Deer (Cervidae) populations are increasing across the temperate zone, threatening forest biodiversity and ecosystem services. However, the fundamental question of what factors make a forest susceptible to deer damage remains unanswered, hampering efforts to mitigate against damage. Previous research has assumed that deer density consistently increases forest damage. However, the effect of deer density is likely to be contingent on a range of other drivers, such as climate and landscape structure. Mitigation measures are expensive, so a sound understanding of these contingencies is required to inform the targeting of appropriate management to forests most at risk of damage. Using records of forest damage from Britain's National Forest Inventory, which comprises over 15,000 plots spanning environmental gradients, we applied a multiscale approach to identify the drivers of forest susceptibility to damage by deer. Damage likelihood was dependent on drivers operating at multiple spatial scales and their interactions. Broadleaved stands with low tree densities and old trees were consistently found to be at high risk across Britain. The statistical influence of surrounding forest cover within 500 m of a site was modified by regional deer density and climate, in addition to landscape‐level perennial cover. The effect of deer density on damage was therefore not straightforward, but context dependent. Synthesis and applications. We predict the likely outcome of afforestation initiatives on the likelihood that a forest site will be damaged by deer, with important implications for management and landscape planning in Britain. The complex interactive effects uncovered are difficult to interpret. We therefore provide an interactive Deer Damage Tool (R Shiny application; https://spake.shinyapps.io/DEERDAMAGETOOL/) for practitioners to visualize how afforestation is likely to influence the probability of deer damage in different forests and regions across Britain.

Habitat loss and fragmentation greatly affect biological diversity. Actions to counteract their negative effects include increasing the quality, amount and connectivity of seminatural habitats at the landscape scale. However, much of the scientific evidence underpinning landscape restoration comes from studies of habitat loss and fragmentation, and it is unclear whether the ecological principles derived from habitat removal investigations are applicable to habitat creation. In addition, the relative importance of local‐ (e.g., improving habitat quality) vs. landscape‐level (e.g., increasing habitat connectivity) actions to restore species is largely unknown, partly because studying species responses over sufficiently large spatial and temporal scales is challenging. We studied small mammal responses to large‐scale woodland creation spanning 150 yr, and assessed the influence of local‐ and landscape‐level characteristics on three small mammal species of varying woodland affinity. Woodland specialists, generalists, and grassland specialists were present in woodlands across a range of ages from 10 to 160 yr, demonstrating that these species can quickly colonize newly created woodlands. However, we found evidence that woodlands become gradually better over time for some species. The responses of individual species corresponded to their habitat specificity. A grassland specialist (Microtus agrestis) was influenced only by landscape attributes; a woodland generalist (Apodemus sylvaticus) and specialist (Myodes glareolus) were primarily influenced by local habitat attributes, and partially by landscape characteristics. At the local scale, high structural heterogeneity, large amounts of deadwood, and a relatively open understory positively influenced woodland species (both generalists and specialists); livestock grazing had strong negative effects on woodland species abundance. Actions to enhance habitat quality at the patch scale focusing on these attributes would benefit these species. Woodland creation in agricultural landscapes is also likely to benefit larger mammals and birds of prey feeding on small mammals and increase ecosystem processes such as seed dispersal.

A key aim of ecology is to understand the drivers of ecological patterns, so that we can accurately predict the effects of global environmental change. However, in many cases, predictors are measured at a finer resolution than the ecological response. We therefore require data aggregation methods that avoid loss of information on fine‐grain heterogeneity. We present a data aggregation method that, unlike current approaches, reduces the loss of information on fine‐grain spatial structure in environmental heterogeneity for use with coarse‐grain ecological datasets. Our method contains three steps: (a) define analysis scales (predictor grain, response grain, scale‐of‐effect); (b) use a moving window to calculate a measure of variability in environment (predictor grain) at the process‐relevant scale (scale‐of‐effect); and (c) aggregate the moving window calculations to the coarsest resolution (response grain). We show the theoretical basis for our method using simulated landscapes and the practical utility with a case study. Our method is available as the grainchanger r package. The simulations show that information about spatial structure is captured that would have been lost using a direct aggregation approach, and that our method is particularly useful in landscapes with spatial autocorrelation in the environmental predictor variable (e.g. fragmented landscapes) and when the scale‐of‐effect is small relative to the response grain. We use our data aggregation method to find the appropriate scale‐of‐effect of land cover diversity on Eurasian jay Garrulus glandarius abundance in the UK. We then model the interactive effect of land cover heterogeneity and temperature on G. glandarius abundance. Our method enables us quantify this interaction despite the different scales at which these factors influence G. glandarius abundance. Our data aggregation method allows us to integrate variables that act at varying scales into one model with limited loss of information, which has wide applicability for spatial analyses beyond the specific ecological context considered here. Key ecological applications include being able to estimate the interactive effect of drivers that vary at different scales (such as climate and land cover), and to systematically examine the scale dependence of the effects of environmental heterogeneity in combination with the effects of climate change on biodiversity.

There is a global drive to increase forest cover to protect biodiversity and help combat climate change. Tree planting is widely used to increase forest cover, although there is growing interest in using natural processes. However, predicting the outcome of natural colonization is challenging as it is a highly variable process and evidence is sparse, especially in temperate landscapes. Our study aims to evaluate the spatial and temporal scale over which natural colonization may be an effective approach to create new forests within temperate agriculturally dominated landscapes. We examine the spatial patterns in tree density and height across 90 sites in the United Kingdom that attempted to use natural colonization to create new forests between 1994 and 2004. Tree density and tree height were measured using light detecting and ranging point cloud data, an increasingly common technique for surveying forest characteristics. This research shows that natural colonization is a highly variable, relatively slow process in temperate agricultural landscapes, spatially restricted to a narrow fringe around existing forests and trees (105 m; 95% CI: 70–174 m, within approximately 19 years), although exact distances vary with former land use. This suggests that in some circumstances natural colonization will need to be assisted and supplemented with tree planting to increase forest cover, especially in areas away from a seed source. In reality, a blend of approaches will be needed to meet policy and land manager objectives, increase forest cover and tackle the biodiversity and climate crises.

Aim: Large‐scale habitat creation is crucial to mitigate the current ecological crisis, but scientific evidence on its effects on biodiversity is scarce. Here, we assess how assemblages of a biodiverse group (moths) develop over time in habitat creation sites. We use temperate woodlands as a case study, and compare species assemblages in restored and mature habitat patches. We also identify local‐ and landscape‐level attributes associated with high species richness and abundance.Location: Central Scotland, United Kingdom.Methods: We surveyed moths in a chronosequence of 79 temperate woodland patches encompassing woodland creation sites (20–160 years old) and mature “ancient” woodlands (250+ years old). We used structural equation models, generalized linear models and ordination techniques to quantify moth community responses to woodland creation, and degree of similarity to moth assemblages in ancient woodlands.Results: Woodland creation sites harboured large numbers of moth species (212), were dominated by woodland generalists and had high species turnover. Moth abundance and diversity increased with woodland connectivity. Macromoths were more abundant and diverse in younger woodlands; micromoth specialists occurred more frequently in older woodland creation sites. Ancient woodlands had similar moth abundance/richness than woodland creation sites (except for fewer macromoth woodland specialist species), but their species composition was somewhat different. Patterns of beta diversity (low nestedness) indicated that moth species in woodland creation sites are not simply subsets of species in ancient woodlands.Main conclusions: To benefit moth communities, woodland creation sites should be structurally diverse and in close proximity to other woodlands. At the landscape scale, a mosaic of woodland patches of different ages is likely to increase moth beta (and consequently gamma) diversity. Ancient woodlands and woodland creation sites each host substantial proportions of “unique” species; individual woodland patches contain distinctive moth assemblages and should be protected and valued for their contribution to regional moth diversity.