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This report provides an overview of the forest vegetation and the status of its conservation in Romania. Due to a large range of climates and soils, and a long-lasting postglacial vegetation history, the Romanian forests are highly diverse and species-rich ecosystems. Approximately 150 natural types of forest ecosystems have been described. Seven zonal forest formations were distinguished: (1) forest steppes and dry oak forests; (2) forests with Oriental hornbeam (Carpinus orientalis); (3) forests with oaks (Quercus spp.) and hornbeam (Carpinus betulus); (4) beech forests: Fagus sylvatica and Fagus sylvatica mixed forests; (5) beech-fir (Abies alba)-spruce (Picea abies) mixed mountain forests; (6) spruce forests; (7) subalpine shrubland with dwarf pine (Pinus mugo subsp. mugo). On extreme sites, azonal forests occur, dominated by (8) black pine (Pinus nigra subsp. banatica); (9) Scots pine (Pinus sylvestris); (10) Carpathian larch (Larix decidua subsp. carpatica) and stone pine (Pinus cembra); (11) valuable broadleaf species, including maple (Acer spp.), ash (Fraxinus spp.), elm (Ulmus spp.), linden (Tilia spec). Along water courses with periodical inundations, riparian forests and shrub- lands occur, dominated by (12) black alder (Alnus glutinosa); (13) grey alder (A. incana); (14) tamarisk (Myricaria germanica) pioneer copse; (15) pioneer forest with poplar (Populus spp.) and willow (Salix spp.); (16) riparian hardwood forest with oak, elm (Ulmus spp.), ash (Fraxinus spp.). In the EU countries virgin (primeval) and old growth forests account for less than 3% of the total forest area. Most alarming is the situation of temperate virgin and old-growth forest. About 80% of them are situated in the Carpathians, mainly formed by beech, fir, and spruce. Estimations of virgin and quasi-virgin, old-growth forests in Romania range between 150,000 and 200,000 ha. Between 2001 and 2019 about 350,000 ha disappeared through illegal and legal logging. Legislation in Romania demands that production forests have to be managed sustainably, and virgin forests have to be protected. Romanian forests are also subject to European law, such as the Habitats and Birds Directives. However, there is a severe lack of enforcement at all administration levels, even in National Parks. Sanctioning activities by the EU authorities are hardly visible. It follows: (1) It must be in the interest of all of Europe to preserve and protect the last large areas of primeval forest in Europe. (2) The community of EU countries, the Parliament and the European Commission must provide clear guidelines and care for their implementation, connected with attractive, secure and long-term funding programs (compensation for non-use). (3) At a regional level, new creative ideas and concrete initiatives must integrate wilderness areas into regional value creation concepts.

Poor drought tolerance of European beech trees raised concerns in Europe. We hypothesized that beech could show an opposite physiological response to the same level of climatic drought with change in edaphic drought. We performed a combined analysis of δ13C and δ18O in tree rings to reveal retrospective temporal physiological responses of trees to drought. The edaphic drought was assessed by quantifying the capacity of soil to store water in plots (classified as “dry” and “less-dry”) near the drought limit of the species in three near-natural oak-beech ecotones in Germany and Switzerland. Neighbourhood competition was quantified. A climatic drought index was calculated from meteorological records and related to the δ13C and δ18O values of the trees. Trees from dry plots showed a higher response to drought and climatic dependency than less-dry plots. Neighbourhood competetion increased δ18O values significantly. Dual isotope analysis shows a tendency of greater stomatal resistance in dry plots and higher stomatal conductance in less-dry plots. We conclude that beech trees belonging to the same population under changing soil water availability can show different physiological responses under climatic drought stress. Our finding indicates the high plasticity of the beech trees to survive drought stress with changing site conditions.

Poor drought tolerance of European beech trees raised concerns in Europe. We hypothesized that beech could show an opposite physiological response to the same level of climatic drought with change in edaphic drought. We performed a combined analysis of δ$^{13}$C and δ$^{18}$O in tree rings to reveal retrospective temporal physiological responses of trees to drought. The edaphic drought was assessed by quantifying the capacity of soil to store water in plots (classified as “dry” and “less-dry”) near the drought limit of the species in three near-natural oak-beech ecotones in Germany and Switzerland. Neighbourhood competition was quantified. A climatic drought index was calculated from meteorological records and related to the δ$^{13}$C and δ$^{18}$O values of the trees. Trees from dry plots showed a higher response to drought and climatic dependency than less-dry plots. Neighbourhood competetion increased δ$^{18}$O values significantly. Dual isotope analysis shows a tendency of greater stomatal resistance in dry plots and higher stomatal conductance in less-dry plots. We conclude that beech trees belonging to the same population under changing soil water availability can show different physiological responses under climatic drought stress. Our finding indicates the high plasticity of the beech trees to survive drought stress with changing site conditions.

Natural disturbances are largely suppressed in Central European landscapes due to economic and human safety concerns. European goals to increase the extent of secondary wilderness areas have the potential to support the restoration of threatened habitats associated with natural disturbances. Germany is among the Central European countries with the most advanced wilderness goals. This study aimed to investigate whether habitat types shaped by natural disturbances are mostly red-listed as threatened and require special consideration within systematic conservation planning (SCP). First, we reviewed literature and the German Red List of Threatened Habitat Types to identify the conservation status of habitat types associated with three natural abiotic disturbance types in Germany: floods, forest fires and landslides. Second, we mapped the potential area coverage of these disturbance types and identified gaps in the current network of strictly protected areas (PA) to inform SCP. Fifty-two per cent of the habitat types associated with the three disturbance types floods, forest fires and landslides were listed as & ldquo;critically endangered & rdquo; (n = 1) or & ldquo;endangered to critically endangered & rdquo; (n = 9). The potential area for river dynamics accounted for 4.3% of German terrestrial territory, areas potentially subject to forest fires accounted for 0.9% and areas with a very high susceptibility to landslides for 1.1%. Areas potentially subject to forest fires (0.15% strict PA coverage) and river dynamics (0.81%) were underrepresented in German National Parks and the core zones of Biosphere Reserve, whereas strict PA coverage of areas with a very high susceptibility to landslides was higher (6.8%). European and German wilderness goals can support the restoration of threatened habitat types associated with natural disturbances if spatial information on those areas is integrated into SCP concepts. Yet, sophisticated management regimes will be required to resolve conflicts between wilderness areas subject to natural disturbances and the surrounding cultural landscape and infrastructure.(c) 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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Retention forestry, which retains a portion of the original stand at the time of harvesting to maintain continuity of structural and compositional diversity, has been originally developed to mitigate the impacts of clear‐cutting. Retention of habitat trees and deadwood has since become common practice also in continuous‐cover forests of Central Europe. While the use of retention in these forests is plausible, the evidence base for its application is lacking, trade‐offs have not been quantified, it is not clear what support it receives from forest owners and other stakeholders and how it is best integrated into forest management practices. The Research Training Group ConFoBi (Conservation of Forest Biodiversity in Multiple‐use Landscapes of Central Europe) focusses on the effectiveness of retention forestry, combining ecological studies on forest biodiversity with social and economic studies of biodiversity conservation across multiple spatial scales. The aim of ConFoBi is to assess whether and how structural retention measures are appropriate for the conservation of forest biodiversity in uneven‐aged and selectively harvested continuous‐cover forests of temperate Europe. The study design is based on a pool of 135 plots (1 ha) distributed along gradients of forest connectivity and structure. The main objectives are (a) to investigate the effects of structural elements and landscape context on multiple taxa, including different trophic and functional groups, to evaluate the effectiveness of retention practices for biodiversity conservation; (b) to analyze how forest biodiversity conservation is perceived and practiced, and what costs and benefits it creates; and (c) to identify how biodiversity conservation can be effectively integrated in multi‐functional forest management. ConFoBi will quantify retention levels required across the landscape, as well as the socio‐economic prerequisites for their implementation by forest owners and managers. ConFoBi's research results will provide an evidence base for integrating biodiversity conservation into forest management in temperate forests., This paper describes the background, research questions and design of the Research Training Group “ConFoBi” (Conservation of Forest Biodiversity in Multiple‐use Landscapes of Central Europe). ConFoBi focusses on the effectiveness of retention forestry, that is, retaining structural elements of old forests within a production forest matrix, and combines ecological studies on forest biodiversity with social and economic studies of biodiversity conservation across multiple spatial scales. The aim of ConFoBi is to assess whether and how structural retention measures are appropriate for the conservation of forest biodiversity in multiple‐use landscapes of temperate Europe.

The current state of forests as well as tree species composition in stands is the result of past de-velopment and somehow a record of all previous influences. As a base for better projections of future forest development and the development of sustainable management strategies we should recognize developmental processes in forests and understand their drivers. Mixed mountain forests in Montenegro, with an exceptionally large variation of environmental conditions, provide an excel-lent opportunity to study eastern-Mediterranean mixed mountain forests near their southern distribu-tion limit. The goals of this study were 1) to floristically characterize mountain forests in an Eastern Mediterranean region and 2) to assess their physical site properties as determinants of forest types. Research was based on data collected from 158 sampling plots in the territory of the mountain Bjela-sica, north-east Montenegro. The influence of topographic, climatic and edaphic site characteristics on the differentiation of vegetation and formation of forest types was assessed using numerical ordination and classification. Three types of mountain forests were separated based on their floristic composition, which can be easily characterized by the composition of their tree layer: 1) Mixed forests with spruce, silver fir and beech, 2) monodominant beech forests resulting from over-exploitation of type 1, and 3) heliophytic mixed forests with pioneer species (pine, aspen and birch) and European hop-hornbeam. The types are discussed regarding their physical site characteristics and put in a European context. Mountain forests of Montenegro are quite similar to forests in other regions of Europe and can be arranged into the existing “Classification of European beech forests” (WILLNER et al. 2017) and according to WILLNER & GRABHERR (2007).

Im montanen Gipfelbereich des Hartmannswillerkopfes in den Vogesen wurde durch Kriegsereignisse und Feuer vor 60 bzw. 80 Jahren die gesamte Waldvegetation zerstört. Die sich einstellende Sukzession konnte über mehrere Jahrzehnte - bis heute - fast ungestört ablaufen. Aufgrund standörtlicher Unterschiede haben sich mehrere Vorwaldgesellschaften herausgebildet. Auf reichen, gut mit Wasser versorgten Bräunerden löste ein Bergahorn-Eschen-Spitzahorn-Wald (Fraxino-Aceretum typicum) den vorangegangenen salweiden-reichen Vorwald ab. Auf mittleren und ärmeren Standorten hielt sich die Salweide bis heute als die wichtigste Baumart, vergesellschaftet mit Edellaubhölzern (mittlere Standorte) bzw. Hasel (ärmere Standorte). Die Sukzessionsstadien azonaler Standorte sind heute als eschenreicher Quellwald (Carici remotae-Fraxinetum bzw. Stellario-Alnetum), als Bergahorn-Eschen-Schluchtwald mit Silberblatt (Fraxino-Aceretum lunarietosum; schattige Blockhänge), als Haselgebüsch (sonnige Blockhänge), und als Traubeneichen-Wald (Betulo-Quercetum petraeae; sonnige Felshänge) anzusprechen. Die Bedeutung der Vorwälder im Hinblick auf Waldbau, Vegetationskunde und Naturschutz wird diskutiert. 60 to 80 years ago, the forest vegetation of the montane belt near the summit of the "Hartmannswillerkopf" (Vosges mountains, Alsace, France) was completely destroyed during and after the First World War. Until today, the ongoing succession has not been disturbed by man. Because of site differences, several pioneer forest types could establish. On nutrient-rich, moist sites, a goat willow (Salix caprea) forest was succeeded by a maple (Acer pseudoplatanus, A. platanoides) ash (Fraxinus excelsior) forest. On "average" sites, Salix caprea remained dominant in the canopy, associated with maples (richer sites) or hazel (Corylus avellana) on poorer sites. Azonal vegetation near springs was formed by ash (Fraxinus excelsior) forests, on humid boulder slopes by maple-ash forests with Lunaria rediviva, on dry boulder slopes by azel, on sunny, dry rocks by sessile oak (Quercus petraea). The importance of these pioneer forests for silviculture, phytosociology, and nature conservation is discussed.

Hartholzauwälder gehören mit bis zu acht Baumarten in der Kronenschicht zu den Wäldern mit der höchsten Baumartenvielfalt in Europa und beherbergen eine Vielzahl gefährdeter Pflanzen- und Tierarten. Das Fehlen von Eichen in der Etablierungsphase in ansonsten eichenreichen Waldgesellschaften wie Hartholzauen ist daher naturschutzfachlich gravierend. Vielerorts wird mit starken waldbaulichen Eingriffen und finanziellem Aufwand versucht, zumindest einen Anteil an Stieleiche in die nächste Bestandesgeneration hinüber zu retten. Hinzu kommt die eher konzeptionelle Frage der Natürlichkeit der Stieleiche in Hartholzauwäldern. In der Hartholzaue im Naturschutzgebiet Kühkopf-Knoblochsaue in Hessen wurde Stieleichenverjüngung in der Etablierungsphase auf zwei unterschiedlichen ungesteuerten Sukzessionsflächen untersucht, welche nach starken Hochwässern entstanden und von Hochwasser geprägt sind. Dies beinhaltet die Beschreibung des Standorts, die Quantifizierung der Eichenanteile, die Einschätzung ihrer Vitalität sowie die Charakterisierung des Wuchses der Stieleiche. Auf der insgesamt 4,53 Hektar großen Inventurfläche fanden sich fünf Strukturtypen (Straten) in Form (1) eines strauchreichen Pionierwalds; (2) eines offenen bis lückigen Gehölzkomplexes; (3) eines halboffenen bis geschlossenen Gehölzkomplexes; (4) eines fast geschlossenen Gebüschkomplexes, gezäunt; sowie (5) eines geschlossenen Pionierwalds, gezäunt. Auf diesen kamen insgesamt 155 Stieleichen vor und wurden aufgenommen (34 Stieleichen/ha). Es zeigte sich, dass Wildverbiss die Etablierung der Eiche zwar behinderte, dennoch in allen Straten stabile, vitale Jungeichen heranwachsen konnten. Starke Überschirmung und Konkurrenz durch Bodenvegetation wirkten sich negativ auf das Wachstum aus, bis hin zum Ausfall von Eichenverjüngung in Herden von Goldrute (Solidago canadensis) und Reitgras (Calamagrostis epigeios). Die Bestände am Kühkopf zeigen, dass sich die Stieleiche nach starken Hochwasserereignissen auf neu aufgelandetem Substrat unter den dann konkurrenzarmen Bedingungen und bei zugleich kontrolliertem Wildstand in Hartholzauen erfolgreich natürlich etabliert und auch in die Baumschicht einwächst, also Bestandteil der natürlichen Vegetation dieses Lebensraumes ist. Das Ausbleiben der natürlichen Eichenetablierung in den heutigen Überflutungsauen ist demnach auf die dort weitgehend fehlende Substratdynamik nach starken Hochwässern und damit fehlende natürliche Auensukzession sowie hohe Rehwilddichten zurückzuführen. Hardwood floodplain forests can have as many as eight tree species in the forest canopy. This puts them among the forests with the highest tree species diversity in Europe. Additionally, these forests are home to a large number of endangered plant and animal species. However, the absence of oak seedlings during the stand establishment phase of hardwood riparian zones, in what are frequently oak forest communities, is a serious concern for nature conservation. In many places the establishment of oak has been assisted by expensive silvicultural procedures to ensure that Pedunculate oak will constitute at least a small proportion of the species composition in the next generation. An additional theoretical question is, whether Pedunculate oak is a natural component in such floodplain forests, or not. In the Hardwood Floodplain Nature Reserve Kühkopf-Knoblochsaue, located in the state of Hesse, Germany, Pedunculate oak regeneration was studied during an establishment phase on two different unmanaged areas. Here succession was occurring on land newly created by the deposition of sediments near the high water mark following heavy flooding. The data collected included site description, total number of Pedunculate oak, an assessment of their vitality as well as a characterization of their growth. The 4.53 hectare study area contained five structural vegetation types, namely (1) shrub-rich pioneer forest; (2) open to gappy woodland; (3) semi-open to closed woodland; (4) nearly closed woodland, fenced; (5) closed pioneer forest, fenced. On these a total of 155 oaks were inventoried (34 oak trees per ha). Although browsing had hindered the establishment of oak, many vigorous and sturdy specimens were found in all strata. There was strong competition from ground vegetation such as the shade produced which impaired oak seedling growth. Where especially dense stands of goldenrod (Solidago canadensis) and reed grass (Calamagrostis epigeios) occurred, oak regeneration was absent. The stands in the Kühkopf demonstrate that Pedunculate oak can establish successfully on newly created environments such as those resulting from sedimentation after large floods. In these hardwood riparian environments, where competition was initially low and wildlife controlled, the establishment of Pedunculate oak was natural and the trees grew into the tree canopy layer. This is evidence that oak is indeed a natural component of this biotope. The absence of Pedunculate oak natural regeneration, as seen today in many riparian oak stands, can be attributed to changes in flood deposition dynamics that fail to provide the appropriate conditions required for natural oak regeneration processes to occur, combined with high rowdeer densities.

Bilberry (Vaccinium myrtillus L.) is a dwarf shrub with high ecological relevance as habitat and as a food source for many animals in mountain forests of central Europe. This species benefits from conifer forests and declines with an increase of broadleaved tree species in the canopy. The ongoing large-scale conversion from conifer to broadleaved forests may significantly alter the ground vegetation, especially the dominance of a key species such as bilberry. We used morphological indicators to investigate the vitality of bilberry. The first objective was to determine whether the vitality of bilberry is negatively impacted by increasing the proportion of beech (Fagus sylvatica L.) in Norway spruce (Picea abies Karst.) forests. The vitality of bilberry was measured by its cover, height, biomass, shoot length and basal diameter. The second objective was to determine whether these changes in bilberry vitality were related to light, canopy cover, soil pH, organic layer mass and tree species. The data was collected from three study areas in the southern and central Black Forest. The bedrock consisted of gneiss and granite whereas the stands were either: pure beech, a mixture of beech and spruce or pure spruce. The stands were located adjacent to each other. On all three areas a higher vitality of bilberry was observed under spruce compared to beech. Mixed effect models show that the occurrence of spruce is the most important variable explaining the increase in bilberry biomass. Light had a small positive effect, whereas soil properties had negligible effects and were site specific. These results are a strong indication of the negative influence that beech has on bilberry in conifer dominated forests. This has to be taken into consideration when developing silvicultural approaches and should be a consideration when making plans for the preservation of habitat for species like capercaillie (Tetrao urogallus L.). This is even more important today because the recent trend in central European forestry is to increase the proportion of beech. Die Heidelbeere (Vaccinium myrtillus L.) hat große ökologische Bedeutung im Bereich der montanen mitteleuropäischen Bergmischwälder, unter anderem als Lebensraum und Nahrungsgrundlage für viele Tierarten. Dieser Zwergstrauch wird durch nadelholzreiche Bestände begünstigt. Der heute praktizierte Waldumbau hin zu höheren Laubholzanteilen verändert die Bodenvegetation und insbesondere die Anteile der Schlüsselart Heidelbeere. Auf der Grundlage morphologischer Indikatoren wurde die Vitalität der Art untersucht. Ziele dieser Studie waren: Eine Analyse, inwiefern die Vitalität 1. der Heidelbeere in durch die Fichte (Picea abies Karst.) geprägten Wirtschaftswäldern durch einen zunehmenden Anteil an Buche (Fagus sylvatica L.) beeinträchtigt wird. Hierzu wurden vitalitätsbezogene Merkmale wie Bodenbedeckung, Wuchshöhe, Biomasse, Sprosslänge und Sprossdurchmesser am Wurzelansatz der Heidelbeere gemessen. 2. war es Ziel, den Einfluss der Lichtversorgung, der Deckung des Kronendaches, des pH-Wertes des Bodens, der organischen Auflage, der bestockenden Baumarten und des Standortes auf die Veränderungen von Morphologie und Vitalität der Heidelbeere zu analysieren. Hierzu wurden im Südlichen und Mittleren Schwarzwald in drei Untersuchungsgebieten auf Gneiss bzw. Granit die entsprechenden Daten erhoben. In diesen Gebieten grenzten ein Buchenbestand, ein Ökoton mit einer Mischbestockung aus Fichte und Buche (nur in zwei Gebieten), sowie ein Fichtenbestand direkt aneinander.In allen drei untersuchten Gebieten zeigte sich unter Fichtenbestockung eine wesentlich höhere Vitalität der Heidelbeere. Die Bestockung erwies sich auch in der Analyse unter Verwendung gemischter Modelle als die wichtigste erklärende Variable hinsichtlich eines Anstiegs der Biomasse der Heidelbeere. Licht hatte einen geringen positiven Einfluss, der Einfluss der Bodeneigenschaften war gering und geologiebedingt standortsspezifisch. Somit konnte gezeigt werden, dass das Auftreten von Buche in fichtendominierten Wäldern sich stark negativ auf die Heidelbeere auswirkt. Dies gilt es bei waldbaulichen Planungen zu berücksichtigen, beispielsweise wenn es um Planungen zum Schutz beerstrauchreicher Lebensräume und der von ihnen abhängigen Arten geht, darunter auch das Auerhuhn (Tetrao urogallus L.). Dies ist auch insofern von großer Bedeutung, da gerade heute in der mitteleuropäischen Forstwirtschaft eine Zunahme der Buche in nadelholzgeprägten Wäldern befürwortet und praktiziert wird.

Seit den 1980er Jahren wird in Baden-Württemberg die Bodenschutzkalkung angewendet, um Säureeinträge aus der Luft zu kompensieren. Die vorliegende Arbeit ist eine Auswertung der Kalkungsdokumentation aus Daten der Unteren Forstbehörden in Baden-Württemberg, die 2005 erstmalig von der FVA zusammengeführt wurde. Es wird dargestellt, dass der Fokus der Kalkungen bisher deutlich auf den Waldflächen des Schwarzwaldes lag, die durch die Grundgesteine des Buntsandsteins und des kristallinen Grundgebirges natürlicherweise und auch immissionsbedingt zu starken Bodenversauerungen neigen. Aber auch im Keuperbergland, dem Odenwald und im Verbreitungsgebiet der Altmoräne in Oberschwaben sind seit den 1980er Jahren regelmäßig Kalkungen durchgeführt worden. Die lehmigen Böden der Nördlichen Altmoräne wurden insbesondere seit 2005 deutlich mehr gekalkt, was die Veränderung der Kalkungsausrichtung hin zu den produktiveren, lehmigen Standorten zeigt. Die Auswertung der Kalkungsdokumentation geht auf verwendete Ausbringungsmaterialien und -techniken ein und stellt die unterschiedliche Flächenbedeutung der Waldkalkung für die zwei Schwerpunkt-Regionen Nordschwarzwald und Nördliche Altmoräne dar. Die Kalkungsdokumentation beruht auf analogen Karteneinträgen der Forstämter, welche die gekalkten Waldstandorte auf Ebene der Distrikte und Waldabteilungen abbilden, aber nicht detailscharf auf die Aussparung kalkungssensitiver Biotope eingehen. Since the 1980s, forest liming has been used to compensate for atmospheric inorganic acid deposited in Baden-Württemberg. This study evaluates existing forest liming data first compiled by the FVA Baden-Württemberg in 2005. We show a clear concentration of forest liming in the Black Forest, where soils on red sandstone and crystalline rock are prone to acidification. Liming has also been regularly carried out in the Keuper Uplands, the Forest of Odes and on glacial sediments of the Alpine foothills in Upper Swabia. The loamy soils of the lower moraine have experienced a particular increase in forest liming since 2005, demonstrating a shift in liming objectives towards loamy, productive sites. Evaluation of the liming data focuses on materials and techniques and the various liming emphases for the northern Black Forest and northern lower Alpine foothills. The liming documentation is based on analogous maps of the forest offices (scale: forest districts or compartments).

Der Eintrag starker anorganischer Säuren in Wälder führte zu tiefen pH-Werten und hohen Al3+-Konzentrationen im Boden. Dem versuchte man in Deutschland seit den 1980er Jahren durch Kalkung unter Verwendung dolomitischer Kalke zu begegnen. In den ersten Jahren nach Kalkung werden organische Auflagen abgebaut und die darin enthaltenen Nährstoffe, v. a. Stickstoff (N), mobilisiert und teils im humosen Oberboden gespeichert, teils aufgenommen, teils ins Grundwasser ausgewaschen. Die Bodenvegetation reagiert auf Kalkungmit einer Zunahme an nährstoff- und stickstoffliebenden Arten, Azidophyten gehen zurück. Die Artenzusammensetzung von Mykorrhizapilzen und Bodenfauna verändern sich vollständig. Die Baumwurzeln ziehen sich in den mineralischen Oberboden zurück. Bis die basischen Kationen eine Tiefe von 30 cm erreichen, vergehen viele Jahre. Seit 1990 gingen die Depositionen an Schwefel (S) stark zurück, doch der N-Eintrag blieb bis heute auf hohem Niveau. In Nadelbaumbeständen ist der N-Eintrag wesentlich höher als in Laubwäldern oder im Freiland. Hohe N-Einträge tragen zur fortdauernden Bodenversauerung bei, zugleich eutrophieren sie Waldökosysteme, welche von Natur aus N-limitiert sind. Das verstärkte Wachstum der Waldbestände zieht einen erhöhten Bedarf an anderen Nährstoffen nach sich. In vielen Wäldern wird die kritische Belastungsgrenze („critical load“) des Eintrags von ca. 10 bis 20 kg N ha-1 a-1 überschritten. Solche Wälder werden mit N übersättigt und geben überschüssiges Nitrat, das nicht im Humus eingebaut oder von der Waldvegetation aufgenommen wird, ans Grundwasser ab. Bis heute werden in Baden-Württemberg, Rheinland-Pfalz, Hessen, Niedersachsen, Sachsen, Nordrhein-Westfalen, Thüringen und neuerdings Sachsen-Anhalt große Waldflächen mit drei bis vier Tonnen dolomitischem Kalk pro Hektar und Jahrzehnt gekalkt. Ziel ist es, eine weitere säurebedingte Verwitterung von Tonmineralen zu verhindern und die Vitalität der Waldbestände zu erhöhen. Oftmals werden dem Kalk auch Phosphor- (P) und/oder Kaliumverbindungen (K) beigemengt. Bayern, Brandenburg und Mecklenburg-Vorpommern verzichten auf Waldkalkungen oder wenden sie nur in sehr spezifischen Fällen an. Die mitteleuropäischen Hauptbaumarten Buche, Fichte, Wald-Kiefer, Tanne und Eichen sind dort ähnlich vital, da diese edaphisch eine weite ökologische Amplitude besitzen. Analysen von Blatt- und Nadelspiegeln belegen eine geringe, doch ausreichende Nährelementversorgung selbst auf den sauersten Waldböden. Heute stellt nicht Bodenversauerung, sondern N-Eutrophierung (und Klimawandel) die Hauptgefährdung der Waldökosysteme dar. Eutrophierung gefährdet die Lebensgemeinschaften auf schwach gepufferten Böden in besonderem Maße, insbesondere oligotrophe Kiefern- und Eichenwälder. Kalkung in eutrophierten Wäldern wirkt der Versauerung entgegen und führt langfristig zu tieferer Durchwurzelung. Zugleich jedoch verbessert sie angesichts hohen N-Eintrags die Verfügbarkeit limitierender Nährstoffe und verstärkt dadurch die Auswirkungen der Eutrophierung. Daher fällt die Bewertung der Kalkung ambivalent aus. Nur eine Reduzierung des N-Eintrags stellt eine wirklich gute Lösung dar. Aus Naturschutzsicht besonders bedenklich ist Waldkalkung auf natürlich basenarmen Substraten und ihren oligotraphenten Lebensgemeinschaften. Deren Habitate müssen durch Pufferzonen und angepasste Verabreichungstechniken gegen Kalkeinträge geschützt werden. Auf bestimmten mesotrophen, aber versauerungsanfälligen Lehmböden kann Kalkung fallweise toleriert werden. Die Anreicherung mit P und K entspricht einer Düngung und ist daher nicht akzeptabel. Um die Auswirkungen von Waldkalkung abwägen zu können, sollten ausreichend große ungekalkte Kontrollflächen ausgewiesen werden. Angesichts eines heute relativ hohen Waldwachstums sollte eine weitere Förderung von Waldkalkung überdacht werden. The deposition of strong inorganic acids in forests leads to low pH values and high concentrations of Al3+ in the soil. Forest liming neutralizes acidity and leads to an increase in base cations. Additionally, surface organic layers decay more rapidly and stored nutrients are mobilized. The ground vegetation responds to liming with an increase in nutrient-loving species and a decline in acidophytes. The mycorrhizal fungi and soil fauna species composition change dramatically. Tree roots, at least initially, retreat from the topsoil. It takes several years for the base cations to reach the deeper soil horizons (up to about 30 cm) and they rarely go deeper.Since 1990 sulfur deposition has greatly declined. However N deposition rates remain at high levels (conifer stands > deciduous > open areas). High N inputs continue to contribute to soil acidification and at the same time cause the eutrophication of forest ecosystems which are naturally N-limited. The increased rate in forest growth results in an increased need for other nutrients. In many forests, the critical deposition threshold (“critical load”) of approximately 10 to 20 kg N ha -1 yr -1 has been exceeded. In stands where the soils are supersaturated with nitrogen, the nitrate which is not retained by the humus or assimilated by the forest vegetation leaches into the ground water.Up until today in Baden-Wuerttemberg, Rhineland-Palatinate, Hesse, Lower Saxony, North Rhine-Westphalia, Thuringia and recently in Saxony-Anhalt large areas of forest have been limed using three to four tons of dolomitic lime per hectare per decade. The aim is to prevent the ongoing acidinduced degradation of clay minerals in order to increase forest vitality. Often P and / or K are added to the lime. Bavaria, Brandenburg and Mecklenburg-Western Pomerania either do not lime their forests or only do so in a very restricted manner. In these states the central European tree species beech, spruce, Scots pine, fir and oak growing there are no less vital than elsewhere. These tree species grow in a wide range of ecological soil types. Analyses of leaves and needles show that a small, but adequate nutrient supply exists even in the most acidic forest soils. Today it is not soil acidification but eutrophication (and climate change) which are the main threats to forest ecosystems, especially for oligotrophic communities on sandy soils. Liming in eutrophic forests counteracts acidification and eventually leads to deeper rooting. But it also increases nitrogen availability and other limiting nutrients and adds to the process of eutrophication. Therefore, the results evaluating of the effects of liming are ambivalent. The problem can only be solved by a reduction in N deposition. From a nature conservation standpoint it is of particular concern that liming is done on oligotrophic forest communities which are naturally low in base substrates. These habitats need to be protected from the addition of lime. In mesotrophic clay soils susceptible to acidification, liming can be occasionally tolerated. The enrichment with P and K means fertilisation and is therefore not acceptable. In order to weigh the impacts of forest liming, unlimed control plots should be established. In the light of today's relatively high forest groth rates further funding for forest liming should be reassessed.

Robinson Crusoe Island (RCI), part of Juan Fernández Archipelago, contains more endemic plant species per area than any other island system of the world (1.9 species/km²). Currently, exotic plants are invading all habitats on the island with higher or lower intensity. As two-thirds of the vascular plant species are threatened by extinction, the island has a high conservation priority. Protection of the island’s biodiversity is of utmost importance both locally and globally. Using already published information, the main vegetation types defined for RCI were reviewed, considering plant species richness on the International Union for Conservation of Nature conservation categories, amount of invasive exotic plants, and the occurrence of land bird species. The highest number of endemic and endangered plant species was found in the upper and lower montane forest, in which only highly threatened and threatened bird species live. Furthermore, the scientific literature about Juan Fernández Archipelago was reviewed in order to identify missing data needed for effective conservational efforts. So far research in Juan Fernández and RCI has been mainly focused on Botany, usually dealing with taxonomical aspects of singular plant taxa. Detailed studies of ecology, structure, dynamics, processes and services of the forests on RCI are missing in scientific literature. It appears as highly important to fill this knowledge gap in order to be successful in future conservation and restoration initiatives. La isla Robinson Crusoe, parte del Archipiélago Juan Fernández, contiene más especies de plantas endémicas por área que cualquier otro sistema insular en el mundo (1,9 especies/km²). Actualmente los hábitats de la isla son invadidos por plantas exóticas con mayor o menor intensidad. Dos tercios de las especies de plantas vasculares se consideran en peligro de extinción, por lo que la isla representa una prioridad de conservación para la biodiversidad a escala local y global. Utilizando información ya publicada, se revisan los principales tipos de vegetación definidos para la isla Robinson Crusoe, considerando la riqueza de especies en categorías UICN (Unión Internacional para la Conservación de la Naturaleza), la cantidad de plantas exóticas invasivas y la ocurrencia de especies de aves terrestres. La mayor proporción y número de especies de plantas endémicas se ubicaron en el bosque montano alto y bajo de la isla, donde habitan en mayor abundancia especies de aves endémicas altamente amenazadas. Adicionalmente, para percibir necesidades de información para la conservación, se analizaron los principales temas de publicaciones científicas desarrolladas sobre el archipiélago Juan Fernández. Hasta hoy la investigación en Juan Fernández se ha centrado en botánica, normalmente, en temas relacionados con aspectos taxonómicos de especies de plantas singulares. Estudios en ecología, estructura, dinámica y procesos de los bosques de la isla Robinson Crusoe han sido escasamente tratados en publicaciones científicas. Es urgente abarcar, comprender y vincular estos temas hacia iniciativas de conservación y restauración aplicada.

This study describes the impact of a wildfire caused by a tourist at Torres del Paine Biosphere Reserve in 2005, which destroyed approximately 2,000 ha of forests. Changes on biodiversity attributes of Nothofagus pumilio stands including structure, floristic composition and regeneration, are shown. We compared three plot groups having similar site and structure: Cordón Masle burned plots (CMBP); Cordón Masle unburned plots (CMUP), adjacent to the first ones; and Cerro Paine unburned plots (CPUP), outside the fire perimeter. Data was analyzed using univariate (Mann-Whitney) and multivariate (MRPP and ISA) non-parametric analysis. In CMBP, the fire reduced in average 91.7 % of the tree density and 70.9 % of the basal area. In the unburned plots the average of seedling was 23,625 and 22,750 ha-1 in CPUP and CMUP respectively, whereas in burned ones it was only 1,125 ha-1 in CMBP. Canopy layer collapsed and species richness and cover on ground increased significantly in burned plots. The average of exotics increased from 1.5 and 0.6 in CPUP and CMUP respectively to 11.9 in CMBP. Tree mortality, lower regeneration, biological invasion and broken canopy-ground balance in burned stands, are altering the successional pathways of forests, making difficult the forest regeneration and restoration efforts. Based on this information, we propose managers to encourage efforts in fire prevention and to incorporate a database on biodiversity indicators for management plans, in order to know more about the ecological integrity of ecosystems and the impacts provoked by recreation. Se describe el impacto de un incendio causado por un turista en la reserva de la biosfera Torres del Paine en el 2005 que destruyó aproximadamente 2.000 ha de bosques. Se muestran los cambios ocurridos en atributos de bosques de Nothofagus pumilio incluyendo estructura, regeneración y composición florística. Se comparan tres grupos de parcelas con sitio y estructura semejantes: parcelas incendiadas (CMBP) y parcelas adyacentes no incendiadas (CMUP) del Cordón Masle, y parcelas no incendiadas de Cerro Paine (CPUP), fuera del perímetro del incendio. Se utilizó análisis no paramétricos univariados (Mann-Whitney) y multivariados (MRPP e ISA). En los sitios incendiados, el fuego redujo en promedio el 91,7 % de la densidad arbórea y el 70,9 % del área basal. El promedio de plántulas fue de 23.625 y 22.750 ha-1 en CPUP y CMUP, respectivamente, mientras que en CMBP se redujo a 1.125 ha-1. El dosel colapsó y la cobertura y riqueza de especies de sotobosque incrementó significativamente en las parcelas incendiadas. El promedio de exóticas incrementó de 1,5 y 0,7 especies en CPUP y CMUP, respectivamente, hasta 11,9 especies en CMBP. La mortalidad de árboles, escasa regeneración, invasión biológica y el colapso del dosel, están alterando las vías sucesionales de los bosques reduciendo su capacidad de recuperación, dificultando los esfuerzos de restauración. Se propone a los administradores enfatizar esfuerzos en prevención de incendios y desarrollar información sobre indicadores de biodiversidad para los planes de manejo, para así conocer más sobre la integridad ecológica de los ecosistemas y el impacto provocado por la recreación.

Over the last decade a shelterwood system promoting natural regeneration has been applied in the southern Chilean old-growth Nothofagus forests. However, most of these forests are naturally uneven-aged, and the effect of the application of this silvicultural system has been the homogenisation and simplification of the stand structure. An ecological understanding of natural disturbance processes is necessary to improve the current silvicultural practices. This study analysed the effects of natural small-scale disturbances on the below-canopy solar radiation conditions, the regeneration patterns (density and growth), and the browsing damage to young trees caused by Lama guanicoe in an old-growth Nothofagus betuloides forest (Fig. 1). The study was carried out in 13 canopy gaps (21-92 m(2)) (Tab. 1). The regeneration was sampled in 65 plots (4 m(2)) in and around the canopy gaps along a solar radiation gradient. The results revealed that the non-cosine-corrected direct solar radiation ranged from 3.2 to 19.4%, the transmitted diffuse radiation ranged from 3.1 to 16.7% and the global solar radiation ranged from 3.2 to 17.6% (Tab. 2). As expected, the transmitted solar radiation was highest in the gaps, and the adjacent southeastern borders. All N. betuloides seedlings and saplings were counted in height classes, together with browsing damage caused by L. guanicoe (Tab. 3). The height growth and radial increment were measured for the tallest seedling or sapling in each plot (Tab. 5). The absolute radial and height growth of seedlings and saplings were affected by the total size and age of the plants and the below-canopy diffuse solar radiation (Tab. 6, Fig. 2 and 3). The proportions of seedlings browsed by L. guanicoe were low (0.7 to 2.8% of the total). Browsing damage to young trees was observed below canopy gaps as well as beneath closed canopy, demonstrating no particular preference (Tab. 3). The seedlings and saplings of N. betuloides exhibited a high shade tolerance, apparently not requiring the presence of large gaps to establish. The heterogeneous canopy of old-growth N. betuloides stands with only very small canopy gaps produced a variety of mosaics in the understorey, with seedlings and saplings present in a range of ages and heights. It could be shown, that - different to other South American Nothofagus species - N. betuloides seedlings and saplings can tolerate long periods of dense shade. Similar to some New Zealand Nothofagus forests, N. betuloides forests are able to regenerate also in a continuous process. This allows to develop perspectives for successful transformations of virgin N. betuloides forests into seminatural stands, which could be sustainably managed as selection forests, still having a multi-layered structure and high biodiversity with native species.

We describe the structure of the endemic Robinson Crusoe Island forest. We analyse the regeneration strategies of the trees: Myrceugenia fernandeziana, Fagara mayu, and Drimys confertifolia. Inventories were taken on nearly intact montane forest remnants with emphasis on spatial patterns by using Ripley's K (t) function. We hypothesized that i) ornithochorous and barochorous species should show a clumped regeneration, as a consequence of seed rain; ii) nurse effect, if present, should also contribute to a clustered pattern; iii) clustering should disappear at more developed life-stages due to self-thinning; iv) if gaps influence tree mortality and regeneration, these will present grouped patterns. Myrceugenia fernandeziana was the most abundant tree species, followed by F. mayu and D. confertifolia. The diameter distribution of M. fernandeziana suggested a continuous regeneration. The diameter distribution of F. mayu was typical of species that require disturbances to regenerate, whereas the diametric pattern of D. confertifolia was intermediate compared with the previous species. M. fernandeziana demonstrated a spatially clumped regeneration given its dispersal mode (hypothesis i), but did not show association with the large tree individuals, discarding a possible nurse effect (hypothesis ii). The large specimens of M.fernandeziana were randomly distributed, likely due to self-thinning (hypothesis iii). Mortality of M. fernandeziana trees did not seem to be a consequence of local disturbances, rejecting hypothesis iv). Fagara mayu distributed randomly showing in cases some aggregation. Drimys confertifolia presented a clustered pattern. Regeneration of F. mayu and D. confertifolia occurred mainly in gaps, but also under canopy for the latter species. D. confertifolia tended to regenerate near larger trees of the same species (hypothesis ii). M. fernandeziana seems to exhibit shade tolerance, although it showed plasticity to use different regeneration environments. F. mayu showed characteristics of a shade intolerant species, possibly requiring gaps, or larger disturbances to regenerate. D. confertifolia seems to be a shade semi-tolerant species, requiring areas with low canopy cover to establish. Se describe la estructura del bosque endémico de la Isla Robinson Crusoe. Se analizan las estrategias de regeneración de los árboles: Myrceugenia fernandeziana, Fagara mayu, y Drimys confertifolia. Se inventariaron remanentes de bosque montano, con énfasis en los patrones espaciales usando la función K(t) de Ripley. Se hipotetiza que: i) especies ornitócoras y barócoras debieran mostrar regeneración agrupada, a consecuencia de la lluvia de semillas; ii) si existe efecto nodriza, existirá también un patrón agregado de regeneración; iii) en estados de desarrollo avanzado la agregación se atenuará, a consecuencia del autorraleo; iv) si las aperturas de dosel influencian la regeneración y mortalidad, estas presentarán patrones agrupados. M. fernandeziana fue la especie arbórea más abundante, seguida por F. mayu y D. confertifolia. La distribución diamétrica de M. fernandeziana sugirió una regeneración continua. F. mayu exhibió una distribución típica de especies con regeneración esporádica. La distribución diamétrica de D. confertifolia fue intermedia respecto a las otras especies. La regeneración de M. fernandeziana fue espacialmente agrupada, dado su modo de dispersión (hipótesis i), pero no mostró asociación con individuos adultos, descartándose un posible efecto nodriza (hipótesis ii). Los individuos adultos de M. fernandeziana se distribuyeron aleatoriamente probablemente debido a autorraleo (hipótesis iii). La mortalidad de adultos de M. fernandeziana no pareció responder a alteraciones locales, descartándose la hipótesis iv. F. mayu se distribuyó aleatoriamente exhibiendo, en casos, leve agregación. D. confertifolia presentó un patrón agrupado. La regeneración de F. mayu y D. confertifolia ocurrió principalmente en claros, aunque esta última especie se presentó también bajo dosel. D. confertifolia tiende a regenerar cercana a ejemplares adultos de la propia especie (hipótesis ii). M. fernandeziana mostró tolerancia a la sombra, aunque es muy plástica, ocupando diferentes ambientes de regeneración. F. mayu mostró características de intolerante a la sombra; posiblemente requiera claros, o disturbios mayores para regenerar. D. confertifolia parece ser semitolerante a la sombra requiriendo claros, o áreas con menor cobertura para establecerse.