Sedum and Parnassius were collected and also analyzed for percent total nitrogen and sarmentosin levels. Although sarmentosin levels differed between sites, no correlation could be draw between sarmentosin levels in the plants and those in corresponding butterflies. A direct relationship was observed between percent total nitrogen and sarmentosin concentrations. With N fertilization, the more total percent N content, the more sarmentosin was produced for defense. Introduction Nitrogen deposition is an environmental problem occurring all around the world as a result of nitrates, ammonia, etc.
Excess nitrogen has the potential to severely alter the natural balance of an ecosystem.
As a major component of fertilizers, nitrogen used in moderation has greatly increased productivity in agriculture. However, extreme levels of nitrogen can have acute effects on an ecosystem such as changing a species abundance, altering the biomass of an ecosystem, increasing the acidity of water sources, and affecting plant competition. In fact, the annual inorganic wet deposition level along this area of Front Range is about twice the levels of the Pacific States and comparable to numerous sites in the northeastern United States. From what direction this nitrogen deposition is originating is still quite ambiguous and controversial. Two explanations have been suggested regarding the pollution source resulting in abnormally high nitrogen levels on Niwot Ridge.