Vertical growth of the invasive fern Lygodium microphyllum: A potential productivity - reproduction tradeoff

Authors: Aquino-Thomas, Jessene; DAVID, AARON - Archbold Biological Station; LAKE, ELLEN - Mt Cuba Center; Dray Jr, Forrest; Carmona Cortes, Andrea; Smith, Melissa

Submitted to: American Fern Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2024
Publication Date: 3/4/2025
Citation: Aquino-Thomas, J.M., David, A.S., Lake, E.C., Dray Jr, F.A., Carmona Cortes, A., Smith, M. 2025. Vertical growth of the invasive fern Lygodium microphyllum: A potential productivity - reproduction tradeoff. American Fern Journal. https://doi.org/10.1640/0002-8444-115.1.1.
DOI: https://doi.org/10.1640/0002-8444-115.1.1

Interpretive Summary: Old World climbing fern, Lygodium microphyllum is widely invasive in natural areas and impacts much of South Florida. The fern has several attributes that contribute to it being so invasive, its fast growth rate and large reproductive output are high on the list. We conducted a field study to determine the vertical distribution of the biological control agent, Floracarus (F) perrepae, fertile fronds, and to evaluate the potential productivity - reproduction tradeoff in L. microphyllum. Reproduction and biological control agent activity were found on different vertical positions on the plant, with galls formed by F. perrepae at the bottom of the trellises and fertile fronds at the top of the trellises. We found the higher proportion of fertile fronds the less biomass. Moreover, damage from biological control agents can cause the host plant to reinvest energy from biomass production towards reproduction.

Technical Abstract: Old World climbing fern, Lygodium microphyllum (Cav.) R. Br. (Schizeales: Lygodiaceae) invades and negatively impacts natural areas throughout south Florida. Its invasiveness is attributed, in part, to its fast growth rate that allows it to climb rapidly on neighboring vegetation and large reproductive output via aerially distributed, self-compatible spores which are borne on modified leaves or fertile fronds. We conducted a field study to determine the within-plant distribution of the biological control agent, Floracarus perrepae Knihinicki & Boczek (Acariformes: Eriophyidae), the vertical distributions of sterile and fertile fronds, and to evaluate the potential productivity - reproduction tradeoff in L. microphyllum. The 3-m vertical trellises were spatially segregated with galls formed by Floracarus (F.) perrepae at the bottom of the trellises and reproduction (i.e., the development of fertile fronds) at the top of the trellises. Our findings suggest a productivity-reproduction tradeoff exists, particularly at high levels of productivity/biomass.