Abstract:

In many Northern Hemisphere salt marshes, recovery of disturbance-generated bare areas usually occurs within a few years. However, in some southwestern Atlantic marshes, bare patches may remain unchanged for several years. Here we investigated biological and physical factors that might affect bare patch colonization in a Mar Chiquita coastal lagoon salt marsh (Argentina). We evaluated natural seedling emergence of the pioneer pickleweed plant Sarcocornia perennis, considering distance to mature plants and the herbivory/bioturbation exerted by the crab Neohelice granulata (using exclosures). Almost no seedling emergence was observed in patches distant from mature plants, while higher emergence resulted in close patches. Crab exclusion did not affect seedling counts. Nevertheless, most of these seedlings did not survive high-temperature months. We analyzed if colonization was favored by increasing the availability of S. perennis seeds, and we found similar seedling emergence in patches both close and distant to mature plants. As in the previous experiment, most of them did not survive the high-temperature months, but some seedlings could establish within crab exclosures. Finally, we used a shade cloth to reduce solar radiation, but this did not increase seedling survival, which was only favored in crab exclosures. In summary, our results suggest that seed availability, followed by the presence of crabs (but not solar radiation), affect the rate of patch recovery. Additionally, our results show that life-history traits (seed ecology) of the colonizer can be a key and are a usually overlooked driver of salt marsh secondary succession.

Author affiliation: Kaminsky, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. ; Argentina

Author affiliation: Alberti, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Author affiliation: Aguiar, Martin Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. ; Argentina

Author affiliation: Iribarne, Oscar Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Abstract:

Biomass dynamics, decomposition and nutrient cycling were studied in a Sarcocornia perennis salt marsh in the Bahia Blanca estuary (Argentina) to achieve a better understanding of these processes and provide information about a species and a region underrepresented in the literature. Above and belowground biomass stocks and carbon (C), nitrogen (N) and phosphorus (P) concentration in plant tissues were monitored every two months during a year. Decomposition rate and the concentration of C, N and P during the process were also estimated in above and belowground tissues. Biomass values were low (mean of 363 ± 43 and 242 ± 27 g m-2 for aboveground and belowground tissues, respectively), presumably associated to the high salinity of this estuary. The general trend of higher values for aboveground biomass is in agreement with other reports for this species and has an effect on nutrients pools, which are higher for aboveground tissues for C and N. Above and belowground decomposition rates were high (64 and 70 % after a year, respectively), meaning this process play a significant role in the cycling of organic matter. C/N and C/P ratios changed during decomposition, but final ratios were usually higher, suggesting a net release of nutrients. Our results indicate that significant amounts of C, N and P are recycled by S. perennis, highlighting the role of this species and suggesting important consequences of its lost in the study area

Author affiliation: Negrin, Vanesa Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina

Author affiliation: Pratolongo, Paula Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina

Author affiliation: de Villalobos, Ana Elena. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios en Conservacion y Manejo; Argentina

Author affiliation: Botté, Sandra Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina

Author affiliation: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentina

Abstract:

Interactions among plants have been hypothesized to be context dependent, shifting between facilitative and competitive in response to variation in physical and biological stresses. This hypothesis has been supported by studies of the importance of positive and negative interactions along abiotic stress gradients (e.g., salinity, desiccation), but few studies have tested how variation in biotic stresses can mediate the nature and strength of plant interactions. We examined the hypothesis that herbivory regulates the strength of competitive and facilitative interactions during succession in Argentinean marshes dominated by Spartina densiflora and Sarcocornia perennis. Spartina densiflora is preferred by the dominant herbivore in the system, the crab Chasmagnathus granulatus. We experimentally manipulated crab herbivory, plant structure, and shade, and we found that, when herbivory was low in the spring and summer, competitive interactions between plants were dominant, but in the fall, when herbivory was highest, facilitative interactions dominated, and Spartina densiflora survival was completely dependent upon association with Sarcocornia perennis. Moreover, experimental removal of Sarcocornia perennis across recently disturbed tidal flats revealed that, while Sarcocornia perennis positively affected small Spartina densiflora patches by decreasing herbivory, as patch size increases and they can withstand the impact of herbivory, competitive interactions predominated and Spartina densiflora ultimately outcompeted Sarcocornia perennis. These results show that herbivory can mediate the balance between facilitative and competitive processes in vascular plant communities and that the strength of consumer regulation of interactions can vary seasonally and with patch size

Author affiliation: Alberti, Juan. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Biología. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Escapa, Mauricio. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Biología. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina

Author affiliation: Iribarne, Oscar Osvaldo. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Biología. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Silliman, Brian Red. University of Florida; Estados Unidos

Author affiliation: Bertness, Mark. University Brown; Estados Unidos

Abstract:

Tannery is an industry that generates wastewater characterised by high levels of organic matter, chrome, dissolved solids, sulphides and high salinity. The aim of this work was to evaluate at laboratory scale, the decrease of chemical oxygen demand (COD) and salinity from effluents from tanning sheepskins, using physical chemical methods in primary treatment, and bioreactor and wetlands for secondary and tertiary treatment, respectively. Effluents were collected from tanning processes of sheepskins carried out on the Center of Research and Technology on leather tannery plant, La Plata, Argentina. Conventional primary treatments selecting coagulants and flocculants were employed. For secondary treatment, batch bioreactors were designed, and the maximum COD removal was 60-70%. For the tertiary treatment, wetlands at laboratory scale were employed. In this test wetlands were filled with granite stone, with and without the plant Sarcocornia perennis, and COD decreased on average by 64% additional and chlorides concentration decreased by around 15%.

Author affiliation: Cortizo, Lorena. Instituto Nacional de Tecnología Industrial. Centro de Investigación y Desarrollo del Cuero. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Centíficas. Centro de Investigación y Desarrollo del Cuero; Argentina

Author affiliation: Scelsio, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; Argentina

Author affiliation: Perotti, Sergio. Instituto Nacional de Tecnología Industrial. Centro de Investigación y Desarrollo del Cuero. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Centíficas. Centro de Investigación y Desarrollo del Cuero; Argentina

Author affiliation: Martegani, José Eduardo. Instituto Nacional de Tecnología Industrial. Centro de Investigación y Desarrollo del Cuero. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Centíficas. Centro de Investigación y Desarrollo del Cuero; Argentina

Author affiliation: Lopez, Laura Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial. Centro de Investigación y Desarrollo del Cuero. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Centíficas. Centro de Investigación y Desarrollo del Cuero; Argentina

Abstract:

Phytochelatins (PCs) and monothiols and their relation with trace element concentrations were studied in three plant species from two Portuguese salt marshes. Belowground tissues showed always higher element concentrations, while enhanced values of monothiols were found in aboveground biomass. Glutathione was usually the most abundant monothiol. The concentration of total PCs was higher in leaves or stems than in roots of Halimione portulacoides and Sarcocornia perennis, while in Spartina maritima the highest concentrations were reported in large roots. PC2 was synthesized by all tissues and species and was higher in large roots of S. maritima. PC4 and PC5 were in high levels in small roots of S. maritima. PC2 was positively correlated with As, Zn and Pb. Although being the first evidence of PCs and monothiols in these species under natural conditions, our results do not point to a simple relationship with elements concentrations, suggesting a complex mechanism involved.

Author affiliation: Negrin, Vanesa Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Instituto Português do Mar e da Atmosfera; Portugal

Author affiliation: Teixeira, Bárbara. Instituto Português do Mar e da Atmosfera; Portugal

Author affiliation: Godinho, Rita M.. Instituto Português do Mar e da Atmosfera; Portugal

Author affiliation: Mendes, Rogério. Instituto Português do Mar e da Atmosfera; Portugal

Author affiliation: Vale, Carlos. Instituto Português do Mar e da Atmosfera; Portugal. Universidad de Porto; Portugal

Abstract:

La planta Sarcocornia perennis es un común integrante del ecosistema del estuario de Bahía Blanca. Lo que muy pocos conocen, son sus maravillosas potencialidades nutricionales. En los últimos 20 años ha sido exhaustivamente estudiada y el mundo ha cambiado su mirada hacia ella. Actualmente se considera un excelente recurso en áreas que a menudo son clasificadas como desprovistas de valor económico.

Author affiliation: Cervellini, María Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Bahia Blanca. Instituto de Ciencias Biologicas y Biomedicas del Sur; Argentina. Universidad Nacional del Sur; Argentina

Author affiliation: Angeletti, Sabrina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Bahia Blanca. Instituto de Ciencias Biologicas y Biomedicas del Sur; Argentina. Universidad Nacional del Sur; Argentina

Abstract:

The roles of Sarcocornia perennis and tidal flooding on sediment biogeochemistry were evaluated within a wetland in the Bahı´a Blanca estuary. pH and Eh were measured in sediments while particulate organic carbon (POC) and dissolved inorganic nutrient concentrations were determined in porewater, at three sites with different conditions according to vegetation and flooding. Grain size was also analysed. pH varied in a narrow range (7 8.2) and was lower in the vegetated site. Eh values (50 250 mV) imply that sediment conditions were moderately reduced, in agreement with the relatively high percentage of sand; it was influenced by both factors. POC concentration was high (26.2491.62 mg/l), especially at the vegetated site. The concentrations of ammonium and nitrate were similar (21.3091.83 and 18.7793.06 mmol/l, respectively) and not affected by flooding; only nitrate was affected by vegetation. Phosphate was rather constant (13.4391.19 mmol/l) and affected mainly by flooding. Silicate was high (566.45976.06 mmol/l) and not affected by either factor. These results suggest that the sediment biogeochemistry of this environment is significantly influenced by flooding and, especially, by S. perennis, as vegetation affected a higher number of parameters.

Author affiliation: Negrin, Vanesa Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto Argentino de Oceanografia (i); Argentina

Author affiliation: Spetter, Carla Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto Argentino de Oceanografia (i); Argentina. Universidad Nacional del Sur. Departamento de Química; Argentina

Author affiliation: Guinder, Valeria Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto Argentino de Oceanografia (i); Argentina

Author affiliation: Perillo, Gerardo Miguel E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto Argentino de Oceanografia (i); Argentina. Universidad Nacional del Sur. Departamento de Geología; Argentina

Author affiliation: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto Argentino de Oceanografia (i); Argentina. Universidad Tecnológica Nacional. Facultad Regional Bahía Blanca; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentina