Conservation parks are growing, so why are species still declining?

It’s now five years since the International Year of Biodiversity, and nearly 15% of Earth’s land surface is protected in parks and reserves. By 2020, we should reach the agreed global target of 17%. This is good news for species diversity, right?

Not really. Biodiversity loss continues apace despite these global agreements and conservation actions, and is unlikely to stop any time soon.

We explored this apparent paradox with the help of a simple model that simulates the current relative proportions globally of the area of remaining tropical forest, and the area that has been cleared for agricultural development. We used the model to look at what happens to these proportions when networks of conservation reserves expand.

Our research led to two insights: both the area of forest protection and the area of clearing for development can expand at the same time; and the governance regimes responsible for protected areas can actually be weakened by protected area expansion. This is because pressure for the creation of new protected areas comes largely from public discourse.

Forests and forces

In our model we depicted tropical forestlands as consisting of protected forests; traditionally managed or “unallocated” forests; and cleared agricultural land – plausible categories that broadly reflect the current status and areas.

We then modelled the different governance regimes (and feedbacks such as public discourse) responsible for this current status, regimes that:

a) protect unallocated forest;

b) develop (and clear) unallocated forest for agriculture;

c) maintain current habitat and restore agricultural land to forest, thereby opposing clearing for development.

We use the model to present three plausible scenarios of governance regime and land-use change trajectories.

The forces that affect land use in forested areas.

Our dynamic hypothesis depicted in the figure shows how the driving forces of development and protection, while competing for the remaining stock of forest habitat, do not necessarily oppose each other. Consequently the total stock of forest habitat can decrease while the area of protected forest increases.

The force that directly opposes clearance of forests for development is the one that maintains existing unprotected forest use regimes or that seeks to restore cleared forest.

The relative power of the governance regimes that “develop”, “protect”, or “maintain/restore” will determine what ultimately happens to the area of remaining forest habitat. Biodiversity loss will only stop when the net loss of forest habitat each year is zero - which means halting the clearing of tropical forest for agricultural development, as well as increasing protected areas.

But in the real world we are doing the opposite - investing heavily in the force that drives tropical forest clearing. The leaders of the G20 nations recently gave a huge boost to the power of development regimes, by pledging to invest up to US$70 trillion on new infrastructure projects by the year 2030. This is precisely the kind of driving force that will harm wildlife conservation, and which the growth of protected areas will fail to counter.

It seems counter-intuitive, but our research suggests that increasing the area of the world’s conservation reserves can also reduce the perception of the risk of ongoing biodiversity loss, primarily because the focus on the 17% protection targets takes our eye off the critical issue of halting habitat loss. As a result, the global distribution of protected areas is currently “high and far”, skewed toward mountainous areas and places far from development frontiers. If achieving 17% leads the public to conclude that biodiversity is now safe, it can lower the main feedback currently giving power to the protect force - public pressure for political action.

This is compounded by the phenomenon of extinction debt – the time delay between habitat loss and the resulting extinction of species that live here – which hides the impact of development on wildlife in both protected and unprotected areas.

What do we do about it?

Conservation has traditionally sought to identify and protect “representative samples” of different types of ecosystems. Recently, however, there has been an increased interest in identifying and protecting areas based on cost-effectiveness criteria.

We suggest instead that one useful leverage point for slowing tropical biodiversity decline would be to concentrate on placing protected areas near active agricultural frontiers, which could help to constrain the march of agriculture through tropical forests.

This approach has already been shown to work in urban planning, including in Australia, where it has been used to fight urban sprawl. A second useful leverage point is to set global targets that include both a percentage for protection and an overall percentage for remaining forest habitat. Globally, forest cover now is at 62% of its original extent, while 75% has recently been identified as the extent necessary to stay within planetary boundaries.

Sharing is caring

There is currently much debate in the conservation literature about “land sparing or land sharing”. Our scenarios suggests that while land sparing through rapid protected area expansion has immediate conservation benefits, these benefits are lost over time as species populations eventually crash. The land-sharing scenario, through strengthening the power to maintain current forest habitats, suggests better biodiversity outcomes in the long term.

Realising these long-term benefits may only be possible with a resurgence in traditional forest-management practices that promote wildlife-friendly agriculture, and that restore forest habitat. All too often the governance regimes of traditional forest owners have been subsumed by the State in order to allow commercial forestry or forest clearance for agriculture. However, there are signs that this may be changing in some places through commercially viable drivers of sustainability.

Our analysis suggests that human activity will continue to damage wildlife diversity, in spite of successful efforts to meet the target of protecting 17% of Earth’s land surface. The reason is that a large percentage of natural habitats are disappearing in the face of development, particularly through the clearing of tropical forests for agriculture.

This destruction will continue because the overall balance of land management is still geared towards ongoing clearing for development rather than sustainable re-development of our current human footprint. Getting out of this trap will require an understanding of the processes that reinforce this perverse situation, and the realisation that this system needs to be redesigned.

This is a new frontier in conservation science, and our new analysis is hopefully a first step towards unravelling this complex social-ecological problem.

What we need to do next is to identify the critical feedback relationships that can empower natural resource management, and to put reasonable limits on the power of development regimes. Otherwise, the world’s biodiversity will continue to dwindle even if conservation reserves expand rapidly.

This article was coauthored by Craig Miller, a former researcher with CSIRO Sustainable Ecosystems.

Ro Hill receives funding from the Australian Government to support her work with CSIRO. She is a member of IUCN's World Commission on Protected Area and Commission on Environment, Economic and Social Policy, the Indigenous and Local Knowledge Expert Taskforce of the Intergovernmental Platform on Biodiversity and Ecosystem Services, and the Australian Conservation Foundation.

Iain Gordon receives funding from Scottish Government and Australian Government.

Barry Newell and Michael Dunlop do not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article. They also have no relevant affiliations.