Rethinking Our Approach to Protected Areas for Conservation

Written by Justine Atkins

Over the last fifty years, there has been progressively more widespread recognition that species’ biodiversity is rapidly declining. This is a huge problem, and not only ethically: biodiversity also has crucial economic returns such as ecotourism and promoting ecosystem resilience to climate change and invasive species. It is now well-established that the overwhelming responsibility for this decline rests firmly on our shoulders. Therefore, humans must change the way in which we interact with the environment.

One of the key ways in which we have responded to this ecological crisis is through the establishment of protected areas. These areas of land or ocean are sectioned off and restricted from human use, (theoretically) protecting the ecosystems within them from negative anthropogenic impacts such as deforestation and hunting. At least four international treaties have been established with the aim of protecting a representative example of all ecosystems and species types that exist in the world today [1]. Most recently, the Convention on Biological Diversity (CBD) set targets of protecting 17% of terrestrial area and 10% of the world’s oceans by 2020, to be specifically achieved through the establishment and expansion of strategically designed and managed protected area (PA) networks.

Perhaps surprisingly, global PA coverage is actually moving steadily towards these targets. Unfortunately, equally surprising is that biodiversity continues to decline despite this increased investment in conservation. The disconnect between the potential and realized impact of these reserves has led scientists to begin questioning the efficacy of PAs as a strategy for conserving biodiversity. This shift in perspective has, in turn, forced researchers to look more closely at how the effectiveness of PAs is assessed. Past evaluations have proven inconclusive, demonstrating both the huge benefits and significant shortcomings of protection. For example, many populations of large mammals within Africa’s reserves are still showing declines, while, on the other hand, raptor species in Botswana are much more abundant within PAs than outside these areas.

Why are there such contrasting outcomes? The answer involves several complex and interacting issues. Firstly, there is a wide variety of ways in which PAs can intervene in the environment — each with its own set of costs and benefits. Marine PAs, for example, can save declining fisheries stocks but are likely to negatively affect species living outside these areas as fisherman move their activities to neighboring areas. Secondly, establishing a PA has complicated socioeconomic impacts; these can range from being helpful, such as providing jobs, to harmful, such as forcing indigenous people off their land. Thirdly, because we lack a unified framework, past assessments of the consequences of any particular protection method have had to rely on “before-and-after” style analysis. This method is problematic because it fails to account for what would have happened to, for example, the biodiversity in a PA if that area had not been put under protection. Making direct comparisons to a baseline of conditions is crucial in science and is also referred to as the use of “control groups” (Box 1).

Box 1. Impact evaluation
Impact evaluation (IE) is a method of assessing the potential or realized consequences of a conservation policy (e.g. protected areas). IE involves the use of scientifically rigorous paired comparisons to assess the effects of an intervention. Unlike performance measurement, which monitors changes in ecological and socioeconomic indicators (such as number of species within a given area) over time, evaluating the impact of a protected area also accounts for changes that might have occurred in that area even in the absence of protection. In this way, we can get a picture of the transformations that have occurred within a protected area that are i) the direct result of the establishment of protection and ii) simply due to natural fluctuations in ecosystem characteristics over time and space.

Several closely related experimental techniques are key to the IE method:

- Control groups are groups of test subjects or sites which very closely resemble the subjects or sites receiving an experimental treatment (for example, a clinical trial of a new prescription drug) but are not themselves subject to the treatment. These groups ‘control’ for factors beside the treatment that could influence the outcome.

- Matched pair experimental design directly compares each ‘treated’ site or subject with a matching ‘control’ site or subject.

- Counterfactual is a quantified assessment of what would have happened if there had been no intervention in an area, or, to continue with the drug trial example, if no medication had been given to a sick patient.

A great ecological experiment that incorporates these techniques is found at La Selva research station in Costa Rica in which many comparative experiments are being carried out using plots of intact primary forest paired with plots of land that are, in all ecological aspects (e.g. elevation, gradient, size), very similar but were cut down or burnt different numbers of years ago (e.g. 10, 20, etc.) for a variety of purposes.

Recognizing the urgency of this problem for biodiversity conservation, the prominent journal Philosophical Transactions of the Royal Society B (Phil Trans for short) emphasized the need for a revised methodology of PA assessment in a recent special issue. As a way forward, this collection of articles proposes and presents several applications of a new control group-oriented technique called impact evaluation (Box 1). Impact evaluation (IE) is a growing field in conservation science. Like previous assessment strategies, IE measures the effects of an intervention (such as building a new PA). Unlike before, however, IE also explicitly considers what would have happened without any intervention, described by researchers as the “counterfactual” (Box 1).

The Phil Trans articles convincingly argue that considering the counterfactual is the only way to truly quantify how protected areas affect biodiversity, ecosystem conservation, and human welfare. Collectively, the authors show that this new method is crucial given the limited budgets in conservation. If implemented on a broad scale, IE could allow for much greater payoff in protected area development than is currently being observed.

While this goal of minimizing biodiversity loss and maximizing socioeconomic benefits may seem ambitious, there is already empirical evidence that suggests such a goal is within reach. So far, IE research has concentrated on measuring PA effectiveness in relation to changes in deforestation rates and species loss. With a baseline of unprotected areas for comparison, researchers have specifically quantified how the impact of a PA changes according to variation in environmental and socioeconomic characteristics. The Phil Trans issue documents how this approach is applied effectively in areas as varied as the Brazilian Amazon and freshwater systems in Northern Australia. Results of IE show, for example, that PA management has led to a greater reduction in the spread of an invasive mimosa plant in Kakadu National Park than would have been observed in the absence of a PA.

Great Barrier Reef
The Great Barrier Reef on the eastern coast of Australia is one of the largest marine protected areas in the world. While protection has allowed this ecosystem to remain a highly complex and biodiverse environment, this status and the future of the reef’s marine life remain under increasing threat. In large part, this is because it was initially judged ‘effective enough’ to have only a small percent of the area as specific ‘no-take’ zones, with commercial fishing and oil and gas exploration still allowed in many regions. This approach, now subject to ongoing review and revision, calls into question current methods for measuring the effectiveness of protected areas. Photo credit: Jurgen Freund / NaturePL

Socioeconomic effects are also more readily identified within the IE framework. The debate over PAs and poverty is long-running and controversial. In large part, this disagreement is because there is weak and inconclusive quantitative evidence of the impact of PAs on people. People instead rely on highly subjective assumptions and inconsistent anecdotal findings. However, under the direction of IE, conservation scientists can recommend reserve strategies that more accurately describe the direct benefits and costs of PAs for human welfare. For example, in Bolivia, an impact-based assessment of PAs provided empirical support for earlier qualitative findings that PAs are in fact not linked with poverty traps. Using pre-, mid- and post-implementation IE, researchers found similarly counterintuitive results in relation to the socioeconomic impacts of marine PAs in Indonesia.

It is understandably difficult to see why such an approach has not been the established practice for many years. Unfortunately, those in a position to transition to using IE in the context of PAs have little incentive to do so. In an increasing publication-centered field, academics are reluctant to commit to projects evaluating the impact of conservation initiatives because i) generally, prestige journals prefer to focus on core science and are less likely to publish such work and ii) funding for this line of research is limited. A recent opinion piece in Conservation Magazine from the directors at the Wildlife Conservation Society highlights this paradox.

On a more hopeful note, international funding agencies could be a lifeline for the facilitation of IE. These organizations not only have monetary means, they are also key stakeholders in that they control a vast proportion of the funding for PAs and would benefit greatly from the decreased cost: benefit ratio that impact evaluation could deliver.

In light of the continuing rate of species’ extinctions on our planet, it is crucial that we invest in preserving biodiversity. Protected areas have the potential to be highly valuable conservation tools, but to achieve this potential, we need a good way of objectively assessing the effectiveness of PAs. The Philosophical Transactions issue clearly demonstrates that widespread uptake of IE could fulfill this need and re-establish protection-based strategies as a cornerstone of conservation science.


[1] The Stockholm Declaration (1972), World Charter for Nature (1982), the Rio Declaration at the Earth Summit (1992), and the Johannesburg Declaration (2002).


Justine is a first-year PhD student in the Ecology and Evolutionary Biology department at Princeton University. She is interested in the interaction between animal movement behavior and environmental heterogeneity, particularly in relation to individual and collective decision-making processes, as well as conservation applications.

A Precarious Puzzle of Expanding Deserts: How arid Asia has varied over time and the confusion over recent desertification

Written by Jane Baldwin

Inner Mongolia (Nei MengGu in Mandarin Chinese) lies right at the border of the nation of Mongolia within mainland China (see Figure 1). Pictures of yurts, traditional pony races, Mongolian wrestlers, and most of all rolling grasslands attract many Chinese tourists to this region each year (see Figure 2). In summer 2009, while I was an undergraduate studying Mandarin Chinese in Beijing, I also became enticed to this region. Tasked by my program to use my newly polished Mandarin to conduct a “social study” in an area outside Beijing, Inner Mongolia seemed both a very foreign and fascinating locale to investigate.

Jane Fig 1
Figure 1. Inner Mongolia, a Chinese province, lies just south of the nation of Mongolia. It is part of the arid lands that stretch across interior Asia. Source: adapted from Nasurt, 2011.

A group of my classmates and I took an overnight train from Beijing to Hohhot, and then a bus far into the countryside to our first yurt encampment. As expected, the great expanse of the scenery was stunning—the landscape stretched out before us only punctuated by occasional small hills, yurts, and sheep. However, we were shocked to discover the lush grasses in pictures were reduced to dry scrub only an inch or two high (see Figure 3).

Jane Fig 2
Figure 2. The Inner Mongolian pastoral ideal branded by Chinese tourist agencies. Source:
Jane Fig 3
Figure 3. The state that many grasslands in Inner Mongolia are currently in or approaching following recent desertification. Source:

I was concerned by this difference, and decided to focus my interviews with the local people on these environmental changes. The local nomadic herders informed me that desertification (or shamohua in Mandarin—literally translated as “change into desert”) had become a serious issue in this region over the past 20 years or so. One herder I interviewed recalled that as a teenager, the grasses had reached as high as his horse’s flank, while now they extended no higher than his horse’s hoof. These observations led me to wonder many questions which did not yield firm answers through my interviews: What was the cause of these dramatic changes? Were the local people responsible for the degradation? Or was it caused by larger scale climate variations outside of their control? And what would be the appropriate policy response to deal with the degradation and still respect the people who had lived there for generations?


Since that summer, this suite of questions around deserts and desertification has inspired much of my study and research, both as an undergraduate and now a PhD candidate in Atmospheric and Oceanic Sciences. My PhD research focuses broadly on understanding the climate of arid and semi-arid regions across Asia that define the margins of these grasslands (see Figure 1). As the largest deserts outside the tropics, this region presents a number of interesting climate dynamics questions. However, through research, classwork, and personal reading I have also sought to understand this region from a variety of angles beyond climatological, in particular geological, historical, and political. While spiraling in towards the desertification question, I have developed a mental narrative for this region, and its changes and controls of its climate over different periods of time.

Observing sediments and fossils, geologists have pieced together a record of arid Asia that shows this region to have varied greatly over the long geological timescales of millions of years. 50 Ma (million years ago), what is now Central and northern East Asia was covered in warm, damp forest populated by ancient horses, and rhino ancestors larger than modern elephants. A few theories exist for what spurred the relatively rapid (few million year-long) transition to the cool, dry climate we know today. Around this time India’s collision with the Eurasian subcontinent was creating the colossal Tibetan Plateau and Himalayas. The longest running theory for the formation of these deserts is that this newly risen topography blocked moisture from reaching Central and northern East Asia, drying this region. Climate modeling studies have indeed indicated that the Tibetan Plateau creates significant aridity outside the tropics in Asia . However, new research presents an alternative theory for the formation of this region. A large inland sea on the western margin of Central Asia, called the Paratethys, was recently found to have retreated just prior to the transition of this region to an arid environment; the migration of this moisture source may have played a dominant role in drying Central Asia. Which of these mechanisms (Tibetan Plateau uplift or the retreating Paratethys) was most important for the drying of Asia, and whether they might be linked, are both still open and actively researched questions.

More recent environmental history (i.e. the past few thousand years) is recorded in tree rings. When trees are water-stressed, how much their trunks grow radially depends in large part on how much rainfall there is. Widths of tree rings thus provide a proxy for historical drought/wet periods. The dry climate of this region over the past few thousand years, and its variations in precipitation recorded in these tree rings are hypothesized to have played key roles in human history, with the most dramatic example being the expansion of the Mongol Empire. Genghis Khan and the nomadic steppe tribes allied with him relied on horses for travel, sustenance, and warfare. Tree rings suggest that during the 13th century when the Mongol Empire expanded to cover China, Central Asia, and parts of the Middle East and Europe, the region was warm and persistently wet; these climatic conditions favored high grassland productivity, supporting Mongol political and military power during this critical period. This is but one example of how climatic and historical changes link tightly in this water-stressed region.

Over the past hundred years, the clearest climatic trend on the global scale has been warming caused by anthropogenic carbon emissions, primarily CO2 released from burning fossil fuels. How this global signal will translate to the regional scale is still a topic of active research in the climate science community. The most recent UN Intergovernmental Panel on Climate Change (IPCC) report shows that warming is clearly predicted over Asia as carbon emissions continue to increase. However, there is little consensus among climate modeling studies regarding how precipitation will change over arid Asia. This uncertainty is concerning for an environment that is already exhibiting symptoms of increasing water-stress. Desertification or land degradation has occurred across the margins of arid Asia over the past few decades, including places as diverse as the former Soviet countries that exist in the Aral Sea drainage basin, Qinghai Province on the Tibetan Plateau, and of course Inner Mongolia. While the UN Convention to Combat Desertification has motivated countries to submit plans to fight this degradation, on-the-ground action has been slow and limited. Facing the double threat of ill-planned development and global warming, these delicate regions on the border of Asia’s great deserts are currently in a precarious position.


While my understanding of arid environments and particularly their variability has increased significantly since I first visited Inner Mongolia in the summer of 2009, the recent desertification of this region is still a puzzle for me and for the scientific community at large. Over the past decade, the Chinese government has tried a number of strategies to deal with the desertification in Inner Mongolia. Citing overgrazing as the cause of the increased aridity, the government has resettled pastoralist nomads into cities—nomads who have grazed the steppe for thousands of years. Since 2003, the total number of urban resettlements in Inner Mongolia is 450,000. Meanwhile, in the tradition of the great engineering emperors of yore, the Chinese government is supporting a “Great Green Wall” of trees planted to halt the expanding desert and decrease dust transport. By the project’s planned end in 2050, it is intended to stretch 4,500km (2,800 miles) along the edge of China’s Northern deserts, covering 405 million hectares—a truly massive endeavor.

Unfortunately, without knowing the root cause of the desertification or how this region will respond to ongoing global warming, it is difficult to predict whether these policies are appropriate. While the Chinese government points its finger at overgrazing, some experts believe that it was the government’s prior actions in this region (fencing land and supporting agriculture over pastoralism) and ongoing mining pollution that has pushed this region away from a sustainable equilibrium and towards desertification. Adding flame to the fire, ecologists and hydrologists wonder whether the Great Green Wall’s trees will grow successfully or just deplete the water supply further. Meanwhile, recent climate studies provide an alternative explanation to these land-use centric arguments, suggesting that non-local climatic causes such as global warming and decreasing East Asian monsoon strength may explain the increasing aridity.

In this quagmire of rapid environmental change and scientific uncertainty one thing is clear: it is critical for there to be a robust dialogue between scientists and policy makers for Inner Mongolia, and the dry climates in Asia at large, to have a chance at developing sustainably.



Jane is a PhD candidate in Princeton’s Atmospheric and Oceanic Sciences program in joint with NOAA’s Geophysical Fluid Dynamics Laboratory, where she is advised by Dr. Gabriel Vecchi. Her research employs a combination of dynamical climate models and earth observations to elucidate the ties between global and regional climate, and move towards useful predictions of climate change at regional levels.