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Quercus spp. are one of the most important tree genera in temperate deciduous forests in terms of biodiversity, economic and cultural perspectives. However, natural regeneration of oaks, depending on specific environmental conditions, is still not sufficiently understood. Oak regeneration dynamics are impacted by climate change, but these climate impacts will depend on local forest management and light and temperature conditions.Here, we studied germination, survival and seedling performance (i.e. aboveground biomass, height, root collar diameter and specific leaf area) of four oak species (Q. cerris, Q. ilex, Q. robur and Q. petraea). Acorns were sown across a wide latitudinal gradient, from Italy to Sweden, and across several microclimatic gradients located within and beyond the species' natural ranges. Microclimatic gradients were applied in terms of forest structure, distance to the forest edge and experimental warming.We found strong interactions between species and latitude, as well as between microclimate and latitude or species. The species thus reacted differently to local and regional changes in light and temperature ; in southern regions the temperate Q. robur and Q. petraea performed best in plots with a complex structure, whereas the Mediterranean Q. ilex and Q. cerris performed better in simply structured forests with a reduced microclimatic buffering capacity. The experimental warming treatment only enhanced height and aboveground biomass of Mediterranean species.Our results show that local microclimatic gradients play a key role in the initial stages of oak regeneration; however, one needs to consider the species‐specific responses to forest structure and the macroclimatic context. [ABSTRACT FROM AUTHOR]

Climate change, eutrophication and intensified forest management are affecting forest understorey plants, a major component of forest biodiversity. The main impacts of these drivers have often been studied, but we lack a good understanding of how key understorey species are affected by potential interactive effects of these drivers and which species drive community changes.Here we assessed the responses of 15 species occurring in the understorey of a deciduous temperate forest to experimental warming, light addition and enhanced nitrogen inputs in permanent plots surveyed for 9 years. We analysed vegetation cover and key functional traits (plant height, specific leaf area and reproductive traits) at the species level and identified the species driving community change with principal response curves (PRC).Light addition and warming, and to a lesser extent also nitrogen addition, had profound effects on cover and functional traits. Many species showed directional change over time, and this change can either be strengthened or weakened by treatments, indicating the importance of long‐term monitoring. Against expectations, we observed few interactions between treatments. Species responses to treatments were related to ecological strategies (generalists versus forest specialist). Generalists, such as Rubus fruticosus, benefitted from the warming and light treatments and outcompeted forest specialists.This might ultimately lead to biotic homogenization. Since the treatment effects of light and warming were additive, keeping the canopy closed will only mitigate, but not stop, the effects of global warming on the forest understorey plants. [ABSTRACT FROM AUTHOR]

Global environmental changes such as climate change, overexploitation and human population growth increase the interest in woody biomass from forests as a resource for green energy, chemistry and materials. Whole Tree Harvesting (WTH) can provide additional woody biomass, mainly for bioenergy, by harvesting parts of the crown not harvested under conventional Stem-Only Harvesting (SOH). However, WTH also increases nutrient export, potentially depleting soil nutrients and threatening future stand productivity. Here we assess the impacts of WTH in Corsican pine stands ( Pinus nigra ssp. Laricio var. Corsicana Loud.) with a rotation period of 48 years on poor, sandy soils in Belgium. We performed a detailed nutrient budget assessment before and after thinnings and clear-cuts under scenarios of WTH and modelled the long-term changes in ecosystem nutrients under both WTH and SOH. Our results demonstrate a strong immediate impact of WTH on aboveground nutrient stocks (mainly in clear-cuts). In clear-cuts with WTH, half of the base cations (calcium, potassium, magnesium) in the trees and forest floor were exported. The amount of available cations in the soil is not sufficient to immediately compensate for this export. Only one fourth of the amount exported were available for biota in the top 50 cm of the soil. We also modelled long-term development of ecosystem nutrients (available nutrients in the soil and nutrients in trees and forest floor) and found that the available soil calcium, potassium and phosphorus stocks are insufficiently replenished by deposition and weathering to sustain WTH on the long term. We found no indications of potential depletion of ecosystem cations and phosphorus for the next ten rotation periods under SOH management. Our results thus support a less intensive management in pine stands on poor, sandy soils, for instance, by adopting SOH and/or longer rotation periods. [ABSTRACT FROM AUTHOR]

• Decision-making survey on motivations, challenges and targets in forest management. • Respondents focus on climate change, biodiversity loss and forest regeneration. • Managers need to consider role of herbaceous understory to address these issues. • Requirement for a decision support tool that accounts for understory dynamics. Numerous decision-makers have an interest in how forest biodiversity and functioning will alter under environmental change. These decision-makers may have varied motivations underlying their management response to environmental change by focusing on contrasting management challenges and targets. Decision-makers may use different tools to aid their decision-making when facing uncertainty. We specifically investigate whether decision-makers in forest management across Europe consider the understory (i.e. herbaceous layer) in decision making, as this component constitutes the vast majority of floral biodiversity in temperate forests, and has an important functional role. To address this question, we distributed an online questionnaire to more than 800 forest management decision-makers across Europe, and received 100 completed responses. We assess what objectives drive management decisions, and whether these are consistent depending on respondents' occupations. Interestingly, regardless of respondent profile, biodiversity loss and climate change are expected to permeate management decisions in the coming decades, motivated primarily by a sense of environmental protection. Priority management targets did not vary across respondent profiles (i.e. occupation) either, and focused on biodiversity values, adaptation and mitigation to climate change, and forest regeneration. The majority of respondents identified the understory as an "Important" target for forest management decisions. Respondents used a mix of personal experience and literature sources to base management decisions on, while infrequently using recognised decision support systems (DSS). No utilised system considered the understory at the moment. Indeed, our review of available forest management DSS, conducted in parallel to the questionnaire, shows that an understory DSS tool, especially one that can consider changing socio-environmental conditions, is lacking for decision-makers. Based on (1) forest management decision-makers' wide concern around biodiversity loss, climate change and forest regeneration, (2) the known functional role of temperate forest understories, and (3) an apparent lack of existing DSS with an understory component, we identify the requirement for an agile tool that accounts for understory dynamics. Such a tool, especially when integrated into existing DSS, will strongly support decision-makers in their quest to attain more biodiverse, functional and resilient forests for the future. [ABSTRACT FROM AUTHOR]