Felix Eigenbrod

Global hotspots of species richness are not congruent with endemism or threat

Biodiversity hotspots have a prominent role in conservation biology, but it remains controversial to what extent different types of hotspot are congruent. Previous studies were unable to provide a general answer because they used a single biodiversity index, were geographically restricted, compared areas of unequal size or did not quantitatively compare hotspot types. Here we use a new global database on the breeding distribution of all known extant bird species to test for congruence across three types of hotspot. We demonstrate that hotspots of species richness, threat and endemism do not show the same geographical distribution. Only 2.5% of hotspot areas are common to all three aspects of diversity, with over 80% of hotspots being idiosyncratic. More generally, there is a surprisingly low overall congruence of biodiversity indices, with any one index explaining less than 24% of variation in the other indices. These results suggest that, even within a single taxonomic class, different mechanisms are responsible for the origin and maintenance of different aspects of diversity. Consequently, the different types of hotspots also vary greatly in their utility as conservation tools.

The impact of projected increases in urbanization on ecosystem services

Alteration in land use is likely to be a major driver of changes in the distribution of ecosystem services before 2050. In Europe, urbanization will probably be the main cause of land-use change. This increase in urbanization will result in spatial shifts in both supplies of ecosystem services and the beneficiaries of those services; the net outcome of such shifts remains to be determined. Here, we model changes in urban land cover in Britain based on large (16%) projected increases in the human population by 2031, and the consequences for three different services—flood mitigation, agricultural production and carbon storage. We show that under a scenario of densification of urban areas, the combined effect of increasing population and loss of permeable surfaces is likely to result in 1.7 million people living within 1 km of rivers with at least 10 per cent increases in projected peak flows, but that increasing suburban ‘sprawl’ will have little effect on flood mitigation services. Conversely, losses of stored carbon and agricultural production are over three times as high under the sprawl as under the ‘densification’ urban growth scenarios. Our results illustrate the challenges of meeting, but also of predicting, future demands and patterns of ecosystem services in the face of increasing urbanization.

Balancing alternative land uses in conservation prioritization

Pressure on ecosystems to provide various different and often conflicting services is immense and likely to increase. The impacts and success of conservation prioritization will be enhanced if the needs of competing land uses are recognized at the planning stage. We develop such methods and illustrate them with data about competing land uses in Great Britain, with the aim of developing a conservation priority ranking that balances between needs of biodiversity conservation, carbon storage, agricultural value, and urban development potential. While both carbon stocks and biodiversity are desirable features from the point of view of conservation, they compete with the needs of agriculture and urban development. In Britain the greatest conflicts exist between biodiversity and urban areas, while the largest carbon stocks occur mostly in Scotland in areas with low agricultural or urban pressure. In our application, we were able successfully to balance the spatial allocation of alternative land uses so that conflicts between them were much smaller than had they been developed separately. The proposed methods and software, Zonation, are applicable to structurally similar prioritization problems globally.

Ecosystem service benefits of contrasting conservation strategies in a human-dominated region

The hope among policy-makers and scientists alike is that conservation strategies designed to protect biodiversity also provide direct benefits to people by protecting other vital ecosystem services. The few studies that have examined the delivery of ecosystem services by existing conservation efforts have concentrated on large, ‘wilderness’-style biodiversity reserves. However, such reserves are not realistic options for densely populated regions. Here, we provide the first analyses that compare representation of biodiversity and three other ecosystem services across several contrasting conservation strategies in a human-dominated landscape (England). We show that small protected areas and protected landscapes (restrictive zoning) deliver high carbon storage and biodiversity, while existing incentive payment (agri-environment) schemes target areas that offer little advantage over other parts of England in terms of biodiversity, carbon storage and agricultural production. A fourth ecosystem service—recreation—is under-represented by all three strategies. Our findings are encouraging as they illustrate that restrictive zoning can play a major role in protecting natural capital assets in densely populated regions. However, trade-offs exist even among the four ecosystem services we considered, suggesting that a portfolio of conservation and sustainability investments will be needed to deliver both biodiversity and the other ecosystem services demanded by society.

Accessible habitat: an improved measure of the effects of habitat loss and roads on wildlife populations

Habitat loss is known to be the main cause of the current global decline in biodiversity, and roads are thought to affect the persistence of many species by restricting movement between habitat patches. However, measuring the effects of roads and habitat loss separately means that the configuration of habitat relative to roads is not considered. We present a new measure of the combined effects of roads and habitat amount: accessible habitat. We define accessible habitat as the amount of habitat that can be reached from a focal habitat patch without crossing a road, and make available a GIS tool to calculate accessible habitat. We hypothesize that accessible habitat will be the best predictor of the effects of habitat loss and roads for any species for which roads are a major barrier to movement. We conducted a case study of the utility of the accessible habitat concept using a data set of anuran species richness from 27 ponds near a motorway. We defined habitat as forest in this example. We found that accessible habitat was not only a better predictor of species richness than total habitat in the landscape or distance to the motorway, but also that by failing to consider accessible habitat we would have incorrectly concluded that there was no effect of habitat amount on species richness.

Reconciling biodiversity and carbon conservation

Climate change is leading to the development of land-based mitigation and adaptation strategies that are likely to have substantial impacts on global biodiversity. Of these, approaches to maintain carbon within existing natural ecosystems could have particularly large benefits for biodiversity. However, the geographical distributions of terrestrial carbon stocks and biodiversity differ. Using conservation planning analyses for the New World and Britain, we conclude that a carbon-only strategy would not be effective at conserving biodiversity, as have previous studies. Nonetheless, we find that a combined carbon-biodiversity strategy could simultaneously protect 90% of carbon stocks (relative to a carbon-only conservation strategy) and > 90% of the biodiversity (relative to a biodiversity-only strategy) in both regions. This combined approach encapsulates the principle of complementarity, whereby locations that contain different sets of species are prioritised, and hence disproportionately safeguard localised species that are not protected effectively by carbon-only strategies. It is efficient because localised species are concentrated into small parts of the terrestrial land surface, whereas carbon is somewhat more evenly distributed; and carbon stocks protected in one location are equivalent to those protected elsewhere. Efficient compromises can only be achieved when biodiversity and carbon are incorporated together within a spatial planning process.

Food security in a perfect storm: using the ecosystem services framework to increase understanding

Achieving food security in a ‘perfect storm’ scenario is a grand challenge for society. Climate change and an expanding global population act in concert to make global food security even more complex and demanding. As achieving food security and the millennium development goal (MDG) to eradicate hunger influences the attainment of other MDGs, it is imperative that we offer solutions which are complementary and do not oppose one another. Sustainable intensification of agriculture has been proposed as a way to address hunger while also minimizing further environmental impact. However, the desire to raise productivity and yields has historically led to a degraded environment, reduced biodiversity and a reduction in ecosystem services (ES), with the greatest impacts affecting the poor. This paper proposes that the ES framework coupled with a policy response framework, for example Driver-Pressure-State-Impact-Response (DPSIR), can allow food security to be delivered alongside healthy ecosystems, which provide many other valuable services to humankind. Too often, agro-ecosystems have been considered as separate from other natural ecosystems and insufficient attention has been paid to the way in which services can flow to and from the agro-ecosystem to surrounding ecosystems. Highlighting recent research in a large multi-disciplinary project (ASSETS), we illustrate the ES approach to food security using a case study from the Zomba district of Malawi.

Behavioral Responses of Northern Leopard Frogs (Rana pipiens) to Roads and Traffic: Implications for Population Persistence

A key goal in road ecology is to determine which species are most vulnerable to the negative effects of roads on population persistence. Theory suggests that species that avoid roads are less likely to be negatively affected by roads than those that do not avoid roads. The goal of this study was to take a step toward testing this prediction by evaluating the behavioral response to roads and traffic of a species whose populations are known to be negatively affected by roads and traffic, the northern leopard frog (Rana pipiens). We studied the movement patterns of northern leopard frogs during their spring migration from overwintering sites in a river to various breeding ponds that were disconnected from the river by roads. We performed short-distance translocations of migrating frogs, followed them visually, and documented their movement coordinates following each hop, both near the roads and in non-roaded areas. We found that frogs took longer to move near roads with more traffic and that their movement was quickest in areas without roads nearby. Frogs tended to deviate more from a straight-line course when they were released near roads than compared with control areas, but this response was independent of traffic volume. All frogs released near roads attempted to cross the road. On very low traffic roads (10.86 mean vehicles per hour), 94% of frogs crossed the road successfully, whereas at higher traffic roads (58.29 mean vehicles per hour) 72% were successful. Our results suggest that frogs inability to avoid going onto roads and their slow movement combine to make them particularly vulnerable to road mortality, which likely explains the strong negative effects of roads on frog population abundance. Conservation efforts should focus on preventing frogs from accessing the road surface through the use of drift fencing and culverts.

Effects of methodology and stakeholder disaggregation on ecosystem service valuation

Contingent valuation is one of the most commonly used methodologies utilized in ecosystem service valuation, thereby including a participatory approach to many such assessments. However, inclusion of nonmonetary stakeholder priorities is still uncommon in ecosystem service valuations and disaggregation of stakeholders is all but absent from practice. We look at four site-scale wetland ecosystem service valuations from Asia that used nonmonetary participatory stated preference techniques from a range of stakeholders, and compare these prioritizations to those obtained from the largest monetary assessments available globally, the Ecosystem Service Value Database (ESVD). Stakeholder assessment suggests very different priorities to those from monetary assessments, yet priorities between different sites remained broadly consistent. Disaggregation of beneficiaries in one site showed marked differences in values between stakeholders. Monetary values correlate positively with values held by government officers and business owners, but negatively with fishermen and women who are relying most directly on the wetland ecosystem services. Our findings emphasize that ecosystem service assessment, monetary or otherwise, must capture the diversity of values present across stakeholder groups to incorporate site scale management issues, particularly in relation to poverty alleviation.

What is macroecology

The symposium ‘What is Macroecology?’ was held in London on 20 June 2012. The event was the inaugural meeting of the Macroecology Special Interest Group of the British Ecological Society and was attended by nearly 100 scientists from 11 countries. The meeting reviewed the recent development of the macroecological agenda. The key themes that emerged were a shift towards more explicit modelling of ecological processes, a growing synthesis across systems and scales, and new opportunities to apply macroecological concepts in other research fields.