CPNS2018-1/28: The ALAN phenomenon in the broader frame of urban evolutionary ecology�

A. Gini (1,2), M. A. L. Zuffi (2)

(1) Via A. Gramsci 191, 55100 Lucca (Lucca), Italy – andreaeugenio.gini@gmail.com

(2) Museo di Storia Naturale, Università di Pisa, via Roma 79, 56011 Calci (Pisa) – Italy – marco.zuffi@unipi.it


Artificial light at night (ALAN) is a threat to ecosystem, which due to
urbanization it is increasing globally. This review is part of a wider
project proposal of evolutionary ecology in urban and peri-urban
populations of the Italian fauna. Here we provide an overview of
the effects of light pollution on a plethora of organisms, as well as
of ecosystem functions. Cloud cover can increase the area where
light irradiance arrives, potentially affecting peri-urban habitats
like wetlands. Polluted aerosols and the different thermal regimes
of cities can increase the phenomenon of cloud cover, directly
amplifying ALAN.
Light alters both physiology functions like metabolism, circadian
rhythms and behaviours like activity and interactions. This
alteration in a wetland area can potentially affect the entire
ecology of zooplankton, aquatic insects, urodeles, and anurans.
Another common effect of ALAN is the attraction of nocturnal
insects, especially moths. They can provide a window to small-
scale evolutionary and trophic alteration studies, because they
affect the diet of their predators and the delicate equilibrium of
the ecosystem. Lastly, an augmented presence of light can alter
the effects of communication signals, or create new ones. Visual
communication mediated by colours, shapes, and signals is very
common between animals, especially for courtship. Light can
dimmer the contrast between the environment and an organism,
blinding the communication, but can also exacerbate a shape or a
reflectance colour in camouflaged animals.
All of these phenomena participate with many others in the
differentiation of the urban environment, and they are all necessary
to enlighten how the evolution acts in their ecology.

KEYWORDS: ALAN, urban ecology, evolution, natural selection, adaptation,

Men at work on CPNS2018 presentations on the ferry