Initial reforestation efforts in the Western Mediterranean basin aimed to convert degraded lands into forests dominated by native Mediterranean oaks following a successional trajectory in which pine pioneer species were extensively used to ameliorate abiotic conditions. However, the transformation into mixed oak forests has not occurred due to changing land use priorities, land abandonment and lack of active forest management leaving a large extent of homogenous pinewood landscapes. Homogenous forests face significant adaptation challenges in the current climate crisis, including susceptibility to pests, diseases, and catastrophic wildfires. This study explores the use of harvest gaps similar to the establishment cuts of the irregular shelter-wood system (ISS), adapted for Mediterranean conditions to transform pure Pinus pinaster reforested stands into mixed-oak forests under the assumption that transforming light-demanding monocultures into mixed forests enhance resilience. The method involves creating small gaps (< 0.02 ha) to avoid natural pine regeneration while allowing for oak establishment and planted oak saplings development. The results indicate that oak seedling survival is higher in gaps compared to control plots, with no significant difference between gap sizes. Pine regeneration density is higher in larger gaps, while oak regeneration density is positively influenced by the presence of harvest residues. Survival of planted oak is high although browsing prevents full height development. Small harvest gaps are effective in controlling pine regeneration while supporting oak survival and growth. However, additional measures like fencing may be required to address browsing. The findings highlight the challenges and potential solutions for transforming homogenous forests into more resilient mixed forests.

During the second half of the 20th century, Eucalyptus globulus was widely planted in SW Spain, in areas of abrupt relief and poor acidic soils, not suitable for agriculture. E. globulus , a fast-growing tree native to Australia, was able to grow much faster than any native tree species in the area, which made it valuable for producing pulp. Later, as the demand for pulp declined and the climate became more arid, some plantations were abandoned, leading to novel assemblages of the non-native E. globulus mixed up with native shrubs and trees. Meanwhile, the growing concern for climate change has led society to turn their demands for forest products to other values and services, such as biodiversity conservation and carbon sink. Abandoned plantations of non-native trees represent a challenge and an opportunity to obtain new services while recovering biodiversity. In Aracena mountains of Huelva province (SW Spain), the following coexisting tree assemblages can be found: 1) managed eucalypt plantations under exploitation, 2) recently-abandoned eucalypt plantations (<10 years, tree age 16-27 years), 3) long-abandoned eucalypt plantations (>25 years, tree age 40-68), and 4) native forests of Quercus suber . Here we explore the capacity of these forest types to store carbon. Eight circular forest plots with a radius of 10 m were selected in each forest type. Among the managed eucalypt plantations, we selected those that were close to being harvested (13.7 years old on average). In each plot we measured the diameter at breast height (DBH) and height of every adult tree (DBH>7.5 cm), which were used to calculate above and belowground tree mass with species-specific allometric equations. Within a subplot of 5 x 5 m per plot, we characterized the undercanopy by registering every shrub/small tree (DBH<7.5 cm) species, estimated shrub height and cover, and calculated aboveground shrub mass using shrub-formation specific equations. Biomass was transformed into carbon mass by multiplying it by the species-specific carbon content. In each plot, we collected three 20 x 20 cm subsamples of litter and humus, and three soil cores up to 27 cm of depth, from which we extracted and weighed the roots. All these fractions were analyzed for carbon content. Subsequently, we calculated the total and per fraction (above- and belowground tree mass, aboveground shrub mass, litter, humus, soil and roots) carbon stock in Mg ha -1 . These values were compared across forest types. Overall, soil and tree mass (above and belowground) were the forest compartments with largest carbon content, followed by shrub mass, dead wood, humus, litter, and soil roots. The forest type with larger total carbon content was the long-abandoned eucalypt plantation, with the three remaining forest types showing similar values (Fig. 1). Long-abandoned eucalypt plantations exhibited the highest carbon content across all major forest compartments (tree mass, shrubs, dead wood and soil). However, carbon stocks in Q. suber forest soils and in aboveground trees of managed eucalypt plantations did not differ from those in long-abandoned eucalypt plantations. Carbon stock in dead wood increased in eucalypt plantations with time since abandonment, being c.a. zero in managed plantations and in native forests. Our results suggest that secondary succession leads to an increase of the forest carbon stock, largely above the value shown by native Quercus suber forests. This may be partly due to the forest management associated with cork harvest, which maintains the forest relatively open. However, the greater biomass accumulated in long-abandoned eucalypt plantations, particularly in dead wood, poses a higher risk of fire. Thus, although abandoned eucalypt plantations play a relevant role as carbon sinks, attention should be paid to reduce fire risk.

This study evaluates the performance of the ZEB Horizon RT portable mobile laser scanner (MLS) in simulating silvicultural thinning operations across three different Tuscan forests dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), Italian cypress (Cupressus sempervirens L.), and Stone pine (Pinus pinea L.). The aim is to compare the efficiency and accuracy of the MLS with traditional dendrometric methods. The study established three marteloscopes, each covering a 50 m × 50 m plot area (0.25 ha). Traditional dendrometric methods involved a team georeferencing trees using a total station and measuring the diameter at breast height (DBH) and selected tree heights (H) to calculate the growing stock volume (GSV). The MLS survey was carried out by a two-person team, who processed the point cloud data with LiDAR 360 software to automatically identify the tree positions, DBH, and H. The methods were compared based on the time, cost, and simulated felling volume. The MLS method was more time-efficient, saving nearly one and a half hours per marteloscope, equivalent to EUR 170. This advantage was most significant in denser stands, especially the Italian cypress forest. Both methods were comparable in terms of accuracy for Douglas-fir and Stone pine stands, with no significant differences in felling number or volume, although greater differences were noted for the Italian cypress forest.

Balancing increasing demand for wood products while also maintaining forest biodiversity is a paramount challenge. Europe’s Biodiversity and Forest Strategies for 2030 attempt to address this challenge. Together, they call for strict protection of 10

Quercus robur/Quercus petraea and Pinus sylvestris are light demanding, drought resistant wide spread European tree species occupying a similar ecological niche on mesotrophic xeric and mesic sites. Increasing drought and heat-spells will decrease their growth, but growth reductions depend on the timing of drought within a year, site characteristics, and inter- and intraspecific competition.In this study we analysed tree ring series of 1589 trees growing on 36 triplets installed across Europe, spanning a gradient of mean annual temperatures from 5.5°C to 11.5°C. Tree ring data were analysed using a generalized additive model with random effects for triplet, year and tree level and a random slope for age, explaining 87 % of the variation of diameter increment.High values for potential evapotranspiration in spring and autumn, indicating warm temperatures, positively and non-linearly influenced diameter increment of both species, while the effect in June was linear and negative. Across Europe, June was the most influential month for tree growth. Further, tree growth declined with age and local density and increased with social position.Modelled random patterns showed no large scale trend, when plotted per site and year indicating highly site specific shifts in competitive advantages.

Forest biodiversity studies conducted across Europe use a multitude of forestry terms,often inconsistently.This hinders the comparability across studies and makes the assessment of the impacts of forest management on biodiversity highly context-dependent.Recent attempts to standardize forestry and stand description terminology mostly used a top-down approach that did not account for the perspectives and approaches of forest biodiversity experts.This work aims to establish common standards for silvicultural and vegetation definitions,creating a shared conceptual framework for a consistent study on the effects of forest management on biodiversity.We have identified both strengths and weaknesses of the silvicultural and vegetation information provided in forest biodiversity studies.While quantitative data on forest biomass and dominant tree species are frequently included,information on silvicultural activities and vegetation composition is often lacking,shallow,or based on broad and heterogeneous classifications.We discuss the existing classifications and their use in European forest biodiversity studies through a novel bottom-up and top-driven review process,and ultimately propose a common framework.This will enhance the comparability of forest biodiversity studies in Europe,and puts the basis for effective implementation and monitoring of sustainable forest management policies.The standards here proposed are potentially adaptable and applicable to other geographical areas and could be extended to other forest interventions.

Many studies show that mixed species stands can have higher gross growth, or so-called overyielding, compared with monocultures. However, much less is known about mortality in mixed stands. Knowledge is lacking, for example, of how much of the gross growth is retained in the standing stock and how much is lost due to mor-tality. Here, we addressed this knowledge gap of mixed stand dynamics by evaluating 23 middle-aged, unthinned triplets of monospecific and mixed plots of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) repeatedly surveyed over 6-8 years throughout Europe. For explanation of technical terms in this abstract see Box 1.First, mixed stands produced more gross growth (+10%) but less net growth (-28%) compared with the weighted mean growth of monospecific stands. In monospecific stands, 73% of the gross growth was accumu-lated in the standing stock, whereas only 48% was accumulated in mixed stands. The gross overyielding of pine (2%) was lower than that of beech (18%). However, the net overyielding of beech was still 10%, whereas low growth and dropout of pine caused a substantial reduction from gross to net growth.Second, the mortality rates, the self-and alien-thinning strength, and the stem volume dropout were higher in mixed stands than monospecific stands. The main reason was the lower survival of pine, whereas beech persisted more similarly in mixed compared with monospecific stands.Third, we found a 10% higher stand density in mixed stands compared with monospecific stands at the first survey. This superiority decreased to 5% in the second survey.Fourth, the mixing proportion of Scots pine decreased from 46% to 44% between the first and second survey. The more than doubling of the segregation index (S) calculated by Pielou index (S increased from 0.2 to 0.5), indicated a strong tendency towards demixing due to pine.Fifth, we showed that with increasing water supply the dropout fraction of the gross growth in the mixture slightly decreased for pine, strongly increased for beech, and also increased for the stand as a whole. We discuss how the reduction of inter-specific competition by thinning may enable a continuous benefit of diversity and overyielding of mixed compared with monospecific stands of Scots pine and European beech.

The increasing disturbances in monocultures around the world are testimony to their instability under global change. Many studies have claimed that temporal stability of productivity increases with species richness, although the ecological fundamentals have mainly been investigated through diversity experiments. To adequately manage forest ecosystems, it is necessary to have a comprehensive understanding of the effect of mixing species on the temporal stability of productivity and the way in which it is influenced by climate conditions across large geographical areas. Here, we used a unique dataset of 261 stands combining pure and two-species mixtures of four relevant tree species over a wide range of climate conditions in Europe to examine the effect of species mixing on the level and temporal stability of productivity. Structural equation modelling was employed to further explore the direct and indirect influence of climate, overyielding, species asynchrony and additive effect (i.e. temporal stability expected from the species growth in monospecific stands) on temporal stability in mixed forests. We showed that by adding only one tree species to monocultures, the level (overyielding: +6%) and stability (temporal stability: +12%) of stand growth increased significantly. We identified the key effect of temperature on destabilizing stand growth, which may be mitigated by mixing species. We further confirmed asynchrony as the main driver of temporal stability in mixed stands, through both the additive effect and species interactions, which modify between-species asynchrony in mixtures in comparison to monocultures. Synthesis and applications. This study highlights the emergent properties associated with mixing two species, which result in resource efficient and temporally stable production systems. We reveal the negative impact of mean temperature on temporal stability of forest productivity and how the stabilizing effect of mixing two species can counterbalance this impact. The overyielding and temporal stability of growth addressed in this paper are essential for ecosystem services closely linked with the level and rhythm of forest growth. Our results underline that mixing two species can be a realistic and effective nature-based climate solution, which could contribute towards meeting EU climate target policies.

Interaction of global change drivers affects forest resilience. Land‐use changes (land abandonment) and climate change (a higher frequency and intensity of droughts) are interacting in the Mediterranean Region. Components of resilience in secondary stem growth have been widely studied but, despite the importance of root systems in forest functionality and resilience, non‐previous studies have assessed them in coarse roots. In this study, we use Juniperus thurifera tree‐ring chronologies in coarse roots and stems to assess biomass allometry and tree resilience to drought events comparing two stages of a forest expansion gradient (mature forests and transition zone) in Alto Tajo Natural Park. We extracted cores of stems and coarse roots in 48 trees distributed in different developmental stages and calculated cross‐sectional area increments, root‐stem allometric relationship and resilience components for both organs in each individual for two drought events (2005 and 2012). Stem and root growth as well as its allometric exponent were higher in the transition zone than in mature forests. Both organs exhibited a trade‐off between resistance and recovery in mature forests but maintenance of higher values in the transition zone. Resilience did not show differences between organs being higher in the transition zone than in mature forests. However, relative resilience in roots in the transition zone was higher than in mature forests, without differences in stems between stages. Finally, the 2012 drought event showed a higher impact on the components of resilience than the 2005 drought event. Synthesis. This study extends the knowledge of root response to drought events and highlights the potential of land‐use legacies to reduce the negative impact of climate change by promoting increased root recovery after drought events in trees established in past agricultural lands.

Increasing species diversity is considered a promising strategy to mitigate the negative impacts of global change on forests. However, the interactions between regional climate conditions and species-mixing effects on climate-growth relationships and drought resistance remain poorly documented. In this study, we investigated the patterns of species-mixing effects over a large gradient of environmental conditions throughout Europe for European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.), two species with contrasted ecological traits. We hypothesized that across large geographical scales, the difference of climate-growth relationships and drought resistance between pure and mixed stands would be dependent on regional climate. We used tree ring chronologies derived from 1143 beech and 1164 pine trees sampled in 30 study sites, each composed of one mixed stand of beech and pine and of the two corresponding pure stands located in similar site conditions. For each site and stand, we used Bootstrapped Correlation Coefficients (BCCs) on standardized chronologies and growth reduction during drought years on raw chronologies to analyze the difference in climate-tree growth relationships and resistance to drought between pure and mixed stands. We found consistent large-scale spatial patterns of climate-growth relationships. Those patterns were similar for both species. With the exception of the driest climates where pure and mixed beech stands tended to display differences in growth correlation with the main climatic drivers, the mixing effects on the BCCs were highly variable, resulting in the lack of a coherent response to mixing. No consistent species-mixing effect on drought resistance was found within and across climate zones. On average, mixing had no significant effect on drought resistance for neither species, yet it increased pine resistance in sites with higher climatic water balance in autumn. Also, beech and pine most often differed in the timing of their drought response within similar sites, irrespective of the regional climate, which might increase the temporal stability of growth in mixed compared to pure stands. Our results showed that the impact of species mixing on tree response to climate did not strongly differ between groups of sites with distinct climate characteristics and climate-growth relationships, indicating the interacting influences of species identity, stand characteristics, drought events characteristics as well as local site conditions.

Heterogeneity of structure can increase mechanical stability, stress resistance and resilience, biodiversity and many other functions and services of forest stands. That is why many silvicultural measures aim at enhancing structural diversity. However, the effectiveness and potential of structuring may depend on the site conditions. Here, we revealed how the stand structure is determined by site quality and results from site-dependent partitioning of growth and mortality among the trees. We based our study on 90 mature, even-aged, fully stocked monocultures of Scots pine (Pinus sylvestris L.) sampled in 21 countries along a productivity gradient across Europe. A mini-simulation study further analyzed the site-dependency of the interplay between growth and mortality and the resulting stand structure. The overarching hypothesis was that the stand structure changes with site quality and results from the site-dependent asymmetry of competition and mortality. First, we show that Scots pine stands structure across Europe become more homogeneous with increasing site quality. The coefficient of variation and Gini coefficient of stem diameter and tree height continuously decreased, whereas Stand Density Index and stand basal area increased with site index. Second, we reveal a site-dependency of the growth distribution among the trees and the mortality. With increasing site index, the asymmetry of both competition and growth distribution increased and suggested, at first glance, an increase in stand heterogeneity. However, with increasing site index, mortality eliminates mainly small instead of all-sized trees, cancels the size variation and reduces the structural heterogeneity. Third, we modelled the site-dependent interplay between growth partitioning and mortality. By scenario runs for different site conditions, we can show how the site-dependent structure at the stand level emerges from the asymmetric competition and mortality at the tree level and how the interplay changes with increasing site quality across Europe. Our most interesting finding was that the growth partitioning became more asymmetric and structuring with increasing site quality, but that the mortality eliminated predominantly small trees, reduced their size variation and thus reversed the impact of site quality on the structure. Finally, the reverse effects of mode of growth partitioning and mortality on the stand structure resulted in the highest size variation on poor sites and decreased structural heterogeneity with increasing site quality. Since our results indicate where heterogeneous structures need silviculture interventions and where they emerge naturally, we conclude that these findings may improve system understanding and modelling and guide forest management aiming at structurally rich forests.

Forests host most terrestrial biodiversity and their sustainable management is crucial to halt biodiversity loss. Although scientific evidence indicates that sustainable forest management (SFM) should be assessed by monitoring multi-taxon biodiversity, most current SFM criteria and indicators account only for trees or consider indirect biodiversity proxies. Several projects performed multi-taxon sampling to investigate the effects of forest management on biodiversity, but the large variability of their sampling approaches hampers the identification of general trends, and limits broad-scale inference for designing SFM. Here we address the need of common sampling protocols for forest structure and multi-taxon biodiversity to be used at broad spatial scales. We established a network of researchers involved in 41 projects on forest multi-taxon biodiversity across 13 European countries. The network data structure comprised the assessment of at least three taxa, and the measurement of forest stand structure in the same plots or stands. We mapped the sampling approaches to multi-taxon biodiversity, standing trees and deadwood, and used this overview to provide operational answers to two simple, yet crucial, questions: what to sample? How to sample? The most commonly sampled taxonomic groups are vascular plants (83% of datasets), beetles (80%), lichens (66%), birds (66%), fungi (61%), bryophytes (49%). They cover different forest structures and habitats, with a limited focus on soil, litter and forest canopy. Notwithstanding the common goal of assessing forest management effects on biodiversity, sampling approaches differed widely within and among taxonomic groups. Differences derive from sampling units (plots size, use of stand vs. plot scale), and from the focus on different substrates or functional groups of organisms. Sampling methods for standing trees and lying deadwood were relatively homogeneous and focused on volume calculations, but with a great variability in sampling units and diameter thresholds. We developed a handbook of sampling methods (SI 3) aimed at the greatest possible comparability across taxonomic groups and studies as a basis for European-wide biodiversity monitoring programs, robust understanding of biodiversity response to forest structure and management, and the identification of direct indicators of SFM.

Questions While positive effects of tree diversity on tree community biomass have often been reported in mature stands, the debate on whether diversity effects may be detectable at the seedling level persists, with opposing outcomes found so far. We still lack a comprehensive evaluation of the biodiversity effects (so-called 'complementarity' and 'selection' effects), as well as the phenotypic drivers at play, underlying early-community biomass. Even less is known about whether such biodiversity effects may change under water-limited conditions. Location Seeds from four tree species coexisting in a Mediterranean forest (Spain). Methods We built experimental tree seedling assemblages with three diversity levels - monocultures, two-species and four-species mixtures - and under two soil moisture conditions. We quantified the extent to which species richness, species identity, community-weighted mean (CWM) and functional dissimilarity (FD) influence complementarity and selection effects. We computed CWM and FD for seven functional traits related to water and light acquisition; and we calculated the complementarity and selection effects from above- and below-ground biomass measures at the community level. Results Our results showed that complementarity drove the greater biomass in more diverse assemblages at the seedling stage. This pattern was largely favored by a particular species, Quercus faginea, with distinct phenotypic traits (great height, lateral ramification and root biomass with high dry matter content), which induced a positive effect of CWM on community biomass. Moreover, our study showed that the water deficit limited the production of above-ground biomass without interacting with the community's species richness. Conclusion Our study provides evidence that positive biodiversity effects on community biomass occur early, at the seedling stage, and it highlights the essential role that certain tree species play from their initial development stages by favoring spatial resource partitioning. Our work motivates future studies to apply integrated approaches in assessing both the community-wide and species-specific effects to understand the biodiversity-biomass relationship.

Unimodal response of tree species richness to increases in aboveground productivity is evident in grasslands but to a lesser extent in forests, where confounding factors (e.g., abiotic factors and management regimes) may alter the response and compromise the delivery of ecosystem services. We hypothesize that unimodal response of biomass accumulation through increased species richness leads to greater tree above ground carbon (AGC) stocks and thus climate regulation but not necessarily higher timber volume production for human consumption across portions of North American and European forests. We first evaluated the biodiversity-productivity pattern and assessed if the addition of potential confounding variables altered the response. Afterwards, we integrated direct and indirect effects of species richness and confounding factors in the modelling of aboveground carbon stock and timber volume. We confirm an increase in carbon stocks concomitant with an increase in tree species richness up to an optimum biomass value in both regions. Tree species richness had a marginal effect on both aboveground carbon stocks and timber volume with a trade-off in the eastern US. Biomass accumulation is lower in tree plantations than in natural forests, although volume increased with species richness. Naturally-regenerated forests needed as much as double the number of tree species than plantations to reach the same carbon stocks. Distinct ecosystem services (AGC and timber volume) showed unique pathways of achieving their maximum provisioning. As increasing forest resilience to global change requires a fundamental understanding of how tree species combine with changing climatic conditions to drive the provisioning of various ecosystem services, further examination of this study's findings across additional biogeographical regions may lead the way to unraveling such dynamics and empowering adaptive management.

41 Context Over the last decades, there has been an increasing interest in mixed species forests because of 42 their expected positive impacts on ecosystem services (including productivity), ecosystem stability and risk 43 management. However, the mechanisms at play in species interaction and their dependency on spatial 44 and temporal variations of environmental conditions are still insufficiently understood. 45 Methods To assess the impact of species mixture on tree response to water availability, we constructed 46 22-year time series of wood carbon isotope compositions from a network of 17 sites covering a large 47 gradient of environmental conditions throughout Europe. Each site included a mixed Fagus sylvatica L. / 48 Pinus sylvestris L. stand and one monospecific stand of each species, with all the stands at a given site in 49 similar environmental conditions. 50 Results A positive species-mixture effect for both species was found on dry sites. On moderately wet sites, 51 the results were contrasted, with pine showing a negative effect and beech a positive one. The contrasted 52 results can be explained by the differences in how each species manages the trade-off between carbon 53 acquisition and water loss, which are highlighted in pure plots. No species-mixture effect was found on 54 extremely dry or extremely wet sites. There were no differences in reactions to drought between pure and 55 mixed stands. 56 Conclusion Mixing species did not improve trees response to a drought event but influenced their average 57 isotopic composition according to the species-specific functional traits and average site conditions. The 58 pattern of mixing effect along the gradient of water availability was not linear but showed threshold points. 59

Abstract European forests are expanding and becoming denser following the widespread abandonment of farmland and rural areas. Spontaneous forest regrowth provides a cost‐effective opportunity to restore ecosystems, enhance multifunctionality and sustainability and mitigate climate change. Yet, little is known about the goods and services that such forests provide to people. We assessed the changes in nature's contributions to people (NCP) from spontaneous forest regrowth, i.e. forest expansion and densification, in South‐West Europe. We investigated 65 forest plots in four different landscapes with contrasting ecological and societal contexts. Two landscapes are located in rural areas undergoing human exodus and forest expansion and densification; the other two, in peri‐urban areas with intense land use and forest densification but negligible expansion. For each forest plot, we estimated variables related to ten out of the 18 main NCP defined by the Intergovernmental Science‐Policy Platform on Biodiversity and Ecosystem Services (IPBES). Regulating and material NCP were addressed using variables measured in the field as proxies. Non‐material NCP were studied through stakeholder interviews. Our results show across the cases that forest expansion and densification are generally associated with greater climate regulation and energy provision. Changes in other NCP, especially in non‐material ones, were strongly context‐dependent. The social perception of spontaneous forest regrowth was primarily negative in rural areas and more positive in peri‐urban landscapes. Passive restoration through spontaneous forest expansion and densification can enhance regulating and material NCP, especially when adaptive management is applied. To optimise NCP and to increase the societal awareness of and interest in spontaneous forest regrowth, the effects of this process should be analysed in close coordination with local stakeholders to unveil and quantify the many and complex trade‐offs involved in rural or peri‐urban social perceptions. A free Plain Language Summary can be found within the Supporting Information of this article.

The adoption of new silvicultural methods and approaches requires an understanding of the differences between those and “old” or “conventional” approaches, along with extensive training to break previous knowledge bias. Forestry is in transition towards ecosystem-based management, and new silvicultural approaches are appearing worldwide. However, the adoption of an alternative silvicultural approach is difficult in practice. We analyzed the effect of forestry background and demographic variables (gender and age) of 24 raters on the application of the systemic approach (SA) and the conventional approach (CA) in the Northern Apennines (Italy) and compared this with tree marking performed by experts. Data were analyzed as raters’ departures from experts’ selections at the stand and the individual tree level. The probability of tree selection was also calculated. At the stand level, raters with forestry background performed the SA as if they were marking for crown thinning, whereas the CA was less intense than experts’ crown thinning. Non-foresters differentiated poorly between the SA and the CA. At the individual tree level, background and gender affected tree selection. The adoption of the SA as a silvicultural system may be conditioned by previous knowledge. The difference between SA and CA remains unclear when it comes to non-foresters. Gender was a more important variable than age in selecting which trees would be harvested.