Initial soil amendments still affect plant community composition after nine years in succession on a heavy metal contaminated mountainside

Abstract

Many efforts to restore disturbed landscapes seek to meet ecological goals over timescales from decades to centuries. It is thus crucial to know how different actions available to restoration practitioners may affect ecosystems in the long term, yet few such data exist. Here, we test the effects of seed and compost applications on plant community composition 9 years after their application, by taking advantage of a well‐controlled restoration experiment on a mountainside severely degraded by over 80 years of zinc smelting emissions. We asked whether plots have converged on similar plant communities regardless of initial seed and compost treatments, or if these initial treatments have given rise to lasting differences in whole plant communities or in the richness and abundance of native, exotic, and planted species. We found that compost types significantly affected plant communities 9 years later, but seed mix species composition did not. Observed differences in species richness and vegetative cover were negatively correlated, and both were related to the differences in plant communities associated with different compost types. These observed differences are due primarily to the number and abundance of species not in original seed mixes, of which notably many are native. Our results underscore the importance of soils in shaping the aboveground composition of ecosystems. Differences in soil characteristics can affect plant diversity and cover, which are both common restoration targets. Even in highly polluted and devegetated sites, compost and seed application can reinstate high vegetative cover and allow continued colonization of native species.

Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils

“…Therefore, manipulating AMF colonization is not likely to affect plant metal uptake under field conditions. Land managers seeking to modulate a plant community's metal uptake may be better served by seeding desired plant species or using soil amendments such as compost, fertilizer, or lime, to alter soil chemistry and/or plant community composition (Dietterich and Casper 2016). We also highlight that, in light of the high local variability of soil chemistry and its close association with plant species identity, the particular plant species growing in a patch of soil could provide significant information about the chemical composition of that soil.…”

Framework for assessment and phytoremediation of asbestos-contaminated sites

“…Similarly to solutions already used in other Superfund sites contaminated with Pb or Zn, we propose to place soil amendments on top of the soil up to 5 cm thick and use cultivated plant crop cultivars (Dietterich and Casper 2016; Brown and Chaney 2016) or serpentinophytes. This solution seems economically more realizable than capping up to two meters of non-contaminated soils and with placement of a water permeable barrier below the 2 meters of soil.…”

Soil amendment interacts with invasive grass and drought to uniquely influence aboveground versus belowground biomass in aridland restoration

“…As climate conditions in the arid and semiarid western United States are predicted to become more variable (Archer & Predick ) and invasive species will continue to hinder successful revegetation efforts (Brown et al ), soil amendments such as SAP that can interact with environmental variables and can have long‐term effects on the trajectories of restored plant communities (e.g. Paschke et al ; Dietterich & Casper ) should be used with caution. As in other studies (Johnston & Garbowski ) SAP benefited both seeded species and B. tectorum .…”