International Day of Biodiversity: can protected areas help biodiversity?

This is the first in a series of weekly blog posts that will cover conservation topics with a focus on protected areas and the laws and institutions that support them (or don’t).

int day of biodiv

Happy International Day of Biodiversity! If you are unfamiliar with the term, biodiversity is broadly defined as the sum total of the variety of life on earth. This could include genetic diversity, species diversity, or even ecosystem diversity. In the scheme of things, the term biodiversity is relatively new – it was formalized several decades ago by pioneering conservation scientists including E.O. Wilson and Tom Lovejoy. These scientists felt that it was important to conceptualize the term and include it in our lexicon; if you lack the term for something, you cannot begin to understand or save it. Ever since, the use of the term biodiversity has grown exponentially: it is incorporated into international treaties and conventions, the missions of many non-governmental organizations, and countless policies and management objectives.

biodiv is us

Although it has been defined and incorporated broadly in policies, the term biodiversity is still quite abstract; hence, it may be difficult to conceptualize. Think about it – biodiversity is the diversity of ALL life on Earth. As you can imagine, biodiversity can be measured in many ways. Is it measured as a count of the number of species? The number of populations within a species? The genetic diversity within a species or between species? The variety of species across the landscape? The variety of ecosystems within a certain place? Yes to all of the above. Because biodiversity can be defined in many different ways and quantified using a host of metrics (species richness, Shannon diversity, functional diversity, among others), the scientific community is still working to understand how much biodiversity exists on earth. In addition, much of global biodiversity, especially insects, microbes, and those species found in the deep oceans, have yet to be identified or catalogued.

Despite the semantic difficulties of the term biodiversity, one thing is certain. Global biodiversity is in crisis. Current rates of species extinction have been estimated to be 100 to 1000 times higher than background rates. Certain taxa are particularly in peril, including coral reefs, amphibians, and sharks and rays. Human activities have contributed significantly to the top threats to biodiversity including habitat loss, climate change, habitat fragmentation, over-exploitation, and pollution. Given this crisis, what can be done?

Traditionally, conservationists have worked tirelessly to stave off the biodiversity crisis by establishing protected areas – specially designated places that restrict or manage certain human activities. These protected areas have been established across the landscapes and seascapes of countries around the world and now cover about 15% of the land and 3% of the oceans.


World Database of Protected Areas,

In general, is the establishment of protected areas a good strategy to protect biodiversity? Overall, yes. Protected areas have been documented to provide benefits to biodiversity and also to human societies. Protected areas provide services to people including fresh water, recreation opportunities, and carbon storage to help mitigate climate change. Protected areas seem like the obvious choice when contemplating conservation strategies that could help species and ecosystems. Protected areas are set aside and protected forever, right? Unfortunately, the story is not so straightforward in practice.

Laws change: protected area downgrading, downsizing, and degazettement (PADDD)

Although many assume that protected areas are established in perpetuity, evidence suggests that protected areas around the world can be subject to legal changes. Laws can make protected areas weaker by allowing additional activities to occur within them (downgrades). Laws can also make protected areas smaller (downsizes) or delete them entirely (degazettes). For example, a proposal to drill for oil in Virunga National Park in the Democratic Republic of the Congo is being considered. Yosemite National Park in the United States was once about 30% larger than it is today. Several protected areas were recently removed from protection to build hydropower dams in Brazil. Thousands of examples of PADDD events have been documented around the world – 2,000 laws have been enacted and more than 2,300 laws have been proposed that would change the size and status of protected areas. These figures represent a conservative estimate of the extent of PADDD worldwide.


Global map of PADDD – learn more at

Where and why do PADDD events occur?

PADDD has been documented globally and has occurred sporadically from 1900 to the present. Laws have been passed and proposed that would open up protected areas for industrial activities such as infrastructure development (building roads and dams), industrial agriculture, mining, and oil and gas development. In addition, protected area laws have also been changed for local reasons – to allow for subsistence-level extraction, land claims and rural settlements for indigenous people. Future blog posts will focus on particular legal changes at the national, regional and individual protected area levels.

Cause of enacted PADDD

Causes of Enacted PADDD Events. Key: F: forestry; M: mining; OG: oil and gas; IA: industrial agriculture; In: Industrialization; If: Infrastructure; LC: land claims; RS: rural settlement; S: subsistence; D: degradation; CP: conservation planning; O: other; U: unknown. Not shown: Proposed PADDD events. Data from

PADDD and biodiversity

Bringing it back to biodiversity – does it matter if laws to protected areas change? Do legal changes actually affect biodiversity? Evidence suggests that it might and it likely depends on the context and cause of the legal change. PADDD has been linked to increased habitat fragmentation in areas formerly part of Yosemite National Park. As habitat fragmentation is considered a top threat to biodiversity, it is likely that PADDD could have contributed to biodiversity loss in this case. In addition, PADDD has been linked to higher rates of deforestation and carbon emissions in several tropical, biodiversity-rich nations. These findings suggest that PADDD may have negative consequences for biodiversity. However, many questions remain and much more research is needed to understand the impacts of PADDD on biodiversity. On one hand, PADDD events that are proximally caused by extractive activities (mining, oil and gas development) are likely to negatively affect biodiversity. On the other hand, PADDD events driven by conservation planning purposes could be beneficial overall for biodiversity. If for instance, a nation deems that a protected area has served its purpose and reallocates those funds for other protected areas or conservation strategies, then PADDD may have a net benefit over time across that nation. Teasing out the causal effects of PADDD on biodiversity is likely to be complex, but ultimately may demonstrate a critical connection between national-level decisions and site-specific biodiversity.

On this International Biodiversity Day, check out the protected areas and PADDD events near you to learn more about the factors affecting your local biodiversity.