Dataset on the isotopic (ẟ13C, ẟ15N) and elemental (C, N) composition of estuarine primary producers in the subtropical Southwestern Atlantic coast

Benthic and pelagic primary producers had their isotopic (ẟ13C, ẟ15N) and elemental (C, N) composition monitored in the Patos Lagoons estuary, in southern Brazil. The present dataset comprises temporal data obtained through seasonal samplings of C3 (Scirpus spp.) and C4 (Spartina densiflora) salt marsh plants, ephemerous bloom-forming drift macroalgae (Ulvophyceae), the widgeon grass Ruppia maritima, particulate (POM) and sedimentary (SOM) organic matter in shallow waters (< 2m) of a subtropical estuary from austral summer 2010 to autumn 2016. POM and SOM were collected as proxies of phytoplankton and microphytobenthos, respectively. Salt marsh plants were randomly sampled (N = 126) at a regularly flooded low marsh area, whereas submerged drift macroalgae (N = 29) and Ruppia plants (N = 14) were collected in adjacent mudflats. POM was collected (N = 33) by filtering water samples using glass fiber filter. SOM was obtained (N = 35) by removing superficial sediment. In laboratory, samples were processed and further analyzed for total organic carbon (TOC), total nitrogen (TN) and carbon (13C/12C) and nitrogen (15N/14N) stable isotopes ratios. With a total of 237 samples analyzed, this dataset provides key information on the isotopic and elemental composition of distinct estuarine primary producers and sources of particulate organic matter (POM and SOM) and their temporal variability in a highly variable aquatic environment. Such knowledge may add to ecological studies investigating food webs, biogeochemical cycles and sources tracking in coastal systems.

Effects of fungal inoculation on the growth of Salicornia (Amaranthaceae) under different salinity conditions

Endophytic fungi are known to be present in roots of salt marsh plants, but their ecological role in this symbiosis is still largely unknown. Generally considered parasitic or saprophytic, they may still be mutualistic, at least under certain circumstances. Among salt marsh plants, Salicornia spp. are recognized as particularly salt-tolerant and their frequent colonization by root endophytes has also been reported. This study aimed to investigate whether the inoculation of Salicornia with different root endophytes isolated from field-collected Salicornia affects biomass production, nutrient uptake and photosynthesis (assessed via chlorophyll fluorescence). In addition, we investigated whether fungal inoculation confers tolerance to salt stress given that endophytes are suggested to increase salt tolerance and improve plant fitness in other less salt-tolerant plants. The inoculation of Salicornia with an isolate of the genus Stemphylium positively influenced total biomass production and nitrogen concentration in roots at optimum salinity condition (150 mM NaCl). However, under salt stress (650 mM NaCl), no significant effects of fungal inoculation on biomass production and photosynthesis were observed. Further, positive and negative effects of fungal inoculation on nutrient concentrations were observed in roots and shoots, respectively. Our results indicate that different endophytic fungi and their interaction result in distinct fungal species-specific plant growth responses of Salicornia under different growth conditions.

Wave-Energy Dissipation: Seaweeds and Marine Plants Are Ecosystem Engineers

Ocean waves deliver an immense amount of energy to coasts around the planet, powering high-velocity flows that interact with nearshore marine plants and animals. Although some of these interactions are beneficial, it is often advantageous for subtidal and intertidal ecological communities if wave-induced water velocities can be reduced by safely dissipating wave energy. This function is often fulfilled by seaweeds and marine plants, which thereby act as ecosystem engineers, modifying the environment to the benefit of the community. Recent advances in hydro-mechanical theory help to explain the mechanisms by which vegetation dissipates wave energy, highlighting the role that organisms’ tendency to bend in flow—their structural flexibility—plays in their ability to engineer wave-induced flows. Here, I review these theories and their application to salt marsh plants, seagrasses, mangroves, and seaweeds, focusing on the ways that marine vegetation serves a foundational role in community function.

Living Shoreline Monitoring—How do I evaluate the environmental benefits of my living shoreline?

Living shorelines are structures made of natural materials such as oyster shell, sand, mangroves, salt marsh plants, and other organic materials built to protect properties from erosion. In addition to increasing shoreline stability, living shorelines enhance many valuable ecosystem functions. In this new 11-page publication of the UF/IFAS Department of Soil and Water Sciences, we provide homeowners, land managers, and Extension agents materials lists, protocols, and data sheets for measuring change in ecosystem function. Measuring and interpreting these measurements will help evaluate living shorelines projects as well as provide the foundation for monetarizing the value of these structures. Written by Laura K. Reynolds, Natalie C. Stephens, Savanna C. Barry, and Ashley R. Smyth.https://edis.ifas.ufl.edu/ss694

Importance of Biotic and Soil Factors in Determining the Distribution Strategies of Coastal Salt Marsh Plants

The distribution of plant communities in the salt marshes of the southwestern coasts of South Korea was studied, along with environmental or plant factors, by canonical correspondence analysis (CCA) and the competitor (C), stress tolerator (S), and ruderal (R) (CSR) ecological strategies. The coastal salt-marsh plants were classified into three plant-factor groups in the CCA biplot diagram. Group 1 was correlated with LS and FP. Group 2 was correlated with CH and SLA, and Group 3 was correlated with LA, LDMC and LDW. The salt-marsh plants were classified into four soil-factor groups in the CCA biplot diagram. First, the group factor was correlated with TN, TOC, and Ca2+. Second, the group factor was distributed according to Mg2+, soil texture as Clay and Silt. Third, the group factor was distributed according to Salinity and Na+ content. Fourth, the group factor was distributed according to Sand content. To clarify the relative significance of competition, stress, and disturbance in the distribution process of plant communities, the CSR distribution model was adopted. The nine species showed CR (competitor-ruderal) strategies: Artemisia fukudo, Artemisia scoparis, Aster tripolium, Atriplex gmelinii, Imperata cylindrica var. koenigii, Salicornia europaea, Suaeda japonica, and Suaeda maritima. The four species with C (competitor) strategies were Artemisia capillaris, Limonium tetragonum, Triglochin maritimum, and Zoysia sinica. Carex scabrifolia and Phragmites communis displayed SC (stress-tolerant-competitor). Both distribution patterns of the CCA diagrams and CSR triangles may provide a useful scientific basis for protecting and restoring salt marshes and their valuable ecosystem services, considering the increasing disturbances.