Plant invasions from a belowground nematocentric perspective

Chemical, biological and mechanical control methods are helpful in restricting the progress of invasive plants, but they may lack the full potential for the long-term goal of habitat management and restoration. Interactions and feedbacks between plant and soil microbiota represent potentially important factors regulating and facilitating the invasion process. ee Melaleuca quinquenervia, a native of Australia, invades all types of habitats in South Florida. Thus far, the invasion has converted >200,000 ha of South Florida ecosystems to closed-canopy M. quinquenervia forests with 60–80% loss of native biodiversity. The shrub Baccharis halimifolia, a native to South Florida, is spreading in coastal Australia. mined the impact of plant–soil biota feedbacks set in motion by the exotic plants in 2 × 2 factorial (species × location) field and microcosm experiments both within the invasive as well as natural range of both plant species using a metagenetic nematocentric approach. The results were inconsistent and did not lend themselves to simple generalizations as responses of nematode community composition patterns were specific to plant species, locations, years, and even to experimental conditions. For instance, greater diversity of plant-parasitic nematodes was confirmed for both plant species in their native ranges, but only in the field surveys (not microcosms) and only in the first year of sampling (not the second). Equally importantly, the specificity was only observed at the “near species” level allowed by the metagenetic approach and as the identification of nematodes became less resolved, i.e., as identification moved from the “near species”-level to coarser levels of taxonomic resolution, the specific responses generally diminished.