Using habitat suitability models to scale up population persistence targets

Moreno Di Marco, Luca Santini, Piero Visconti, Alessio Mortelliti, Luigi Boitani & Carlo Rondinini


ARC Setting operational targets for the protection of species is crucial for identifying conservation priorities and for monitoring conservation actions’ effectiveness. The use of quantitative targets for global species conservation has grown in the past ten years as a response to the commitment of reducing extinction rates established by the Convention on Biological Diversity. We reviewed the use of conservation targets in global scale conservation analyses, and found that most of the publications adopted species representation targets, corresponding to an amount of area to be protected. We found no work adequately targeting species’ persistence, i.e. the complement to species extinction risk. Despite the adoption of pragmatic population targets, consisting in a number of individuals to be protected, has been recently proposed for global species conservation, the use of these targets at the species level is not always warranted. Pros and cons of using population persistence targets for species conservation have been discussed, yet the fundamental issue of how to scale these targets from populations to species is still unresolved. We discuss the process of “scaling up” population persistence targets to the species level using habitat distribution models, and test our approach in a case study on the European ground squirrel (Spermophilus citellus). We identified three main steps to be followed: (i) definition of a population target, (ii) characterisation of the species’ populations by means of a habitat suitability model, and (iii) definition of a scaled species target. An up-scaled species target should include multiple conditions reflecting species persistence (number, size, location of the populations to be protected), uniqueness (e.g. evolutionary potential) and representativeness (e.g. presence in different ecosystems). Adopting scaled up species persistence targets within conservation planning approaches can allow protected area plans to give the highest contribution to reducing global species extinction risk.
figure-1-distribution-range-of-spermophilus-citellus-suitable-habitat-coloured-area

Distribution range of Spermophilus citellus. Suitable habitat (coloured area) is surrounded by a potential dispersal matrix (shaded area) within the species range (in light grey). Areas smaller than the defined target area are reported in dark green, while clusters of suitable habitat larger than the target area are reported in random colours (with different colours indicating different clusters).  

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Assessing the umbrella value of a range-wide conservation network for jaguars

Daniel Thornton, Kathy Zeller, Carlo Rondinini, Luigi Boitani, Kevin Crooks, Christopher Burdett, Alan Rabinowitz and Howard Quigley.

Umbrella species are employed as conservation short-cuts for the design of reserves or reserve networks. However, empirical data on the effectiveness of umbrellas is equivocal, which has prevented more widespread application of this conservation strategy. We perform a novel, large-scale evaluation of umbrella species by assessing the potential umbrella value of a jaguar (Panthera onca) conservation network (consisting of viable populations and corridors) that extends from Mexico to Argentina. Using species richness, habitat quality, and fragmentation indices of ~1500 co-occurring mammal species, we show that jaguar populations and corridors overlap a substantial amount and percentage of high-quality habitat for co-occurring mammals and that the jaguar network performs better than random networks in protecting high-quality, interior habitat. Significantly, the effectiveness of the jaguar network as an umbrella would not have been noticeable had we focused on species richness as our sole metric of umbrella utility. Substantial inter-order variability existed, indicating the need for complementary conservation strategies for certain groups of mammals. We offer several reasons for the positive result we document, including the large spatial scale of our analysis and our focus on multiple metrics of umbrella effectiveness. Taken together, our results demonstrate that a regional, single-species conservation strategy can serve as an effective umbrella for the larger community and should help conserve viable populations and connectivity for a suite of co-occurring mammals. Current and future range-wide planning exercises for other large predators may therefore have important umbrella benefits.

thornton2016-trascinato

A map of the jaguar conservation network for the Americas. The network consists of Jaguar Conservation Units (JCUs; in black), which maintain viable populations of jaguars, and jaguar corridors (in gray), linking the JCUs.

 

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Toward quantification of the impact of 21st‐century deforestation on the extinction risk of terrestrial vertebrates

Łukasz Tracewski, Stuart H.M. Butchart, Moreno Di Marco, Gentile F. Ficetola, Carlo Rondinini, Andy Symes, Hannah Wheatley, Alison E. Beresford, and Graeme M. Buchanan

Conservation actions need to be prioritised, often taking into account species’ extinction risk. The International Union for Conservation of Nature (IUCN) Red List provides an accepted objective framework for the assessment of extinction risk, but field data to apply the IUCN Red List criteria are often limited. Information collected through remote sensing can inform these assessments, and forests are perhaps the best-studied habitat type for use in this approach. Using an open-access 30 m resolution map of tree cover and its change between 2000 and 2012, the extent of forest cover and loss within the distributions of 11,186 forest-dependent amphibians, birds and mammals worldwide was assessed. Sixteen species have experienced sufficiently high rates of forest loss to be considered at elevated extinction risk under Red List criterion A, owing to inferred rapid population declines. This number would increase to 23 if data deficient species (i.e., those with insufficient information previously to apply the Red List criteria) were included. Some 484 species (855 if data deficient species are included) may be considered at elevated extinction risk under Red List criterion B2, owing to restricted areas of occupancy resulting from little forest cover remaining within their ranges. This would increase the proportion of species of conservation concern by 32.8% for amphibians, 15.1% for birds and 24.7% for mammals. Central America, the Northern Andes, Madagascar, the Eastern Arc forests in Africa and the islands of South-East Asia are hotspots for these species. The analyses illustrate the utility of satellite imagery for global extinction risk assessment and measurement of progress towards international environmental agreement targets. We highlight areas for which subsequent analyses could be performed on satellite image data in order to improve our knowledge of extinction risk of species.

tracewski_et_al-2016-conservation_biology-trascinato

Number of species potentially qualifying for a higher International Union for Conservation of Nature Red List threat category: (a) amphibians, (b) birds, (c) mammals, and (d) all species combined. Data deficient species are excluded.

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Analysing biodiversity and conservation knowledge products to support regional environmental assessments

Thomas M. Brooks, H. Resit Akçakaya, Neil D. Burgess, Stuart H.M. Butchart, Craig Hilton-Taylor, Michael Hoffmann, Diego Juffe-Bignoli, Naomi Kingston, Brian MacSharry, Mike Parr, Laurence Perianin, Eugenie C. Regan, Ana S.L. Rodrigues, Carlo Rondinini, Yara Shennan-Farpon & Bruce E. Young.

Two processes for regional environmental assessment are currently underway: the Global Environment Outlook (GEO) and Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Both face constraints of data, time, capacity, and resources. To support these assessments, we disaggregate three global knowledge products according to their regions and subregions. These products are: The IUCN Red List of Threatened Species, Key Biodiversity Areas (specifically Important Bird & Biodiversity Areas [IBAs], and Alliance for Zero Extinction [AZE] sites), and Protected Planet. We present fourteen Data citations: numbers of species occurring and percentages threatened; numbers of endemics and percentages threatened; downscaled Red List Indices for mammals, birds, and amphibians; numbers, mean sizes, and percentage coverages of IBAs and AZE sites; percentage coverage of land and sea by protected areas; and trends in percentages of IBAs and AZE sites wholly covered by protected areas. These data will inform the regional/subregional assessment chapters on the status of biodiversity, drivers of its decline, and institutional responses, and greatly facilitate comparability and consistency between the different regional/subregional assessments.

sdata20167-f3

Proportion of species, by Red List Category, in comprehensively assessed groups on The IUCN Red List of Threatened Species (Version 2015-2) occurring in each IPBES region (a) and subregion (b); and proportion of endemic species, by Red List Category, in comprehensively assessed groups on The IUCN Red List of Threatened Species (Version 2015-2) occurring in each IPBES region (c) and subregion (d). The vertical red lines show the best estimate for the proportion of extant species considered threatened (CR, EN and VU) if Data Deficient species are Threatened in the same proportion as data-sufficient species. The numbers to the right of each bar represent the total number of species assessed and in parentheses the best estimate of the percentage threatened. CR, critically endangered; DD, data deficient; EN, endangered; EW, extinct in the wild; EX, extinct; LC, least concern; NT, near threatened; VU, vulnerable.

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Connectivity of the global network of protected areas

Luca Santini, Santiago Saura & Carlo Rondinini.

Aim
Millennia of human activity have drastically shaped the Earth’s surface confining wildlife in ever more rare and sparse habitat fragments. Within the strategic Plan for Biodiversity 2011–2020, Aichi Target 11 aims at the expansion of the current protected area (PA) system and the maintenance and improvement of its connectivity. This study aims at providing the first overview of the functionality of the PA networks across the six continents at different dispersal distances relevant for terrestrial mammals.

Location
Global.

Methods
We used a graph theory approach to assess the connectivity of PA networks of different continents across a wide range of dispersal distances. We assessed the connectivity of country-level PA networks, the connectivity of con- tinental PA networks and the contribution of country-level PA networks to continental connectivity.
Results National and continental networks are characterized by very different spatial arrangements that translate into different levels of connectivity, ranging from networks where the reachable area is mostly determined by structural connectivity within PAs (e.g. Africa) to networks where connectivity mostly depends on animal dispersal among PAs (e.g. Europe). PA size correlates positively with connectivity for all species, followed by PA number; dispersal contributes less and positively interacts with number of PAs.

Main conclusions
Continental networks perform worse than national networks. Transboundary connectivity is often weak and should be improved, especially for countries that are important in promoting continental connectivity. Increasing PA coverage and size is a good strategy to improve multispecies connectivity.

figure-1-percentage-of-reachable-area-ecanorm-for-the-protected-area-networks-within

Percentage of reachable area (ECAnorm) for the protected area networks within world countries. (a) represents ECAnorm for the lowest dispersal distance considered (177 m). (b) represents the difference in ECAnorm between the lowest and the maximum dispersal distance considered (99.58 km), thus indicating the sensitivity to dispersal distance of each country’s network.

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Synergies and trade-offs in achieving global biodiversity targets

Moreno Di Marco, Stuart H. M. Butchart, Piero Visconti, Graeme M. Buchanan, Gentile F. Ficetola and Carlo Rondinini.

Following their failure to achieve a significant reduction in the global rate of biodiversity loss by 2010, world governments adopted 20 new ambitious Aichi biodiversity targets to be met by 2020.There is growing recognition that efforts to achieve one particular biodiversity target can contribute to achieving others, yet little attention is given to the fact that different targets may require conflicting solutions. Consequently, there is a risk that lack of strategic thinking might result, once again, in a failure to achieve governmental commitments to biodiversity conservation. We illustrate this dilemma by focusing on Aichi Target 11. This requires an expansion of terrestrial protected area coverage, which could also contribute to reducing the loss of natural habitats (Target 5), reducing human-induced species decline and extinction (Target 12), and maintaining global carbon stocks (Target 15). We consider the potential impact of expanding protected areas to mitigate global deforestation and the consequences for the distribution of suitable habitat for >10000 species of forest vertebrates (amphibians, birds and mammals). We found that expanding protected areas toward locations with the highest deforestation rates (Target 5) or the highest potential loss of aggregate species’ suitable habitat (Target 12) would result in partially different protected area network configurations (overlapping with each other by ca. 73%). Moreover, the latter approach would contribute to safeguarding ca. 30% more global carbon stocks (measures as tons/ha) than the former. Further investigation of synergies and trade-offs between targets would shed light on these and other complex interactions, such as the interaction between reducing overexploitation of natural resources (Targets 6, 7), controlling invasive alien species (Target 9) and preventing extinctions of native species (Target 12). Synergies between targets must be identified and secured soon and trade-offs must be minimized, before the options for co-benefits are reduced by human pressures.

figure-1-current-protected-areas-and-areas-with-highest-deforestation-impact-the-maps

Current protected areas and areas with highest deforestation impact. The maps represent: (a) current extension of the protected area network; (b) areas of synergy, i.e. places where highest forest loss correspond to highest habitat loss aggregated across species; (c) areas of forest trade-off, where highest forest loss is expected, but not highest loss of aggregate species habitat; (d) areas of species trade-off, where highest loss of aggregate species habitat is expected, but not highest forest loss. See Supporting Information for a color version of the map.

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Global Trends in the Status of Bird and Mammal Pollinators

Eugenie C. Regan, Luca Santini, Lisa Ingwall-King, Michael Hoffmann, Carlo Rondinini, Andy Symes, Joseph Taylor, & Stuart H.M. Butchart.

Biodiversity is declining, with direct and indirect effects on ecosystem functions and services that are poorly quantified. Here we develop the first global assessment of trends in pollinators, focusing on pollinating birds and mammals. A Red List Index for these species shows that, overall, pollinating bird and mammal species are deteriorating in status, with more species moving towards extinction than away from it. On average, 2.4 species per year have moved one Red List category towards extinction in recent decades, representing a substantial increase in extinction risk across this set of species. This may be impacting the delivery of benefits to people that these species provide. We recommend that the index is expanded to include taxonomic groups that contribute more significantly to pollination, such as bees, wasps and butterflies, thereby giving a more complete picture of the state of pollinating species worldwide.

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Red List Indices for (a) pollinating and nonpollinating bird species; (b) pollinating and nonpollinating mammal species; and (c) aggregated pollinating and nonpollinating birds and mammals. An RLI value of 1 equates to all species being Least Concern; an RLI value of 0 equates to all species being Extinct. Improvements in species conservation status lead to increases in the RLI; deteriorations lead to declines. A downward trend in the RLI value means that the net expected rate of species extinctions is increasing.

 

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Shortfalls and solutions for meeting national and global conservation area targets

Stuart H.M. Butchart, Martin Clarke, Robert J. Smith, Rachel E. Sykes, Jorn P.W. Scharlemann, Mike Harfoot, Graeme M. Buchanan, Ariadne Angulo, Andrew Balmford, Bastian Bertzky, Thomas M. Brooks, Kent E. Carpenter, Mia T. Comeros-Raynal, John Cornell, G. Francesco Ficetola, Lincoln D.C. Fishpool, Richard A. Fuller1, Jonas Geldmann, Heather Harwell, Craig Hilton-Taylor, Michael Hoffmann, Ackbar Joolia, Lucas Joppa, Naomi Kingston, Ian May, Amy Milam, Beth Polidoro, Gina Ralph, Nadia Richman, Carlo Rondinini, Daniel B. Segan, Benjamin Skolnik, Mark D. Spalding, Simon N. Stuart, Andy Symes, Joseph Taylor, Piero Visconti, James E.M. Watson, Louisa Wood, & Neil D. Burgess.

Governments have committed to conserving ≥17% of terrestrial and ≥10% of marine environments globally, especially “areas of particular importance for biodiversity” through “ecologically representative” Protected Area (PA) systems or other “area-based conservation measures,” while individual countries have committed to conserve 3–50% of their land area. We estimate that PAs currently cover 14.6% of terrestrial and 2.8% of marine extent, but 59–68% of ecoregions, 77–78% of important sites for biodiversity, and 57% of 25,380 species have inadequate coverage. The existing 19.7 million km2 terrestrial PA network needs only 3.3 million km2 to be added to achieve 17% terrestrial coverage. However, it would require nearly doubling to achieve, cost-efficiently, coverage targets for all countries, ecoregions, important sites, and species. Poorer countries have the largest relative shortfalls. Such extensive and rapid expansion of formal PAs is unlikely to be achievable. Greater focus is therefore needed on alternative approaches, including community- and privately managed sites and other effective area-based conservation measures.

figure-4-proportion-of-planning-units-requiring-conservation-areas-to-be-establishedProportion of planning units requiring conservation areas to be established within them for each country (a) plotted against log gross domestic product (GDP) per capita; and (b) mapped. Colors in the graph match those in the map legend.

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Scenarios of large mammal loss in Europe for the 21 st century: Scenarios of Mammal Loss

Carlo Rondinini & Piero Visconti

Distributions and populations of large mammals are declining globally, leading to an increase in their extinction risk. We forecasted the distribution of extant European large mammals (17 carnivores and 10 ungulates) based on 2 Rio+20 scenarios of socioeconomic development: business as usual and reduced impact through changes in human consumption of natural resources. These scenarios are linked to scenarios of land-use change and climate change through the spatial allocation of land conversion up to 2050. We used a hierarchical framework to forecast the extent and distribution of mammal habitat based on species’ habitat preferences (as described in the International Union for Conservation of Nature Red List database) within a suitable climatic space fitted to the species’ current geographic range. We analyzed the geographic and taxonomic variation of habitat loss for large mammals and the potential effect of the reduced impact policy on loss mitigation. Averaging across scenarios, European large mammals were predicted to lose 10% of their habitat by 2050 (25% in the worst-case scenario). Predicted loss was much higher for species in northwestern Europe, where habitat is expected to be lost due to climate and land-use change. Change in human consumption patterns was predicted to substantially improve the conservation of habitat for European large mammals, but not enough to reduce extinction risk if species cannot adapt locally to climate change or disperse.

rondinini__visconti_conbio2015-4-trascinato

Richness of European large mammals and geometric mean change of the extent of habitat (d-ESH%) between 2000 and 2050: (a, b). business-as-usual scenario (a) without dispersal and (b) with maximum dispersal and (c, d) change-in-human- consumption scenario (c) without dispersal, and (d) with maximum dispersal (white, regions with <5 species that were excluded from the analyses). Climate adaptation scenario not shown.

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