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An ecological niche model based on a broad calcium-gradient reveals additional habitat preferences of the invasive charophyte Nitellopsis obtusa.

Authors :
Harrow-Lyle, Tyler J.
Kirkwood, Andrea E.
Source :
Aquatic Botany. Jun2021, Vol. 172, pN.PAG-N.PAG. 1p.
Publication Year :
2021

Abstract

• Nitellopsis obtusa was documented at 19 of the 60 lakes surveyed. • Shallow sites, that were closer to boat launches had higher densities of N. obtusa. • Cations other than calcium have a strong influence on N. obtusa distribution. Nitellopsis obtusa (also known as Starry Stonewort) is a Eurasian charophyte first introduced into the Laurentian Great Lakes in the 1970s. Over the last decade, there have been increasing reports of N. obtusa invasion of inland lakes in the Great Lakes basin. To improve our understanding of N. obtusa 's habitat preferences, we sampled 60 lakes across a geological transition zone in Ontario, Canada. Targeting this geological transition zone allowed us to study an array of lakes representing broad nutrient and water-hardness gradients within the same geographic and climatic region. Calcium is an important macronutrient for N. obtusa , thus it was anticipated that the presence of N. obtusa would respond strongly to calcium availability. Nitellopsis obtusa was documented at 37 sites in 19 of the 60 lakes surveyed. Lakes with N. obtusa had significantly higher cation (calcium, potassium, sodium, and magnesium) concentrations than lakes without N. obtusa (general linear mixed model with binomial error, p < 0.05). An ecological niche model based on a boosted regression tree (BRT) identified habitat features most associated with N. obtusa occurrence. Interestingly, the BRT model demonstrated that depth and the cations potassium, magnesium, and sodium were better predictors of N. obtusa presence than calcium. Although N. obtusa was found within a constrained range of calcium (15 – 57.9 mg L−1 Ca), it appears that other environmental parameters have a stronger influence on N. obtusa distribution in Ontario lakes. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03043770
Volume :
172
Database :
Academic Search Index
Journal :
Aquatic Botany
Publication Type :
Academic Journal
Accession number :
150465584
Full Text :
https://doi.org/10.1016/j.aquabot.2021.103397