A Dynamic Forest Floor

by Harrison Tasoff, UC Santa Barbara

Walk along the beach after a winter storm and you’ll see a shore littered with wracks of giant kelp, some 30 to 40 feet long — evidence of the storm’s impact on coastal kelp forests.

The kelp forest’s rugged seafloor provides ample room for communities of invertebrates and algae, which rise and fall in dominance. Photo courtesy of Bob Miller & UC Santa Barbara.

Less apparent to the casual beachgoer is what happens to the submarine forests after the storm’s fury dies down. This is precisely the topic of a new study led by Raine Detmer, a graduate student at UC Santa Barbara. She developed a mathematical model describing the effects of severe storms on kelp forest ecosystems, particularly the seafloor, or benthic, communities. The research, published in Ecology, reveals an ecosystem whose variability is key to its diversity.

Giant kelp forests are a wonder of the underwater world. They share many similarities with terrestrial forests: lush understories, diverse fauna and verdant canopies that stretch skyward toward the sunlight. However, they also have features completely foreign to any woodland. Giant kelp is among the fastest growing organisms on Earth — able to grow up to two feet per day under ideal conditions — with a lifecycle much shorter than that of any tree. Also, unlike trees, the presence of the giant algae can change rapidly: Storms can uproot entire kelp forests in February that grow back by September.

Read more here: https://www.news.ucsb.edu/2021/020182/dynamic-forest-floor

Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3304