Supporting Spartina: Interdisciplinary Perspective Shows Spartina As A Distinct Solid Genus

In 2014, a DNA-based phylogenetic study confirming the paraphyly of the grass subtribe Sporobolinae proposed the creation of a large monophyletic genus Sporobolus, including (among others) species previously included in the genera Spartina, Calamovilfa, and Sporobolus. Spartina species have contributed substantially (and continue contributing) to our knowledge in multiple disciplines, including ecology, evolutionary biology, molecular biology, biogeography, experimental ecology, biological invasions, environmental management, restoration ecology, history, economics, and sociology. There is no rationale so compelling to subsume the name Spartina as a subgenus that could rival the striking, global iconic history and use of the name Spartina for over 200 yr. We do not agree with the subjective arguments underlying the proposal to change Spartina to Sporobolus. We understand the importance of both the objective phylogenetic insights and of the subjective formalized nomenclature and hope that by opening this debate we will encourage positive feedback that will strengthen taxonomic decisions with an interdisciplinary perspective. We consider that the strongly distinct, monophyletic clade Spartina should simply and efficiently be treated as the genus Spartina

MODELLING THE EFFECTS OF GLOBAL TEMPERATURE INCREASE ON THE GROWTH OF SALT MARSH PLANTS

Gradual increases in temperature and atmospheric CO2 concentrations have resulted from the increased human use of fossil fuels since the beginning of industrial activity. In coastal wetland ecosystems, salt marshes constitute important habitats because they play important ecological roles, acting as carbon sinks by capturing atmospheric CO2 and storing it in living plant tissue. Ecological models are important tools for understanding the results of anthropogenic impacts on a global scale. Global warming poses threats to salt marshes through different effects, e.g., increases in sea level. The objectives of this study were i) to assess how temperature increases will influence the growth of salt marsh plants, ii) to infer the carbon budget of salt marshes under temperature increase scenarios and iii) to predict how salt marsh plants will keep pace with increases in sea level. These goals were achieved by developing growth models of three different plants (Spartina maritima, Scirpus maritimus and Zostera noltei) found in the Mondego estuary. Models were developed for C3 and C4 plant species. The results suggest that a temperature increase enhances the aboveground biomass of salt marsh plants. According to the predictions of the models, the sedimentation rate of S. maritima and Z. noltei can keep pace with increases in sea level, but this is apparently not the case for S. maritimus. If S. maritimus disappears from the Mondego estuary, the carbon sequestration ability of the system should decrease due to the loss of active plant tissue. This conclusion is based on the fact that S. maritimus accumulated more than 80% of the total carbon sequestered in the tissues by the three studied species. Keywords: plant growth model, sea level increase, sedimentation, salt marsh, estuarie

Microplastics as a vector for heavy metal contamination in the marine environment

The permanent presence of microplastics in the marine environment is considered a global threat to several marine animals. Heavy metals and microplastics are typically included in two different classes of pollutants but the interaction between these two stressors is poorly understood. During 14 days of experimental manipulation, we examined the adsorption of two heavy metals, copper (Cu) and zinc (Zn), leached from an antifouling paint to virgin polystyrene (PS) beads and aged polyvinyl chloride (PVC) fragments in seawater. We demonstrated that heavy metals were released from the antifouling paint to the water and both microplastic types adsorbed the two heavy metals. This adsorption kinetics was described using partition coefficients and mathematical models. Partition coefficients between pellets and water ranged between 650 and 850 for Cu on PS and PVC, respectively. The adsorption of Cu was significantly greater in PVC fragments than in PS, probably due to higher surface area and polarity of PVC. Concentrations of Cu and Zn increased significantly on PVC and PS over the course of the experiment with the exception of Zn on PS. As a result, we show a significant interaction between these types of microplastics and heavy metals, which can have implications for marine life and the environment. These results strongly support recent findings where plastics can play a key role as vectors for heavy metal ions in the marine system. Finally, our findings highlight the importance of monitoring marine litter and heavy metals, mainly associated with antifouling paints, particularly in the framework of the Marine Strategy Framework Directive (MSFD)

Supporting Spartina: Interdisciplinary perspective shows Spartina as a distinct solid genus

In 2014, a DNA-based phylogenetic study confirming the paraphyly of the grass subtribe Sporobolinae proposed the creation of a large monophyletic genus Sporobolus, including (among others) species previously included in the genera Spartina, Calamovilfa, and Sporobolus. Spartina species have contributed substantially (and continue contributing) to our knowledge in multiple disciplines, including ecology, evolutionary biology, molecular biology, biogeography, experimental ecology, biological invasions, environmental management, restoration ecology, history, economics, and sociology. There is no rationale so compelling to subsume the name Spartina as a subgenus that could rival the striking, global iconic history and use of the name Spartina for over 200 yr. We do not agree with the subjective arguments underlying the proposal to change Spartina to Sporobolus. We understand the importance of both the objective phylogenetic insights and of the subjective formalized nomenclature and hope that by opening this debate we will encourage positive feedback that will strengthen taxonomic decisions with an interdisciplinary perspective. We consider that the strongly distinct, monophyletic clade Spartina should simply and efficiently be treated as the genus Spartina