Abstract:

Nutrient distribution within soils is highly spatially heterogenous, forcing plant root foraging behavior to adapt to heterogeneous soil nutrients. By adjusting root foraging scales, foraging precision and rate, plants can maximize soil nutrients. Successful invaders are heavily influenced by soil nutrients and other environmental conditions (e.g. water content, light, etc.) as successful invasion depends on the successful competitive interaction of an exotic species with a native species. In recent years, the foraging behavior of exotic invasive plants has attracted more attention, and studies are increasing worldwide. To date, foraging behavior studies have found: (1) Invasive plants have increased root foraging abilities compared to native plants, although the trade-off between foraging scale and precision are uncertain. (2) Soil nutrient heterogeneity influences the competitive outcome between invasive and native plants, as competition alters root foraging strategy. (3) Arbuscular mycorrhizal fungi (AMF) facilitate root foraging of invasive plants, and invasive plants experience positive feedbacks with invasion by altering their AMF preference. Additionally, the interaction between AMF and native plants can influence the competitive ability of invasive plants. Further studies are necessary to understand the relationship between interspecific competition and AMF on root foraging behavior of invasive plants in heterogeneous nutrient conditions. Due to global change, root foraging strategies and related mechanisms of invasive species may be altering. Increased research on root foraging behavior in successful exotic plant invasions can provide a greater understanding of these mechanisms and a theoretical basis for control and management of invasive plants through nutrient regulation.

Key words: root foraging, exotic invasive plants, soil nutrient heterogeneity, arbuscular mycorrhizal fungi, competition, root distribution