In today’s Academic Minute, Dr. Daniel Kissling or Aarhus University explains what the number and type of palm species in tropical forests reveal about the climate of the deep past.
Daniel Kissling is a research scientist in the Ecoinformatics and Biodiversity Research Group at Aarhus University in Aarhus, Denmark. With a focus on quantitative biodiversity, his work relies on recent advances in computing, numerical databasing, Geographic Information Systems, and environmental modeling to better understand the broad-scale distribution of life on Earth. He holds a Ph.D. from the University of Mainz.
Dr. Daniel Kissling – Palm Trees and Climate History
Imagine you are in the middle of a tropical rainforest in Amazonia. You feel the hot and humid air, and you see the tall trees and the dense leaves in the understory. Such a warm and wet environment is not only found in South America, but also in Africa and Southeast Asia. However, the rainforests on these continents have very different kinds of plants and animals.
Our new research has revealed that the species composition in rainforests is strongly formed by climate change over millions of years. We focused our research on palms, a group of tropical plants that is almost 100 million years old. Most people know the coconut palm, but actually there are more than 2400 species of palms in the world. How many and what kind of palm species you will find in a rainforest differs dramatically between South America, Africa and Southeast Asia.
By studying palms, we found that tropical rainforests in South America are particularly species rich, while African rainforests have only few species of palms. Furthermore, South American palm assemblages are dominated by closely related species, while African palm assemblages have a relict nature. These differences can be explained by climate change over the last 50 million years. While South America had a relatively stable humid and warm climate, Africa was hit by a severe drying. This dramatically diminished its rainforest during the last 10-30 million years, and caused extinctions of many palms on this continent.
By studying the long-term changes in tropical rainforests we can thus learn a lot about how climate change affects the living world on our planet. Such knowledge is urgently needed, because we are faced with climate change in the next century, and we need to know how this will affect biodiversity and the well-being of human societies.