Interactive effects of canopy-driven changes in light, scour and water flow on microscopic recruits in kelp

Masayuki Tatsumi; Cayne Layton; Matthew J Cameron; Victor Shelamoff; Craig R Johnson; Jeffrey T Wright

doi:10.1016/j.marenvres.2021.105450

Interactive effects of canopy-driven changes in light, scour and water flow on microscopic recruits in kelp

Mar Environ Res. 2021 Oct:171:105450. doi: 10.1016/j.marenvres.2021.105450. Epub 2021 Aug 28.

Authors

Masayuki Tatsumi¹, Cayne Layton², Matthew J Cameron³, Victor Shelamoff⁴, Craig R Johnson⁵, Jeffrey T Wright⁶

Affiliations

¹ Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia. Electronic address: Masayuki.Tatsumi@utas.edu.au.
² Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia. Electronic address: Cayne.Layton@utas.edu.au.
³ Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia.
⁴ Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia. Electronic address: Victor.Shelamoff@utas.edu.au.
⁵ Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia. Electronic address: Craig.Johnson@utas.edu.au.
⁶ Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia. Electronic address: Jeffrey.Wright@utas.edu.au.

PMID: 34543878
DOI: 10.1016/j.marenvres.2021.105450

Abstract

Ecosystem engineering kelp forms habitat and influences associated communities by altering abiotic conditions. These conditions can also affect the engineer's own demographic rates but the mechanisms underpinning these feedbacks are not well known. Here, we tested the interactive effects of three abiotic factors engineered by the Australasian kelp Ecklonia radiata (light, water flow and scour) on the early survivorship and growth of its outplanted microscopic recruits. After six weeks, recruit survivorship was high in the absence of scour and low light (2-3 times higher than when scour was present) and under low water flow-ambient light conditions. Growth of sporophytes was strongly related to light, with recruits under ambient light approximately four times larger after six weeks. Overall, reduced scour (for survivorship) and ambient light (for growth) appear crucial for maximising E. radiata recruitment suggesting a healthy forest can provide microenvironments to enhance survivorship while gaps in the canopy enhance growth.

Keywords: Ecklonia radiata; Ecosystem engineering; Feedback; Kelp; Positive; Recruitment.

MeSH terms

Ecosystem
Forests
Kelp*
Phaeophyceae*
Water

Substances

Water