Biology subjects

Stanton, D.

Publications and source records attributed to Stanton, D..

3 recordsLinked to original sources

bioRxiv2026

Moving to the city changed you! Rapid photobiont turnover enables acclimation of lichen symbioses to urban environments

Symbioses are widespread and highly successful but vulnerable to the stress sensitivity of either symbiont. In some symbioses, turnover of symbionts has been shown to confer resilience to stressors. While similar mechanisms have been proposed for lichen symbioses, direct evidence for rapid adaptive symbiont turnover has not been shown. We tested the photobiont community composition and physiological responses of the foliose lichen symbiosis Flavoparmelia caperata-Trebouxia to urbanization-induced stress in a transplant experiment. We found evidence for significant compositional change in the photobiont community along an urbanization gradient (measured as vegetation cover), reflecting a turnover in dominance of Trebouxia OTUs from A46 to I05 in more urbanized transplant sites. This change in symbiont composition is associated with a greater physiological tolerance for urbanization, consistent with the hypothesized adaptive role of photobiont turnover. These findings support rapid photobiont turnover as a potential adaptive response to environmental change in lichen symbioses.

ecology↗

bioRxiv2023

Can biocrust moss hide from climate change? Multiscale habitat buffering improves summer-stress resistance in Syntrichia caninervis

PremiseMosses provide many ecosystem functions and are the most vulnerable of biocrust organisms to climate change due to their sensitive water relations stressed by summer aridity. Given their small size, moss stress resistance may be more dependent on fine-scale habitat than macroscale (climate and community), but this sheltering role of habitat (i.e. habitat buffering) has never been compared to macroclimate and may have important implications for predicting critical biocrust refugia in changing climates. MethodsWe located three populations of a keystone biocrust moss, Syntrichia caninervis, spanning 1200-m of altitude comprising three plant communities (elevation-plant zones) in the Mojave Desert. We stratified 96 microsites along three habitat aridity gradients: elevation-zone, topography (aspect), and microhabitat (shrub proximity). We estimated summer photosynthetic stress (Fv/Fm) and aridity exposure (macroclimate, irradiance, and shade). ResultsMicrosite aridity exposure varied greatly revealing exposed and buffered microhabitats in all elevation-zones. Moss stress did not differ by elevation zone despite the extensive macroclimate gradient, failing to support the high-elevation refugia hypothesis. Instead, stress was lowest on N-facing slopes and microhabitats with higher shrub shading, while the importance of (and interactions between) topography, irradiance, and shade varied by elevation zone. ConclusionsWe demonstrate fine-scale habitat buffering is physiologically more protective than high-elevation climate, and thus, may allow some mosses to hide from the brunt of climate change in widespread microrefugia throughout their current ranges. Our findings support a scale-focused vulnerability paradigm: microrefugia may be more important than macrorefugia for bolstering biocrust moss resistance to summer climate stress.

plant biology↗

bioRxiv2019

Transmission bias's fundamental role in biodiversity change

There is a great need to understand how and why biodiversity, which we define as the variety of organisms found in a given place, changes over time. Current estimates suggest strikingly slow change in traditional measures of biodiversity. These estimates seem to contradict rapid shifts in the abundance of individual species and have led to a rethinking of the mechanisms shaping biodiversity. Conceptual models emphasize the role of competition among species or, more recently, selection on species identity (i.e. selection that favors some species at the expense of others). However, it is difficult to quantify how these mechanisms contribute to biodiversity change. To illustrate this point we present cases where strong competition or selection on species identity leads to no biodiversity change. In view of this disconnect we develop a new approach to studying biodiversity change using the Price equation. We show that biodiversity change responds to selection on species rarity, rather than to either competition or selection on species identity. We then show how this insight can be used to quantify the effects of the mechanisms previously thought to influence biodiversity: 1) selection, 2) (ecological) drift, 3) immigration and 4) speciation. Our results suggest the connection between species fates and their rarity is fundamental to understanding biodiversity change.

ecology↗