Economics of species change subject to risk of climate change and increasing information: a (quasi-)option value analysis

Context

In the context of climate change, several forest adaptation options have to be advocated such as a shift to more resistant species.

Aims

We provide an economic analysis of timber species change as a tool for adapting forests to climate change.

Methods

We use the framework of cost–benefit analysis, taking uncertainty into account both exogenously (sensitivity analysis) and endogenously [(quasi-)option value calculations]. We apply the method to assess the economic rationale for converting Norway spruce stands to Douglas-fir in the French Black Mountain.

Results

We find that the Douglas-fir conversion is land expectation value (LEV) maximizing under a wide range of a priori (subjective) probabilities attached to high mortality of Norway spruce under climate change (for probabilities higher than 0.25–0.31). If information about the impacts of climate change is expected to increase over time, and given the large sunk costs attached to conversion, a delay strategy may be preferable to transition and to status quo when the impacts of climate change on Norway spruce mortality are sufficiently ambiguous. In such cases, getting information earlier increases the LEV by €5–60/ha.

Conclusion

Beyond the specifics of the case study, this paper suggests that quasi-option value is a relevant tool to provide insights to forest owners dealing with adaptation decisions in the context of climate change.     

Projections of regional changes in forest net primary productivity for different tree species in Europe driven by climate change and carbon dioxide

? Context

Projecting changes in forest productivity in Europe is crucial for adapting forest management to changing environmental conditions.

? Aims

The objective of this paper is to project forest productivity changes under different climate change scenarios at a large number of sites in Europe with a stand-scale process-based model.

? Methods

We applied the process-based forest growth model 4C at 132 typical forest sites of important European tree species in ten environmental zones using climate change scenarios from three different climate models and two different assumptions about CO₂ effects on productivity.

? Results

This paper shows that future forest productivity will be affected by climate change and that these effects depend strongly on the climate scenario used and the persistence of CO₂ effects. We find that productivity increases in Northern Europe, increases or decreases in Central Europe, and decreases in Southern Europe. This geographical pattern is mirrored by the responses of the individual tree species. The productivity of Scots pine and Norway spruce, mostly located in central and northern Europe, increases while the productivity of Common beech and oak in southern regions decreases. It is important to note that we consider the physiological response to climate change excluding disturbances or management.

? Conclusions

Different climate change scenarios and assumptions about the persistence of CO₂ effects lead to uncertain projections of future forest productivity. These uncertainties need to be integrated into forest management planning and adaptation of forest management to climate change using adaptive management frameworks.     

Understory dynamics after disturbance accelerate succession from spruce to beech-dominated forest—the Siggaboda case study

??Context

It is assumed that climate change will favour European beech (Fagus sylvatica L.) to Norway spruce (Picea abies [L.] Karst.) at its northern range margins due to climate change and induced disturbance events.

??Aims

An old-growth mixed forest of spruce and beech, situated near the northern beech margin, was studied to reveal effects of disturbances and response processes on natural forest dynamics, focussing on the understory.

??Methods

We carried out analyses on understory dynamics of beech and spruce in relation to overstory release. This was done based on a sequence of stand and tree vitality inventories after a series of abiotic and biotic disturbances.

??Results

It became apparent that beech (understory) has a larger adaptive capacity to disturbance impacts and overstory release (68 % standing volume loss) than spruce. Understory dynamics can play a key role for forest succession from spruce to beech-dominated forests. Disturbances display an acceleration effect on forest succession in the face of climate change.

??Conclusion

Beech is poised strategically to replace spruce as the dominant tree species at the study area. Due to an increasing productivity and a lower risk of stand failure, beech may raise into the focus of forestry in southern Sweden.     

Is leaf area of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> L. Karst.) and European larch (<Emphasis Type="Italic">Larix decidua</Emphasis> Mill.) affected by mixture proportion and stand density?

Key message

Trees with otherwise equal dimensions have different leaf areas if they are located in different stand types. While leaf area of European larch is affected by mixture proportion, leaf area of Norway spruce is affected by stand density.

Context

Leaf area is a key parameter for evaluating growth efficiency of trees, and therefore needs to be measured as consistently and accurately as possible. This is even more important when comparing monospecific and mixed stands.

Aims

The aim of the study is to find combinations of parameters and allometric relationships that can be used to estimate accurately the leaf area of individual trees.

Methods

Allometries of the measured leaf area of 194 trees in 12 stands were analysed in order to find variables affecting leaf area. Existing functions from the literature were validated. Finally, models were fitted to find the most appropriate method for estimating leaf area of mixed and monospecific stands of Norway spruce and European larch.

Results

Allometric relationships of leaf area to other measurable characteristics of trees vary in different stand types. Besides individual tree dimensions such as diameter and crown surface area, leaf area of Norway spruce is related to stand density, whereas the leaf area of European larch is dependent on the admixture of Norway spruce in the stand.

Conclusion

In contrast to models for estimating individual tree leaf area of Norway spruce, models for leaf area of European larch have to consider mixture proportions in order to correctly interpret the growth efficiency of mixed stands.

     

Persisting bark beetle outbreak indicates the unsustainability of secondary Norway spruce forests: case study from Central Europe

? Context

Secondary Norway spruce forests in the Western Beskids are among the most damaged forests in Europe. Although spruce bark beetle (Ips typographus) has been recently causing large-scale damage to these forests, our understanding of I. typographus dynamics in this environment is inadequate for evaluating forest sustainability.

? Aim

This study aims to evaluate the patterns of damage caused by I. typographus to spruce forests with compromised ecological stability.

? Methods

Forest infestation by I. typographus was inferred from sanitary felling data collected from 1998 to 2004. Stand and site data were obtained from forest management plans. Spatial-dependence analysis, ordinary kriging and neural network-based regression modelling were used to investigate the patterns of infestation and the casual relationships in the studied ecosystem.

? Results

I. typographus long-distance dispersal substantially decreased with outbreak culmination. The spread of infestation was only weakly related to stand and site parameters. Infestations spread isotropically at the stand and patch level but directionally at the regional scale.

? Conclusions

The large-scale spread of infestation can be explained by the uniform age and species composition of the investigated forests and by the ability of populations to overwhelm suboptimal trees. The observations presented here suggest that secondary spruce forests in Europe may be unsustainable due to unprecedented bark beetle outbreaks, which can be further amplified by changing climate.     

Intra- and interspecific competition differently influence growth and stem quality of young oaks (Quercus robur L. and Quercus petraea (Mattuschka) Liebl.)

Context

Cluster planting has become a conventional establishment method for oaks in Central Europe, where the spacing of seedlings within clusters varies between ‘nests’ (0.2?×?0.2 m) and ‘groups’ (1?×?1 m). Although the space between clusters is expected to fill with voluntary regeneration, its competitive effect on oak growth and quality had not been studied yet.

Aims

The aim of the study was to analyse the effects of inter- and intraspecific interactions on growth and quality of oaks grown in cluster plantings by quantifying the influence of neighbouring trees. In addition, we analysed whether the spatial position of oaks within groups (inner section or periphery) influenced their quality development.

Methods

Using Hegyi’s competition index, the influence of competition from intra- and interspecific trees from early, mid- and late-successional species, on diameter, height, slenderness and quality (length of branch-free bole) of 10- to 26-year-old oaks grown in cluster planting stands was quantified at seven sites in Baden-Württemberg and Hessen, Germany.

Results

In general, mid- and late-successional trees exerted a stronger competitive influence on growth of target oaks in clusters than the conspecific oaks and pioneer tree species. Oak quality development benefited from intraspecific competition, but self-pruning was not further promoted through additional interspecific competition. Within groups, inner oaks had a higher probability of developing into potential future crop trees than outer oaks.

Conclusion

Our study showed that intra- and interspecific competition had different effects on target oak trees and that these effect differed between nest and group plantings. The development of naturally regenerated and planted trainer trees in group plantings should be monitored carefully and if necessary be controlled through thinning or pollarding.     

Recovery of forest structure and composition to harvesting in different strata of mixed even-aged central Appalachian hardwoods

Context

Implementing nature-based silviculture requires understanding the structural and compositional changes that occur in forested stands under known disturbance types and intensities.

Aims

The objectives were to assess the (a) resistance of hardwood forests to change, (b) their trajectory of recovery following disturbance, and (c) how closely resulting forests resemble original forests.

Methods

We characterized tree structure and composition at three points in time (pre-disturbance, 1-year post-disturbance, and ～15 years following disturbance) along a harvesting disturbance gradient created by removing trees in different forest canopy strata.

Results

Significant differences to pre-disturbance conditions were noted immediately post-harvest for tree basal area, density, species richness, and tree species composition; treatment differences were observed for all parameters except diversity. Plots exposed to the least extreme harvesting disturbances (cutting small and intermediate trees) had returned to pre-disturbance conditions for most parameters after 15 years, while the most extreme harvesting disturbance (cutting large trees) had not yet recovered.

Conclusions

Although not initially resistant, Central Appalachian eastern hardwoods are fairly resilient to the removal of trees in the subcanopy or a mixture of the subcanopy and canopy; only the removal of solely canopy trees (i.e., high grading) and complete removal (i.e., clearcutting) appear to impose harvesting disturbances to which these forests may not be resilient.     

Waterlogging under simulated late-winter conditions had little impact on the physiology and growth of Norway spruce seedlings

Context

Waterlogging is predicted to become more common in boreal forests during winter and early spring with climate change. So far, little is known about the waterlogging tolerance of boreal tree species during their winter dormancy.

Aim

The aim was to quantify the degree of waterlogging tolerance of 1-year-old dormant Norway spruce (Picea abies (L.) Karst.) seedlings.

Methods

The seedlings were exposed to waterlogging in a growth chamber at temperature of 2 °C for 4 weeks and then allowed to recover for 6 weeks during the growth stage. Shoot and root responses were monitored by physiological and growth measurements.

Results

No effect was found in the seedling biomass, but root mortality increased slightly during the early growth stage following waterlogging. The water potential of the needles became less negative at the end of the waterlogging and the early growth stage. The ratio of apoplastic to symplastic electrical resistance (R _e/R _i) of the needles was lower after waterlogging, indicating changes in the proportions of symplastic and apoplastic space. No differences were found between the treatments in the dark-acclimated chlorophyll fluorescence (F _v/F _m) of the needles. Slightly greater accumulation of starch and temporary reductions of some mineral nutrients in needles were found after waterlogging.

Conclusions

We conclude that in late winter and early spring, Norway spruce seedlings potentially tolerate short periods of waterlogging.     

Regeneration strategies influence ground bryophyte composition and diversity after forest clearcutting

Context

Natural regeneration with broadleaved species and reforestation with coniferous trees are two widely practiced forest regeneration strategies after timber harvesting. They lead to different tree species composition and may cause different understory biodiversity, but the effects on ground bryophyte composition and diversity are not well-known.

Aims

We tested whether natural regeneration with broadleaved species and reforestation with spruce induced different diversities of the ground bryophyte populations 20–40 years after old-growth spruce forest clearcutting in the subalpine regions of southwestern China.

Methods

Differences between natural stands and plantations were compared through the analysis of 13 paired stands, with 78 plots, 390 shrub/herb quadrats, and a total of 1,560 bryophyte quadrats.

Results

Naturally regenerated forests were characterized by lower density and cover and lower tree height but higher herbaceous plant height, shrub cover, and bryophyte diversity. They also harbored many more ground bryophytes. The species richness of pleurocarpous mosses and fans, mats, and turfs were significantly higher in naturally regenerated forests. Frequency difference analysis demonstrated that more bryophyte species preferred ground habitats in naturally regenerated forests than in plantations (116 vs. 48 species). The canonical correspondence analysis indicated that stand structure attributes were more important determinants of ground bryophyte diversity and abundance.

Conclusion

Natural regeneration and reforestation resulted in large differences in ground bryophyte populations. A larger diversity was observed in the former case, and natural regeneration practices can be an effective measure for the protection of ground bryophyte diversity after clearcutting.     

Modeling recent bark stripping by red deer (Cervus elaphus) in South Belgium coniferous stands

? Context

Over the past few decades, the impact of large herbivorous ungulates on forest vegetation has been clearly highlighted. Among those impacts, bark stripping of coniferous trees is one of the most damaging. Bark stripping leads to rot development, inducing serious loss of timber value.

? Aims

The present study aimed firstly at evidencing the factors explaining the variations observed in fresh bark peeling rate for spruce and Douglas-fir in southern Belgium and secondly at identifying the key factors to consider when setting up a deer management plan.

? Method

Fresh bark peeling rate was recorded with a systematic sampling survey from 2004 to 2007. The covered territory was then divided into 63 distinct hunting zones of area ranging from 1,000 to 25,000 ha. About 5,000 plots were monitored annually. Each zone was characterized with a large number of explanatory variables. The explanatory variables were integrated firstly into fixed linear models using a stepwise procedure, and then into a mixed model.

? Results

The significant variables included in the model (R ²?=?44 %) are (by decreasing order of importance) red deer densities, proportion of coniferous stands and agricultural areas, snow cover, distance to urban habitats, and species diversity in the understory.

? Conclusion

The models revealed the impacts of several factors on bark peeling: deer density, deer-carrying capacity of the territory, landscape structure, and severity of winter conditions. The adjusted model allowed subtracting the impact of winter conditions in order to produce a relevant indicator for hunting management. In addition, the model was used to assess the sensitivity of a forested area to bark peeling based on its environmental characteristics.     

Coastal and interior Douglas-fir provenances differ in growth performance and response to drought episodes at adult age

Context

Since the 2003 drought and heat wave, Douglas-fir dieback has been reported in France in trees older than 30 years. Consequently, it is questioned whether selected Douglas-fir provenances are suited to the frequent and severe drought events which are forecast due to climate change.

Aims

Our objective was to contribute to the screening of variability in productivity and growth response to soil-water deficit of mature trees from provenances not currently used for plantation in France.

Methods

We sampled 22 provenances, including coastal and interior Douglas-fir, covering a wide part of its natural distribution, from Oregon to California for coastal provenances and from British Columbia to New Mexico for interior provenances. These provenances were planted at the mid 1970s in two provenance trials located in the south-west area of France. Variability of productivity, of wood density, and of radial growth in response to drought episodes among provenances was quantified and related to soil-water deficit computed by daily water balance calculations.

Results

Whatever the provenance, annual radial growth is highly dependent on local soil-water deficit (Felines R ² = 0.57, Le Treps R² = 0.49). Radial growth and wood properties exhibit large differences between provenances at 30 years old. Variability between provenances for all wood characteristics studied is mainly structured geographically. Coastal provenances perform best for productivity at 30 years old (619 cm²?±?59), and exhibit a small growth reduction in 2004, the second successive year of drought (?10.7 %?±?3.8). Surprisingly, the southern interior provenances from the driest environments in the natural range show a large growth reduction in 2004 (?30.5 %?±?5.2).

Conclusions

The provenances tested exhibited significant differences in growth performance and growth reduction induced by the soil-water deficit. The approach coupling retrospective analysis of radial growth on mature trees and water balance modelling is relevant for evaluating provenance adaptation to more frequent or severe drought episodes.     

Drought sensitivity of Norway spruce is higher than that of silver fir along an altitudinal gradient in southwestern Germany

Context

For Central Europe, climate projections foresee an increase in temperature combined with decreasing summer precipitation, resulting in drier conditions during the growing season. This might negatively affect forest growth, especially at sites that are already water-limited, i.e., at low elevation. At higher altitudes trees might profit from increasing temperatures.

Aims

We analyzed variations in radial growth of silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) Karst.) along an altitudinal gradient from 400 until 1,140 m a.s.l. in the Black Forest, to assess climate responses with increasing elevation.

Methods

Climate–growth relationships were analyzed retrospectively using tree-ring and climate data. In total, we sampled stem discs of 135 trees to build 27 species- and site-specific chronologies (n _fir?=?13, n _spruce?=?14).

Results

Our results indicate distinct differences in climate–growth relations between fir and spruce along the gradient. Growth of high-altitude fir was positively related to temperature from January till March. Growth of low-altitude fir and spruce at all elevations was positively related to precipitation and negatively to temperature during the growing season, particularly in July. A self-calibrating Palmer drought severity index underlined summer drought sensitivity of these trees.

Conclusion

Overall, we found that climatic control of tree growth changes over altitude for fir. For spruce, a remarkable synchrony in growth variation and climate response was shown, which indicates that this species is drought sensitive at all studied elevations. In a future warmer climate, the growth of low-altitude fir and spruce along the entire studied gradient may be negatively affected in the Black Forest, if an increased evaporative demand cannot be compensated by increased water supply.     

The extent of historic translocation of Norway spruce forest reproductive material in Europe

Key message

Norway spruce seed has been traded extensively for at least three centuries throughout the natural distribution range in Europe and beyond. However, our knowledge about these transfers is limited. Historic data are essential tools to trace back human-mediated gene flow and for interpretation of recent genetic studies.

Context

Human-mediated gene flow can potentially have a major impact on the genetic composition of forest tree populations, yet our knowledge about seed sources used within the current species’ range is still limited. Norway spruce is one of the most important coniferous species in European forestry, and data drawing conclusions about the genetic composition of current populations are vital with regard to gene conservation and sustainable forest management. Because molecular data are not available on a more detailed scale, historic records provide crucial information about translocations.

Aims

Our aim is to provide the first pan-European review on Norway spruce translocations from the seventeenth until the twentieth century.

Methods

We analysed historic and recent literature compiling information on the cultivation and transfer of Norway spruce reproductive material. Historic records are compared with recent molecular studies.

Results

Seed exchanges have profoundly altered the native genetic population structure of Norway spruce. Especially, Central European seeds have been used throughout and beyond the natural distribution area. Figures illustrating the historic plantings in Europe are provided.

Conclusion

Recent molecular data reveal persisting effects of past translocations. Historical records can be extremely useful for providing information about autochthony and thus guide gene conservation strategies and explain the performance of extant populations.

     

Survival to prescribed fire of plantation-grown Corsican black pine in northern Portugal

Context

The current fire regime threatens black pine (Pinus nigra Arn.) persistence in the Mediterranean Basin, which recommends larger-scale fuel treatments. Prescribed burning is an option for stand protection but its use in young stands (which are particularly at risk) is hindered by the scarce knowledge on post-fire tree survival.

Aims

The objectives were to characterize bark thickness as a fire-resistance trait in P. nigra and to describe how post-fire tree survival responds to tree size and fire effects in a 16-year-old plantation.

Methods

Bark thickness was related to diameter at breast height and height in the stem. Metrics describing tree size and stem and crown damage were measured 1?year after prescribed burning in 259 trees. Tree survival was modeled with logistic regression and Classification and Regression Tree analysis.

Results

Bark thickness increased linearly with diameter at breast height (dbh) and decreased with height in the stem. Tree survival was primarily a function of crown injury. Stem damage was an influent factor in small trees.

Conclusion

Due to thinner bark and lower tolerance to crown damage, young P. nigra trees are less fire-resistant than other Mediterranean pines, e.g., Pinus pinaster. Prescribed fire should not be attempted if dbh <10?cm. Mechanical clearing is the treatment of choice in young stands with a significant shrub layer.     

Interspecific differences in the oleoresin production of Copaifera L. (Fabaceae) in the Amazon rainforest

? Context

Copaifera species produce an oleoresin of commercial importance that is widely extracted in Amazon communities.

? Aims

This paper addresses two questions. (1) What are the morphological characteristics of Copaifera species that influence oleoresin production? (2) How do different Copaifera species respond to repeated harvests?

? Methods

We performed a large-scale experiment in the Brazilian Amazon. We tapped 110 Copaifera trees belonging to four species, and several morphological tree characteristics were measured to determine their effect on oleoresin production.

? Results

The proportion of Copaifera reticulata and Copaifera paupera trees that yielded more than 1 ml oleoresin was higher than the other species. The oleoresin volumes from yielding Copaifera pubiflora trees were significantly higher than those from C. reticulata and C. paupera, with Copaifera multijuga yielding intermediate values. Interestingly, none of the studied morphological tree characteristics had a significant effect on the proportion of yielding trees. Hollowed trees yielded significantly smaller volumes than non-hollowed trees. Both the proportion of yielding trees and oleoresin volumes decreased from the first to the second harvests for C. reticulata and C. paupera; however, the opposite pattern was observed for C. pubiflora.

? Conclusions

Oleoresin production capacity varies by species, and management protocols should account for these differences.     

Within-population variability in architectural traits and suitability to forestry conditions in Nothofagus nervosa (= N. alpina; Nothofagaceae)

? Context

There is evidence that Nothofagus nervosa (= N. alpina) is suitable for timber production in temperate regions due to its wood quality and fast growth. However, high intra-specific variability in the architectural traits of this species limits its usefulness.

? Aims

This study was aimed at evaluating intra-specific variability in the architecture of N. nervosa trees at the population level, with emphasis on traits related to the suitability of trees for timber production.

? Methods

The size of 13-year-old trees installed in an experimental field population and the extent of differentiation between trunk and branches were compared among families (trees derived from different mother trees).

? Results

The large majority of trees exhibited architectural features indicative of high suitability for timber production: clear differentiation between trunk and main branches and few occurrences of permanent trunk forks, apex deaths, and sylleptic branching. Trees belonging to different families differed in height and trunk diameter. Micro-environmental conditions had a very significant effect on most architectural traits, including the trunk differentiation.

? Conclusions

N. nervosa emerges as a suitable option for timber production in temperate regions. Trunk growth seems to be under both environmental and genetic control in this species.     

Tree species exhibit complex patterns of distribution in bottomland hardwood forests

?Context

Understanding tree interactions requires an insight into their spatial distribution.

?Aims

We looked for presence and extent of tree intraspecific spatial point pattern (random, aggregated, or overdispersed) and interspecific spatial point pattern (independent, aggregated, or segregated).

?Methods

We established twelve 0.64-ha plots in natural bottomland hardwood stands in the southeastern USA.

?Results

Spatial point pattern analyses (Ripley’s K, L, and L ₁₂) indicated that, when species were combined, trees were frequently aggregated and less commonly overdispersed. Plots with larger trees were more likely to exhibit overdispersion, confirming a shift to this pattern as trees grow. The intraspecific pattern of cherrybark oak and water oak was either aggregated or random. Sweetgum was aggregated on all plots and always at smaller distances (less than 5 m) than the two oak species. Intraspecific overdispersion was very rare. Interspecific segregation among the two oak species was more commonly observed (six plots) than aggregation (one plot). Cherrybark oak and sweetgum were segregated at some scale on seven of the 12 plots and aggregated on only two plots.

?Conclusion

The results from the analyses suggest that strong interspecific competition may result in segregation of trees from different species, while weaker intraspecific competition may lead to aggregations of conspecifics.     

European oak powdery mildew: impact on trees,effects of environmental factors,and potential effects of climate change

? Context

Powdery mildew is one of the most common diseases of oaks in Europe. After alarming reports in the beginning of the twentieth century following the presumed introduction of the invasive fungus, the disease has become familiar to foresters. However, its impact may vary greatly according to intrinsic and extrinsic factors.

? Aims

We aimed at providing updated and synthesised information on the impact of powdery mildew on oak and on the effects of environment on disease.

? Methods

A comprehensive literature review was performed, including old reports of the early epidemics to more recent data.

? Results

Tree growth patterns are of critical importance to explain the severity of the disease and the differences between juvenile and mature trees. A critical element, especially for infection of mature trees, is the availability of spores during the production of the first leaf flush. High disease impact is often related to modified growth patterns, either by environmental factors (insects or frost) or silvicultural practices (e.g., coppicing).

? Conclusion

Powdery mildew can have important impacts in natural oak regenerations and a significant role in decline of mature trees. Climate change might influence the disease severity mainly by altering the host pathogen phenological synchrony. Process-based models are required for reliable predictions.     

Uneven-aged management options to promote forest resilience for climate change adaptation: effects of group selection and harvesting intensity

Context

Climate change is expected to increase forest vulnerability through disturbances such as windstorms and droughts. Forest managers are therefore investigating strategies to increase forest resistance and resilience, especially by promoting uneven-aged and mixed forests through group selection, and by reducing stand stocking and large trees proportion. However, there is little information on the long-term impacts of these two practices.

Aims

The objectives of this study were (1) to develop an original silviculture algorithm designed for uneven-aged management and (2) to use it to assess the effects of the above-mentioned management methods in long-term simulations.

Methods

We simulated individual and group selection techniques in order to study the effects of group size, harvesting intensity and their interactions on wood production, stand heterogeneity, and regeneration in mountain spruce–fir forests. We used the spatially explicit individual-based forest model Samsara2 to simulate forest dynamics.

Results

Our simulation results confirmed the positive effect of group selection practices on structure diversity and regeneration but not on spruce maintenance. Increasing harvesting intensity enabled forest destocking but decreased structure diversity and led to non-sustained yields for the most intensive scenarios.

Conclusion

As adaptation measure, we thus recommend moderate group selection harvesting creating 500 m² gaps.