Our Natural Heritage

Dr. Scot Duncan On Alabama's Amazing Biodiversity

If you surveyed people around the country and asked them what comes to mind when they think of Alabama, you would probably get a lot of unflattering answers about our state. To many, we are emblematic of the South’s worst stereotypes. Oftentimes our state finds itself near the bottom of national lists with regards to matters like education and healthcare. You might not know that Alabama ranks top on one very important list, relevant to everything from economic well-being to the sustained existence of humans. That list is biodiversity.

Dr. Scot Duncan, head of Birmingham-Southern's biology department, is not just a familiar face around campus but also an ecologist, conservation scientist, and author. In 2013, he published the book Southern Wonder: Alabama’s Surprising Biodiversity. Intended as a guide for the general public, the book addresses our state’s great biodiversity, why we have it, and why it is important.

In order to answer these questions, we must first understand the meaning of biodiversity.  Dr. Duncan explains that it could refer to the number of different types of ecosystems in a region or the distribution of genes in an area. However, Dr. Duncan believes that the term is mostly used to refer to the diversity of species. In Alabama, we rank #5 in the country and #1 east of the Mississippi for species biodiversity. What is especially noteworthy is the biodiversity of our rivers and streams.

Photo via Dr. Scot Duncan

Photo via Dr. Scot Duncan

“If you look at particular groups of species, Alabama isn’t just in first place; it's a global hotspot for biodiversity,” Duncan said. “We are the global hotspot for freshwater fishes in the temperate zone, [and] we're the global hotspot with no qualifiers for freshwater snails, freshwater mussels, crayfish, and freshwater turtles.”

Historically, Alabama ranks #2 in terms of total number of extinct species. The two main threats to our biodiversity are dams and sediment pollution. As many ecologists will tell you, a dam’s destructiveness comes from the barriers it creates. These artificial structures prevent animals from migrating, mating, and doing anything else that requires geographical movement.

“[The dams’] effect on river and stream ecosystems is devastating. They’re the biggest threat to our diversity of aquatic species,” Duncan said. “[However] dams have done things like economic development, hydropower, flood control, and river navigation.”

While dams impede natural movement, sediment pollution degrades animals’ habitats. If left unregulated, these processes would decimate our aquatic biodiversity.

“Every time it rains, silt, clay, and sand from farmland, construction sites, and even urban areas wind up washing into our rivers and streams," Duncan said. “Because they block light as they float downstream, they cut off the supply of sunlight to the algae that are growing on the bottom of the stream and make it difficult for organisms to find each other for food and mating purposes.”

Despite all there is to say about biodiversity, it still seems difficult to connect with people enough to get them to care. After all, change only occurs when people and governments want it to happen. Dr. Duncan thinks this problem can be answered in two ways.

For many people, including myself, we feel that it’s a moral obligation to share this planet with other species; this is their home just as much as it is for us," Duncan said. We've [also] got a strong body of evidence illustrating the connection between biodiversity levels in our ecosystems and how well those ecosystems provide what are called ecological services for us.”

He further explained that ecological services include clean water and air, good soil to raise crops with, and natural materials like fibers and fuels to harvest. This is important to us, as humans, because Duncan believes that our economy would crumble if our ecosystems stopped providing these ecological services on which we depend. To get this message out to the public, Dr. Duncan wrote Southern Wonder. His journey of writing started with the classes he taught at BSC.

“I started to weave Alabama’s biodiversity into my courses, [and] it involved me reading a lot of different books and talking to a lot of different experts about why we have so much biodiversity in this state," Duncan said. "There was no one source that could pull it all together.”

On his first sabbatical, he set out to be that one source, and the message ended up being a lot larger than he had initially thought.

“The more I learned, the more I realized that people needed a chapter about each of the different sections of the state, a chapter about rivers, a chapter about evolution, a chapter about geology, and so forth," Duncan said. "I wrote it for people with a high school education or better to have a reference they could go to that introduces them to what a great state this is in terms of biodiversity and why that’s important."

Dr. Duncan's effort to make people aware of our state’s treasures never really ends. On October 11th, he published an article on Al.com with James McClintock and E.O. Wilson, two prominent figures in popular science. The topic was Amendment 2, a funding measure for our state parks that will be on the upcoming election ballot. Among southern states, Alabama ranks last in number of state parks, and without this kind of lasting support and preservation, our biodiversity would be lost.

Feature photo via Dr. Scot Duncan