Local Ecosystems are Experiencing
a Massive Metamorphosis

A metamorphosis is taking place across our planet. As coral reefs become stressed by a warming ocean, algae and seaweed are reshaping these once vibrant and thriving ecosystems. In some marine areas, species are being replaced entirely by unknown inhabitants that are triggering fundamental changes to the surrounding environment.

A new study published in Science found that the richness of biodiversity is not changing in many local ecosystems. Rather, it’s the actual species that inhabit these local areas that are changing. Using BioTime, an open access database that “quantifies biodiversity change in nearly 400 ecosystems from around the world”, the authors drew on 239 studies addressing 50,000 biodiversity time series. In other words, they studied information that traces the types of species inhabiting specific ecosystems and their abundance within these areas over varying periods of time.

The survey found that over a quarter of all plant and animal species living in surveyed ecosystems have been replaced by another species every decade. In an interview with the Washington Post, the study’s co-author (macroecologist Maria Azeredo de Dornelas) compared these changes to musical chairs, where wildlife shuffle around before some eventually lose their chair. While changes have been observed in land-based ecosystems, ocean ecosystems have been hit the hardest, especially reefs.

So, what’s causing this metamorphosis?

In addition to human activity, reorganization is likely the result of:

– Species extinction at the local level
– Climate change
– Migration caused by climate change
– Intensity of land use

How will this impact humans?

Biodiversity freely provides natural benefits to humans. Referred to as ECOSYSTEM SERVICES, these naturally occurring systems provide basic human necessities, such as clean water and air along with rich soil that nourishes our food crops. They also enhance our quality of life and wellbeing. We rely on thousands of species for food, medicine, clothing and building materials. Changes occurring in ecosystems threaten their ability to provide for us and for the species that inhabit them.

Conserving Local Ecosystems

The good news is that these findings, while alarming, can help inform local conservation efforts. When studying biodiversity in ecosystems, focus is often placed on population levels. What the study reveals is the importance of looking at what type of species are vanishing from ecosystems, what new species are inhabiting them, and how these changes impact the health and function of the ecosystem. As the study identified ‘hotspots’ for biodiversity change based on a set of criteria, conservation scientists can prioritize local areas and determine whether they are in need of restoration (reactive) or protection (proactive). For example, the study points out that many forest biomes are experiencing slower reorganization rates. Therefore, protective measures such as shielding them from human disturbances, is more appropriate. However, once major reorganizations have occurred, it’s incredibly difficult to return an ecosystem to its previous state. Therefore, ‘reactive’ conservation efforts may be necessary.