5. Below-ground traits

Variation in root traits among species has large ramifications for their ecology. Fine roots are the primary organs for water and nutrient acquisition and they are also responsible for transferring resources between below-ground and above-ground parts. Fine roots can acquire resources directly or through symbionts. When accessing soil resources directly, fine roots selectively acquire mineral nutrients from a complex range of soil solutions and soil particles, while modifying soil chemistry via exudation of a range of compounds. Roots also must respond to heterogeneity of resource availability at multiple spatial and temporal scales, while resisting attacks from a wide range of organisms and environmental stresses.

There is no single evolutionary solution to all the variable challenges of acquiring soil resources in different ecosystems. Measuring several independent root traits in combination may help better understand the below-ground strategies of multiple species. Here, we describe three main sets of traits.