Phenology and light pollution (part 1)

We've heard about the Urban Heat Island effect before where plant phenology is affected by increased temperatures around urban areas. But, different species' phenologies are affected by many factors other than temperature. In this post and the next one I'll look at how light pollution can affect phenologies (Fig. 1).

Fig. 1 From Light Cities: Sea Level by David Stephenson (2012)

Birds
Light pollution can affect bird migration, but can't really affect the timing (phenology). Interestingly, some migratory birds are guided by stars in the night sky, and light pollution confuses them on their way and they can collide into each other and die (Longcore and Rich, 2004; Poot et al., 2008)!

Zooplankton
Aquatic invertebrates move up and down the water column in response to changing light conditions over 24 hours, something called "diel vertical migration" (Gliwicz 1986; cited in Longcore and Rich, 2004). Daphnia is an aquatic invertebrate (Fig. 2). Moore et al. (2000 cited in Longcore and Rich, 2004) found that the range of its diel vertical migration is affected by artifical light sources.

from http://www.micromagus.net/microscopes/pondlife_cladocera.html

More next time...