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The amount of carbon stored in deadwood is equivalent to about 8 per cent of the global forest carbon stocks1. The decomposition of deadwood is largely governed by climate2,3,4,5 with decomposer groups—such as microorganisms and insects—contributing to variations in the decomposition rates2,6,7. At the global scale, the contribution of insects to the decomposition of deadwood and carbon release remains poorly understood7. Here we present a field experiment of wood decomposition across 55 forest sites and 6 continents. We find that the deadwood decomposition rates increase with temperature, and the strongest temperature effect is found at high precipitation levels. Precipitation affects the decomposition rates negatively at low temperatures and positively at high temperatures. As a net effect—including the direct consumption by insects and indirect effects through interactions with microorganisms—insects accelerate the decomposition in tropical forests (3.9% median mass loss per year). In temperate and boreal forests, we find weak positive and negative effects with a median mass loss of 0.9 per cent and −0.1 per cent per year, respectively. Furthermore, we apply the experimentally derived decomposition function to a global map of deadwood carbon synthesized from empirical and remote-sensing data, obtaining an estimate of 10.9 ± 3.2 petagram of carbon per year released from deadwood globally, with 93 per cent originating from tropical forests. Globally, the net effect of insects may account for 29 per cent of the carbon flux from deadwood, which suggests a functional importance of insects in the decomposition of deadwood and the carbon cycle.

Logging to "salvage" economic returns from forests affected by natural disturbances has become increasingly prevalent globally. Despite potential negative effects on biodiversity, salvage logging is often conducted, even in areas otherwise excluded from logging and reserved for nature conservation, inter alia because strategic priorities for post-disturbance management are widely lacking. A review of the existing literature revealed that most studies investigating the effects of salvage logging on biodiversity have been conducted less than 5 years following natural disturbances, and focused on non-saproxylic organisms. A meta-analysis across 24 species groups revealed that salvage logging significantly decreases numbers of species of eight taxonomic groups. Richness of dead wood dependent taxa (i.e. saproxylic organisms) decreased more strongly than richness of non-saproxylic taxa. In contrast, taxonomic groups typically associated with open habitats increased in the number of species after salvage logging. By analysing 134 original species abundance matrices, we demonstrate that salvage logging significantly alters community composition in 7 of 17 species groups, particularly affecting saproxylic assemblages. Synthesis and applications. Our results suggest that salvage logging is not consistent with the management objectives of protected areas. Substantial changes, such as the retention of dead wood in naturally disturbed forests, are needed to support biodiversity. Future research should investigate the amount and spatio-temporal distribution of retained dead wood needed to maintain all components of biodiversity.

Land-stewardship programmes are a major focus of investment by governments for conserving biodiversity in agricultural landscapes. These programmes are generally large-scale (e.g. >1000 km) spanning multiple biogeographic regions but developed using spatially limited (e.g. landscape-scale; <100 km) ecological data interpolated across broad areas for one, or a few, well-studied taxonomic groups. Information about how less-studied taxa respond to regional differences in management and environmental effects has potential to further inform land-stewardship conservation programmes, but suitable data sets are rarely available. In this study, we sought to enhance planning of large-scale conservation programmes by quantifying relationships between reptile assemblages and key environmental attributes at regional scales within a large-scale (>172 000 km2) Australian land-stewardship programme. Using 234 remnant woodland monitoring sites spanning four distinct biogeographic regions, we asked: Do reptile assemblages show different environmental associations across biogeographically distinct regions? We found that environmental features important to reptile diversity differed over each region. Abundance and rare species richness of reptiles responded at regional-scales to elevation, native groundcover and aspect. We identified four implications from our study: (1) large-scale conservation schemes can achieve better outcomes for reptiles using regional-scale knowledge of environmental associations; (2) regional-scale knowledge is particularly valuable for conservation of rare reptile taxa; (3) consideration of abiotic environmental features which cannot be directly managed (e.g. aspect, elevation) is important; (4) programmes can be tailored to better support reptile groups at higher conservation risk. Our study shows that reptile-environment associations differ among biogeographic regions, and this presents opportunity for tailoring stronger policy and management strate

Increasingly governments and the private sector are using planted forests to offset carbon emissions. Few studies, however, examine how tree diversity — defined here as species richness and/or stand composition — affects carbon storage in these plantings. Using aboveground tree biomass as a proxy for carbon storage, we used meta-analysis to compare carbon storage in tree mixtures with monoculture plantings. Tree mixes stored at least as much carbon as monocultures consisting of the mixture's most productive species and at times outperformed monoculture plantings. In mixed-species stands, individual species, and in particular nitrogen-fixing trees, increased stand biomass. Further motivations for incorporating tree richness into planted forests include the contribution of diversity to total forest carbon-pool development, carbon-pool stability and the provision of extra ecosystem services. Our findings suggest a two-pronged strategy for designing carbon plantings including: (1) increased tree species richness; and (2) the addition of species that contribute to carbon storage and other target functions.

AimMost risk assessments and decisions in conservation are based on surrogate approaches, where a group of species or environmental indicators are selected as proxies for other aspects of biodiversity. In the focal species approach, a suite of species is selected based on life history characteristics, such as dispersal limitation and area requirements. Testing the validity of the focal species concept has proved difficult, due to a lack of theory justifying the underlying framework, explicit objectives and measures of success. We sought to understand the conditions under which the focal species concept has merit for conservation decisions. LocationOur model system comprised 10 vertebrate species in 39 patches of native forest embedded in pine plantation in New South Wales, Australia. MethodsWe selected three focal species based on ecological traits. We used a multiple-species reserve selection method that minimizes the expected loss of species, by estimating the risk of extinction with a metapopulation model. We found optimal reserve solutions for multiple species, including all 10 species, the three focal species, for all possible combinations of three species, and for each species individually. ResultsOur case study suggests that the focal species approach can work: the reserve system that minimized the expected loss of the focal species also minimized the expected species loss in the larger set of 10 species. How well the solution would perform for other species and given landscape dynamics remains unknown. Main conclusionsThe focal species approach may have merit as a conservation short cut if placed within a quantitative decision-making framework, where the aspects of biodiversity for which the focal species act as proxies are explicitly defined, and success is determined by whether the use of the proxy results in the same decision. Our methods provide a framework for testing other surrogate approaches used in conservation decision-making and risk assessment.

Understanding how landscape characteristics affect biodiversity patterns and ecological processes at local and landscape scales is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest eight hypotheses, which we hope will encourage more systematic research on the role of landscape composition and configuration in determining the structure of ecological communities, ecosystem functioning and services. We organize the eight hypotheses under four overarching themes. Section A: ‘landscape moderation of biodiversity patterns' includes (1) the landscape species pool hypothesis—the size of the landscape-wide species pool moderates local (alpha) biodiversity, and (2) the dominance of beta diversity hypothesis—landscape-moderated dissimilarity of local communities determines landscape-wide biodiversity and overrides negative local effects of habitat fragmentation on biodiversity. Section B: ‘landscape moderation of population dynamics' includes (3) the cross-habitat spillover hypothesis—landscape-moderated spillover of energy, resources and organisms across habitats, including between managed and natural ecosystems, influences landscape-wide community structure and associated processes and (4) the landscape-moderated concentration and dilution hypothesis—spatial and temporal changes in landscape composition can cause transient concentration or dilution of populations with functional consequences. Section C: ‘landscape moderation of functional trait selection’ includes (5) the landscape-moderated functional trait selection hypothesis—landscape moderation of species trait selection shapes the functional role and trajectory of community assembly, and (6) the landscape-moderated insurance hypothesis—landscape complexity provides spatial and temporal insurance, i.e. high resilience and stability of ecological processes in changing environments. Section D: ‘landscape constraints on conserva

We investigated the species richness and composition of bird communities in mallee woodland remnants in a highly fragmented landscape, focusing specifically on honeyeaters and their foraging behaviour. We observed birds around flowering Eremophila glabra ssp. glabra plants in three replicated contexts: (1) the interior of large remnants, (2) linear remnants within ~3 km of a large remnant, and (3) linear remnants 5-7 km from a large remnant. We found species richness differed among elements, with an increase in the number of species that tolerate disturbed, open habitat and a decrease in the number of woodland-dependent species in linear elements. Honeyeater assemblages were similar in species richness and abundance among the elements, but differed in composition due to a higher number of large-sized honeyeater species in distant elements. Honeyeater movement patterns into a site and within a site were similar among the elements. Floral visitation varied among honeyeater species and was positively correlated with their abundance in the far element. Our results demonstrate that bird species respond differently to the spatial context of remnants in a fragmented landscape; however, the degree of isolation of linear remnants was not important. Linear remnants appear to be frequently used by honeyeaters, but the changes in community composition among the elements may influence the quality of pollination, which could have implications for plant reproduction.

Recent reviews of the conservation literature indicate that significant biases exist in the published literature regarding the regions, ecosystems and species that have been examined by researchers. Despite the global threat of climatic change, similar biases may be occurring within the sub-discipline of climate-change ecology. Here we hope to foster critical thought and discussion by considering the directions taken by conservation researchers when addressing climate change. To form a quantitative basis for our perspective, we assessed 248 papers from the climate change literature that considered the conservation management of biodiversity and ecosystems. We found that roughly half of the studies considered climate change in isolation from other threatening processes. We also found that the majority of surveyed scientific publications were conducted in the temperate forests of Europe and North America. Regions such as Latin America that are rich in biodiversity but may have low adaptive capacity to climate change were not well represented. We caution that such biases in research effort may be distracting our attention away from vulnerable regions, ecosystems and species. Specifically we suggest that the under-representation of research from regions low in adaptive capacity and rich in biodiversity requires international collaboration by those experienced in climate-change research, with researchers from less wealthy nations who are familiar with local issues, ecosystems and species. Furthermore, we caution that the propensity of ecologists to work in essentially unmodified ecosystems may fundamentally hamper our ability to make useful recommendations in a world that is experiencing significant global change.

Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today's ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether "patchiness" is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring.

The management of landscapes for biological conservation and ecologically sustainable natural resource use are crucial global issues. Research for over two decades has resulted in a large literature, yet there is little consensus on the applicability or even the existence of general principles or broad considerations that could guide landscape conservation. We assess six major themes in the ecology and conservation of landscapes. We identify 13 important issues that need to be considered in developing approaches to landscape conservation. They include recognizing the importance of landscape mosaics (including the integration of terrestrial and aquatic areas), recognizing interactions between vegetation cover and vegetation configuration, using an appropriate landscape conceptual model, maintaining the capacity to recover from disturbance and managing landscapes in an adaptive framework. These considerations are influenced by landscape context, species assemblages and management goals and do not translate directly into on-the-ground management guidelines but they should be recognized by researchers and resource managers when developing guidelines for specific cases. Two crucial overarching issues are: (i) a clearly articulated vision for landscape conservation and (ii) quantifiable objectives that offer unambiguous signposts for measuring progress.

Policy-makers and managers in natural resource management (NRM) often complain that researchers are out of touch. Researchers often complain that policy-makers and managers make poorly informed decisions. In this article, we report on a meeting between researchers, policy-makers and managers convened to identify practical solutions to improve engagement between these camps. A necessary starting point is that every researcher and policy-maker should understand, and tap into, the motivations and reward systems of the other when seeking engagement. For example, researchers can be motivated to engage in policy development if there is a promise of outputs that align with their reward systems such as co-authored publications. Successful research–policy partnerships are built around personal relationships. As a researcher, you cannot therefore expect your results to inform policy by only publishing in journals. As a policy-maker, you cannot guarantee engagement from researchers by publicly inviting comment on a document. Actively building and maintaining relationships with key individuals through discussions, meetings, workshops or field days will increase the likelihood that research outcomes will inform policy decisions. We identified secondments, sabbaticals, fellowships and ‘buddies’, an annual national NRM conference and ‘contact mapping’ (a Facebook-type network) as forums that can catalyse new relationships between researchers and policy-makers. We challenge every researcher, policy-maker and manager in NRM to build one new cross-cultural relationship each year.

There has been much debate about the relative merits of single-species vs ecosystem-oriented research for conservation. This debate has become increasingly important in recent times as resource managers and policy makers in some jurisdictions focus on ecosystem-level problems. We highlight the potential strengths and limitations of both kinds of research, discuss their complementarity and highlight problems that may arise where competition occurs between the two kinds of research. While a combination of approaches is ideal, a scarcity of funding, time, and expertise means it is impossible to study and manage each species, ecological process, or ecological pattern separately. Making decisions about priorities for the kinds of research, priorities for the kinds of conservation management, and associated allocation of scarce funds is a non-trivial task. We argue for an approach whereby limited resources for conservation research are targeted at projects most likely to close important knowledge gaps, while also promoting ongoing synergies between single-species and ecosystem-oriented research.

Dunn and Majer discuss limitations of the continuum model proposed by Fischer and Lindenmayer and describe a new patch-based model. We argue that a range of landscape models are required to solve different problems and meet particular objectives of land management or conservation. The key issue is not whether one type of model is superior to another, but rather: what are the particular strengths and limitations of a particular model? And, given these, under what circumstances will a particular model be most appropriate? The primary value of the continuum model is that it provides a strong theoretical foundation for the management of landscape heterogeneity in addition to the protection of large patches of native vegetation.

This study investigated associations between the relative abundance of the threatened ngwayir (western ringtail possum, Pseudocheirus occidentalis) and anthropogenic disturbances at local and landscape scales within the publicly-managed jarrah (Eucalyptus marginata) forests of south-western Australia. Logging, fire, fox (Vulpes vulpes) control and forest fragmentation were investigated in relation to the relative abundance of ngwayir at 90 sites within an area of 285,000 ha east of Manjimup; the location of the last remaining substantial population of ngwayir in jarrah forest. Overall, ngwayir abundance was greatest in areas with limited anthropogenic disturbance. At the local-scale, ngwayir abundance was negatively associated with greater fire intensity. At the landscape-scale, it was positively associated with fox control and negatively associated with forest fragmentation and distance from non-remnant vegetation (i.e., agriculture and tree plantations). Abundance was also greatest in predominantly unlogged landscapes and in forests that had been regrowing for an average of 40 years since the landscape was most recently logged, in other words, where logging was historically least intense. Interactions between fox control efforts and forest fragmentation were also important. This study emphasises the importance of conducting research at appropriate spatial scales and to account for the synergistic effects of the causes of decline. An adaptive management approach to the mitigation of the agents of decline is recommended. Indirect evidence indicates that high value habitat for ngwayir has in all likelihood been selectively cleared for agriculture, owing to its fertile and productive nature. Habitat loss is, therefore, also likely to be a major cause of the modern decline of the species. While many jarrah forest areas that support remaining high abundances of the ngwayir have been incorporated into reserves, conservation of ngwayir habitat and populations outside rese

Although the aim of conservation planning is the persistence of biodiversity, current methods trade-off ecological realism at a species level in favour of including multiple species and landscape features. For conservation planning to be relevant, the impact of landscape configuration on population processes and the viability of species needs to be considered. We present a novel method for selecting reserve systems that maximize persistence across multiple species, subject to a conservation budget. We use a spatially explicit metapopulation model to estimate extinction risk, a function of the ecology of the species and the amount, quality and configuration of habitat. We compare our new method with more traditional, area-based reserve selection methods, using a ten-species case study, and find that the expected loss of species is reduced 20-fold. Unlike previous methods, we avoid designating arbitrary weightings between reserve size and configuration; rather, our method is based on population processes and is grounded in ecological theory

A review of the value for fauna of conifer and eucalypt plantations in Australia is presented. Five key reasons highlight a need for wildlife conservation as part of plantation management. These are: (1) The plantation estate in Australia is set to triple in the coming decades, and where new plantations are located and how they are managed will influence the biota that currently exist in such landscapes. This is particularly critical in many semi-cleared former grazing landscapes where the establishment of new plantations is focused. This is because: (1) (a) native vegetation communities in these areas are poorly represented in the existing reserve system, and, (b) uses such as wood and pulp production need to be balanced with other management values such as wildlife conservation. (2) The maintenance of some elements of the biota within plantations could have benefits for key ecosystem processes like pest control. (3) Although some species cannot be conserved in plantation-dominated landscapes, many species can be through the adoption of (sometimes minor) modifications to forest management. (4) The maintenance (or loss) of biota in plantations is relevant for moves toward ecological standards and the certification of plantations in many parts of the world. And, (5) simple plantation forestry which has a narrow and intensive management focus on producing a forest crop for a limited array of purposes, may not meet societal demands for a range of outputs from plantations in addition to wood and pulp. It also may not be congruent with the principles of ecological sustainability. Our review showed that almost all research undertaken in Australian plantations, both in conifers and eucalypts, highlighted the importance of landscape heterogeneity and stand structural complexity for fauna conservation. At the landscape level, patches of retained native vegetation, strips of riparian vegetation, dams, open and clearing areas can significantly increase the number of native spe

We present a brief introduction to current attempts to understand and mitigate the effects of fragmentation on species survival. We provide a short overview of the contributions of empiricists, modellers, and practitioners in this issue of Biodiversity and Conservation, which were initiated during a workshop held in Australia in February 2002 on the topic ‘Species Survival in Fragmented Landscapes: Where are we now?’. These contributions address the themes ‘uncertainty in research and management’, ‘tools for quantifying risk and predicting species sensitivity to fragmentation’, and ‘tools for reassembling fragmented landscapes’. A final contribution provides a synthesis across the contributions and highlights the most important areas for future research on species survival in fragmented landscapes.

We summarise the contributions of empiricists, modellers, and practitioners in this issue of Biodiversity and Conservation, and highlight the most important areas for future research on species survival in fragmented landscapes. Under the theme 'uncertainty in research and management', we highlight five areas for future research. First, we know little about the effects of density dependence on the viability of metapopulations, a requirement for fragmented landscapes. Second, successful early attempts suggest that it is worth developing more rigorous calibration methods for population viability analysis with spatially explicit, individual-based models. In particular, the balance between model complexity, ease of calibration, and precision, needs to be addressed. Third, we need to improve methods to discriminate between models, including alternatives to time-series approaches. Fourth, when our ability to reduce model uncertainty is weak, we need to incorporate this uncertainty in population viability analysis. Fifth, population viability analysis and decision analysis can be integrated to make uncertainty an explicit part of the decision process. An important future direction is extending the decision framework to adaptive management. Under the theme 'tools for quantifying risk and predicting species sensitivity to fragmentation', we highlight three areas for future research. First, we need to develop tools to support comparative approaches to population viability analysis. Second, population modelling can be used to find rules of thumb to support conservation decisions when very little is known about a species. Rules of thumb need to be extended to the problem of managing for multiple species. Third, species' traits might be useful for predicting sensitivity but predictions could be further refined by considering the relative importance of population processes at different scales. Under the theme 'tools for reassembling fragmented landscapes', we consider the 'focal

There are five key reasons why biodiversity conservation should be considered a part of plantation management. (1) The plantation estate is large, and balancing various land management values with wood and pulp production is important when extensive areas of land are involved. (2) The locations and management of new plantations will affect the biota that currently exist in such landscapes. (3) Maintaining some elements of biodiversity within plantations can have benefits for stand productivity and the maintenance of key ecosystem processes such as pest control. (4) The retention (or loss) of biota in plantations is relevant to the formulation of ecological standards and the certification of plantations in many parts of the world. (5) Plantation forestry has a narrow and intensive management focus on producing a forest crop for a limited array of purposes. It will not meet future societal demands for a range of outputs from plantations (in addition to wood and pulp supply), and will not be congruent with the principles of ecological sustainability. This paper briefly reviews the biodiversity conservation values of Australian plantation s. It shows that almost all work in Australian plantations, whether conifer or eucalypt, highlights the importance of landscape heterogeneity and stand structural complexity for enhancing biodiversity. Management of plantations to promote landscape heterogeneity and stand structural complexity and enhance the conservation of biodiversity will, in many cases, involve tradeoffs that will affect wood and pulp production. The extent to which this occurs will depend on the objectives of plantation management and how far they extend towards the more complex plantation forestry models that incorporate social and environmental values. We argue that the widespread adoption of plantation forestry that leads to homogenous stands of extensive monocultures will risk re-creating the array of negative environmental outcomes that have been associated