Land use change and climate change are major threats to biodiversity, and understanding these threats is nowhere as important as in the Afrotropics, one of the world's biogeographical realms, which includes the African continent and the southern Arabian Peninsula, according to Sarah Ivory, associate professor in the Department of Geosciences at Penn State.
An international team of researchers, including Ivory, was recently awarded a six-year, $13.88 million grant from the European Research Council (ERC) to investigate how human activities, climate and wildfire have shaped landscapes and biodiversity across Africa and Arabia over the past six thousand years.
The project, Ecological Archaeologies of the Afrotropics or EcoArch, brings together researchers with expertise in archaeology, paleoecology, evolutionary ecology and land-cover modeling to synergistically address fundamental questions about the relationship between humans and the environment over time by documenting landscape changes in the Afrotropics over the last 6,000 years.
"Ecosystems as we see them today are the sum of lots of climatic and biological influences that have played out over thousands of years," said Ivory, also a faculty affiliate in Penn State's Alliance for Education, Science, Engineering, and Design with Africa (AESEDA), Earth and Environmental Systems Institute (EESI), and Institute of Energy and the Environment (IEE). "In particular, in Africa, humans have been a big part of that for longer than anywhere else on Earth. Our project brings together this interdisciplinary team that is really needed to truly capture all of those dimensions and figure out the most important levers of change."
The project is funded by ERC's Synergy grant program, which funds small groups of two to four principal investigators to jointly address ambitious research problems that enable substantial advances at the frontiers of knowledge with the potential of becoming a benchmark on a global scale. Other investigators include project lead David Wright and Sanne Boessenkool, both professors at the University of Oslo in Norway, and Sandra Harrison, professor at the University of Reading in the United Kingdom.
"Our research focuses on a diverse range of African and Arabian ecosystems to understand human-climate interactions from the region with the longest history of humanity on the planet," Wright said. "We will be using and developing new approaches with stable isotopes, biomarkers and ancient sedimentary DNA as well as applying artificial intelligence tools to identify pollen from lake cores we collect. We will also be using state-of-the-art climate and fire models to understand what's going on at local, regional and continental scales."
The African and Arabian tropical region today is home to nearly one billion people and is facing some of the most severe impacts of global climate change. Yet scientists currently lack detailed, observationally constrained data on how past environmental changes occurred, what drove them and how they may affect people's livelihoods in coming decades, according to the researchers.
EcoArch aims to fill this gap by generating high-resolution reconstructions of land cover and climate, which will improve the accuracy of computer simulations used to predict future climate scenarios.
"This project has the potential to really change the way that scientists studying the past do business," Ivory said. "For example, we know that ancient data is extremely important for understanding future change, but it is currently very time intensive to produce and, thus, what we have is really patchy. This project will provide resources to Penn State to develop a network of scientists working throughout Africa to produce high volumes of data that were not possible before."
New techniques and automated approaches to data analysis, coupled with major advances in the ability to model key aspects of the terrestrial biosphere, provide unprecedented opportunities to document changes in natural ecosystems and anthropogenic land use in the past, specifically since 6,000 years ago following the introduction and spread of agriculture across the Afrotropics, according to the researchers.
"Our ability to predict the future of ecosystems and biodiversity is specifically hampered by the lack of understanding of the complex interactions among climate, vegetation and wildfires and of the relative influence of human activities," Ivory said. "Human interactions with landscapes aren't always negative, and people all over the world have managed healthy landscapes for thousands of years. However, until this project is done, we don't really understand these roles or even potentially how anthropogenic changes to landscapes play a role in changing regional or global climates."
Ivory will receive $3.1 million to fund her team's contributions, and part of her focus will be to build large datasets of fossil pollen from environments all over Africa. Her team will conduct fieldwork in Cameroon, Uganda, Malawi, Senegal and Oman as well as collaborate with a new network of African scientists working throughout the continent. They will automate pollen identification to generate large volumes of data to create a high-resolution picture of vegetation change in Africa over the past six millennia.
