scholarly journals PRODUCTIVIDAD PRIMARIA EN LAGUNA LARGA, CAYO COCO, CUBA

2011 ◽  
Vol 3 ◽  
pp. 31 ◽  
Author(s):  
Mayrene Guimarais Bermejo ◽  
Roberto González de Zayas
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Net Primary Production ◽  
Ruppia Maritima ◽  
Halodule Wrightii ◽  
Phytoplankton Productivity ◽  
North Central ◽  
Net Production ◽  
The North ◽  
Total Productivity

Se determinó la productividad primaria en Laguna Larga, ubicada en la costa norte y central de Cayo Coco. La producción primaria del fitoplancton y la biomasa del macrofitobentos fueron medidas durante el 2008-2009 en dos sectores de la laguna. La producción primaria neta acuática del sector este fue de 4.32 ± 3.59 g C m-2 día-1 y en el sector oeste fue de 0.71 ± 0.41 g C m-2 día-1. Ambos sectores, atendiendo a la relación producción/respiración anual, fueron autotróficos para el oxígeno e hipertróficos para el carbono. Entre las especies más productivas del macrofitobentos estuvieron: Cladophoropsis sp., Halodule wrightii, Cladophora sp. y Ruppia maritima. La alta producción neta acuática registrada en el sector este, con respecto al oeste, se debe a la contribución del macrofitobentos a la productividad total. El fitoplancton en el sector este exhibió baja productividad (0.12 ± 0.07 g C m-2 día-1) con respecto al oeste (0.71 ± 0.41 g C m-2 día-1), lo que puede deberse a la competencia del macrofitobentos por los nutrientes.ABSTRACT Phytoplankton primary productivity and macrophyte biomass were determined during 2008-2009 for Laguna Larga, located on the north-central coast of Cayo Coco, Cuba. Aquatic net primary production was measured in two different sectors of the lagoon resulting in 4.32 ± 3.59 g C m-2 d-1 and 0.71 ± 0.41 g C m-2 d-1 in the eastern and western part, respectively. In regard to the annual production to respiration ratio, both sections showed autotrophic and hypertrophic levels for the oxygen and carbon metabolisms. The most productive species were Cladophoropsis sp., Halodule wrightii, Cladophora sp. and Ruppia maritima. Aquatic net production recorded for the eastern lobe was higher than the western lobe because of the macrophytobenthos contribution to total productivity. On the contrary, phytoplankton productivity in the eastern part was lower (0.12 ± 0.07 g C m-2 d-1) than the western lobe (0.71 ± 0.41 g C m-2 d-1), probably due to the macrophyte competition for nutrients.

scholarly journals Nutrient limitation of primary productivity in the Southeast Pacific (BIOSOPE cruise)

2008 ◽  
Vol 5 (1) ◽  
pp. 215-225 ◽  
Author(s):  
S. Bonnet ◽  
C. Guieu ◽  
F. Bruyant ◽  
O. Prášil ◽  
F. Van Wambeke ◽  
...  
Keyword(s):  
Primary Productivity ◽  
World Ocean ◽  
Dinitrogen Fixation ◽  
Global Ocean ◽  
Physiological Status ◽  
Phytoplankton Productivity ◽  
The North ◽  
Southeast Pacific ◽  
Essential Nutrient ◽  
South Pacific Gyre

Abstract. Iron is an essential nutrient involved in a variety of biological processes in the ocean, including photosynthesis, respiration and dinitrogen fixation. Atmospheric deposition of aerosols is recognized as the main source of iron for the surface ocean. In high nutrient, low chlorophyll areas, it is now clearly established that iron limits phytoplankton productivity but its biogeochemical role in low nutrient, low chlorophyll environments has been poorly studied. We investigated this question in the unexplored southeast Pacific, arguably the most oligotrophic area of the global ocean. Situated far from any continental aerosol source, the atmospheric iron flux to this province is amongst the lowest of the world ocean. Here we report that, despite low dissolved iron concentrations (~0.1 nmol l−1) across the whole gyre (3 stations located in the center and at the western and the eastern edges), primary productivity are only limited by iron availability at the border of the gyre, but not in the center. The seasonal stability of the gyre has apparently allowed for the development of populations acclimated to these extreme oligotrophic conditions. Moreover, despite clear evidence of nitrogen limitation in the central gyre, we were unable to measure dinitrogen fixation in our experiments, even after iron and/or phosphate additions, and cyanobacterial nif H gene abundances were extremely low compared to the North Pacific Gyre. The South Pacific gyre is therefore unique with respect to the physiological status of its phytoplankton populations.

Carbon Flow in a Tundra Stream Ecosystem

1986 ◽  
Vol 43 (6) ◽  
pp. 1259-1270 ◽  
Author(s):  
Bruce J. Peterson ◽  
John E. Hobbie ◽  
Teresa L. Corliss
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Primary Productivity ◽  
Net Primary Production ◽  
Epilithic Algae ◽  
Net Production ◽  
Organic Carbon Concentration ◽  
Temperate Streams ◽  
Tundra Vegetation ◽  
Order Of Magnitude

The carbon cycle of the Kuparuk River, a meandering tundra stream, is dominated by inputs of eroding peat and leaching dissolved organic carbon from the tundra. Net production of epilithic algae is about 13 g C∙m−2∙yr−1, an order of magnitude less than inputs of allochthonous particulate organic carbon and two orders of magnitude less than inputs of dissolved organic carbon. The streamwater has a mean total organic carbon concentration of 6.8 mg∙L−1, and the annual export of organic carbon from the watershed is 2–3 t∙km−2∙yr−1; both are similar to the average for temperate streams. However, because of the low primary productivity of tundra vegetation, the export of organic carbon from the watershed via the river is a larger fraction (2–6%) of the total watershed net primary production than the 0.1–0.4% usually found for temperate rivers.

Optimizing models for remotely estimating primary production in Antarctic coastal waters

2000 ◽  
Vol 12 (1) ◽  
pp. 20-32 ◽  
Author(s):  
H.M. Dierssen ◽  
M. Vernet ◽  
R.C. Smith
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Coastal Waters ◽  
Time Series Data ◽  
Cold Water ◽  
Water System ◽  
Environmental Parameters ◽  
Day Length ◽  
Series Data ◽  
Phytoplankton Productivity

Primary productivity and associated biogeochemical fluxes within the Southern Ocean are globally significant, sensitive to change and poorly known compared to temperate marine ecosystems. We present seasonal time series data of chlorophyll a, primary productivity and in-water irradiance measured in the coastal waters of the Western Antarctica Peninsula and build upon existing models to provide a more optimum parameterization for the estimation of primary productivity in Antarctic coastal waters. These and other data provide strong evidence that bio-optical characteristics and phytoplankton productivity in Antarctic waters are different from temperate waters. For these waters we show that over 60% of the variability in primary production can be explained by the surface chlorophyll a concentration alone, a characteristic, which lends itself to remote sensing models. If chlorophyll a concentrations are accurately determined, then the largest source of error (13–18%) results from estimates of the photoadaptive variable (PBopt). Further, the overall magnitude of PBopt is low (median 1.09 mg C mg chl−1 h−1) for these data compared to other regions and generally fits that expected for a cold water system. However, the variability of PBopt over the course of a season (0.4 to 3 mg C mg chl−1 h−1) is not consistently correlated with other possible environmental parameters, such as chlorophyll, sea surface temperature, incident irradiance, day length, salinity, or taxonomic composition. Nonetheless, by tuning a standard depth-integrated primary productivity model to fit representative PBopt values and the relatively uniform chlorophyll-normalized production profile found in these waters, we can improve the model to account for approximately 72–73% variability in primary production both for our data as well as for independent historic Antarctic data.

Impacts of Oyster Reef Restoration on Primary Productivity and Nutrient Dynamics in Tidal Creeks of the North Central Gulf of Mexico

2010 ◽  
Vol 33 (6) ◽  
pp. 1355-1364 ◽  
Author(s):  
Rochelle Plutchak ◽  
Kelly Major ◽  
Just Cebrian ◽  
C. Drew Foster ◽  
Mary-Elizabeth C. Miller ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Primary Productivity ◽  
Nutrient Dynamics ◽  
Oyster Reef ◽  
Tidal Creeks ◽  
North Central ◽  
Reef Restoration ◽  
The North

scholarly journals Reconstructing past variations in environmental conditions and paleoproductivity over the last  ∼ 8000 years off north-central Chile (30° S)

2020 ◽  
Vol 17 (22) ◽  
pp. 5763-5785
Author(s):  
Práxedes Muñoz ◽  
Lorena Rebolledo ◽  
Laurent Dezileau ◽  
Antonio Maldonado ◽  
Christoph Mayr ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Productivity ◽  
Environmental Conditions ◽  
Time Interval ◽  
Coastal Zones ◽  
Moisture Index ◽  
Subtropical Anticyclone ◽  
North Central ◽  
The North ◽  
Lower Productivity

Abstract. The aim of this project was to establish past variations in the main oceanographic and climatic features of a transitional semiarid ecosystem on the north-central Chilean coast. We analyzed recent sedimentary records retrieved from two bays, Guanaqueros and Tongoy (30∘ S), for geochemical and biological analyses, including the following: sensitive redox trace elements, biogenic opal, total organic carbon (TOC), diatoms and stable isotopes of organic carbon and nitrogen. Three remarkable periods were established with different environmental conditions and productivities: (1) > 6600 cal BP, (2) 4500–1800 cal BP and (3) 140 cal BP to the present (2015 CE). The first period was characterized by a remarkably higher productivity (higher diatom abundances and opal) in which large fluxes of organic compounds were also inferred from the accumulation of elements, such as Ba, Ca, Ni, Cd and P, in the sediments. Meanwhile, significantly reduced conditions at the bottom of the bays were suggested based on the large accumulation of Mo, Re and U, showing a peak at 6600 cal BP, when sulfidic conditions could have been present. According to the pollen moisture index (PMI), this was also identified as the driest interval. These conditions should be associated with an intensification of the Southern Pacific Subtropical Anticyclone (SPSA) and stronger southerly western winds, emulating La Niña-like conditions, as has been described for the SE Pacific during the early Holocene and part of the mid-Holocene. During most of the second period, lower productivity was observed; however, a small increase was identified between 3400 and 4000 cal BP, although lower amounts of diatom (valves g−1) and nutrient-type metal accumulations were evident. Anoxic conditions at the bottom of the bays changed to an almost stable suboxic condition during this time interval. The third period was marked by intense oxygenation after 1800 cal BP, as observed by a drastic change in the accumulation of U, Mo and Re. This was followed by a return to more reduced conditions over the past 2 centuries, characterized by a small productivity rise after ∼140 cal BP, as suggested by the opal accumulations. Overall, lower primary productivity, lower reduced conditions at the bottom and higher-humidity conditions were established after 6600 cal BP to the present. We suggest that the oxygenation might be associated with a weak effect from the oxygen minimum zone over the shelf and intensified El Niño activity, introducing oxygenated waters to the coastal zones through the propagation of equatorial waves and establishment of conditions that reduced the primary productivity from the mid-Holocene toward the beginning of the modern era.

scholarly journals Association Between Estuary Characteristics and Activities of the Critically Endangered Indo-Pacific Humpback Dolphin (Sousa chinensis)

2021 ◽  
Vol 8 ◽  
Author(s):  
Chi-hung Lin ◽  
Hsing-Juh Lin ◽  
Jian-Ping Suen ◽  
Lien-Siang Chou
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
River Estuary ◽  
Late Summer ◽  
Critically Endangered ◽  
Physical Factors ◽  
Factors Affecting ◽  
Net Production ◽  
Sousa Chinensis ◽  
Autumn And Winter

The Indo-Pacific humpback dolphin (Sousa chinensis) has been reported to prefer estuary habitats. This study explored the environmental factors affecting a critically endangered population off the coast of Yunlin, Taiwan. We measured dolphin sighting rates and estuary characteristics affected by the watershed, including seven physical factors (watershed rainfall, watershed runoff, estuarine turbidity, pH, salinity, temperature, and dissolved oxygen) and two biological factors (estuarine net primary production and chlorophyll a concentration), at the Hsinhuwei River estuary in Taiwan. Dolphin activity was measured by sighting rate and behavioral indices for feeding and traveling between 2017 and 2018. We observed that when the maximum net production increased alongside rising temperatures in spring, both the dolphin sighting rate and foraging activity increased. This trend was maintained until heavy rainfall or increased river runoff occurred during late summer, which resulted in high turbidity in autumn and winter. Turbidity was significantly negatively correlated with dolphin activity (sighting rate and foraging). Furthermore, we found that dolphin traveling positively correlated with the chlorophyll a concentration and maximum net production factors, which could attract dolphins expecting more abundant prey fish in the estuary supported by the high primary production. This study provides empirical evidence on how estuary characteristics affected by the watershed can affect the sighting rate and behavioral activities of Indo-Pacific humpback dolphins.

scholarly journals Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

2016 ◽  
Vol 13 (5) ◽  
pp. 1597-1607 ◽  
Author(s):  
Wolfgang Buermann ◽  
Claudie Beaulieu ◽  
Bikash Parida ◽  
David Medvigy ◽  
George J. Collatz ◽  
...  
Keyword(s):  
Climate Variability ◽  
Primary Production ◽  
North Atlantic ◽  
Large Scale ◽  
Net Primary Production ◽  
Carbon Sink ◽  
Northern Eurasia ◽  
Sink Strength ◽  
Independent Evidence ◽  
The North

Abstract. The world's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, have uncovered an abrupt, substantial ( ∼  1 PgC yr−1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been  ∼  30 % larger than observed (or  ∼  12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production significantly increased in the late 1980s (more so than heterotrophic respiration), consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

Variation in foliar nitrogen and aboveground net primary production in young postfire lodgepole pine

2009 ◽  
Vol 39 (5) ◽  
pp. 1024-1035 ◽  
Author(s):  
Monica G. Turner ◽  
Erica A.H. Smithwick ◽  
Daniel B. Tinker ◽  
William H. Romme
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Lodgepole Pine ◽  
Tree Density ◽  
Aboveground Net Primary Production ◽  
Foliar Nitrogen ◽  
Net Production ◽  
Foliar N ◽  
N Concentration ◽  
Foliar N Concentration

Understanding nutrient dynamics of young postfire forests may yield important insights about how stands develop following stand-replacing wildfires. We studied 15-year-old lodgepole pine stands that regenerated naturally following the 1988 Yellowstone fires to address two questions: (1) How do foliar nitrogen (N) concentration and total foliar N vary with lodgepole pine density and aboveground net primary production? (2) Is foliar N related to litter production and to rates of gross production, consumption, and net production of soil NH4+ and NO3–? Foliar N concentration of new lodgepole pine needles averaged 1.38%; only stands at very high density (>80 000 trees·ha–1) approached moderate N limitation. Foliar N concentration in composite (all-age) needles averaged 1.08%, varied among stands (0.87%–1.39%), and declined with increasing tree density. The foliar N pool averaged 48.3 kg N·ha–1, varied among stands (3.6–218.4 kg N·ha–1), and increased with aboveground net primary production. Total foliar N was not related to laboratory estimates of net production of NH4+ or NO3– in soils. Lodgepole pine foliage is a strong N sink, and N does not appear to be limiting at this early successional state. The initial spatial patterns of postfire tree density strongly influence landscape patterns of N storage.

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