Introduction

People, governments, and organizations worldwide are increasingly realizing ecosystems’ importance for survival. Many organizations and governments are now undertaking ecosystem restoration projects in various habitats and spatial scales. Current ecosystem restoration projects range from extensive watershed-scale activities like the one at the Chesapeake Bay and mangrove forests in Andhra Pradesh to smaller restoration efforts in many different countries.

The United Nations Environmental Program estimates that we’ve destroyed around a third of the planet’s ecosystems. International and community organizations have begun to take notice of the economic and social benefits of restoring degraded ecosystems. And with climate change accelerating, it is crucial for us to anticipate how our ecosystems will change in the future.

Ecologists and scientists have long realized that understanding an ecosystem’s pre-historic conditions and how those conditions varied through time is vital to developing a framework of goals for its restoration. However, most historical observations of ecosystems are often limited to a single snapshot of the conditions that existed in that ecosystem before a specific disturbance (for example, an earthquake).

This is where paleoecology comes in. An ecosystem is a dynamic network of physical and biological components. These components change over a variety of time scales. Paleoecology helps us identify exactly how and by how much ecosystems have changed throughout these time scales.

What Is Paleoecology and Why Is It Important?

Before we learn about paleoecology, let’s first understand the meaning of ‘ecology’. Ecology refers to a branch of biology dealing with the relationships between different organisms. It also refers to the relationship between an organism and its physical surroundings.

The prefix ‘paleo’ means old or ancient. Therefore, paleoecology means the study of ancient organisms and their relationships with their environment and each other. Tree rings, corals, and fossil assemblages are examples of the mediums through which scientists study paleoecology. These life forms help us understand an ecosystem’s long-term patterns and responses to change. Understanding how an ecosystem adapts to changes in conditions is vital for its effective management and restoration.

How an ecosystem adapted to changing conditions in the past is also a crucial piece of information for decision-makers. Decision-makers and world leaders can use this data to develop measures against and anticipate an ecosystem’s future responses to anthropogenic changes over this and the next century. Only with this type of long-term perspective can leaders make decisions and develop policies that promote ecosystem restoration and management.

We’re already expecting a rise in sea levels and extreme changes in the Earth’s climate patterns. These effects of global warming are urging governments to look beyond short-term time scales.

The Application of Paleoecology in Restoration and Resource Management

Scientists first started paying attention to paleoecology as a solution to degraded ecosystems during the 1990s, when the world first started feeling the impacts of global warming. Since the 1990s, scientists have recorded and observed how ecosystems responded to anthropogenic disturbances well beyond those time scales. We’ll look at a few examples of how paleoecology provided scientists insights into the resilience of species and systems.

1. Forests

Ecosystem restoration and management of forests are particularly difficult. This is due to the longevity of trees and the extremely long time scales over which they develop. A 2015 study examined pollen and charcoal in sediment cores in a forest in Malaysian Borneo tropical peat swamp forests. The study found that the forest remained stable for over 2000 years. This was even despite climate changes, episodic fires, and El Nino events. However, the study also found that in the last 500 years of the forest’s history, wildfires caused by human disturbances exceeded all previous levels. It altered and caused a decline in the forest’s communities.

2. Freshwater Lakes

Lakes are catchment basins. They preserve a fascinating record of natural and anthropogenic changes in their sediments. In 1998, scientists used diatoms from sediment cores to investigate the impacts of industrial pollution on a subalpine lake in Italy. They managed to reconstruct changes in the lake as far back as four centuries. They found that, around the 20^th century, the lake showed signs of copper contamination, acidification, and nitrification. From their studies, they also detected a few periods of improvements in water quality. These periods were associated with advancements in water treatment facilities, reduced industrial runoff into the lake, and additions of lime to counter the acid.

3. Rivers, Wetlands, and Tidal Marshes

Paleoecological studies on wetlands can help us determine the timing and impact of a changing river course, flooding, etc. It can also help us predict how wetlands are going to respond to climate change in the near future.

In 2010, scientists discovered four periods of plant succession in a wetland on the banks of the St. Lawrence River, USA. They were also able to determine that the cattail plant currently dominated the wetland due to agricultural disturbances that occurred in the 1800s.

In 2013, researchers found that gravel mining altered erosion rates in a tidal marsh along the Potomac River, Virginia, USA. Their paleontological study and analyses provided the US National Park Service with invaluable information on how to restore the marsh best.

4. Estuaries and Coastal Zones

39% of the global population lives within 10 km of the world’s coasts. With sea levels expected to rise over this and the next century, paleoecological information on coastal areas becomes essential.

A 2007 study on diatoms in sediment cores in the Gulf of Finland demonstrated the magnitude of eutrophication over the last two centuries. The cores also revealed the impact eutrophication had on the composition and biodiversity of species in the Gulf. However, the study demonstrated that biota at some sites responded amazingly well to a decrease in wastewater discharge. Such information can guide environmental policies in the EU.

Conclusion

Given the uncertain future of the Earth and all its creatures, it is worthwhile to use all our resources to understand the best way we can predict and stop disastrous changes to the environment. Paleoecology proves to be the most invaluable among all these resources. Using information about how our ecosystems responded to climatic disturbances in the past, our leaders can improve restoration and management efforts today. Additionally, we must ensure that even if some ecosystems collapse, other functioning ones can remain and build on.

Also Read: The Magic of Biomes: Exploring Earth’s Diversity