Road salt is retained in the soils along roadways over time, and can cause them to become compact and unstable. According to the Salt Institute, high concentrations of chloride can interfere with a plants absorption of moisture from the soil and cause browning or burning of leaves. It can cause severe root, shoot and leaf damage and affect reproduction. The composition of plant communities is changed as salt intolerant species (such as the sugar maple) are edged out and replaced with salt tolerant ones. Car collisions can increase as moose, deer and other wildlife are attracted to roadsides turned into artificial salt licks by the presence of road salt. Birds may ingest salt, mistaking it for grit, and this can be lethal.