Summary1. Habitat structure is important in explaining species diversity patterns for many animal groups. If we could map habitat structure over large spatial scales, we could use habitat structure-species diversity (HS-SD) relationships to model species diversity and inform conservation planning and management. Traditional approaches for measuring habitat structure cannot be applied over entire landscapes, but remote sensing tools are now able to overcome this limitation. Here, we explore the potential of airborne lidar for the assessment and monitoring of animal species diversity in terrestrial environments. 2. We review the habitat attributes commonly recorded in the study of HS-SD relationships and the spatial scale of their measurement, in papers published between 1960 and 2013. We also gather evidence for the use of lidar to make relevant measurements at similar scales. 3. Eight out of 15 attributes of habitat structure commonly used in published studies relate to the vertical dimension of habitat. The core strength of lidar is that it is a vertical profiler, and this technology can be used to derive estimates of all but one of these structural attributes. Lidar can also be used to improve the measurement of the four commonly used attributes focusing on the horizontal heterogeneity of habitat patches. The spatial grain and extent of HS-SD studies is usually within the operational capability of airborne lidar; when a vertical measure of habitat structure has been employed, this is true in 84% of published studies. The potential efficacy of lidar in this field of biodiversity studies is underlined by several published examples of lidar modelling of animal species diversity. 4. We conclude that lidar remote sensing is fit for the purpose of biodiversity assessment and monitoring through its ability to characterize habitat structure, a key driver of animal species diversity, over large spatial scales. We advocate wider application of lidar-based HS-SD indicators to help tackle the current biodiversity crisis. In combination with other remote sensing products, these indicators may support the implementation and monitoring of environmental legislation, inform gap analyses and the planning of management actions for protected areas and species, and drive greater synergy with forest-based climate change mitigation.

Airborne lidar is a remote-sensing tool of increasing importance in ecological and conservation research due to its ability to characterize three-dimensional vegetation structure. If different aspects of plant species diversity and composition can be related to vegetation structure, landscape-level assessments of plant communities may be possible. We examined this possibility for Mediterranean oak forests in southern Portugal, which are rich in biological diversity but also threatened. We compared data from a discrete, first-and-last return lidar data set collected for 31 plots of cork oak (Quercus suber) and Algerian oak (Quercus canariensis) forest with field data to test whether lidar can be used to predict the vertical structure of vegetation, diversity of plant species, and community type. Lidar- and field-measured structural data were significantly correlated (up to r= 0.85). Diversity of forest species was significantly associated with lidar-measured vegetation height (R(2) = 0.50, p < 0.001). Clustering and ordination of the species data pointed to the presence of 2 main forest classes that could be discriminated with an accuracy of 89% on the basis of lidar data. Lidar can be applied widely for mapping of habitat and assessments of habitat condition (e.g., in support of the European Species and Habitats Directive [92/43/EEC]). However, particular attention needs to be paid to issues of survey design: density of lidar points and geospatial accuracy of ground-truthing and its timing relative to acquisition of lidar data.

This paper examines the impact that different olive cultivation practices have on the nature of the ground flora of olive groves in the region of the Psiloritis massif and Messara Plain in central and southern Crete, Greece. In lower, flatter areas there are areas of both traditional and intensive forms of olive cultivation. In more marginal, upland areas there are traditional terraced olive groves, some of which are being abandoned. The relationship between the vegetation composition of the ground flora and environmental variables was established, by means of TWINSPAN 1 and ordination analysis, using survey data from nineteen sites across the region. Four vegetation communities are identified: olive with herbaceous taxa; olive with sclerophyllous shrub taxa; and two forms of sclerophyllous shrub communities. Ordination results indicate that environmental variables, such as soil characteristics, slope aspect and slope angle, explain about 60 per cent of the species-environment relationships. The remaining variation in species composition is interpreted to be the result of different cultivation practices. The implications for land degradation are examined, in particular the changes in vegetation diversity of both intensive and semi-abandoned olive groves, the potential for increased soil erosion, and the risk of fire as a result of increased fuel loading as flammable shrubs invade abandoned terraces. Intensification of olive cultivation in Crete, and across the Mediterranean, has been encouraged by subsidies from the European Union leading to rapid landscape change. Thus there is a need to monitor changes in olive cultivation practices both at the local scale, by means of ground-based fieldwork, and at landscape and regional scales, by means of remote sensing.

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Shared fire-survival and fire-persistence traits are found in taxonomically unrelated plant species that commonly grow in fire-prone ecosystems. Such traits include resprouting, after fire has killed the above-ground biomass, and postfire seed release after the death of individual plants. Classification of such traits has led to a change in focus from research on the impact of fire as a disturbance factor on individual species, towards research into plant functional types associated with fire. This has led to a better understanding of the timing and geographic evolution of such traits as either fire-adapted or as a selective response to other disturbance factors. The identification of fire-survival and fire-persistence traits in fire-prone ecosystems is the first focus of this paper. It is followed by a discussion of recent research which offers a critical reappraisal of patch mosaic burning as a means to increase landscape heterogeneity and biodiversity, including the role played by plant functional types in determining diversity. The fire-prone ecosystems of mediterranean-type shrublands and heathlands, savannas and grasslands, and boreal and other coniferous forests are the main geographic focus of the paper.

Mediterranean ecosystems contain some of the highest levels of plant diversity of any region on Earth and are amongst those believed to be most at risk from the consequences of global warming. Yet such ecosystems are not static and have responded to environmental changes at a variety of scales and from a variety of causes, particularly climatic and anthropogenic. The purpose of this paper is to review recent research on environmental change and ecosystem response. Long-term records are available to analyse changes over glacial-interglacial cycles, while high resolution records show the sensitivity and coupling of Mediterranean, North Atlantic and Greenland records. For the Holocene, there is continued debate about the relative impact of anthropogenic activity, but there is also increasing recognition that mediterraneantype ecosystems should not be regarded as fragile, degraded landscapes, but are disturbanceadapted. Nevertheless, conservation measures face increasing challenges from contemporary climate change and human pressures. Some insights into the identification of refugial areas, either in glacial times or for present-day conservation purposes, come from molecular biogeographical studies of past faunal and floral distribution.

Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating climate change by storing carbon in wood. However, there remains considerable uncertainty as to whether tropical forests will continue to act as carbon sinks in the face of increased pressure from expanding human activities. Consequently, understanding what drives productivity in tropical forests is critical. We used permanent forest plot data from the Gola Rainforest National Park (Sierra Leone) – one of the largest tracts of intact tropical moist forest in West Africa – to explore how (1) stand basal area and tree diversity, (2) past disturbance associated with past logging, and (3) underlying soil nutrient gradients interact to determine rates of aboveground wood production (AWP). We started by statistically modeling the diameter growth of individual trees and used these models to estimate AWP for 142 permanent forest plots. We then used structural equation modeling to explore the direct and indirect pathways which shape rates of AWP. Across the plot network, stand basal area emerged as the strongest determinant of AWP, with densely packed stands exhibiting the fastest rates of AWP. In addition to stand packing density, both tree diversity and soil phosphorus content were also positively related to productivity. By contrast, historical logging activities negatively impacted AWP through the removal of large trees, which contributed disproportionately to productivity. Understanding what determines variation in wood production across tropical forest landscapes requires accounting for multiple interacting drivers – with stand structure, tree diversity, and soil nutrients all playing a key role. Importantly, our results also indicate that logging activities can have a long‐lasting impact on a forest's ability to sequester and store carbon, emphasizing the importance of safeguarding old‐growth tropical forests.

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