Boreal forests are important reservoirs of biodiversity, carbon and timber stocks. However, timber harvest can alter biodiversity in these forests without clear evidence on the duration needed for biotic groups to recover. Resilience of boreal forest biodiversity to clear-cut harvest was examined with a meta-analysis of 190 datasets from boreal and hemi-boreal forests of Europe/Russia and North America for arthropods, birds, small mammals, lichens, bryophytes and vascular plants. We modelled similarity of community composition between harvested and unharvested stands versus years post harvest. In approximately half of cases, predicted times for recovery to pre-harvest composition were ≤30 years. In other cases, recovery took much longer or had not occurred within the timeframe of our data; for example, in conifer forest: >100 years (bryophytes), >55 years (small mammals), ~95 years (lichens) and ~85 years (vascular plants). Saproxylic beetles showed no resilience within the 16 (conifer forest) or 29 (mixed forest) years post harvest for which we had data. Recovery generally took longer in conifer and mixed than in broadleaf forests, which always showed either resistance (bryophytes, vascular plants) or resilience with recovery within 12–25 years. Conserving biodiversity in boreal forests will require extended rotations, management for ‘old forest’ structural elements and areas protected from harvesting.

Urban forests provide essential ecosystem services, including pest control, biodiversity conservation, and human health benefits. Herbivory is a widespread biotic interaction that shapes ecosystem functions, such as primary productivity and soil fertility, which underpin these services. Urbanization can disrupt plant–herbivore interactions by altering plant traits, such as nutrient content or phenolic compounds (bottom–up factors), or by changing the abundance of herbivore natural enemies (top–down control), potentially threatening pest regulation and the ecosystem services provided by urban forests. Disentangling these drivers of herbivory is crucial for designing and managing urban forests to enhance resilience. To address this, we examined insect leaf herbivory on Quercus robur trees in urban and rural forest stands across 13 European cities (n = 104 trees). To assess top–down effects on herbivory, we excluded vertebrate (e.g. birds, bats), invertebrate (e.g. ants), or both groups of predators from branches on each tree using different exclosure types. We then measured insect damage on both control and predator-excluded branches. To evaluate bottom–up drivers, we measured leaf traits, specifically nutrients and phenolic compounds, and tested for correlations with leaf damage. Additionally, we recorded temperature within stands, an abiotic factor that may modulate both top–down and bottom–up forcing on herbivory. Herbivory was 24% lower on urban trees compared to rural trees. In turn, excluding vertebrate (but not invertebrate) predators increased herbivory, on average, by 40%, but predator effects were stronger in urban stands. Urban trees also had higher leaf quality, with higher nutrient and lower phenolic concentrations; however, these traits did not correlate with herbivory. Temperature was positively associated with urbanization and correlated positively with predation, but did not correlate with herbivory and did not mediate the bottom–up or top–down effects of urbanization. Overall, we find that urbanization affects herbivory through both bottom–up and top–down processes, independent of temperature-related local conditions. Despite stronger predator effects and higher leaf quality, urban trees experienced lower herbivory, suggesting that unmeasured factors, such as changes in herbivore behaviour or community structure, may play an important role. Further studies are needed to deepen our understanding and inform urban forest management.

Climate change is expected to cause latitudinal and elevational shifts in where crops can grow, with major consequences for land use, rural livelihoods and biodiversity. Shifts in agroforestry systems can be especially transformative, as this alters tree cover. We used semi-structured interviews and vegetation surveys to investigate the patterns, drivers, consequences and future trajectories of an upward shift of Arabica coffee agroforestry within its native range in the Afromontane mountains. We observed a climate-, income- and crop raiding-driven upward shift of coffee production into a novel elevational range, with positive feedback mechanisms enhancing the future adoption of agroforestry. Forest and open-land-derived agroforests showed similar woody plant species richness and large overlaps in community composition. Open-land-derived coffee agroforestry is, and is expected to increasingly be, the dominant coffee agroforestry type in the novel range, with positive implications for tree cover, biodiversity and ecosystem services in one of the world’s biodiversity hotspots.

As the climate is changing, species respond by changing their distributions and abundances. The effects of climate are not only direct, but also occur via changes in biotic interactions, such as competition. Yet, the role of competition in mediating the effects of climate is still largely unclear. To examine how climate influences species performance, directly and via competition with other species, we transplanted two moss species differing in climate niches, alone and together at 59 sites along a climate gradient. Growth was monitored over three growing seasons. In the absence of competition, both species performed better under warmer conditions. Yet, when transplanted together, a warmer climate had negative effects on the northern moss, while the effects remained positive for the southern species. The negative effect of a cold climate on the southern species was larger when both species were transplanted together. Over three growing seasons, the southern species almost outcompeted the northern in warmer climates. Our results illustrate how competitive interactions can modify, and even reverse, the direct effects of climate on organism performance. A broader implication of our results is that species interactions can have important effects on how environmental and climate change influence performance and abundance.

The occurrence patterns of invasive species are shaped, on the one hand, by the availability of suitable habitat, and, on the other hand, by how dispersal has progressed since their introduction to the new region. This complicates attempts to understand and predict their distributions, especially if the relative importance of these factors differs between spatial scales. Here, we investigate environmental and dispersal-linked patterns in the distribution of the globally invasive plant Lupinus polyphyllus. For this purpose, we created a uniquely extensive and high-resolution occurrence dataset for the entire country of Sweden by surveying 2100 km of roadside, collected density and size data from 152 populations, and analyzed global distribution patterns using citizen science data. Analyses revealed that at the regional scale (>50 km), lupine occurrence was best explained by climate, with some effects of soil chemistry. However, at smaller scales, both lupine presence and density were best explained by the presence of nearby buildings, suggesting a large role of human-aided dispersal. Furthermore, the results depended on road type: environmental variation (especially soil chemistry) only weakly limited lupine occurrence along highways, suggesting that large roads may act as dispersal corridors across otherwise unsuitable habitat. When integrating modeling results for Sweden with observations from the global range of L. polyphyllus, further northward expansion in Scandinavia appears possible even under the current climate regime, but likely with limited maximum abundance in northern regions. Our results illustrate how a nested study design and a combination of data sources enable a more comprehensive assessment of the factors influencing a biological invasion.

Aim: For improved predictions of the redistribution of species under climate change, there is a need to better understand how interactions among multiple abiotic drivers affect species distributions. We examined whether occupancy patterns of forest plant species change consistently along geographic and macroclimatic gradients. We further tested whether these changes co-vary with species’ edaphic niche widths—specifically, whether niche widths contract as occupancy declines. Finally, we assessed ehether changes in occupancy and niche widths depend on species’ climatic and edaphic niche optima.

Location: Sweden.

Time Period: 2004–2013.

Major Taxa Studied: Vascular plants.

Methods: We used data from the National Forest Inventory on soil (pH and C:N-ratio), and on occurrence of plant species from ca. 7000 inventory plots located along a climatic gradient (MAT −3 to +8°C). We modelled the probability of occurrence, as well as the edaphic pH and C:N-ratio niche widths, along this gradient, using Generalized Additive Mixed Models. We then examined whether species’ occupancy and niche widths vary along the climatic gradient and whether this variation can be explained by climatic and edaphic niche optima quantified by ecological and climatic indicator values.

Results: The probability of occurrence and niche widths of most species either increased or decreased along the temperature gradient. Generally, species that decreased in occurrence and edaphic niche widths towards colder climate had their niche optima in warmer climate and vice versa. Indicators related to the climatic niche of the species generally explained a much larger proportion of the variation in species occurrence and edaphic niche width than soil-related indicator values.

Main Conclusions: The results highlight that climate not only drives species’ redistributions directly, but also indirectly through modulating how plants interact with their soil environments, that is, their edaphic niches—an often-overlooked mechanism important for understanding species responses to climate change.

• Background and Aims Climate influences species performance and distribution both directly, through physiological constraints, and indirectly, by modulating biotic interactions. However, the relative importance of these pathways remains poorly understood, limiting our ability to predict species responses to environmental change. Here, we investigated how microclimate influences the growth of a cold-adapted lichen both directly and indirectly, through effects on mollusc grazing, and whether these effects differ among populations of different origins.
• Methods We conducted a transplant experiment using lobes of Peltigera aphthosa collected from five geographically distant populations along a 1200-km latitudinal gradient in Sweden. The lobes were transplanted to 56 forest sites spanning a broad microclimatic gradient near the species' warm-range margin in Sweden, and we monitored their growth and grazing damage for one year. Using piecewise structural equation models, we quantified the direct and indirect effects of microclimate through grazing on lichen growth and assessed whether these effects differed among source populations.
• Key Results We found no evidence for direct effects of microclimate on lichen growth. Instead, microclimate indirectly influenced growth through mollusc grazing. Grazing damage increased with warmer temperatures (more growing degree days) and higher air humidity (lower vapour pressure deficit) during the growing season and grazing reduced lichen growth. While population origin did not affect direct responses to microclimate, populations differed in their susceptibility to grazing.
• Conclusions Our study highlights the importance of indirect microclimatic effects mediated by biotic interactions in shaping species performance near its warm-range margin. The absence of direct microclimatic effects, combined with intraspecific variation in susceptibility to grazing, underscores the need to consider both biotic interactions and differences among populations when predicting species responses to climate change. Transplant experiments across microclimatic gradients offer a valuable method to gain insights into the complex interplay between local adaptation and abiotic and biotic factors of species performance.

Fast-growing broadleaf (FGB) stands are planted in Northern Europe due to their high biomass production and as part of climate change mitigation and adaptation strategies. Yet, the effects on biodiversity of this intensive forest management that involves short-rotations, and sometimes the use of non-native tree species, are still uncertain. Given the limited number of studies investigating the biodiversity of FGB stands in Sweden, we assessed and compared the biodiversity of three FGB tree species and evaluated how tree species, tree traits, stand variables, and landscape features were associated with lichen diversity patterns. To do that, we studied epiphytic lichens in 48 stands of native birch (Betula pendula), and non-native hybrid aspen (Populus tremula x P. tremuloides) and poplar (Populus trichocarpa hybrids) across southern Sweden. Lichen species richness was the highest in birch stands at both the tree and stand level. For all the stands surveyed, poplar and birch had the same total number of lichen taxa (71 taxa), while hybrid aspen hosted fewer lichen taxa (58 taxa). The lichen species composition of the three tree species differed from each other, although lichen communities on hybrid aspen and poplar lichen communities were more similar to each other than to birch. We found lichen species of conservation interest on all tree species, whereas red-listed species only occurred on hybrid aspen and poplar. Older trees, deeper bark crenulation, and higher understory light levels generally increased lichen species richness, whereas the surrounding landscape vegetation cover also influenced species composition. Our results indicate that using a mix of fast-growing broadleaf tree species, rather than planting only one of them within the landscape, making allowances for older trees, and managing light and landscape context improves the diversity of lichens supported within FGB stands.

Little is known about the effects of invasive bryophytes on native biodiversity. To date, the main documented effect is competition, mostly with other bryophytes. Campylopus introflexus is an invasive moss in Europe and North America that can form dense monocultural carpets that displace native vegetation and influence the composition of native arthropod communities. It was first recorded in Sweden in 1976, where it commonly invades disturbed peatlands and its invasion potential is currently assessed as ‘severe’. Despite this long invasion history, little is understood about its local impacts, including on ground-dwelling arthropods. We analysed the effect of C. introflexus invasion on ground-dwelling beetle and spider communities at 14 sites in south-west Sweden. We collected arthropods along paired transects (50–200 m apart) in disturbed peatlands that were invaded or uninvaded by C. introflexus. Pitfall traps were emptied during the months of July, August, and September. We characterized the ground layer vegetation using quadrats (50 × 50 cm) centred over pitfall traps. We collected 2237 beetles belonging to 109 species from 18 families and 2139 spiders belonging to 85 species from 18 families. We found that C. introflexus invasion was associated with increased beetle abundance, richness, and diversity, but had no effect on spider abundance, richness, and diversity. We found no effect of C. introflexus invasion on beetle or spider community composition. Our results suggest that C. introflexus invasion into disturbed peatlands affects beetle communities, demonstrating that bryophyte invasions can have ecological consequences and highlighting the need for further research on this often overlooked group.

Societal Impact Statement: Tropical forests are rapidly declining. One promising strategy to reverse the loss of tropical forest is the establishment of agroforestry on open land. We combined interviews with biodiversity surveys to learn general lessons from success and nonsuccess stories of the establishment of open-land-derived coffee agroforests in one of the world's biodiversity hotspots, the Brazilian Atlantic Forest. Our findings highlight the need for continued agronomic support to smallholder farmers to avoid abandonment, maintain, and even expand open-land-derived agroforestry. Interestingly, as abandoned agroforests were not converted back to open land, both managed and abandoned agroforests provided ecosystem services and contributed to the restoration of native tree cover across the landscape. Summary: Tropical forests are biodiversity hotspots threatened by deforestation and fragmentation. One strategy to restore tropical forest is to establish agroforestry on open land. However, we lack insights into the social and ecological dynamics of open-land-derived agroforests, and specifically the reasons for and consequences of abandonment. We aimed to understand the reasons leading to the abandonment of management of the main crop and the impact on ecosystem services, disservices and the woody plant community structure. We combined semiquantitative interviews with biodiversity surveys to examine the reasons for abandonment and the consequences for ecosystem services, disservices and the woody plant community in the Atlantic Forest region of Pontal do Paranapanema (SE Brazil) where coffee agroforests were established during the past two decades. Reasons for abandonment were primarily agronomic (failure of crop establishment and decline in productivity), whereas only a few farmers reported socioeconomic reasons. Interestingly, ecosystem services, disservices and woody plant community structure had not (yet) differentiated after the abandonment of management. Our findings underscore that more and continued agronomic governmental and non-governmental support to smallholder farmers is essential to maintain and expand open-land-derived agroforestry. Notably, as abandoned agroforests were not converted back to open land, partly due to legal restrictions, they continued to provide ecosystem services and contributed to the restoration of native tree cover across the landscape.