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The sensitivity of Austrian forests to scenarios of climatic change: A large-scale risk assessment based on a modified gap model and forest inventory data

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Abstract

In a spatially explicit climate change impact assessment the modified patch model PICUS v1.2 was applied to simulate the transient response of current forests in Austria under three climate change scenarios which were based on regionalized GCM-scenario data. The forest model was initialized with ground-true stand and soil data from more than 2800 sample plots of the Austrian Forest Inventory (AFI). A comparison of simulated equilibrium species composition under current climate and expert reconstructions of PNV at the sample plots of AFI showed that the model responded realistically to the spatial variability of soil and climate characteristics. In deriving potential climate change impacts the simulation under current climate was used as a reference. Impact criteria representing the period 2000–2050 and long-term criteria derived from simulated site-specific potential natural vegetation (PNV) were used in a multiple-criteria approach to calculate short-/mid-term as well as long-term climate change impact indices. The study showed that neither transient short-/mid-term nor long-term PNV-based indices alone are sufficient to indicate the possible consequences of climate change on existing forests. Based on the results of the study the combined use of such climate change impact indices is recommended. A major finding was that beyond a temperature increase of approximately +1 °C (no changes in precipitation) the proportion of inventory plots showing severe climate change impacts increased markedly. While at higher elevations under warmer climates the set of suitable tree species increased due to increased competitivity of broadleaved species, the study suggests that under the set of analysed climate change scenarios at low-elevation sites Picea abies would become unsuitable as a crop species. Limitations of the presented approach are discussed and conclusions regarding possible consequences for forest management are drawn.

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... In Europe, for example, climate-induced negative impacts on forest productivity will thus occur predominantly at low elevations and in southern and continental areas, whereas temperature-limited forests at high elevations and latitudes are expected to feature increased productivity and biomass (Lindner et al. 2010, Hartl-Meier et al. 2014, Reyer et al. 2014, Schelhaas et al. 2015, Morin et al. 2018). Second, tree species are expected to shift their distributions poleward in latitude and upward in elevation, while being replaced by more drought-and warmth-adapted species at their low latitude and elevation range limit (Lexer et al. 2002, Walther et al. 2002, Peñuelas and Boada 2003, Morin et al. 2008, Hanewinkel et al. 2013, Takolander et al. 2019. ...
... Thus, our results suggest a heterogeneous response of these strata to CC depending on site-specific water and nitrogen availability, particularly in dry inneralpine environments. Therefore, the general expectation of positive CC induced effects on forests at higher elevations due to increasing temperature (e.g., Lexer et al. 2002, Harsch et al. 2009, Jochner et al. 2018) should be considered with caution. This is supported by recent empirical evidence (van der Maaten- Theunissen et al. 2012, Charru et al. 2013, Martin-Benito et al. 2018 and model-based studies (Henne et al. 2011) showing regional and local variations in growth responses to CC suggesting an interplay of warming with local water and nutrient limitations. ...
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The increasing impacts of climate change on forest ecosystems have triggered multiple model‐based impact assessments for the future, which typically focused either on a small number of stand‐scale case studies or on large scale analyses (i.e., continental to global). Therefore, substantial uncertainty remains regarding the local impacts over large areas (i.e., regions to countries), which is particularly problematic for forest management. We provide a comprehensive, high‐resolution assessment of the climate change sensitivity of managed Swiss forests (ca. 10’000 km2), which cover a wide range of environmental conditions. We used a dynamic vegetation model to project the development of typical forest stands derived from a stratification of the 3rd National Forest Inventory until the end of the 22nd century. Two types of simulations were conducted: one limited to using the extant local species, the other enabling immigration of potentially more climate‐adapted species. Moreover, to assess the robustness of our projections, we quantified and decomposed the uncertainty in model projections resulting from the following sources: (i) climate change scenarios, (ii) local site conditions and (iii) the dynamic vegetation model itself (i.e., represented by a set of model versions), an aspect hitherto rarely taken into account. The simulations showed substantial changes in basal area and species composition, with dissimilar sensitivity to climate change across and within elevation zones. Higher‐elevation stands generally profited from increased temperature, but soil conditions strongly modulated this response. Low‐elevation stands were increasingly subject to drought, with strong negative impacts on forest growth. Furthermore, current stand structure had a strong effect on the simulated response. The admixture of drought‐tolerant species was found advisable across all elevations to mitigate future adverse climate‐induced effects. The largest uncertainty in model projections was associated with climate change scenarios. Uncertainty induced by the model version was generally largest where overall simulated climate change impacts were small, thus corroborating the utility of the model for making projections into the future. Yet, the large influence of both site conditions and the model version on some of the projections indicates that uncertainty sources other than climate change scenarios need to be considered in climate change impact assessments.
... Other studies about forest sensitivity to climate change rather investigated whether a specific region would still be favourable to forest growth no matter of anticipated shifts in species composition, and focused on mature trees and their productivity (e.g. Griesbauer et al., 2011;Lasch et al., 2002;Lexer et al., 2002;Lindner et al., 2010). ...
... This matches with the hypothesized stronger sensitivity of pine forests, because they grew in drier habitats in our study ( Fig. 2e and h). Lexer et al. (2002) modelled impact of climate change on Austrian forest ecosystems and found that an increase of ≥1 • C, which is well in the range of contextdependent fluctuations found in this study, would severely impact many forests. ...
Article
Forest canopy generally moderates below-canopy air temperature and relative humidity and thus creates a specific microclimate for tree seedling growth. Climate change will alter the moderating capacity, which may render the below-canopy conditions unsuitable for recruitment of the hitherto dominant tree species. We assigned long-term meteorological data (1997-2010) recorded inside and outside of 14 different forest ecosystems in Switzerland to three forest types (broadleaved, non-pine conifer, pine), two altitudinal levels (low, high), the four seasons and general weather situations (normal, hot/dry, cold/wet) to compare moderating capacity of each of these classifiers. Our results confirmed a general moderating effect of canopy on below-canopy microclimate with a decrease of daily maximum air temperature of up to 5.1 • C (overall average: 1.8 • C) and an increase of daily minimum relative humidity of up to 12.4% (overall average: 5.1%) in the long-term average, respectively. Broadleaved and non-pine conifer forests moderated daytime microclimate about twice as much as pine forests, while at nighttime considerably less cooling down and even negative effects on levels of relative humidity compared to the open area were recorded at the pine forest sites. Moderating capacity was stronger at low altitude than at high altitude. It was strongest during the growing season, particularly in summer, and depended in a complex way on the general weather situation. Deviations from the general seasonal and weather condition patterns most likely occurred when soil moisture pools were depleted. Despite the moderating capacity, below-canopy microclimate did not lag behind open area microclimate. Based on our results we conclude that natural recruitment in pine forests and high-altitude forests may respond most sensitively to climate change.
... ). These models were mainly used to simulate forest development and long-term succession in natural forest stands under different climatic conditions with a focus on species composition and biomass (e.g., Bugmann & Pfister, 2000; Busing & Mailly, 2004; Heiri et al., 2006; Lexer et al., 2002; Talkkari & Hypén, 1996). Especially in Europe, the application as well as the validation of gap models has been constrained by the fact that the majority of European forests are either still strongly managed, or they have been influenced by humans to a variable and – particularly in the more distant past – often unknown degree (e.g., timber and litter harvesting, grazing by domestic animals). ...
... Even though they did not use data from natural forests, their results suggested that such data would be quite valuable for model testing and improvement. Due to the lack of long-term data from many unmanaged sites, several alternative approaches have been used to evaluate the performance of gap models: (i) comparisons with potential natural vegetation (e.g., Lexer et al., 2002), (ii) comparisons with national inventory data (Talkkari & Hypén, 1996) or (iii) the use of palaeo-ecological records to evaluate predictions of truly long-term vegetation dynamics (e.g., Heiri et al., 2006; Lischke et al., 2002). While these approaches may be appropriate to validate the simulation of tree species composition and biomass, they are not sufficient if structural forest patterns such as size distributions shall be examined. ...
Thesis
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For a long time, management was the main driver of forest dynamics in European forests. Over the last decades, management in many forests was abandoned, either due to financial constraints or within the context of biodiversity policies. Thus, natural processes have again become the main driver of successional dynamics in these forests. The present thesis aimed to increase our understanding of the long-term dynamics of unmanaged forests by combining empirical and theoretical approaches. Specifically, a first systematic analysis of natural forest dynamics in Switzerland was conducted using the extensive data pool of the ETH forest reserve project. Thereby, (1) patterns and processes of natural forest development after management cessation were identified, (2) observed dynamics were compared with established succession theories, and (3) the reserve data were used for a rigorous testing of the succession model FORCLIM. Chapter I. Forest development was investigated in six beech (Fagus sylvatica) reserves in the Swiss lowlands using descriptive and multivariate statistical methods. During the nearly 40 years covered by the nventory data, forest dynamics showed a clear trend towards a broadening of the diameter distribution, an increase in basal area and standing dead wood, an increase in beech dominance and a reduction of tree species diversity over time. However, the development of specific structural features such as significant amounts of large living trees and snags or a small-scale mosaic of various developmental phases appears to take longer than the time elapsed since the cessation of management. The observed loss in tree species richness could be attributed to decreasing light availability, as almost all species that disappeared were shade-intolerant. Additionally, the shade-intolerant tree species had a characteristic bell-shaped diameter distribution, indicating a lack of recruits, whereas shade-tolerant species had an irregular to monotonically decreasing diameter distribution, demonstrating sustained regeneration. Along the environmental gradient covered by the reserves, abiotic factors were sufficient to explain tree species distribution. This suggests that at larger scales, tree species composition is determined by abiotic factors, and historical management strategies were well adapted to the species’ autecological requirements. Chapter II. Inventory data of 36 permanent plots from five mountain forest reserves dominated by Norway spruce (Picea abies) and/or silver fir (Abies alba) were analyzed to quantify the observed patterns of stand structure and species composition and their changes over time, and to compare these findings with a widely used scheme of forest succession developed by Leibundgut (1993). By combining cluster analysis with a ew stand structure index, we were able to identify a clear relationship between stand structure (diameter distributions) and species composition for the early and late successional phases. As two athways of early succession were evident we could conclude that the spatial extent of disturbances in spruce–fir forests strongly determines the pathway in early succession. Contrary to Leibundgut’s descriptions our data did not reveal a clear relationship between stand structure and species composition for the early, mid- and late optimum phases. The five reserves are characterized by highly different climatic and soil conditions, but their temporal development was found to fit well into a single successional scheme, suggesting that in spruce–fir mountain forests the life history strategies of the tree species have a stronger influence on successional trajectories than site conditions. Chapter III. Combining these empirical data with dynamic modeling allows to extend the time frame of investigation and also to test our current understanding of the underlying processes of natural forest dynamics. We used data from ten reserves to assess the performance of the gap model FORCLIM with respect to its ability to accurately simulate stand structural dynamics. First simulations with the model version 2.9.6 indicated that due to an overestimation of stress-related mortality small trees were under-represented and very shade-tolerant species were lacking in the understory. Changing the formulation of the background mortality led to a considerable improvement of model fit for small diameter trees and to a higher abundance of very shade-tolerant species. However, the new model version 2.9.7 underestimated the abundance of large diameter trees, which was most evident at the montane and subalpine simulation sites. Nevertheless, we conclude that FORCLIM is suitable to address questions on the future development of tand structural attributes, although some model shortcomings could be identified and suggestions for further model improvement were made. Using empirical stand data from forest reserves covering a wide range of environmental conditions proved to be highly valuable for testing model performance and for identifying future research needs. Overall, I conclude that forest reserve data are valuable for analyzing patterns and processes of natural forest dynamics, and they are highly suitable for rigorous model testing and to identify processes in need of improvement. Analyses such as conducted in this thesis could provide the foundation for refining forest management systems as well as for developing effective and target-oriented conservation strategies. Moreover, testing forest models with empirical data increases their predictive capabilities, which is of special importance for addressing questions on the influence of climate change on long-term forest dynamics.
... Beech dominated 455 ± 38 9.6 ± 6.6 11.1 ± 3.9 AM1 was simulated only in mature and uneven-aged stand types because the model poorly supported the application of single-tree selection forest management in pole stage stands and stands under regeneration b AM3 was simulated only in selected stand types since regeneration in the fenced areas corresponded only to these stand types c Thinning and regeneration harvest intensity are given per operations (1-4 or 1-3, respectively), expressed in % of stand volume current climate as well as under two climate change scenarios (Lexer et al. 2002). ...
... The decline of conifers was clearly sensitive to elevation, which is closely related to climate conditions; a similar pattern was projected for the Austrian Alps (Lexer et al. 2002). The decline was simulated to be strongest in lowelevation (between 500 and 800 m a.s.l.) and mid-elevation stands (between 750 and 1100 m a.s.l.), especially on south-facing sites (results not shown). ...
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In the Dinaric Mountains, the future of silver fir and Norway spruce appears to be uncertain, especially given the threat of climate change to both species and browsing pressure on fir. Stand development of mixed Dinaric mountain forest in Slovenia was simulated for the period 2010–2110 using the ForClim model to explore the prospects of both target species under five management scenarios (business-as-usual, no management, single-tree selection, fir conservation and exclusion of browsing) and three climate scenarios (current climate and two climate change scenarios). Simulations under the current climate revealed a decrease in fir proportion from 53% in 2010 to 14–37% in 2110, while the proportion of spruce remained relatively constant (13% in 2010 and 9–13% in 2110). Climate change may intensify the decline of both species along an elevation gradient. An upward shift was projected for fir in the observed period; in low-elevation stands (600–800 m a.s.l.), fir could almost disappear, while at
... Field studies by Delzon et al. (2013) have confirmed a steady colonisation of Holm oak (Quercus ilex) northwards from its natural range in the last century, and simulations predict a probable ongoing of this development during this century (Cheaib et al., 2012). Meanwhile, coniferous species ranges will be confined to higher altitudes (Lexer et al., 2002) and latitudes (Delzon et al., 2013), where more suited climatic conditions are to be expected. ...
... The predicted climate change can only amplify these problems (see e.g. Lexer et al., 2002). ...
Thesis
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The renewable material wood and hereof derived structural engineered wood products (EWPs) is widely acknowledged as being the major pillar of sustainable building construction. Due to the strongly increasing demand and technical assets the wood resource hardwoods, previously less used as compared to softwoods, is gaining a high momentum for EWPs. Here, the species white oak (Quercus robur, petraea) representing beside beech (Fagus sylvatica) the largest hardwood stocks in Europe is investigated. This work addresses the need of improved understanding and modeling of the variability of stiffness and strength along and between boards and the resulting impact on the size-effect of glued laminated timber (GLT) made of oak. A set of 53 oak boards (Quercus robur) was used to study the variation of mechanical properties along the board's main axis. For each board, detailed information regarding size and position of knots was obtained, which was then used to digitally reproduce the geometry of the knots. The modulus of elasticity (MOE) parallel to the fiber was measured in tension along each board in 15 consecutive segments of 100 mm in length. The boards were tested in tension until failure and the remnants were then tested in secondary tension tests, when possible. Thus, multiple values for tensile strength were obtained per board. Based on the MOE results, a first order autoregressive [AR(1)] model for the simulation of local MOE profiles within board was developed. The model considers the non-stationarity of the MOE profiles by means of a two step method. Firstly, a Gaussian AR process is conducted and then mapped to the normalized MOE distribution. In a second step, the result in scaled to fit a specified global MOE value. The tensile strength data was analyzed by means of survival analysis, where different parametric and regression type statistical models were fitted. The tensile strength models were coupled to the localized MOE AR(1) model by means of a cross-correlation coefficient, thus obtaining a modified vector autoregressive (VAR) model for the local MOE and tensile strength along board. Numerical simulations with the fitted tensile strength models predicted a relatively high size effect, i.e. length effect, characterized by a size-effect exponent of around 0.23 at the 5%-quantile level. A stochastic finite element model for the analysis of GLT beams was developed. The model considers the local variation of mechanical properties within each lamination, simulated by the derived VAR model, as well as the stochastic distribution of finger-joints connecting adjacent boards. A simple energy-based failure mechanism is considered for the evolution of tensile damage in wood and finger-joint elements. The model was calibrated with experiments of oak GLT beams of three different cross-sections tested at the MPA, University of Stuttgart, and then applied to simulate a second database of oak GLT beams tested at FCBA, France. The results obtained with the model are in good agreement with the experiments. In particular, the size effect of beam depth is correctly represented. The influence of the used material models for wood and finger-joints was analyzed parametrically. It is shown that the lower tail of the local tensile strength distribution, which can be estimated rather accurately by survival analysis dominates the GLT bending strength. This is fortunate, as the lower tails can be estimated by means of survival analysis in a rather accurate manner, while the upper tails require further assumptions. The author hopes that the presented work contributes to stimulate the discussion on modelling of structural timber elements made of hardwoods.
... Moreover, species specific responses to insect attacks, pest and pathogens, may shape the structure of future forests. For example, in Germany and Austria, an increase in mortality risk is predicted especially for spruce at low altitudes, while beech and oak may be more robust to climate change (Lexer et al., 2002;Nothdurft, 2013;Ding et al., 2017), which could be supported by the observations from Switzerland reported in this study. ...
Article
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Climate-induced tree mortality became a global phenomenon during the last century and it is expected to increase in many regions in the future along with a further increase in the frequency of drought and heat events. However, tree mortality at the ecosystem level remains challenging to quantify since long-term, tree- individual, reliable observations are scarce. Here, we present a unique data set of monitoring records from 126 forest stands across Switzerland, which include five major European tree species (Norway spruce, Scots pine, silver fir, European beech, and sessile and common oak) and cover a time span of over one century (1898-2013), with inventory periods of 5 to 10 years. The long-term average annual mortality rate of the investigated forest stands was 1.5%. In general, species-specific annual mortality rates did not consistently increase over the last decades, except for Scots pine forests at lower altitudes, which exhibited a clear increase of mortality since the 1960s. Temporal trends of tree mortality varied also depending on diameter at breast height (DBH), with large trees generally experiencing an increase in mortality, while mortality of small trees tended to decrease. Normalized mortality rates were remarkably similar between species and a modest, but consistent and steady increasing trend was apparent throughout the study period. Mixed effects models revealed that gradually changing stand parameters (stand basal area and stand age) had the strongest impact on mortality rates, modulated by climate, which had increasing importance during the last decades. Hereby, recent climatic changes had highly variable effects on tree mortality rates, depending on the species in combination with abiotic and biotic stand and site conditions. This suggests that forest species composition and species ranges may change under future climate conditions. Our data set highlight the complexity of forest dynamical processes such as long-term, gradual changes of forest structure, demography and species composition, which together with climate determine mortality rates.
... Each cell indicates the simulated forest type for 1ha. Forest types were classified according toLexer et al. (2002). ...
... The concept of ''potential natural vegetation'' (PNV), first introduced by Tüxen (1956), refers to the final state of vegetation that ''would become established if all succession sequences were completed without interference by man under present climatic and edaphic conditions (including those by man)'' (Mueller-Dombois and Ellenberg 1974, p. 422). Initially developed for vegetation mapping purposes in cultural landscapes (Zerbe 1998;Bastian 2000;Blasi et al. 2000;Carranza et al. 2003;Hemsing 2010), PNV integrates abiotic factors and phytogeographic information combined with structure, dynamics and ecology of plant communities, and is widely used in landscape planning and management (del Rio et al. 2005) to develop climate change scenarios (Lexer et al. 2002), to define biogeographical classifications at regional levels (Gallizia Vuerich et al. 2001), and to determine conservation priorities (Anav and Mariotti 2011). Recent developments regarding the concept of PNV have led to the inclusion of additional environmental parameters such as topographic and edaphic features, as compared to the original focus on a climate-constrained analysis (Gallizia Vuerich et al. 2001). ...
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Turkey, containing three of the world’s biodiversity hotspots, is a hub for genetic biodiversity. However, the vegetation cover has drastically changed in recent decades as a result of substantial transformations in land-use practices. A map of the potential natural vegetation can be used to represent the biodiversity of a country, and therefore a reference to effectively develop conservation strategies. The multinomial logistic regression is used to simulate the probability of different biomes occurring in the country using elevation, climatological data and natural vegetation data. A correlation test was applied to the climatological data to determine which predictors influence vegetation the most. These were temperature, precipitation, relative humidity and cloudiness. The Ordinary Kriging method was employed to transform the data into the format for the multinomial logistic regression model. The model showed that temperature was the most influencing factor with respect to Turkey’s vegetation and distribution follows a similar distribution as the various macroclimates. Broadleaf forests are mostly found in the Black Sea region, which is also the wettest region of the country. The Marmara region is the only other region where there are broadleaf forests. Mixed forests and shrublands are mostly located in Central Anatolia due to the region’s low humidity which favours herbaceous flora. Coniferous forests were dominant in the Aegean and Mediterranean regions, attributed to high temperatures.
... Das Downscaling bezeichnet ein Herunterbrechen von grob aufgelösten Klimamodell-Outputs auf eine feinere, für die Klimafolgenforschung relevante Maßstabsebene. Es wird dabei ein Zusammenhang zwischen großskaligen Prädiktoren und regionalskaligen Prädiktanden hergestellt(Lexer et al., 2002).In dieser Publikation sind die statistischen Downscalingverfahren einer multiplen linearen Regressionsanalyse (MLR) sowie der Analogmethode durchgeführt worden. Dabei ist ein deterministischer Zusammenhang zwischen atmosphärischen Variablen und regionalen Klimaparametern hergestellt worden. ...
Thesis
Die durchgeführten Analysen zeigen, dass ein statistisch belastbarer Zusammenhang zwischen atmosphärischen Zirkulationstyphäufigkeiten und starken Gebietsnieder-schlägen für das Untersuchungsgebiet südliches Mitteleuropa für den Zeitraum 1951–2006 hergestellt werden kann. Durch saisonale und regionale Differenzen der Niederschlagscharakteristik ist es jedoch notwendig, eine Subregionalisierung in Regionen ähnlicher Niederschlagsvariabilität vorzunehmen, die mittels s-modaler Hauptkomponentenanalyse auf saisonaler Basis (Winter: DJF, Frühjahr: MAM, Sommer: JJA, Herbst: SON) erfolgt ist. Starke Gebietsniederschläge sind mittels des Regionen-spezifischen 95 %-Perzentils bestimmt worden. Dabei sind die Indizes Starkniederschlagshäufigkeit (P95fre) und Starkniederschlagssumme (P95sum) zur Beurteilung der Starkniederschlagscharakteristik verwendet worden. Großräumige atmosphärische Zirkulationstypen sind unter Verwendung der COST733 Klassifika-tionssoftware berechnet worden (Philipp et al., 2010). Dabei stellen sich nur wenige (zumeist 3–7) Zirkulationstypen für die erlangten Niederschlagsregionen als stark-niederschlagsrelevant (snr) heraus. Hinsichtlich der Starkniederschlagsrelevanz kann dabei eine klare Unterscheidung vorgenommen werden: Zonale Zirkulationstypen sind snr für die nördlichen Regionen, während sich gemischte Zirkulationstypen in Kombination mit regional wirksamen, orografischen Effekten insbesondere für die nördlich an den Alpenhauptkamm anschließenden Regionen als snr herausstellen. Starke Gebietsniederschläge in allen östlichen und südlichen Regionen sind zumeist die Folge von meridionalen Zirkulationsmustern. In diese Gruppe sind die Cut-off Lows einzuordnen. Für den Beobachtungszeitraum (1951–2006) lassen sich nur einzelne statistisch sig-nifikante Trends von snr Zirkulationstypen ausweisen. Dabei besteht im Winter ein Trend zu häufiger auftretenden zonalen Zirkulationstypen, während Cut-off Lows überwiegend Häufigkeitsabnahmen oder konstante Häufigkeiten aufweisen. Als Resultat wird daher für den Beobachtungszeitraum im Winter der Trend einer signi-fikanten Zunahme der starken Gebietsniederschläge im nordwestlichen Teilbereich des Untersuchungsgebietes festgestellt, während eine signifikante Abnahme im süd-lichen Alpenraum besteht. Im Frühjahr und Sommer sind kaum Änderungen snr Zirkulationstypen gegeben, wobei einige Cut-off Lows Trends einer Reduktion ihrer Auftrittshäufigkeiten aufweisen. Eine Betrachtung der rezenten Trends starker Ge-bietsniederschläge gibt diese Entwicklung wieder, da im Sommer ein Schwerpunkt signifikanter Abnahmen starker Gebietsniederschläge in den östlichen Teilbereichen des Untersuchungsgebietes festzustellen ist, während im Frühjahr signifikante Ab-nahmen südlich der Alpen bestehen. Signifikante Zunahmen der starken Gebietsnie-derschläge resultieren im Frühjahr hingegen im Nordwesten. Der Herbst ist die einzi-ge Jahreszeit mit signifikanten Zunahmen von snr zonalen und meridionaler Zirkula-tionstypen, sodass auch die deutlichsten Änderungssignale der starken Gebietsnie-derschläge mit verbreitet auftretenden, signifikanten Zunahmen resultieren. Die Modellierung starker Gebietsniederschläge für die Klimazukunft ist mittels sta-tistischer Downscalingverfahren realisiert worden. Dabei werden im Rahmen einer multiplen linearen Regressionsanalyse (MLR) die statistischen Zusammenhänge zwi-schen monatlich aggregierten Zirkulationstyphäufigkeiten (Prädiktoren) und starken Gebietsniederschlägen aus dem Beobachtungszeitraum (1951–2006) auf Klimamo-delldaten (ECHAM6, ECHAM5, EC-EARTH) übertragen, um auf diese Weise eine Abschätzung der prozentualen Änderungen der Indizes starker Gebietsniederschläge für die Projektionszeiträume (2021–2050, 2071–2100) gegenüber dem Kontrollzeit-raum (1971–2000) für die Szenarien RCP4.5 und RCP8.5 sowie für A1B (bei ECHAM5) zu erlangen. Um mittels MLR eine Abschätzung der starken Gebietsniederschläge für die Klima-zukunft durchzuführen, sind die Zirkulationstyphäufigkeiten in den Klimamodellen bestimmt worden. Dabei resultieren nur vereinzelte signifikante Änderungen der snr Zirkulationstypen zwischen den Projektionszeiträumen und dem Kontrollzeitraum. Ein Vergleich der Szenarien gibt jedoch Aufschluss über generell höher ausfallende, prozentuale Zu- oder Abnahmen der Zirkulationstyphäufigkeiten bei dem stärkeren RCP8.5 Szenario. Zusätzlich ergeben sich bei der Auswertung einige Differenzen zwischen den Klimamodellen selbst. Es kann ein Unterschied zwischen den CMIP5-Modellen und dem CMIP3-Modell ausgewiesen werden: Nehmen im Winter bei ECHAM6 und EC-EARTH einige zonale und gemischte snr Zirkulationstypen zu, so weisen diese bei ECHAM5 keine Zunahmen auf. Gleichzeitig resultieren bei ECHAM5 Häufigkeitsabnahmen bei einem meridionalen snr Zirkulationstyp. Im Frühjahr bestehen für beide CMIP5-Modelle deutliche Häufigkeitszunahmen eines Cut-off Lows, das den Osten und Süden des Untersuchungsgebiets beeinflusst, wäh-rend ECHAM5 nur zu uneinheitlichen Häufigkeitsveränderungen snr Zirkulationsty-pen führt. Im Sommer besteht unter allen Klimamodellen ein Signal zu verbreiteten Abnahmen oder konstanten Häufigkeiten snr Zirkulationstypen, das unter dem RCP8.5-Szenario am stärksten hervortritt, während im Herbst keine signifikanten Veränderungen auftreten. Mittels der MLR sind die prozentualen Änderungen der starken Gebietsniederschlä-ge zwischen den Projektionsperioden und dem Kontrollzeitraum berechnet worden. Im Winter resultieren keine signifikanten Änderungen starker Gebietsniederschläge bei ECHAM6 und EC-EARTH. Es überwiegen leichte Abnahmen der starken Ge-bietsniederschläge, die südlich der Alpen bei RCP4.5 mit bis zu 5 % und in der Re-gion Ost (2021–2050) bei RCP8.5 mit 6 % noch am deutlichsten ausfallen (ECHAM6). Seltene, leichte Zunahmen finden noch unter RCP8.5 im Nordstau der Alpen sowie vereinzelt in der Region Erzgebirge oder Nordwest statt. Diese Ergeb-nisse stehen im Kontrast zu ECHAM5, das insbesondere in der Projektionsperiode 2071–2100 bis auf eine Ausnahme in allen Regionen des südlichen Mitteleuropas zu einer signifikanten Zunahme der starken Gebietsniederschläge um bis zu 15 % führt. Eine Zweiteilung des Untersuchungsgebietes besteht im Frühjahr. Dabei herrscht weitgehende Modelleinigkeit, sodass im nördlichen Bereich eine Zunahme der starken Gebietsniederschläge ausgewiesen werden kann, während Abnahmen südlich der Alpen auftreten. Die meisten Änderungen weisen jedoch keine Signifi-kanz auf. Eine Ausnahme bildet die signifikante Zunahme der starken Gebietsnie-derschläge im Projektionszeitraum 2071–2100 unter dem RCP8.5-Szenario bei ECHAM6 in den Regionen Nordwest und Erzgebirge um bis zu 12 %. Im Sommer bestehen die meisten signifikanten Zu- und Abnahmen starker Gebietsniederschläge unter ECHAM6, wobei diese bei RCP8.5 am deutlichsten ausfallen: Im Projektions-zeitraum 2021–2050 treten zumeist signifikante Zunahmen bis 10 % für die Regio-nen des Untersuchungsgebiets auf, während im zweiten Zeitraum 2071–2100 signi-fikante Abnahmen um bis zu 16 % bestehen. Die Region Nordwest weist durchge-hend Abnahmen auf, die unter RCP8.5 in beiden Projektionszeiträumen signifikant ausfallen. EC-EARTH und ECHAM5 weisen in dieser Jahreszeit ähnliche Änderun-gen auf. Im Herbst treten zumeist nur insignifikante Änderungen der starken Ge-bietsniederschläge bei allen Modellen auf. Dabei bestehen – ähnlich wie im Sommer – im Zeitraum 2021–2050 überwiegende Zunahmen der starken Gebietsniederschlä-ge, während sie im späteren Projektionszeitraum verbreitet abnehmen. Insgesamt ist keine systematische Erhöhung der Hochwassergefahr aus den Ergebnissen abzulei-ten. Zwischen den beiden Indizes der starken Gebietsniederschläge ergeben sich keine maßgeblichen Differenzen, sodass eine Intensitätssteigerung von Starknieder-schlägen auf Basis der Zirkulationstyphäufigkeiten nicht nachgewiesen werden kann. Ein Vergleich der statistischen Downscalingverfahren der MLR und der Analogme-thode zeigt auf, dass die Ergebnisse im Winter und Sommer von beiden Ansätzen weitgehend bestätigt werden können, während im Herbst und zum Teil im Frühjahr aufgrund der nicht signifikant ausfallenden Änderungen der starken Gebietsnieder-schläge zumeist uneinheitliche Ergebnisse resultieren. Eine auf der Analogmethode aufbauende Extremwertanalyse führt zwar zu insignifikanten Ergebnissen der Ände-rungen der Tages-Niederschlagssummen bei variierenden Wiederkehrintervallen, kann aber dennoch durch vereinzelt vorliegende, systematische Änderungssignale bezüglich der Projektions-zeiträume und/oder Szenarien die prozentualen Änderun-gen der starken Gebiets-niederschläge einiger Regionen aus der MLR und der Ana-logmethode bestätigen, sodass insgesamt davon ausgegangen werden kann, dass im Sommer bei RCP8.5 ein deutliches Klimasignal über die dekadische Klimavariabili-tät dominiert.
... Az elemzés kimutatta, hogy már 1°C-os hőmérséklet emelkedés változatlan csapadékviszonyok mellett is jelentős változá- sokat hozhat az ausztriai erdőkben. Magasabb térszinteken a lombhullató fajok versenyké- pesebbekké válnak a fenyőkkel szemben, míg alsóbb térszinteken a luc állományok nem lesznek fenntarthatóak gazdasági rendeltetésű állományként ( Lexer et al. 2002). ...
... To our knowledge, no comparable study exists so far. However, impacts studies have shown the decisive role of climate for the future of tree species in Austria [61] and neighbouring countries [62,63]. ...
Article
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Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the species potential distribution, but also N driven nutrient enrichment may threaten these habitats. We applied a dynamic geochemical soil model (VSD+) together with a novel niche-based plant response model (PROPS) to 5 forest habitat types (18 forest sites) protected under the EU Directive in Austria. We assessed how future climate change and N deposition might affect habitat suitability, defined as the capacity of a site to host its typical plant species. Our evaluation indicates that climate change will be the main driver of a decrease in habitat suitability in the future in Austria. The expected climate change will increase the occurrence of thermophilic plant species while decreasing cold-tolerant species. In addition to these direct impacts, climate change scenarios caused an increase of the occurrence probability of oligotrophic species due to a higher N immobilisation in woody biomass leading to soil N depletion. As a consequence, climate change did offset eutrophication from N deposition, even when no further reduction in N emissions was assumed. Our results show that climate change may have positive side-effects in forest habitats when multiple drivers of change are considered.
... Conséquences des changements climatiques sur la forêt 3 les stations d'épicéas de basse altitude, tandis que le hêtre et le chêne profiteront probablement des changements climatiques(leXer et al. 2002 ; ro- loFF et grundmann 2008 ; nothdurFt 2013). Une évaluation fiable de tendances nationales et mondiales nécessite un système de monitoring homogène pour que les taux actuels de mortalité puissent être corrélés directement avec des événements déclencheurs(allen et al. 2010 ; hartmann et al. 2015). ...
... There are between these two regions, respectively called Zona da Mata and Sertão, a transition area, known as Agreste. The vegetation is directly related to the climatic variability of a given region (Lexer et al., 2002). ...
Article
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Abstrato: O presente estudo teve como objetivo interpretar e analisar o padrão espacial de NDVI e chuvas no estado de Pernambuco. Utilizamos dados médios mensais de precipitação e NDVI, que obtivemos do satélite Terra / MODIS, com resolução espacial de 1 km, do período 2003-2013. Aplicamos a Análise de Componentes Principais (PCA) para determinar o padrão espacial da variabilidade de variáveis. Nossos resultados mostraram que, em geral, há uma relação entre a distribuição das chuvas e o alívio do estado, não necessariamente em quantidade, mas na distribuição espacial. Além disso, a vegetação reage de acordo com a precipitação da região.
... Recent research has recognized the inter-and intraspecific differences in temperate tree growth and productivity (George et al., 2015;Suvanto et al., 2016) as well as differences in the productivity of different mixtures of species (Bošel'a et al., 2015;Pretzsch et al., 2012Pretzsch et al., , 2015. Such findings have been used in forest management planning and parameterization of forest models for the region (Bošel'a et al., 2013b;Hlásny et al., 2014a;Lexer et al., 2002;Pretzsch et al., 2014). We investigate here three widespread tree species that have high commercial and ecological importance and that constitute some of the original forest communities in Central Europe: Norway spruce (Picea abies L. Karst), European beech (Fagus sylvatica L.), and silver fir (Abies alba Mill.). ...
Article
Climate is an important driver of forest health, productivity, and carbon cycle, but our understanding of these effects is limited for many regions and ecosystems. We present here a large-scale evaluation of climate effects on the productivity of three temperate tree species. We determine whether the National Forest Inventory data (NFI) collected in the Czech Republic (14,000 plots) and Slovakia (1,180 plots) contains sufficient information to be used for designing the regional climate-productivity models. Neural network-based models were used to determine which among 13 tested climate variables best predict the tree species-specific site index (SI). We also explored the differences in climate-productivity interactions between the drier and the moister part of the distribution of the investigated species. We found a strong climatic signal in spruce SI (R 0.45-0.62) but weaker signals in fir and beech (R 0.22-0.46 and 0.00-0.49, respectively). We identified the most influential climate predictors for spruce and fir, and found a distinct unimodal response of SI to some of these predictors. The dominance of water availability-related drivers in the dry-warm part of a species’ range, and vice versa, was not confirmed. Based on our findings, we suggest that (i) the NFI-based SI is quite responsive to climate, particularly for conifers; (ii) climate-productivity models should consider the differences in productivity drivers along ecological gradients, and models should not be based on a mixture of dry and moist sites; and (iii) future studies might consider the subset of influential climate variables identified here as productivity predictors in climate-productivity models.
... In Deutschland und Österreich wird vor allem für tief gelegene Fichtenstandorte eine Zunahme des Mortalitätsrisikos prognostiziert, wogegen Buche und Eiche vermutlich vom Klimawandel profitieren werden (LEXER et al. 2002;ROLOFF und GRUNDMANN 2008;NOTHDURFT 2013 ...
... Therefore, we are keeping each author's definition and rationale for categorizing an indicator. Ecological indicators are explained in more details in Chapters 11 through 17. (Bugmann 1996), FORMIX3 (Huth and Ditzer 2001), PICUS (Lexer et al. 2002), FAREAST (Shuman et al. 2011, Lutz et al. 2013) Structure ...
... (ii) The ecological input parameters are from previous published references and long-term sequenced filed investigations, which are supported by the Qianyanzhou ecological station in the Taihe County. The input of initial community map was derived from forestry inventory data which has made a big contribution to forest studies (Lexer et al., 2002;Corona et al., 2011). (iii) The outputs of our simulation are reasonable, and in accordance with expert knowledge. ...
Article
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In the past three decades, our global climate has been experiencing unprecedented warming. This warming has and will continue to significantly influence the structure and function of forest ecosystems. While studies have been conducted to explore the possible responses of forest landscapes to future climate change, the representative concentration pathways (RCPs) scenarios under the framework of the Coupled Model Intercomparison Project Phase 5 (CMIP5) have not been widely used in quantitative modeling research of forest landscapes. We used LANDIS-II, a forest dynamic landscape model, coupled with a forest ecosystem process model (PnET-II), to simulate spatial interactions and ecological succession processes under RCP scenarios, RCP2.6, RCP4.5 and RCP8.5, respectively. We also modeled a control scenario of extrapolating current climate conditions to examine changes in distribution and aboveground biomass (AGB) among five different forest types for the period of 2010–2100 in Taihe County in southern China, where subtropical coniferous plantations dominate. The results of the simulation show that climate change will significantly influence forest distribution and AGB. (i) Evergreen broad-leaved forests will expand into Chinese fir and Chinese weeping cypress forests. The area percentages of evergreen broad-leaved forests under RCP2.6, RCP4.5, RCP8.5 and the control scenarios account for 18.25%, 18.71%, 18.85% and 17.46% of total forest area, respectively. (ii) The total AGB under RCP4.5 will reach its highest level by the year 2100. Compared with the control scenarios, the total AGB under RCP2.6, RCP4.5 and RCP8.5 increases by 24.1%, 64.2% and 29.8%, respectively. (iii) The forest total AGB increases rapidly at first and then decreases slowly on the temporal dimension. (iv) Even though the fluctuation patterns of total AGB will remain consistent under various future climatic scenarios, there will be certain responsive differences among various forest types.
... Among population dynamics models (or gap models, as they are widely known), the most widely known is JABOWA (Botkin et al., 1972), which has been the basis for the development of many other gap models, such as FORCAT (Waldrop et al., 1986), FORDACK (Kruse and Porter, 1994), FORMIS (Shugard, 1984), FORSKA (Leemans and Prentice, 1987), GROWEST (Fitzpatrick and Nix, 1970) and PICUS (Lexer et al., 2001). These models simulate the dynamics of individual trees, their recruitment, growth and mortality based on a series of either deterministic or stochastic functions. ...
Thesis
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Forests are a valuable resource for humans providing a range of products and services such as construction timber, paper and fuel wood, recreation, as well as living quarters for indigenous populations and habitats for many animal and bird species. Most recent international political agreements such as the Kyoto Protocol emphasise the role of forests as a major sink for atmospheric carbon dioxide mitigation. However, forest areas are rapidly decreasing world wide. Thus, it is vital that efficient strategies and tools are developed to encourage sustainable ecosystem management. These tools must be based on known ecological principles (such as tree physiological and soil nutrient cycle processes), capable of supplying fast and accurate temporal and spatial predictions of the effects of management on both timber production and carbon sequestration. This thesis had two main objectives. The first was to investigate the environmental factors affecting growth and carbon sequestration of Scots pine (Pinus sylvestris L.) across Scotland, by developing a knowledge base through a statistical analysis of old and novel field datasets. Furthermore, the process-based ecosystem model 3-PGN was developed, by coupling the existing models 3-PG and ICBM. 3-PGN calibrated using a Bayesian approach based on Monte Carlo Markov Chain simulations and it was validated for plantation stands. Sensitivity and uncertainty analyses provided an understanding of the internal feedbacks of the model. Further simulations gave a detailed eco-physiological interpretation of the environmental factors affecting Scots pine growth and it provided an assessment of carbon sequestration under the scenario of sustainable, normal production and its effects from the environment. Finally, the study investigated the spatial and temporal patterns of timber production and carbon sequestration by using the spatial version of the model and applying advanced spatial analyses techniques. The second objective was to help close the gap between environmental research and forest management, by setting a strategic framework for a process-based tool for sustainable ecosystem management. The thesis demonstrated the procedures for a site classification scheme based on modelling results and a yield table validation procedure, which can provide a way forward in supporting policies for forest management and ensuring their continued existence in the face of the present and future challenges.
... Indeed, by recognizing vegetation as the leading factor in a terrestrial ecosystem, PNV integrates abiotic factors and phytogeographic information combined with structure, dynamics and ecology of plant communities. PNV has been used in landscape planning and management (Chytrý 1998, del Rio et al. 2005), to test and develop climate change scenarios (Lexer et al. 2002) and to define a biogeographical classification at regional level (Gallizia Vuerich et al. 2001). This paper proposes PNV as a useful tool that contributes to select conservation priorities on a national scale. ...
Article
Protected Areas (PAs) are recognized as the most important core 'units' for in situ conservation. In spite of this, many studies have demonstrated that the existing PAs system often does not represent and protect the biodiversity of a region. Gap analysis methods are widely applied and documented as useful instruments to identify elements that need further protection. In this context, we introduce the concepts of potentiality of a territory using Potential Natural Vegetation mapping for conservation prioritization. A Gap analysis of Natura 2000 network in Itay was performed to evaluate the representativeness of the Potential Natural Vegetation types. In this context, the PNV map, reflecting the diversity and spatial arrangement of the natural terrestrial ecosystems, can be considered as an appropriate proxy of environmental and biogeographical diversity of Italy. The map was compiled by a panel of regional experts from throughout Italy and produced at a scale of 1:250.000. The construction of the potential vegetation map was based on existing remnants of natural ecosystem and their relation to specific abiotic site condition integrated in a hierarchical land classification approach. The adopted conservation target considered that any PNV included for less than the 10% in the Protected Area was defined as a Gap in the system. Results show that more than 32 % of PNV types recognised on the Italian territory are not protected by Natura 2000 network. The proposed PNV approach can help guiding decisions on where and how to spend scarce conservation management resources.
... Déqué et al. (2007Déqué et al. ( , 2012 (2021-2050 versus 1971-2000) for temperature [ °C] and precipitation [%] for most available regional climate simulations within the Alpine region. Based on ENSEMBLES, reclip:century, REMO-UBA Lexer et al., 2000;Lexer et al., 2001;Matulla et al., 2002). Damit wurden potentielle Veränderungen in der Zusammensetzung der Artenvielfalt des österreichischen Waldes beschrieben. ...
... The PICUS forest ecosystem model has already proven its ability as a valuable tool for climate change impact studies (Maroschek et al. 2015;Seidl et al. 2011;Lexer et al. 2002). The model has been evaluated in several validation experiments and has built up substantial credibility for applications in European mountain forests (e.g. ...
Article
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In Central Europe, management of forests for multiple ecosystem services (ES) has a long tradition and is currently drawing much attention due to increasing interest in non-timber services. In face of a changing climate and diverse ES portfolios, a key issue for forest managers is to assess vulnerability of ES provisioning. In a case study catchment of 250 ha in the Eastern Alps, the currently practiced uneven-aged management regime (BAU; business as usual) which is based on irregularly shaped patch cuts along skyline corridors was analysed under historic climate (represented by the period 1961–1990) and five transient climate change scenarios (period 2010–2110) and compared to an unmanaged scenario (NOM). The study addressed (1) the future provisioning of timber, carbon sequestration, protection against gravitational hazards, and nature conservation values under BAU management, (2) the effect of spatial scale (1, 5, 10 ha grain size) in mapping ES indicators and (3) how the spatial scale of ES assessment affects the simultaneous provision of several ES (i.e. multifunctionality). The analysis employed the PICUS forest simulation model in combination with novel landscape assessment tools. In BAU management, timber harvests were smaller than periodic increments. The resulting increase in standing stock benefitted carbon sequestration. In four out of five climate change scenarios, volume increment was increasing. With the exception of the mildest climate change scenario (+2.6 °C, no change in precipitation), all other analysed climate change scenarios reduced standing tree volume, carbon pools and number of large old trees, and increased standing deadwood volume due to an intensifying bark beetle disturbance regime. However, increases in deadwood and patchy canopy openings benefitted bird habitat quality. Under historic climate, the NOM regime showed better performance in all non-timber ES. Under climate change conditions, the damages from bark beetle disturbances increased more in NOM compared with BAU. Despite favourable temperature conditions in climate change scenarios, the share of admixed broadleaved species was not increasing in BAU management, mainly due to the heavy browsing pressure by ungulates. In NOM, it even decreased and mean tree age increased. Thus, in the long run NOM may enter a phase of lower resilience compared with BAU. Most ES indicators were fairly insensitive to the spatial scale of indicator mapping. ES indicators that were based on sparse tree and stand attributes such as rare admixed tree species, large snags and live trees achieved better results when mapped at larger scales. The share of landscape area with simultaneous provisioning of ES at reasonable performance levels (i.e. multifunctionality) decreased with increasing number of considered ES, while it increased with increasing spatial scale of the assessment. In the case study, landscape between 53 and 100 % was classified as multifunctional, depending on number and combinations of ES.
... No obstante que la combinación de condiciones térmicas y de precipitación para escenarios de clima en el futuro y su efecto en selvas en México no ha sido estudiada, es posible que para los grupos funcionales de la SNO se presenten condiciones limitantes para los géneros que habitan estas zonas. En el oste de Estados Unidos (Iverson y Prasad, 1998y 2002, Australia (Lexer et al., 2002) y China (Chen, 2002) estudios de tolerancias climáticas de especies dominantes, prevén una reducción del área de distribución actual de comunidades de bosques templados. De acuerdo con los resultados de este estudio, las comunidades de bosques templados y bosques mesófilos comparten especies de manera importante, lo que sugiere que su vulnerabilidad al cambio climático es similar, no obstante de grados de amenaza diferente. ...
Article
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Temperature raise and changes in precipitation expected under climate change scenarios will impact on species distribution at regional al global level; although in Mexico few studies of plant species vulnerability exist. The objectives of this study were: a) to determine plant functional types of plants based on life forms; b) to determine biogeography distribution and actual climate and altitude gradients and, c) to define vulnerability of plant functional types under climate change scenarios in Sierra Norte of Oaxaca (SNO). Potential response of functional groups was based on an ensemble of eight general circulation models with four emissions scenarios at global scale and, a Japanese model of very high regional resolution (20 × 20 km). To characterize groups of climate response, dominant species were defined for seven vegetation types in SNO. Climate change scenarios ensemble suggested an increment of temperature between 1.5 and 2.5° C, and a change in precipitation between +5 and -10 %. Sensitivity analysis suggested that for climate change scenarios in 2050 genera like Abies and Pinus would diminish their geographic distribution. Results of this study can help to define conservation strategies and manage of those species less tolerant to perturbation in actual and future climate at regional scales.
... Increased forest productivity is also expected in temperate-oceanic areas of northern France [63] and in boreal forests in Sweden [64] and Finland [65,66]. Decreases in forest productivity are expected in south-western France [63], while Norway spruce is expected to become an unsuitable timber species in lowland Austria in the future [67]. Increased temperatures and reduced precipitation resulting from CC is expected to reduce wood production in the Mediterranean area [68]. ...
Article
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Research Highlights: Predicting impacts on forest management of Climate Change (CC) and dynamic timber prices by incorporating these external factors in a Forest Management Decision Support System (FMDSS). Background and Objectives: Forest managers must comply with Sustainable Forest Management (SFM) practices, including considering the long-term impacts that CC and the bioeconomy may have on their forests and their management. The aims of this study are: (1) incorporate the effects of CC and Dynamic Prices (DP) in a FMDSS that was developed for Ireland's peatland forests, (2) analyse the impact of global climate and market scenarios on forest management and forest composition at the landscape level. Materials and Methods: Remsoft Woodstock is a strategic planning decision support system that is widely used for forest management around the world. A linear programming model was developed for Ireland's Western Peatland forests while using Woodstock. Data from Climadapt, which is an expert-based decision support system that was developed in Ireland, were used to include CC effects on forest productivity and species suitability. Dynamic market prices were also included to reflect the changing demands for wood fibre as part of the European Union (EU) and global effort to mitigate CC. Results: DP will likely have more impact on harvest patterns, volumes, and net present value than CC. Higher assortment prices, especially for pulpwood, stimulate the harvesting of forests on marginal sites and offset some of the negative CC growth impacts on forest profitability. Conclusions: Incorporating CC and bioeconomy prices in a forest decision support system is feasible and recommendable. Foresters should incorporate the expected global changes in their long-term management planning to mitigate the negative effects that un-informed management decisions can have on the sustainability of their forests.
... The projected increase of potential ranges of deciduous forests (Querco-Fagetea) is plausibly explained by upward expansion of these summer-green forests at the cost of montane and subalpine coniferous forests (Vaccinio-Piceetea) as also predicted by forest gap models (Lexer et al. 2002) and dynamic vegetation models (Hickler et al. 2012). Thereby, subtypes currently limited to particularly warm parts of Austria and more widespread in sub-Mediterranean areas (e.g. ...
Article
Species distribution models (SDMs) are used to project how suitable ranges of species shift under a warming climate. Conservation management, however, commonly targets habitat types rather than individual species. Such habitat types are often defined by the co-occurrence of a set of characteristic species. Here, we develop a co-occurrence-based index (CRI); which measures how the representation of habitat types in a particular area may change in a future climate. The index is based on stacking projections of distribution models of characteristic species and accounts for changes both in potential range size of each species individually and in spatial range overlap among characteristic species, i.e. co-occurrence patterns. We illustrate the approach by modelling the changing representation of 68 habitat types in Austria under two different climate scenarios. We base index calculations on SDM projections under either the assumption of unrestricted mobility (‘full-dispersal’) or of complete immobility (‘no-dispersal’) of individual species. Moreover, we compare results to those achieved with a simpler occurrence-based index (OI); which only accounts for change in species’ range sizes. All three alternative index calculations suggest that most modelled habitat types will lose area (in particular mires, wetlands and siliceous alpine grasslands) and only a minority will profit from a warming climate (in particular forests of dry and warm sites). ‘Full-dispersal’ CRI and OI are closely, but not perfectly correlated. Importantly, for more than half of the habitat types, accounting for changing co-occurrence patterns amplifies projected losses. The ‘no-dispersal’ CRI (CRInd) delivers the most alarming projections, indicating considerable spatial turn-over of sites suitable to the habitat types. Taken together, our results suggest that modelling re-distribution of habitat types which are defined by species combinations needs to account for modifications of co-occurrence patterns. Moreover, conservation should acknowledge that novel combinations of species will likely emerge under a warming climate.
... Déqué et al. (2007Déqué et al. ( , 2012 (2021-2050 versus 1971-2000) for temperature [ °C] and precipitation [%] for most available regional climate simulations within the Alpine region. Based on ENSEMBLES, reclip:century, REMO-UBA Lexer et al., 2000;Lexer et al., 2001;Matulla et al., 2002). Damit wurden potentielle Veränderungen in der Zusammensetzung der Artenvielfalt des österreichischen Waldes beschrieben. ...
... Our data suggest its occurrence is closely linked to deadwood under a suitable climate, whereby desiccation and deadwood were the key predictors. The precipitation regime could be altered by climate change [36], as could the tree-communities [37] and thus the quality of available deadwood. Although Buxbaumia viridis grew on different host tree species, it showed a preference for spruce, a tree species that will change its area across Europe fundamentally [38]. ...
Article
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Deadwood is a biodiversity hotspot and habitat for numerous highly endangered species. Buxbaumia viridis has been assessed as a flagship species for deadwood-rich forests and is subject to monitoring under the Habitats Directive, yet we lack a solid understanding of the factors controlling its distribution. The study aimed to specify the climate and habitat preferences of Buxbaumia viridis and identify the best predictor variables. We collected presence-absence data of the species at 201 sites between 2016 and 2020. Study sites cover three biogeographic regions (Pannonian, Continental, and Alpine). They also represent a deadwood gradient ranging from managed forests to natural forest reserves and virgin forests. Our results suggest that desiccation and deadwood amount are the best predictor variables. The amount of deadwood at the colonized sites ranged from 1 m3/ha to 288 m3/ha, with a median of 70 m3/ha. The maximum desiccation, i.e., consecutive days without rain and at least 20 ◦C was 9.6 days at colonized sites. The results of logistic regression models suggest that desiccation limits Buxbaumia viridis occurrence on deadwood in the drier continental parts of eastern Austria. Derived details on climate and habitat requirements of Buxbaumia viridis can specify management and conservation. They clearly show how strongly the species is dependent on climate, which can counteract deadwood measures.
... These factors may cause increases in drought severity as well as the risk of extreme precipitation events. Ultimately, the results may be any of: the shifting of the geographical ranges of tree species and altered competition species (Lidner et al. 1997;Lexer et al. 2002;Parmesan 2006;Rouault et al. 2006;Lavergne et al. 2010;Morin et al. 2008;Suttle et al. 2007); the disappearance of less resilient tree species Lindner et al. 2008;Lindner et al. 2010); changes in the distribution of tree species (CCSP 2008;USGCRP 2009;Garzón et al. 2011); changes in tree growth and productivity (Bergh et al. 2003;Loustau et al. 2005;Tilman et al. 2014); changes in the frequencies of pest outbreaks (Volney and Fleming 2000); and deflagration and propagation of forest fires (Mukhopadhyay 2009). ...
... These factors may cause increases in drought severity as well as the risk of extreme precipitation events. Ultimately, the results may be any of: the shifting of the geographical ranges of tree species and altered competition species (Lidner et al. 1997;Lexer et al. 2002;Parmesan 2006;Rouault et al. 2006;Lavergne et al. 2010;Morin et al. 2008;Suttle et al. 2007); the disappearance of less resilient tree species Lindner et al. 2008;Lindner et al. 2010); changes in the distribution of tree species (CCSP 2008;USGCRP 2009;Garzón et al. 2011); changes in tree growth and productivity (Bergh et al. 2003;Loustau et al. 2005;Tilman et al. 2014); changes in the frequencies of pest outbreaks (Volney and Fleming 2000); and deflagration and propagation of forest fires (Mukhopadhyay 2009). ...
Book
Sustainable soil/land management and Climate Change provides a state of the art summary of latest outcomes and future research challenges on organic carbon, greenhouse emission gases, plant soil interactions, microbial approach for alleviation of potentially toxic elements in agricultural soils along with reclaiming saline soil. This book is especially designed for agronomic, soil science and environmental sciences students and researchers and will improve the knowledge of preservation of organic matter, microbial approach as well as soil and plant interactions. . Salient Features (minimum 5):  Explores the latest investigation about the greenhouse emission gases  Highlights the different approaches and managements strategies for the stabilization of soil organic matter  Addresses the new priming techniques in the era of climate change.  Presents valuable information’s on Microbial tactics for alleviation of potentially toxic elements in agricultural soils  Delivers significant knowledge for the all students of soil science, agronomy, plant physiology and environmental sciences related to the most appropriate management technologies to improve soil fertility status.
... PNV has already been integrated in conservation planning, forest management or research on the impact of atmospheric CO 2 concentration on vegetation (e.g. Lexer et al., 2002;Notaro et al., 2005;Ricotta et al., 2002). ...
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Specifying the upper bound of C storage in forest ecosystems allows an estimate of the amount of C that can be stored in the future. The Białowieża Forest in NE Poland is the last relic forest in the European lowlands. Still, it has been subject to various natural and human-induced disturbances and its C stock has been reduced. The main goal of our study was therefore to assess the current and potential C stock in the forest communities of the Białowieża Biosphere Reserve (597 km 2), taking into account the diversity of habitats as well as different protection and management practices. For this we identified 13 forest communities and quantified their current C stock stored in all major pools (living trees, deadwood and soil). We used vegetation and soil data collected in 2018 at 1391 systematically distributed 0.04 ha forest plots (sampling grid 650 × 650 m). We used the concept of potential natural vegetation (PNV) and randomized upscaling of plot level current biomass C stock values to estimate the upper bounds of biomass C stocks possible to obtain at the stand level. We showed that the Białowieża Forest stores currently 300 Mg C ha − 1 (17.2 Tg C), of which 41% is accumulated in biomass, with significant variation among different forest communities and management regimes. We obtained the upper bounds of biomass C stocks ranging from 94 Mg ha − 1 for swamp pine forest to 223 Mg ha − 1 for lime-oak-hornbeam forest. We estimated the gap between the current and potential C stock in biomass at 66 Mg ha − 1 (3.8 Tg); 62% of the potential level is achieved in managed forests, and 76% in the National Park. Our findings may be used in planning forest management aimed toward long-term C storage, and the obtained upper bounds can serve as benchmarks in assessing C storage potential of similar forest types elsewhere. We also suggest that the potential of ecosystems to store C should be considered in the landscape context, i.e. by taking into account the spatial extent of PNV habitats and their unequal capacity to provide C storage service.
... These factors may cause increases in drought severity as well as the risk of extreme precipitation events. Ultimately, the results may be any of: the shifting of the geographical ranges of tree species and altered competition species (Lidner et al. 1997;Lexer et al. 2002;Parmesan 2006;Rouault et al. 2006;Lavergne et al. 2010;Morin et al. 2008;Suttle et al. 2007); the disappearance of less resilient tree species (Thuiller et al. 2005;Lindner et al. 2008;Lindner et al. 2010); changes in the distribution of tree species (CCSP 2008;USGCRP 2009;Garzón et al. 2011); changes in tree growth and productivity (Bergh et al. 2003;Loustau et al. 2005;Tilman et al. 2014); changes in the frequencies of pest outbreaks (Volney and Fleming 2000); and deflagration and propagation of forest fires (Mukhopadhyay 2009). ...
Chapter
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The ongoing increase in global temperatures will simultaneously cause both an alteration in global and local precipitation patterns and effect the existing agricultural ecosystem in most parts of the world. Changes in atmospheric/climate systems, including atmospheric pollutant levels, will have strong impacts on the environment, particularly the functional ability of soils through influencing the hydrological, carbon and nitrogen cycles. This impact will frequently have an adverse effect on the existing ecosystems which are adapted to the prior climate. A major concern is that increased temperature has a negative effect on C sequestration which causes a decrease in soil organic C and a consequent feed forward increase in the global temperature due to the increased CO2 release from soils to the atmosphere. The decrease in the soil’s functional ability (e.g. lower water and nutrient holding ability) due to the low organic matter, increased erosion, greater demand for moisture and other factors will lead to more pressure on agricultural ecosystems, many of which are already struggling to meet the food and fiber demands of increasing local and global populations. Similar to the effects on agricultural ecosystems, ongoing changes in climates which may locally become warmer and drier or wetter can trigger disturbances of structure, composition and function within forest ecosystems. The disturbances in agricultural and forest ecosystems will strongly impair the sustainable provisioning of present ecosystem services.
... physiological processes in physiological models, structural and compositional processes in gap models, or spatial complexity in landscape models. Therefore, forest gap models and hybrids of physiological and gap models have been applied in numerous climate change impact assessments in mountain forests (Lexer et al., 2002;Rasche et al., 2011;Irauschek et al., 2017;Thrippleton et al., 2020). The application of such climate-sensitive forest dynamic models to specific forest site units is a promising approach for evaluating tree species recommendations in circumstances of changing site features. ...
Thesis
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The spatial modelling of forest site information is a broad scientific field, ranging from various topics to various scales. In most cases, it is at the interface between forest ecology and other natural sciences, e.g. geology, climatology, botany, soil science, geography, and statistical computing. In any case, the results are essential for sustainable forest management in times of changing environmental conditions. Only detailed knowledge of site ecological conditions enables decisions to be made with regard to tree species or forest management strategies – which will eventually be ‘judged’ by future climate conditions. Different current topics and methods of forest site classification related to climate change are addressed by the individual publications. These range from the simple forest site classification approach of subdividing mountainous landscapes into vegetation zones along elevational transects (Publication I), individual-based statistical methods for identifying site features driving forest regeneration patterns (Publication II), to the spatial prediction of soil characteristics for forest site information systems (Publications III and IV). Furthermore, different levels of field recordings and modelling scales, from microsites to stand level, are considered. It is common for modern forest site classification systems to use different methodological approaches, but the use and integration of different scales can also help in gaining new insights and recognising patterns that might otherwise not emerge. In the methodology chapter, an overview of the important statistical methods acquired during the doctoral program is presented. Therein, descriptive statistical analysis formed the basis of all studies and novel methods had to be applied especially for handling the dimensionality of the soil data. To add value to already existing soil analysis data, compiling data from different sources was necessary and required preprocessing and standardisation methods. Besides the modelling itself, assessing accuracy and uncertainty was identified as an essential part of spatial prediction. Therefore, a set of validation methods for model performance, bias, and uncertainty were applied, namely accuracy indices, crossvalidation by splitting the dataset with different selections, i.e. either random or spatial block, a description of model uncertainty with estimated rediction intervals, testing for the spatial autocorrelation of the model residuals by applying a sample variogram, and a comparison of the model results of unseen data. Publication I shows an unimodal distribution of soil organic carbon stock along elevation and indicates a peak in highly productive forest types. Regarding the aspect of climate change mitigation, identifying sites with a high soil organic carbon storage capacity will be of interest. Increasing the proportion of remaining deadwood at such sites could provide effective CO2 storage. Publication II indicates, that long regeneration periods in combination with suppressed mixed species tree regeneration due to ungulate browsing, will increase the vulnerability of mountain forests growing on Leptosols to climate change. The temporal pattern of the relative growth rate, with a strong decline in 2018, is interpreted as a response to heat waves and drought. In Publication III, the value of newly developed quantitative information on parent material for soil development is shown. This could stimulate further developments in digital soil mapping, especially in mountain environments. In addition, the characterisation of physical and geochemical soil properties in Publication IV results in practical recommendations for forest management in terms of sustainable biomass use and the risk of soil compaction. This leads us back to the different aims and purposes of forest site classification, which have in common that they support the sustainable management of forest ecosystems. Herein, the thesis on spatial modelling methods for forest site classification in mountain areas attempts to close the gap between sophisticated statistical methods and practical applications.
... Simulationen legen nahe, dass artenreiche Laubwaldtypen ihr potenzielles Verbreitungsgebiet vergrößern werden (Kienast et al., 1998;Lexer et al. 2002) höhere Artenvielfalt in den Borkenkäferflächen festgestellt werden, insbesondere für die gefährdeten "Rote-Liste"-Arten (Beudert et al. 2015 ...
... PICUS includes a flexible management module enabling the implementation of silvicultural treatments at tree level depending on tree attributes and patch location. The model includes 17 parameterized tree species and has been validated (Seidl et al., 2005;Didion et al., 2009a) and applied in numerous studies all over Europe (Lexer et al., 2002;Maroschek et al., 2015;Pardos et al., 2015;Zlatanov et al., 2017). ...
Article
Forest ecosystem models, being widespread science tools and used for forest management decision support are usually evaluated individually against field data sets, while model intercomparison and joint evaluation studies are rare. We tested five forest models according to a harmonized protocol against data from nine forest compartments in the Snĕžnik region, in Slovenia. The suite of models included stand-and landscape-scale, empirical-and process-based models used across Europe. The test dataset originated from inventory data covering 50 years (tree measurements 1963, 1983 and 2013) and included annual harvesting records at tree level. Uncertainties in data and forest conditions were considered by defining 12 scenarios varying initial regeneration, browsing pressure and harvest modalities. We evaluated the models` ability to initialize forest conditions accurately, whether management interventions could be implemented based on harvest records, and how well basal area and diameter structure could be predicted. Simulation results for basal area development showed good to satisfactory performance for all models, at which SAMSARA2, SIBYLA and PICUS showed the best agreement. Comparison of simulated and observed diameter distributions showed good performance of ForClim, PICUS, SAMSARA2 and SIBYLA. Model output variability was between 6% and 24%, indicating the relevance to consider uncertainties that can be attributed to specific sources. There was no clear hierarchy between more empirical or more process-based models regarding accuracy of stand development projections. The cohort-based landscape model LandClim showed the lowest stand-level accuracy and scenario sensitivity, but results nevertheless qualified it for complementary application at landscape scale. Within individual-based models, spatially explicit models seemed to be more suitable for heterogeneous mixed mountain forests. The findings demonstrated the usefulness of inventory datasets for model testing and intercomparison.
... The impact of climate change on crop productivity has become a major area of scientific concern. Various studies are being conducted to assess the impact of climate change on crop productivity such as maize, wheat and rice (Howden et al., 1997;Hoogenboom, 2000;Gbetibouo et al., 2005;Aggarwal et al., 2006a;Aggarwal et al., 2006b;Dhungana et al., 2006;Challinor et al., 2008), forests (Lexer et al., 2002), industry (Harle et al., 2007) and native landscape (Dockerty et al., 2005;Dockerty et al., 2006). Crop and climate models are widely used by the research community to study the crop productivity and soil water balance in the changing climate (Kang et al., 2009). ...
... Compared to uncertainty analyses, sensitivity analyses commonly quantify the effects of model parameters on the simulation results through the Monte Carlo method (Wenger et al., 2013). Sensitivity analyses have the potential to quantify the sensitivity of the forest ecosystem response to climate change by setting temperature and precipitation gradients (Lexer et al., 2002;Shuman et al., 2011). ...
Article
Climate change is more pronounced in boreal forests than in other terrestrial ecosystems, and thus aboveground biomass and species composition of boreal forests have already been altered by increasing temperature and precipitation. There are substantial uncertainties in predicting aboveground biomass and species composition of boreal forests in response to climate change since the uncertainty in climate change predictions. This makes it challenging to design forest management strategies for promoting boreal forests to adaption climate change. In this study, we designed a factorial experiment and a model coupling framework to quantify the sensitivity of aboveground biomass and species composition of boreal forests in response to climate change. Our results showed that the uncertainties in temperature and precipitation predictions caused the divergent responses of aboveground biomass and species composition to climate change in the boreal forests of northeastern China. Aboveground biomass of boreal forests is more sensitive to precipitation than temperature. There are divergent responses of tree species to temperature and precipitation over the 21st century. This suggests that it is necessary to quantify and reduce the uncertainty in climate change predictions through statistical analysis methods before applying the predictions from general circulation models (GCMS) to study the effects of climate change on forest ecosystems.
... Several empirical or process-based models have been developed to link forest stand management with susceptibility to specific damaging agents and infer on associated risks but only a few can deal with two combined hazards, e.g. wind and bark beetles (Temperli et al., 2013), drought and bark beetles (Lexer et al., 2002) or fire and bark beetles (Simard et al., 2011). However, none, to our knowledge, are generic enough to incorporate multiple hazards in many different forest conditions. ...
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Aim of study: Adaptation of silviculture in planted forest may help to mitigate damage due to biotic and abiotic hazards. However, compromises have to be found because it is not possible to minimize the risk from all hazards through application of a single forest management approach. The objective of this study was to improve a multi-criteria risk analysis (MCRA) method that makes it possible to rank forest management alternatives (FMAs) according to multiple risks. Material and Methods: We defined eight FMAs for maritime pine forests in France, Spain and Portugal. We used as the definition of risk the combination of hazard, susceptibility and exposure. Hazard level was estimated using archive data on occurrence and severity of damaging agents over the last few decades. Forest susceptibility to hazards was evaluated by experts who scored the effect on stand resistance of eleven silvicultural operations characterizing each FMA. Exposure was estimated as value at stake, which combined forest standing volume, simulated with forest growth models, and wood prices. Main Results: Using the PROMETHEE algorithm, we found that the overall ranking of FMAs was consistent across all countries, with short rotation plantations to produce pulpwood or energy wood were the least at risk. The ranking was mainly driven by forest values at stake. We found that by improving the accuracy of forest values exposed to damage, based on growth models and representative wood prices, the MCRA outcomes were more useful and realistic. Research highlights: Our methodology provides a relevant framework to design FMAs that would minimize risks while maintaining income. Keywords: Pinus pinaster; vulnerability; hazards; growth modelling; expert assessment; wood price; southwestern Europe.
... One way of adaptive management is to compare the present composition and natural regeneration of species with the expected vulnerability and degree of adaptation of the main tree species in different change scenarios. The second strategy concerns the formation of mixed and uneven-aged stands [12,25] that have a greater possibility of complementary adaptation to environmental conditions [17,24,33]. In addition to adapting to future climates, mixed forests are considered to be superior in terms of economy [17,18] and ecosystem functioning [2,17]. ...
... Overall, climate change is likely to significantly affect protective forest composition and structure by affecting plant species competitiveness and distribution (e.g. Lexer et al., 2002). On the other hand, besides a change in distribution of vegetation, ice, snow and permafrost zones could be altered under abrupt changes in climatic patterns, resulting in increased erosion and altering slope stability (Kraüchi et al., 2000). ...
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Abiotic and biotic disturbances in alpine forests can reduce forest cover or change the structure of the forest and consequently reduce the protective effect of forest against natural hazards such as avalanches and rockfalls. In this review article, the effect of the main abiotic (forest fire, windthrow, ice break, snow break, avalanche and rockfall) and biotic (insects and pathogens) disturbances in protection forests are presented along with their potential influence on the protective effect of forest against avalanches and rockfalls. In general, natural disturbances negatively affect the protective effect of forest, especially in the case of large-scale and severe events, which in alpine areas are mostly caused by storms, bark beetle outbreaks, avalanches and forest fires. Climate change induced interactions between disturbances are expected to present challenges in the management of protection forests in the future.
... national) scales (e.g. Lexer et al. 2002;Bircher et al. 2015), still only few studies are available for mountain forests at the local scale, providing decision support at the level required by an individual forest enterprise (see, for example, Maroschek et al. 2015). Furthermore, findings from one case study area may apply only to a limited degree to another area, particularly if environmental conditions are markedly different (see, for example, Elkin et al. 2013). ...
Article
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Mountain forest managers face the challenge to anticipate climate change (CC) impacts across large elevational ranges. For management planning, information on site-specific long-term responses to CC as well as the consequences for protection functions is particularly crucial. We used the process-based model ForClim to provide projections of forest development and their protective function as decision support for a large forest enterprise in the Northern Pre-Alps. Specifically, we investigated the impact of three climate scenarios (present climate, low- and high-impact CC) at five representative sites along an elevational gradient (700–1450 m a.s.l.). Relatively small changes to current forest structure and composition were evident under present climate, but divergent trajectories occurred under CC: while the low-elevation sites (≤ 1000 m) were affected by drought-related mortality, high-elevation sites benefited from the warming. Changes at low-elevation sites were accompanied by shifts in species composition, favouring in particular Tilia (‘low-impact’ CC) and Pinus sylvestris (‘high-impact’ CC). Forest management accelerated the shift towards climate-adapted tree species, thereby reducing detrimental effects of the ‘low-impact’ CC scenario. Under the ‘high-impact’ scenario, however, drastic decreases in protective function occurred for the late twenty-first century at low elevations. A set of exemplary disturbance scenarios (windthrow and bark beetle) demonstrated the importance of forest management and low browsing for the resilience of mountain forests. Overall, our results underline the potential of process-based forest models as decision support tools for forest enterprises, providing local projections of CC impacts across large elevational ranges at the site-specific resolution required by forest managers.
... All are then further favoured by a warmer and possibly drier climate (e.g. Matulla et al. 2002;Lexer et al. 2002;Pepin et al. 2015). Marini et al. (2012) found that forest disturbance in the European Alps was seven times higher where spruce was planted in sites that were warmer than those within its historical climatic range. ...
Article
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Mixed mountain forests, primarily made up of Norway spruce (Picea abies (L.) Karst.), silver fir (Abies alba Mill.) and European beech (Fagus sylvatica L.), cover about 10 × 10 6 ha of submontane-subalpine altitudes in Europe. They provide invaluable ecosystem services, e.g. protection against avalanches, landslides or rockfall. However, pure Norway spruce stands have, since mediaeval times, been heavily promoted as productive stand types for salt works at sites naturally supporting mixed mountain forests. Damage to these secondary pure spruce stands has been steadily increasing in recent decades. Furthermore, due to their previous limitation due to low temperatures and a short growing season, forest ecosystems in higher elevations are expected to be strongly affected by climate warming. To address these problems, alternative management concepts are being intensively discussed. A possible option to improve the stability and resilience of the stand is the transformation from pure Norway spruce stands into site-appropriate, sustainable and stable mixed mountain forests. In this study, we have tested seven different transformation scenarios (e.g. slit, shelterwood and gap-coupes, strip clear-cutting, do-nothing) and their impact on five evaluation criteria (forest growth, economics, carbon sequestration, (stand) stability and biodiversity). As there are hardly any practical examples for some of the transformation scenarios available, we have used the forest growth simulator SILVA to assess whether the tested transformation scenarios differ in transformation success and to observe trade-offs between the criteria of evaluation. Of the investigated scenarios, we consider the ones with gap or slit-coupes with the most beneficial overall utility values for the portfolio of the five evaluation criteria. However, we showed with our results that it is possible, by means of several trajectories, to return destabilised forests to sustainable and stable systems. We showed that a transformation is realistic, even if sophisticated silvicultural concepts are not strictly pursued.
... However, the direction of changes may be radically different. Reduced forest growth, basically, due to increased temperatures and decreased precipitation is reported in the Mediterranean and Atlantic countries of Europe-Spain [59], France [60], Ireland [40,61,62], Denmark [63] also in Central Europe-Austria [64] and Slovakia [62]. Both increasing [62,65] and decreasing [62] trends may be observed for Germany, depending on the region, climate change patterns and characteristics of forest and forest management. ...
Article
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Research Highlights: Validating modelling approach which combines global framework conditions in the form of climate and policy scenarios with the use of forest decision support system to assess climate change impacts on the sustainability of forest management. Background and Objectives: Forests and forestry have been confirmed to be sensitive to climate. On the other hand, human efforts to mitigate climate change influence forests and forest management. To facilitate the evaluation of future sustainability of forest management, decision support systems are applied. Our aims are to: (1) Adopt and validate decision support tool to incorporate climate change and its mitigation impacts on forest growth, global timber demands and prices for simulating future trends of forest ecosystem services in Lithuania, (2) determine the magnitude and spatial patterns of climate change effects on Lithuanian forests and forest management in the future, supposing that current forestry practices are continued. Materials and Methods: Upgraded version of Lithuanian forestry simulator Kupolis was used to model the development of all forests in the country until 2120 under management conditions of three climate change scenarios. Selected stand-level forest and forest management characteristics were aggregated to the level of regional branches of the State Forest Enterprise and analyzed for the spatial and temporal patterns of climate change effects. Results: Increased forest growth under a warmer future climate resulted in larger tree dimensions, volumes of growing stock, naturally dying trees, harvested assortments, and also higher profits from forestry activities. Negative impacts were detected for the share of broadleaved tree species in the standing volume and the tree species diversity. Climate change effects resulted in spatially clustered patterns—increasing stand productivity, and amounts of harvested timber were concentrated in the regions with dominating coniferous species, while the same areas were exposed to negative dynamics of biodiversity-related forest attributes. Current forest characteristics explained 70% or more of the variance of climate change effects on key forest and forest management attributes. Conclusions: Using forest decision support systems, climate change scenarios and considering the balance of delivered ecosystem services is suggested as a methodological framework for validating forest management alternatives aiming for more adaptiveness in Lithuanian forestry.
... For example, the fungal endophyte Discula quercina, which inhabits healthy Quercus cerris trees, causes damage to host structure and function when the tree experiences drought stress (Moricca and Ragazzi 2008;Ragazzi et al. 2001). Picea abies (Norway spruce) and other conifers are predicted to become unsuitable for forestry in the central regions of Europe due to rises in temperature (Breymeyer 1996;Fanta 1992), especially at lower elevations (Lexer et al. 2002), which may subject the present large spruce forests to severe stress in the future. Similarly, altered climates may affect BCA function and efficacy. ...
Article
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Like all other plants, trees are vulnerable to attack by a multitude of pests and pathogens. Current control measures for many of these diseases are limited and relatively ineffective. Several methods, including the use of conventional synthetic agro-chemicals, are employed to reduce the impact of pests and diseases. However, because of mounting concerns about adverse effects on the environment and a variety of economic reasons, this limited management of tree diseases by chemical methods is losing ground. The use of biological control, as a more environmentally friendly alternative, is becoming increasingly popular in plant protection. This can include the deployment of soil inoculants and foliar sprays, but the increased knowledge of microbial ecology in the phytosphere, in particular phylloplane microbes and endophytes, has stimulated new thinking for biocontrol approaches. Endophytes are microbes that live within plant tissues. As such, they hold potential as biocontrol agents against plant diseases because they are able to colonize the same ecological niche favoured by many invading pathogens. However, the development and exploitation of endophytes as biocontrol agents will have to overcome numerous challenges. The optimization and improvement of strategies employed in endophyte research can contribute towards discovering effective and competent biocontrol agents. The impact of environment and plant genotype on selecting potentially beneficial and exploitable endophytes for biocontrol is poorly understood. How endophytes synergise or antagonise one another is also an important factor. This review focusses on recent research addressing the biocontrol of plant diseases and pests using endophytic fungi and bacteria, alongside the challenges and limitations encountered and how these can be overcome. We frame this review in the context of tree pests and diseases, since trees are arguably the most difficult plant species to study, work on and manage, yet they represent one of the most important organisms on Earth.
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Climate change is generally recognized as one of the greatest challenges of this century. In the present paper, the climate change impact factors such as precipitation and atmospheric temperature are discussed in the context of Kerala State. The high resolution daily gridded dataset for a period of 100 years (1901-2000) provided by the Climate Research Unit Time Series (CRU TS-version 2.10) was used to analyse the long-term trend of rainfall and temperature in Kerala. The mean annual rainfall and seasonal rainfall over the State showed an insignificant declining trend. The number of wet days during the southwest monsoon increased significantly and decreased during pre-monsoon and winter seasons. However, throughout the State daily average, maximum and minimum temperatures increased irrespective of the season. Among different landuse systems, forests are particularly sensitive to climate change. The forest cover in the State seems to be stabilised to around 17,382 km 2. However, in the context of increasing anthropogenic activities, without adopting suitable strategies, forests cannot contribute to mitigate the ill effects of climate change. Several of the forest conservation measures already taken up by the Kerala Government also represent unintentional climate change mitigation measures. By strengthening or continuing with intentional programmes like social forestry projects and protection and conservation of forests, including sacred groves, adverse effects of climate change can be mitigated. With the long experience in promotion of forest conservation, participatory forest management and forest governance, the Kerala Forest Department can greatly facilitate comprehensive programmes for climate change mitigation.
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All over the world, rice is a significant food in general, and in Asia, about 90% of the world rice (Oryza sativa L.) is produced and consumed. More than half of the world’s population is feeding on rice; however, >400 million people suffering from chronic hunger in the rice-producing areas of Asia, Africa, and South America. However, as the population of the world is increasing day by day the demand for rice as a food increase within the globe which is expected to rise by the further 38% within 30 years according to the United Nations. The rice production in the world stands at 454.6 million tons per annum, with an average yield of 4.25 ton/ha. Food security is the current emerging issues/problem in this era that scientists and policymakers are working it on four dimensions, e.g., Food access, convenience, constancy, and consumption. It exposes the statistic that rice is not only the critical food basis for > 4 billion people, but also the emphasis on composite rice ecosystems that disturb global apprehensions, like poverty mitigation, food security, sustainable development and security of cultural inheritance.
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Due to the very high complexity of modern single-tree based optimization models, uncertainties are often disregarded. In this study we present a modelling approach, which allows partial harvesting but is still simple enough to consider risk. Our modelling approach investigates whether the inclusion of timber price uncertainty influences the harvesting schedule. The model considers positive growth response to the density-reduction that follows harvesting. Testing the impact of uncertainty, we define the discounted net revenues of each harvest operation as random variables. We compare harvest scheduling both with and without the inclusion of uncertainty. We first modelled growth response based on a partial-harvest schedule, without integrating uncertainty from timber price fluctuations. Results showed that harvesting tree cohorts at different times is financially optimal. We ran the same model including the risk of timber price fluctuations. The inclusion of risk led to slightly greater differences in recommended harvest timings. Due to the small difference observed, we conclude that it is unlikely that risk arising from fluctuating timber prices would strongly affect the results for more complex forest economic models concerning the optimal harvest schedules.
Chapter
Soil erosion caused by climate change and changes in land use increases or decreases depending on the geographic location, climate scenarios, precipitation patterns, topographic potential, and land management practices. Forf this reason, the impact of climate change on soil erosion needs to be analysed at the regional and/or local levels. Bearing in mind that climate and land use will change in the future, the purpose of this chapter is to quantify the current intensity of soil erosion, taking the Vranjska Valley (southern Serbia) as an example, to simulate soil losses for 2050 and 2100 due to changes in climate and land use, and to analyse the spatial and temporal grouping of clusters of soil loss for 2015 and 2100. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) of the sediment delivery ratio (SDR) model integrated with the EBU-POM (Eta Belgrade University-Princeton Ocean Model) regional climate model was used with the aim of quantifying erosion intensity in the Vranjska Valley region. The results of research in the Vranjska Valley region show that average erosion intensity during 2015 amounted to 5.33 t ha⁻¹ yr⁻¹. According to the A1B scenario, average annual soil loss is expected to fall for the two periods in the future, by 6.6% (2050) and 41.8% (2100), mainly as a result of a reduction in the rainfall erosivity factor. Measures which could protect soil effectively in the future include reforestation with drought-resistant species, soil conservation, no-till practices, and an evaluation of current erosion models.
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The work introduces a method to quantify potential impact of climate change on cultural ecosystem services in forests. The technique of Hesitant Fuzzy Linguistic Term Set is applied to face with the uncertainty due to climate change as well as subjective opinion of forest experts. Two forest management scenario (current practices as well as climate change-oriented silviculture) are investigated for different time horizons. Results highlight the increasing uncertainty on climate change impact evaluation related to longer time horizons. Potential losses connected to current cultural ecosystem services provision are quantified from spatial as well as economic viewpoint. The method is tested for an illustrative example in the Tuscany region - central Italy.
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Regional risk assessments for the potential effects of climate change rely on plausible small-scale climate change scenario data. To bridge the gap between the coarse scale of general circulation models and the local scale of approximately 11000 sample sites of the Austrian National Forest Inventory (AFI), a seasonally stratified statistical downscaling procedure was applied to a control run and 2 transient experiments of ECHAM4/OPYC3, which are based on the trace gas only or trace gas plus sulphate scenario IPCC IS92a. We fitted multiple linear regression (MLR) models for the micro-scale monthly precipitation and temperature for each AFI point. The meteorological data at the AFI sites were obtained by interpolation of measurements from the dense network of Austrian weather stations for the period 1961-1995. The macro-scale predictors were principal components of monthly NCEP/NCAR reanalysis data (850 and 700 hPa geopotential. height, 850 hPa temperature and 700 hPa relative humidity). The results show spatial and temporal heterogeneity for both temperature and precipitation. In case of temperature MLR leads to increases from +1.4 to +4.0degreesC (trace gas only integration) and from +1.1 to +2.9degreesC (trace gas plus sulphate integration) for a period of about 55 yr relative to the 1961-1995 climatology. The regionalized precipitation changes are both negative and positive. Values range from -44 to + 26 % (trace gas only integration) and from -29 to + 26 % (trace gas plus sulphate integration). As expected, the explained variability for temperature was higher than for precipitation and depended on the season. From a validation experiment for model calibration we conclude that MLR shows reliable results for temperature. Even in the case of precipitation the method seems to yield plausible results. Both temperature and precipitation were better reproduced for winter than for summer.
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Current scientific concerns regarding the impacts of global change include the responses of forest composition and biomass to rapid changes in climate, and forest gap models have often been used to address this issue. These models reflect the concept that forest composition and biomass in the absence of large-scale disturbance are explained by competition among species for light and other resources in canopy gaps formed when dominant trees die. Since their initiation 25 yr ago, a wide variety of gap models have been developed that are applicable to different forest ecosystems all over the world. Few gap models, however, have proved to be equally valid over a wide range of environmental conditions, a problem on which our work is focused. We previously developed a gap model that is capable of simulating forest composition and biomass in temperate forests of Europe and eastern North America based on a single model structure. In the present study, we extend the model to simulate individual tree species response to strong moisture seasonality and low temperature seasonality, and we modify the widespread parabolic temperature response function to mimic nonlinear increases in growth with increased temperature up to species-specific optimal values. The resulting gap model, FORCLIM V2.9, generates realistic projections of tree species composition and biomass across a complex gradient of temperature and moisture in the Pacific Northwest of the United States. The model is evaluated against measured basal area and stand structure data at three elevations of the H. J. Andrews LTER site, yielding satisfactory results. The very same model also provides improved estimates of species composition and stand biomass in eastern North America and central Europe, where it originated. This suggests that the model modifications we introduced are indeed generic. Temperate forests other than those we studied here are characterized by climates that are quite similar to the ones in the three study regions. Therefore we are confident that it is possible to explain forest composition and biomass of all major temperate forests by means of a single hypothesis as embodied in a forest gap model.
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A reformulation of the continuum concept is presented after considering the implications of the community/continuum controversy and current niche theory. Community is a spatial concept dependent on landscape pattern while the continuum is an environmental concept referring to an abstract space. When applying niche theory to plants, the mechanisms of competition are ill-defined and the assumption of bell-shaped response curves for species unrealistic. Eight testable propositions on the pattern of response of vegetation to environmental gradients are presented 1. Environmental gradients are of two types. a) resource gradients or b) direct physiological gradients. 2. The fundamental niche response of species to resource gradients is a series of similar nested response curves. 3. The fundamental niche response of species to direct gradients is a series of separate, independent, overlapping response curves. 4. Species fundamental response curves are such that they have a relative performance advantage in some part of the environmental space. 5. The shape of the realized niche is variable even bimodal but predictable from the fundamental response given the other species present. Propositions 6–8 describe the response shapes of emergent community properties to environmental gradient; species richness is bimodal, dominance trimodal and standing crop unimodal. Detailed comparisons of these propositions are made with the alternative theories of Ellenberg, Gauch and Whittaker, Grime, and Tilman. These theories are incomplete lacking several generally accepted properties of plants and vegetation.
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A methodology for regional application of forest simulation models has been developed as part of an assessment of possible climate change impacts in the Federal state of Brandenburg (Germany). Here we report on the application of a forest gap model to analyse the impacts of climate change on species composition and productivity of natural and managed forests in Brandenburg using a statistical method for the development of climate scenarios. The forest model was linked to a GIS that includes soil and groundwater table maps, as well as gridded climate data with a resolution of 10 × 10 km and simulated a steady-state species composition which was classified into forest types based on the biomass distribution between species. Different climate scenarios were used to assess the sensitivity of species composition to climate change. The simulated forest distribution patterns for current climate were compared with a map of Potential Natural Vegetation (PNV) of Brandenburg. In order to analyse the possible consequences of climate change on forest management, we used forest inventory data to initialize the model with representative forest stands. Simulation experiments with two different management strategies indicated how forest management could respond to the projected impacts of climate change. The combination of regional analysis of natural forest dynamics under climate change with simulation experiments for managed forests outlines possible trends for the forest resources. The implications of the results are discussed, emphasizing the regional differences in environmental risks and the adaptation potentials of forestry in Brandenburg.
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Bergwälder haben eine Fülle von Leistungen zu erbringen: Neben der wichtigen nachhaltigen Bereitstellung von Holz sind es landeskulturelle Leistungen, unter denen im folgenden Beitrag Schutz-, Erholungs-, Wohlfahrts- und ökologische Leistungen verstanden werden. Während die Nachfrage nach diesen Leistungen in vielen Berggebieten immer mehr zunimmt, wird die Erfüllungsfähigkeit in einemmarktbetonten Umfeld immer unzureichender. Die fehlende Inwertsetzung der landeskulturellen Leistungen, die von den Nutznießern immer noch „im Kielwasser“ der Holzproduktion erwartet werden, ist eine Hauptursache des Auseinanderdriftens von Ist und Soll. The performance of mountain forests is expected to be wide and varied. Apart from making the important resource wood available on a sustainable basis, this also involves socio-cultural benefits, dealt with in this paper under the headings conservation, recreation, health effects and ecological impacts. While the demands for these benefits are constantly growing in many mountain regions, market-oriented pressures are making the fulfilment of these demands increasingly difficult and unsatisfactory. Socio-cultural benefits are still expected by users to be provided as a matter of course „in the wake of“ wood production. There is a serious lack of proper valuation of these benefits, the main cause for the widening gap between user demands and the ability to meet them.