Succession

Sitting at my desk, I could hear footsteps behind me. Someone was coming down the hall toward my desk, probably just one of the undergrads using our lab. I ignored it at first, but the footsteps kept coming, encroaching on my workspace. Then all of a sudden, they stopped. I turned around. There stood my adviser, Craig, wearing a damp rain jacket and holding two ancient-looking books. 

"Do you recognize this?" He handed me one of the volumes. 

I checked the spine. Bio-Ecology by Clements and Shelford, published in 1939. "Clements is one of the names you told me to look up," I told him. 

Craig nodded. "Shelford was the other." 

Reading material, Young lab style.

I've been thinking a lot about succession in marine hard-bottom communities lately, so Craig has been giving me reading material. In case you don't know, succession is the process by which groups of organisms sequentially replace one other as a community develops. At first, you typically have fast-growing, fast-reproducing species, but as they die out, they're replaced by long-lived, slow-growing species. The process has been documented in a wide range of habitats - forests, mountainsides, fouling communities on docks. 

Succession, like most ecological concepts, also shows up in the older literature. Actually, one of the classic examples comes from my home state, Michigan. Sand dunes on a lake shore undergo succession from dune grass to meadow to coniferous forest, each stage stabilizing the ground so the next suite of plants can colonize. The modern distribution of these plants reflects their successional origins. Forests, located largely inland, stand on the oldest ground, while sand dunes are the youngest ground closest to the lake shore. 

I'm continually amazed at how much information can be harvested from older literature. Especially when your Ph.D. supervisor is a science history buff, you become acutely aware of the greats who have come before. Sars, Forbes, Agassiz, Thompson - all natural historians, explorers, and ecological thinkers - and, apparently, Clements and Shelford.