands no longer intensively managed for timber and/or of old age and low intensity of forestry somewhat natural features develop typical plantation-like like structure intensively managed 14: Plantation forest of Scots pine

34 Cold and harsh climate (short growing seasons) characterizes the high altitudes of the Alpine region of Europe, making it similar to the boreal zone, except for the light regime and length of the day this determines similar altitudinal vegetation belts,, though at differing altitudes, on all alpine mountain ranges forest tree species composition vary with the vegetation belts (montane/subalpine)) and site ecological conditions. In addition to boreal conifers, Larix decidua Pinus cembra, P. nigra and P. mugo are the naturally dominant species variation in regeneration patterns and horizontal clustering is also related to vegetation belts the management of even-aged stands predominates; selection cutting management is practised only in small areas of productive forest characterized by mixed forest spruce, fir and beech composition 3. Alpine coniferous forest

35 Broadleaved deciduous forest and mixed coniferousbroadleaved forest Cat occur in the nemoral (or temperate) zone and supramediterranean vegetation belt (approx. 40 N to 60 N) Radiation, light and temperature regimes, oceanic influences (in the west) and continental influences (in the east) determine growing conditions the temperate climate increases the competitive ability of broadleaved deciduous trees over conifers the difference between annual precipitation and potential evaporation is an important factor controlling tree growth yields are therefore higher in the western part of the zone,, under oceanic influence, than in the south-eastern part where potential evaporation exceeds precipitation soil parent material are varied and richer than in the boreal zone; the variability in edaphic conditions and water regimes affect tree species composition and forest growth 4. Acidophilous oak and oak-birch forest 5. Mesophytic deciduous forest 6. Beech forest 7. Montane beech forest 8. Thermophilous deciduous forest

36 4. Acidophilous oak and oak-birch forest Related to oligotrophic soils of the nemoral forest zone the tree species composition is poor (1-2 2 species) and characterized by acidophilous oaks (Q. robur, Q. petraea) ) and birch (Betula pendula) oakwoods stocking on poor, acid soils have been managed for a long time for coppice and grazing many coppice forests were converted to high forests during the past decades or otherwise abandoned or converted to conifer forest plantations

37 5. Mesophytic deciduous forest Related to meso- and eutrophic soils of the nemoral zone canopy composition is often mixed,, and characterized by mixtures of Carpinus betulus, Quercus petraea, Quercus robur, Fraxinus, Acer and Tilia cordata due to the association with fertile soils, most of the original mesophytic deciduous forest area has been cleared and soils converted to very productive agricultural land the management of even-aged stands predominates

38 Very wide geographic distribution in lowland to submontane Europe 6. Beech forest it is characterized by the dominance of European beech Fagus sylvatica or of Fagus orientalis in the eastern and southern parts of the Balkan Peninsula; locally important additional trees,, are Betula pendula and mesophytic deciduous species the large distribution is due to the wide climatic and edaphic amplitude of beech and to its competitive strength most of beech forests are managed as even-aged forest, although traditional management practices (like wood pastures, coppice with standards) are still in place in especially in rural areas

39 Related to the montane altitudinal belt of the main European mountain ranges 7. Montane beech forest in the montane vegetation belt coniferous species (spruce, fir) are competitive as beech montane beech forest is thus characterized by the presence of conifers as important forest building trees; ; as for category 6, locally important additional tree species include Betula pendula and mesophytic deciduous species. traditionally montane beech forest have been intensively managed for fuelwood purposes,, in mining areas and in some mountain areas of Apennines and Alps; beech was coppiced for firewood and charcoal; Most of these stands were turned to high forest in the 20th century

40 Related to the supra-mediterranean vegetation belt the mild climatic conditions of the supra- Mediterranean level determine the predominance of mixed deciduous and semi- deciduous forest of thermophilous species, mainly of Quercus; Acer, Ostrya, Fraxinus, Carpinus species are frequent as associated secondary trees anthropogenic exploitation has modified the natural mixed composition of these forests, leading in most cases to the elimination of natural species without a commercial interest or with poor resprouting capacity or, conversely, the introduction of forest species that would not occur naturally (e.g. chestnut) simplified forest structures shaped by traditional silvicultural systems predominate (coppice, coppice with standards, mixed coppice/high forest) of purely cultural origin are also the chestnut- groves, today largely replaced by coppice- woods or left unmanaged high forest-like structures developing from the abandonment of forest cultivation are relatively frequent in the category 8. Thermophilous deciduous forest

41 Related to the thermo- and meso- Mediterranean vegetation belt and to the warm-temperate humid zones of Macaronesia these climates determine a forest physiognomy characterized by the dominance of broadleaved sclerophyllous or lauriphyllous evergreen trees water availability varies considerably between the Macaronesia and thermo- and meso-mediterranean vegetation belts and it is the main climatic factor limiting tree-growth in the Mediterranean, the structure of broadleaved evergreen forest has been profoundly shaped by traditional agro- forestry (dehesas, montados) ) and coppice cultivation systems forest degradation is a very common phenomenon,, due to a complex historical interplay of harsh environmental conditions (drought, aridity, soils prone to erosion) and anthropogenic influences (fire, grazing, intensive forest exploitation) 9. Broadleaved evergreen forest

42 10. Coniferous forests of the Mediterranean, Anatolian and Macaronesian regions It includes a large group of coniferous forests, mainly xerophytic forest communities,, distributed throughout Europe from coastal regions to high mountain ranges forest physiognomy is mainly dominated by species of Pinus, Abies and Juniper, that are variously distributed according to altitudinal vegetation belts due to the relation with dry and, often, with poor or poorly developed soils tree growth is limited although some pine forests under this category are adapted to fire (e.g. P. halepensis, P. canariensis), in the Mediterranean region repeated forest fires (anthropogenic origin) seriously threaten these coniferous forests, by triggering forest degradation from a structural viewpoint, even-aged forest characterize the category

43 Waterlogged peaty soils determine these wetland forests mainly distributed in the boreal zone changes in forest physiognomy are due to the micro-topographic variability of wetland areas and associated variations in edaphic conditions and water regimes 11. Mire and swamp forest Picea abies and Pinus sylvestris build up mire forests; ; species of Alnus, Betula, Quercus and Populus dominate the deciduous swamp forest due to its poor economic value, most of the potential area of swamp forest has been drained and converted to agricultural land or productive coniferous forest plantations present management is targeted to the protection and restoration of these wetland forests

44 The riparian or alluvial hydrological regime (high water table subject to occasional flooding) determine the appearance of forests under this category, distributed along the main European river channels 12. Floodplain forest floodplain forest are species-rich often multi-layered layered communities characterized by different assemblages of species of Alnus, Betula, Populus, Salix, Fraxinus, Ulmus in the Mediterranean and Macaronesian regions local species are also found (e.g. Fraxinus angustifolia, Nerium oleander, Platanus orientalis, Tamarix) forest composition and structure largely depends on the frequency of flooding anthropogenic activities (river damming and canalisation, drainage of riparian areas to provide agricultural land) have brought significant changes in the area of floodplain forest during the last century the conservation and restoration of these riparian forests is the main focus of forest management today

45 13. Non riverine alder, birch, or aspen forest Includes a number of non- riparian, non-marshy often pioneer forest formations dominated by Alnus, Betula or Populus these communities are related to specific ecological conditions (mountain birch formations) or occur as pioneer stages of the forest succession in the boreal zone Betula and Populus build up also secondary forest in large clear cut areas

46 The type level It is mainly intended to describe and further document the variety and the character of forest communities that each category comprises Types correspond to a finer level of division of the category in term of tree species composition; ; in some cases, structural or floristic features vary also significantly amongst forest types the number of types that each category contains reflects the North th- South (Boreal to Mediterranean/Anatolian/Macaronesian Macaronesian) ) and West-East (Atlantic to Continental) gradient in the floristic differentiation ion of European forests communities 14 first level classes (CATEGORIES) second level classes (TYPES)

47 Categories 1. Boreal forest 2. Hemiboreal forest and nemoral coniferous and mixed broadleaved-coniferous forest 3. Alpine coniferous forest 4. Acidophilous oak and oak-birch forest 5. Mesophytic deciduous forest 6. Beech forest 7. Montane beech forest Types 1.1 Spruce and spruce-birch boreal forest 1.2 Pine and pine-birch boreal forest 2.1 Hemiboreal forest 2.2 Nemoral Scots pine forest 2.3 Nemoral Black pine forest 2.4 Mixed Scots pine-birch forest 2.5 Mixed Scots pine-pedunculate oak forest 3.1 Subalpine larch-arolla pine and dwarf pine forest 3.2 Subalpine and montane spruce and montane mixed spruce-silver fir forest 3.3 Alpine Scots pine and Black pine forest 4.1 Acidophilous oakwood 4.2 Oak-birch forest 5.1 Pedunculate oak hornbeam forest 5.2 Sessile oak hornbeam forest 5.3 Ashwood and oak-ash forest 5.4 Maple-oak forest 5.5 Lime-oak forest 5.6 Maple-lime forest 5.7 Lime forest 5.8 Ravine and slope forest 5.9 Other mesophytic deciduous forests 6.1 Lowland beech forest of S-Scandinavia and north central Europe 6.2 Atlantic and subatlantic lowland beech forest 6.3 Subatlantic submontane beech forest 6.4 Central European submontane beech forest 6.5 Carpathian submontane beech forest 6.6 Illyrian submontane beech forest 6.7 Moesian submontane beech forest 7.1 SW-European montane beech forest (Cantabrians Pyrenees Central Massif SW-Alps) 7.2 Central European montane beech forest 7.3 Apennine-Corsican montane beech forest 7.4 Illyrian montane beech forest 7.5 Carpathian montane beech forest 7.6 Moesian montane beech forest 7.7 Crimean montane beech forest 7.8 Oriental beech and hornbeam-oriental beech forest

48 8. Thermophilous deciduous forest 9. Broadleaved evergreen forest 10. Coniferous forests of the Mediterranean, Anatolian and Macaronesian regions 11. Mire and swamp forest 12. Floodplain forest 13. Non riverine alder, birch, or aspen forest 14. Plantations and self sown exotic forest 8.1 Downy oak forest 8.2 Turkey oak, Hungarian oak and Sessile oak forest 8.3 Pyrenean oak forest 8.4 Portuguese oak and Mirbeck s oak Iberian forest 8.5 Macedonian oak forest 8.6 Valonia oak forest 8.7 Chestnut forest 8.8 Other thermophilous deciduous forests 9.1 Mediterranean evergreen oak forest 9.2 Olive-carob forest 9.3 Palm groves 9.4 Macaronesian laurisilva 9.5 Other sclerophlyllous forests 10.1 Mediterranean pine forest 10.2 Mediterranean and Anatolian Black pine forest 10.3 Canarian pine forest 10.4 Mediterranean and Anatolian Scots pine forest 10.5 Alti-Mediterranean pine forest 10.6 Mediterranean and Anatolian fir forest 10.7 Juniper forest 10.8 Cypress forest 10.9 Cedar forest Tetraclinis articulata stands Mediterranean yew stands 11.1 Conifer dominated or mixed mire forest 11.2 Alder swamp forest 11.3 Birch swamp forest 11.4 Pedunculate oak swamp forest 11.5 Aspen swamp forest 12.1 Riparian forest 12.2 Fluvial forest 12.3 Mediterranean and Macaronesian riparian forest 13.1 Alder forest 13.2 Italian alder forest 13.3 Boreal birch forest 13.4 Southern boreal birch forest 13.5 Aspen forest 15.1 Plantations of site-native species 15.2 Plantations of not-site-native species and self-sown exotic forest

49 MCPFE REPORTING more ecologically sound and better informed decisionmaking at pan-european level most compilation of national data on MCPFE indicators uses National Forest Inventories (NFIs( NFIs) ground plot data we recommend the use of types for stratifying NFIs plots and of the fourteen categories for reporting data on MCPFE indicators 14 first level classes (CATEGORIES) second level classes (TYPES) CLASSIFICATION KEY+NOMENCLATURE NFIs ground plots data

50 Classification keys The European Forest Types are provided with a classification key allowing a systematic cross-link (poststratification) of national forest data (e.g. NFIs, forest statistics) to categories and types, based on: simple ecological information (biogeographic region, water regime, site edaphic condition) forest dominant tree species (as resulting from NFIs plots dbh data)

51 Dominant species is defined as the broadleaved deciduous species accounting for >50% of the basal area of the (NFIs( NFIs) ) plot

52

53 Nomenclature The European Forest Types are provided with a nomenclature, a descriptive frame allowing the characterisation of categories and types (forest composition and structure) with the help of classification keys: class definition geographical distribution types descriptions Types are also referenced to: Eunis III level classes EU Habitats Directive Annex I (92/43/EEC)

54 to enable comparison of forests growing in similar ecological conditions and levels of anthropogenic modification,, independent of national borders to provide an harmonized classification for pan- European-level monitoring of forest condition by offering ecologically meaningful units to reference and report national data on indicators 14 first level classes (CATEGORIES) second level classes (TYPES) Final remarks

55 Final remarks The EEA Technical Report on European Forest Types is expected to feed the MCPFE seminar forest types with some useful points of discussions: : e.g. forest types potential in reporting on SFM e.g. improved understanding of the differences in structural, compositional and functional determinants of forest condition across Europe improved MCPFE assessment thanks to a harmonized approach for European-level reporting Cost (increased reporting burden) vs benefits of the newly proposed forest types

56 Final remarks A pan-european perspective should be adopted, as far as possible,, in the discussion of the scheme: the question is not to agree on a classification fully reflecting the variety of forest condition at country level (44 countries!) but at the pan-european one! Is the newly proposed scheme a reasonable compromise?