Meeting Abstract

S9.1-1  Tuesday, Jan. 7 08:00  The micro and macro of nutrients across biological scales WARNE, Robin; Southern Illinois University rwarne@siu.edu

There is a great breadth of research exploring the importance of micro- and macronutrients in physiology, ecology and evolution. Here I provide a synthesis that details the integrated roles and profound affects that limiting nutrients have across biological scales. Our understanding of the biological impacts of macronutrients (protein, lipids and carbohydrates) have been greatly advanced by theories such as ecological stoichiometry and state based models like the Geometric Framework of Raubenheimer and Simpson, as well as empirically by the advent of stable isotope and genomic techniques. It is becoming clear however, that not all nutrients are created equal from a biochemical perspective. Certain classes of nutrients despite their bulk elemental content have a disproportionate effect on organismal function and ultimately influence ecological processes. While it’s clear that micronutrients like highly unsaturated fatty acids (HUFAs) and indispensable amino acids (IAA) influence organismal performance, we do not have a strong understanding of their potential cascading effects on population, community or ecosystem dynamics. Recent work suggests that because the de novo synthesis of HUFAs is largely restricted to aquatic primary producers (e.g. algae, diatoms), most metazoans cannot synthesize these key nutrients, both aquatic and terrestrial consumers assimilate and sequester dietary HUFAs at rates twice that of bulk carbon and nitrogen or other measures of macronutrient flow. Deficiencies in IAA availability are also common and co-limitation with other micronutrients including HUFAs, carotenoids, sterols and limiting salts may alter population and community dynamics. These findings suggest that micronutrients may be significant drivers of ecological feedbacks, perhaps acting as keystone nutrients that could influence ecosystem structure and function.