Biology subjects

Possingham, H. P.

Publications and source records attributed to Possingham, H. P..

8 recordsLinked to original sources

bioRxiv2022

Protected area planning to conserve biodiversity in an uncertain future

Protected areas are a key instrument for conservation. Despite this, they are vulnerable to risks associated with weak governance, land use intensification, and climate change. Using a novel hierarchical optimization approach, we identified priority areas for expanding the global protected area system to explicitly account for such risks whilst maximizing protection of all known terrestrial vertebrate species. We illustrate how reducing exposure to these risks requires expanding the area of the global protected area system by 1.6% while still meeting conservation targets. Incorporating risks from weak governance drove the greatest changes in spatial priorities for protection, while incorporating risks from climate change required the largest increase in global protected area. Conserving wide-ranging species required countries with relatively strong governance to protect more land when bordering nations with comparatively weak governance. Our results underscore the need for cross-jurisdictional coordination and demonstrate how risk can be efficiently incorporated into conservation planning. Article Impact StatementAccounting for governance, land use and climate risks will result in more resilient and effective conservation effort for biodiversity.

ecology↗

bioRxiv2020

Incorporating climate velocity into the design of climate-smart networks of protected areas

Climate change is redistributing terrestrial and marine biodiversity and altering fundamental ecological interactions. To adequately conserve biodiversity and promote its long-term persistence, protected areas should account for the ecological implications of species redistribution. Data paucity across many systems means that achieving this goal requires generic metrics that represent likely responses of multiple taxa to climate change. Climate velocity is one such metric, reflecting potential species range shifts at a generic level. Here, we explore four approaches to incorporating climate velocity metrics into the design of protected areas using the Mediterranean Sea as an illustrative example. Our methods are designed to meet two climate-smart planning objectives: 1) protect climate refugia by selecting slow-moving climate velocity areas, and 2) maintain the capacity of ecological systems to adapt by representing a suite of climate-velocity trajectory classes. We found that incorporating climate velocity as a cost measure in Marxan is the best approach for selecting slower-moving areas, which are good indicators of climate refugia. However, this approach fails to accommodate socio-economic cost data, and is probably impractical. Incorporating climate velocity as a boundary or as a feature provides both selection of slower-moving areas and solutions with lower socio-economic cost. Finally, we were able to design cost-effective networks of protected areas representing a suite of climate-velocity trajectories classes, which have the potential to help species adapt to a changing climate. This work presents simple and practical ways of including climate velocity in conservation plans on land and in the ocean to achieve the key climate-smart objectives of protecting climate refugia and enhancing ecological resilience.

ecology↗

bioRxiv2020

Global shortfalls in extinction risk assessments for endemic flora

The Global Strategy for Plant Conservation (GSPC) ambitiously calls for an assessment of extinction risk for all recognised plant taxa by 20201. It is now clear that this target will not be met in the short-term; only 21-26% of known plant species have been assessed2 - a monumental shortfall in anticipated knowledge. Yet the need for risk assessments has never been more urgent. Plants are rapidly going extinct3,4 and face threats such as climate change5 and permanent deforestation6. Extinction risk assessments continue to provide the critical foundation to inform protection, management and recovery of plant species7,8, the loss of which will have clear consequences for maintaining planetary systems and human well-being9. Here, we rank countries of the world based on progress towards assessing the extinction risk to their endemic flora. Overall, 67% of country-based endemic species do not have an extinction risk assessment completed (143,294 species). We show that some of the worlds wealthiest nations, which also have relatively strong species protections, are failing to protect their unique flora by not systematically assessing risks to their endemic species.

ecology↗

bioRxiv2020

Taking a landscape approach to conservation goals: designing multi-objective landscapes

Designing landscapes to accommodate both humans and nature poses huge challenges, but is increasingly recognised as an essential component of conservation and land management. The land-sparing land-sharing framework has been proposed as a tool to address this challenge. However, it has been largely criticised for its simplicity. We provide a new conceptual framework amenable to the application of structured decision-making that moves beyond the dichotomy of land-sparing or land-sharing. Using this new framework, we present a general system model that can be used to make land management decisions for the conservation of species, ecosystem services and production land at different spatial scales. The model can be parameterised for specific systems using information about: the current state of the landscape, the rates of change between landscape states, and the cost and effectiveness of taking actions. To demonstrate the utility of the model we apply it to three different landscape types. Across our three case studies, we show that investment into one of three management actions (varying degrees of management and restoration) can move the system towards more biodiversity or more managed land depending on the objectives of the land manager. We show that the dynamic and flexible nature of the landscape is important to take into account rather than a static snapshot in time. Rather than focusing on establishing the perfect landscape with a set proportion dedicated to production and to biodiversity conservation, we argue that a more useful approach is to establish incremental movements towards a landscape that meets the goals of multiple objectives. Our framework can be used to illustrate to decision makers the costs and trade-offs of different actions and help them determine land management policy.

ecology↗

bioRxiv2019

Conservation attention necessary across at least 44% of Earth’s terrestrial area to safeguard biodiversity

More ambitious conservation efforts are needed to stop the global biodiversity crisis. Here, we estimate the minimum land area to secure important sites for terrestrial fauna, ecologically intact areas, and the optimal locations for representation of species ranges and ecoregions. We discover that at least 64 million km2 (44% of terrestrial area) requires conservation attention. Over 1.8 billion people live on these lands so responses that promote agency, self-determination, equity, and sustainable management for safeguarding biodiversity are essential. Spatially explicit land-use scenarios suggest that 1.3 million km2 of land requiring conservation could be lost to intensive human land-uses by 2030, which requires immediate attention. However, there is a seven-fold difference between the amount of habitat converted under optimistic and pessimistic scenarios, highlighting an opportunity to avert this crisis. Appropriate targets in the post-2020 Global Biodiversity Framework to ensure conservation of the identified land would contribute substantially to safeguarding biodiversity.

ecology↗

bioRxiv2019

Area requirements to safeguard Earth’s marine species

Despite global policy commitments to preserve Earths marine biodiversity, many species are in a state of decline. Using data on 22,885 marine species, we identify 8.5 million km2 of priority areas that complement existing areas of conservation and biodiversity importance. New conservation priorities are found in over half (56%) of all coastal nations, with key priority regions in the northwest Pacific Ocean and Atlantic Ocean. We identify where different conservation actions, ranging from marine protected areas to broader policy approaches, may best overcome anthropogenic threats to these areas. This analysis shows 26-41% of the ocean (depending on targets used for species representation) needs to be effectively conserved through a combination of site-based actions and wider policy responses to achieve global conservation and sustainable development agendas.\n\nOne Sentence SummaryAt least 26% of the ocean needs a combination of site-based conservation and wider policy responses to achieve global conservation goals.

ecology↗

bioRxiv2018

Operationalizing ecological connectivity in spatial conservation planning with Marxan Connect

O_LIGlobally, protected areas are being established to protect biodiversity and to promote ecosystem resilience. The typical spatial conservation planning process leading to the creation of these protected areas focuses on representation and replication of ecological features, often using decision support systems such as Marxan. Unfortunately, Marxan currently requires manual input or specialised scripts to explicitly consider ecological connectivity, a property critical to metapopulation persistence and resilience.\nC_LIO_LI\"Marxan Connect\" is a new open source, open access Graphical User Interface (GUI) designed to assist conservation planners in the systematic operationalization of ecological connectivity in protected area network planning.\nC_LIO_LIMarxan Connect is able to incorporate estimates of demographic connectivity (e.g. derived from tracking data, dispersal models, or genetics) or structural landscape connectivity (e.g. isolation by resistance). This is accomplished by calculating metapopulation-relevant connectivity metrics (e.g. eigenvector centrality) and treating those as conservation features, or using the connectivity data as a spatial dependency amongst sites to be included in the prioritization process.\nC_LIO_LIMarxan Connect allows a wide group of users to incorporate directional ecological connectivity into conservation plans. The least-cost conservation solutions provided by Marxan Connect, combined with ecologically relevant post-hoc testing, are more likely to support persistent and resilient metapopulations (e.g. fish stocks) and provide better protection for biodiversity than if connectivity is ignored.\nC_LI

ecology↗

bioRxiv2017

Spatially Explicit Approach To Population Abundance Estimation In Field Surveys

The abundance of species is a fundamental consideration in ecology and conservation biology. Although broad models have been proposed to estimate the population abundance using existing data, available data is often limited. With no information available, a population estimation will rely on time consuming field surveys. Typically, time is a critical constraint in conservation and often management decisions must be made quickly under the data limited situation. Depending on time and budgetary constraints, the required accuracy of field survey changes significantly. Hence, it is desirable to set up an effective survey design to minimize time and effort of sampling given required accuracy. We examine a spatially-explicit approach to population estimation using spatial point processes, enabling us to explicitly and consistently discuss various sampling designs. We find that the accuracy of abundance estimation varies with both ecological factors and survey design. Although the spatial scale of sampling does not affect estimation accuracy when the underlying individual distribution is random, it decreases with the sampled unit size if individuals tend to form clusters. These results are derived analytically and checked numerically. Obtained insights provide a benchmark to predict the quality of population estimation, and improve survey designs for ecological studies and conservation.

ecology↗