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Timber‐oriented forest management profoundly alters forest structure and composition, with complex effects on associated biodiversity. However, while species' responses to forest management and resulting structural characteristics have been the subject of numerous studies, direct and indirect effects that cascade through trophic levels are rarely disentangled. As insectivorous bats are particularly sensitive to changes in forest structure, that shape their available flight space, we investigated how forest structure, composition and management also indirectly modify their habitats, for example, by affecting important insect prey groups. We used structural equation models (SEMs) to test bat responses to forest composition, structure (forest heterogeneity, old‐growth attributes) and management intensity, quantifying direct and indirect prey‐mediated effects. For that, three bat guilds—short‐ (SRE), mid‐ (MRE) and long‐range echolocating (LRE) bats—and their prey insects (moths and ground beetles) were analysed from 64 sites in the Black Forest, Germany. We found guild‐specific effects on bats: While the structural heterogeneity of forests directly influenced the activity of bat guilds, the main influence of forest management, composition and structure was mediated through their prey‐groups. SRE activity responded to moths and LRE activity was associated with ground beetles, with positive effects of the insect groups' abundance, but negative effects of the same group's species richness. In addition, the SEM approach revealed a negative top‐down relationship between MRE activities and moths, suggesting predation or avoidance behaviour of moths. While forest management directly or indirectly increased prey insect abundance, it negatively affected the availability of roosting structures for bats. Synthesis and applications. The results highlight the indirect and positive effects of forest management on bats and support the important role of bats in insect regulation within continuous cover forests. Although forest management created small gaps that improved foraging habitats for most bats, it compromised the roosting functionality for bats. The ‘close‐to‐nature forestry’ currently prevalent in Europe mainly promotes continuous‐cover forests in mid‐successional stages. Expanding the forest management portfolio towards open and old‐growth forests would increase roosting opportunities and provide complementary foraging habitats for different bat species, while promoting high biodiversity in managed forest landscapes. [ABSTRACT FROM AUTHOR]

1. There is increasing evidence from local studies carried out in several parts of the world to suggest that increases in the abundance of deer may be depressing population levels of breeding woodland bird populations that are associated with dense understorey habitats. We examine whether habitat modification by deer is likely to be a factor contributing to recent large-scale population declines of woodland birds in lowland England. 2. Novel analytical methods are applied to extensive national bird and deer monitoring data, to examine whether populations of 11 woodland bird species that are associated with dense understorey habitats in lowland England may have been depressed following increases in the abundance of three widespread and abundant deer species: Reeves' muntjac Muntiacus reevesi, roe deer Capreolus capreolus and fallow deer Dama dama. An additional four woodland bird species that are not specifically associated with understorey habitats are included as controls. 3. For five of the 11 understorey species considered, there is evidence that increases in deer are associated with large-scale depression of abundance or population declines in lowland England. Of these species, we suggest that the impacts of deer are likely to have been greatest for two species of conservation concern, common nightingale Luscinia megarhynchos and willow tit Poecile montanus. 4. Synthesis and applications. Large-scale analyses of extensive national monitoring data provide evidence for a negative association between three widespread and abundant deer species and several woodland bird populations that are associated with dense understorey habitats. These findings are consistent with those from small-scale experimental studies and indicate that deer-related habitat modification may be affecting some bird species on far larger scales than previously appreciated. Mainly through their effects on understorey vegetation, high deer populations are now likely to be affecting woodland biodiversity over large parts of lowland England and deer management plans, involving integrated exclusion and culling of deer, need to be co-ordinated on large scales. It is suggested that such management plans could most usefully target areas that still support relatively high populations of species that are sensitive to deer. Knowledge about the form of relationships between deer abundance and habitat quality for birds and other biodiversity is an important knowledge gap that needs to be addressed if sound, collaborative deer management plans are to be developed. [ABSTRACT FROM AUTHOR]

1. Savannas throughout the world are characterized by spatial gradients of resources created by scattered overstorey trees. These gradients are important for maintenance of understorey biodiversity; however, they may be disrupted by woody encroachment, resulting in alterations to understorey vegetation. Little is known about the status of understorey gradients in encroached savannas, or whether they redevelop during restoration and if so, by what mechanism. 2. We used a large-scale restoration experiment with Midwestern oak savannas (USA) to address these issues. We established understorey transects radiating from overstorey Quercus alba L. trees to inter-canopy gaps in four control and four restoration treatment sites. Along each transect, we sampled understorey vegetation over three field seasons and we recorded physical factors in the final year of study. 3. Restoration produced a strong relationship between visible sky (e.g. light penetrating to the understorey) and distance from overstorey trees, while none existed in control sites. Restored sites had greater variability in soil moisture due to higher levels immediately after rain at all distances from trees, coupled with greater drying rates, particularly at farther distances from overstorey trees. With restoration, a positive relationship between cover by understorey vegetation and distance from overstorey trees developed and strengthened over time, whereas no relationship existed in control sites. Cover by each of the major functional groups, forbs, graminoids, and woody species, contributed to this pattern. Furthermore, after restoration, species richness increased with distance from overstorey trees in the final year of study. 4. Nonmetric multidimensional scaling (NMS) showed that common understorey species were correlated with gradients of canopy cover and soil moisture, which were associated with restoration plots, and gradients of soil texture and N, which were associated with both restoration and control plots. Furthermore, restoration strengthened correlations between NMS plot scores and distance from overstorey trees. 5. Synthesis and applications. Re-establishing overstorey structure was an important step during restoration of the oak savannas in this study. While encroached savannas contained a homogenized understorey, restored sites contained understorey patterning typical of intact savannas. The timeframe for re-establishment – within years of restoration, after decades of degradation – demonstrates high resiliency and suggests restorability of other highly degraded sites; however, we recognize the importance of prescribed fire for maintaining open savanna structure and, probably, promoting further understorey pattern development. [ABSTRACT FROM AUTHOR]