Phytoremediation of chloride from marine dredged sediments: A new model based on a natural vegetation recolonization.

Phytoremediation is a type of bioremediation process that involves the use of plants to remove or degrade contaminants from soil, water, or air. In most of the observed phytoremediation models, plants are introduced and planted on a polluted site to take up, absorb, or transform contaminants. This study aims to explore a new mixed phytoremediation approach that involves natural recolonization of a contaminated substrate, by identifying the species growing naturally, their bioaccumulation capacity, and by modeling annual mowing cycles of their aerial parts. This approach aims to evaluate the phytoremediation potential of such a model. Both natural and human interventions are involved in this approach, which is referred to as a mixed phytoremediation process. The study focuses on chloride phytoremediation from a chloride-rich and regulated substrate that is marine dredged sediments abandoned for 12 years and recolonized for 4 years. The sediments are colonized by a Suaeda vera dominated vegetation and possess heterogeneity in lixiviate chloride and conductivity. The study found that despite Suaeda vera is the well adapted species for this environment, it is not an effective species for phytoremediation as it has low bioaccumulation and translocation rates (9.3 and 2.6 respectively), and disturbs chloride leaching below in the substrate. Other identified species, such as Salicornia sp., Suaeda maritima, and Halimione portulacoides, have better phytoaccumulation (respectively 39.8, 40.1, 34.8) and translocation rates (respectively 7.0, 4.5, 5.6) and can successfully remediate the sediment in 2-9 years. The following species have been found to bioaccumulate chloride in aboveground biomass at the following rates: Salicornia sp. (181 g/kg DW), Suaeda maritima (160 g/kg DW), Sarcocornia perennis (150 g/kg DW), Halimione portulacoides (111 g/kg DW) and Suaeda vera (40 g/kg DW).

Assessing Illinois Residents' Support for Natural Recolonization of Apex Predators.

Understanding sources of difference in public attitudes toward wildlife is critical for the design of effective policy instruments. In this article we explored the role of wildlife value orientations and stakeholder group membership (general public versus agricultural producers) in shaping residents support for the natural recolonization of apex predators (black bear, cougar, gray wolf), in Illinois, USA. Results demonstrate differences in attitudes toward recolonization as a function of residents' basic beliefs about the human-wildlife relationship and stakeholder group membership. Results revealed varying degrees of opposition and/or antipathy toward recolonization of apex predators across wildlife values types and stakeholder groups. Individuals that were identified to hold utilitarian beliefs about wildlife (traditionalist orientation) and agricultural producers were found to exhibit the most negative attitudes toward natural recolonization, compared to individuals that believe wildlife have intrinsic rights (mutualist orientation) or members of the general public. Individuals' attitudes toward the recolonization of black bears were found to differ according to their wildlife value orientations, stakeholder group membership, and the combination of the two factors.