The Effect of Carbon Credits on Savanna Land Management and Priorities for Biodiversity Conservation

Carbon finance offers the potential to change land management and conservation planning priorities. We develop a novel approach to planning for improved land management to conserve biodiversity while utilizing potential revenue from carbon biosequestration. We apply our approach in northern Australia's tropical savanna, a region of global significance for biodiversity and carbon storage, both of which are threatened by current fire and grazing regimes. Our approach aims to identify priority locations for protecting species and vegetation communities by retaining existing vegetation and managing fire and grazing regimes at a minimum cost. We explore the impact of accounting for potential carbon revenue (using a carbon price of US$14 per tonne of carbon dioxide equivalent) on priority areas for conservation and the impact of explicitly protecting carbon stocks in addition to biodiversity. Our results show that improved management can potentially raise approximately US$5 per hectare per year in carbon revenue and prevent the release of 1–2 billion tonnes of carbon dioxide equivalent over approximately 90 years. This revenue could be used to reduce the costs of improved land management by three quarters or double the number of biodiversity targets achieved and meet carbon storage targets for the same cost. These results are based on generalised cost and carbon data; more comprehensive applications will rely on fine scale, site-specific data and a supportive policy environment. Our research illustrates that the duel objective of conserving biodiversity and reducing the release of greenhouse gases offers important opportunities for cost-effective land management investments

Progress towards a representative network of Southern Ocean protected areas

Global threats to ocean biodiversity have generated a worldwide movement to take actions to improve conservation and management. Several international initiatives have recommended the adoption of marine protected areas (MPAs) in national and international waters. National governments and the Commission for the Conservation of Antarctic Marine Living Resources have successfully adopted multiple MPAs in the Southern Ocean despite the challenging nature of establishing MPAs in international waters. But are these MPAs representative of Southern Ocean biodiversity? Here we answer this question for both existing and proposed Antarctic MPAs, using benthic and pelagic regionalizations as a proxy for biodiversity. Currently about 11.98% of the Southern Ocean is protected in MPAs, with 4.61% being encompassed by no-take areas. While this is a relatively large proportion of protection when compared to other international waters, current Antarctic MPAs are not representative of the full range of benthic and pelagic ecoregions. Implementing additional protected areas, including those currently under negotiation, would encompass almost 22% of the Southern Ocean. It would also substantially improve representation with 17 benthic and pelagic ecoregions (out of 23 and 19, respectively) achieving at least 10% representation

Carbon stock increases with a simulated improved fire and grazing management regime.

<p>The carbon density averaged across all vegetation zones was modelled by the state and transition carbon model, AuSavan <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0023843#pone.0023843-Hill1" target="_blank">[67]</a>. The simulation was initiated using parameters representing a ‘business as usual’ scenario (i.e. no improved land management) and run for 4 cycles of 113 years ending at year 452. We then introduced a regime change by altering the parameters to reflect improved fire and grazing management.</p

The total carbon potential of the stewardship arrangement was achieved for all biodiversity target levels when carbon biosequestration (tCO₂-e) was specifically targeted (Scenario 3) and when a budget was fixed equivalent to the cost of Scenario 2 (where carbon revenue is deducted from the land stewardship cost) at the same biodiversity target level.

<p>The amount of incidental carbon captured within Scenario 2 rose with an increase of the biodiversity target and the cost.</p

The least cost conservation solution generated by Marxan for Scenario 1 at a carbon price of US$14 tCO₂-e increased steadily as the biodiversity target level was increased from 25% to 200% of the baseline targets.

<p>The cost for Scenario 2 (where carbon revenue is deducted from the cost of land stewardship) remained comparatively constant as the carbon captured increases with the larger biodiversity targets (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0023843#pone-0023843-g005" target="_blank">Figure 5</a>).</p

A comparison of the difference in selection frequency, a measure of investment priority, between scenarios 1 and 2.

<p>A comparison of the difference in selection frequency, a measure of investment priority, between scenarios 1 and 2.</p

A framework to prioritise stewardship payments for improved land management while accounting for potential carbon revenue.

<p>Application of the framework to three scenarios in the context of Australia's northern savannas is described.</p

A Hierarchical Classification of Benthic Biodiversity and Assessment of Protected Areas in the Southern Ocean

<div><p>An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Important to this undertaking is knowledge of the distribution of benthic assemblages. Here, our aim is to identify the areas where benthic marine assemblages are likely to differ from each other in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 28 types of geomorphic features of the seabed, 562 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of existing MPAs. We found that 12 ecoregions are not represented in MPAs and that no ecoregion has their full range of environmental types represented in MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 8 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 107 spatially restricted environmental types, which should be considered for inclusion in future MPAs. Detailed supplementary data including a spatial dataset are provided.</p></div

Benthic ecoregions and their features (see Fig.2 for the location of each ecoregion).

<p>Benthic ecoregions and their features (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100551#pone-0100551-g002" target="_blank">Fig.2</a> for the location of each ecoregion).</p

Circumpolar datasets used within the classification.

<p>Circumpolar datasets used within the classification.</p