scholarly journals Seasonal Variation in Biomass and Production of the Macrophytobenthos in two Lagoons in the Southern Baltic Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Martin Paar ◽  
Maximilian Berthold ◽  
Rhena Schumann ◽  
Sven Dahlke ◽  
Irmgard Blindow
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Coastal Lagoons ◽  
Light Attenuation ◽  
Seasonal Succession ◽  
Trophic Levels ◽  
Seasonal Development ◽  
Nutrient Concentrations ◽  
Eutrophic Lagoon ◽  
The Impact

Baltic coastal lagoons are severely threatened by eutrophication. To evaluate the impact of eutrophication on macrophytobenthos, we compared the seasonal development in macrophytobenthic composition, biomass and production, water column parameters (light, nutrients), phytoplankton biomass and production in one mesotrophic and one eutrophic German coastal lagoon. We hypothesized that light availability is the main driver for primary production, and that net primary production is lower at a higher eutrophication level. In the mesotrophic lagoon, macrophytobenthic biomass was much higher with distinct seasonal succession in species composition. Filamentous algae dominated in spring and late summer and probably caused reduced macrophytobenthic biomass and growth during early summer, thus decreasing vegetation stability. Light attenuation was far higher in the eutrophic lagoon, due to high phytoplankton densities, explaining the low macrophytobenthic biomass and species diversity in every season. Areal net primary production was far lower in the eutrophic lagoon. The “paradox of enrichment” hypothesis predicts lower production at higher trophic levels with increased nutrient concentrations. Our results prove for the first time that this hypothesis may be valid already at the primary producer level in coastal lagoons.

scholarly journals Desertification in Forest, Range and Desert Landuses of Tehran Province, Under the Impact of Climate Change

2016 ◽  
Author(s):  
Hadi Eskandari Dameneh ◽  
Moslem Borji ◽  
Hassan Khosravi ◽  
Ali Salajeghe
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Net Primary Production ◽  
Degradation Process ◽  
Early Warning Systems ◽  
Land Uses ◽  
Emission Scenarios ◽  
Desert Ecosystems ◽  
Tehran Province ◽  
The Impact

Abstract. Persistence of widespread degradation in arid and semi-arid region of Iran necessitates using of monitoring and evaluation systems with appropriate accuracy to determine the degradation process and adoption of early warning systems; because after transition from some thresholds, effective reversible function of ecosystems will not be very easy. This paper tries to monitor the degradation and desertification trends in three land uses including range, forest and desert lands affected by climate change in Tehran province for 2000s and 2030s. For assessing climate changes of Mehrabad synoptic stations the data of two emission scenarios including A2 and B2 were used using statistical downscaling techniques and data generated by SDSM model. The index of net primary production resulting from MODIS satellite images was employed as an indicator of destruction from 2001 to 2010. The results showed that temperature is the most effective driver force which alters the net primary production in rangeland, forest and desert ecosystems of Tehran province. On the basis of monitoring findings under real conditions, in the 2000s, over 60 % of rangelands and 80 % of the forests have been below the average production in the province. On the other hand, the long-term average changes of NPP in rangeland and forests indicated the presence of relatively large areas of these land uses with production rate lower than the desert. The results also showed that, assuming the existence of circumstances of each emission scenarios, the desertification status will not improve significantly in the rangelands and forests of Tehran province.

scholarly journals Primary production sensitivity to phytoplankton light attenuation parameter increases with transient forcing

2017 ◽  
Vol 14 (20) ◽  
pp. 4767-4780 ◽  
Author(s):  
Karin F. Kvale ◽  
Katrin J. Meissner
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Light Attenuation ◽  
Climate Scenario ◽  
Sensitivity Study ◽  
Climate Forcing ◽  
Deep Time ◽  
Underwater Light Field ◽  
Attenuation Parameter ◽  
Biogeochemical Models

Abstract. Treatment of the underwater light field in ocean biogeochemical models has been attracting increasing interest, with some models moving towards more complex parameterisations. We conduct a simple sensitivity study of a typical, highly simplified parameterisation. In our study, we vary the phytoplankton light attenuation parameter over a range constrained by data during both pre-industrial equilibrated and future climate scenario RCP8.5. In equilibrium, lower light attenuation parameters (weaker self-shading) shift net primary production (NPP) towards the high latitudes, while higher values of light attenuation (stronger shelf-shading) shift NPP towards the low latitudes. Climate forcing magnifies this relationship through changes in the distribution of nutrients both within and between ocean regions. Where and how NPP responds to climate forcing can determine the magnitude and sign of global NPP trends in this high CO2 future scenario. Ocean oxygen is particularly sensitive to parameter choice. Under higher CO2 concentrations, two simulations establish a strong biogeochemical feedback between the Southern Ocean and low-latitude Pacific that highlights the potential for regional teleconnection. Our simulations serve as a reminder that shifts in fundamental properties (e.g. light attenuation by phytoplankton) over deep time have the potential to alter global biogeochemistry.

An analysis of primary production in the Daly River, a relatively unimpacted tropical river in northern Australia

2005 ◽  
Vol 56 (3) ◽  
pp. 303 ◽  
Author(s):  
I. T. Webster ◽  
N. Rea ◽  
A. V. Padovan ◽  
P. Dostine ◽  
S. A. Townsend ◽  
...  
Keyword(s):  
Primary Production ◽  
Plant Biomass ◽  
Net Primary Production ◽  
Low Flow ◽  
Nutrient Concentrations ◽  
Tight Coupling ◽  
Tropical River ◽  
Rate Of Photosynthesis ◽  
Curve Method ◽  
Tropical Australia

In this paper, the dynamics of primary production in the Daly River in tropical Australia are investigated. We used the diurnal-curve method for both oxygen and pH to calculate photosynthesis and respiration rates as indicators of whole-river productivity. The Daly River has maximum discharges during the summer, monsoonal season. Flow during the dry season is maintained by groundwater discharge via springs. The study investigated how primary production and respiration evolve during the period of low flow in the river (April–November). The relationship between primary production and the availability of light and nutrients enabled the role of these factors to be assessed in a clear, oligotrophic tropical river. The measured rate of photosynthesis was broadly consistent with the estimated mass of chlorophyll associated with the main primary producers in the river (phytoplankton, epibenthic algae, macroalgae, macrophytes). A significant result of the analysis is that during the time that plant biomass re-established after recession of the flows, net primary production proved to be ~4% of the rate of photosynthesis. This result and the observed low-nutrient concentrations in the river suggest a tight coupling between photosynthetic fixation of carbon and the microbial degradation of photosynthetic products comprising plant material and exudates.

Biomass, nutrient distribution, and net production in alpine communities of the Kluane Mountains, Yukon Territory, Canada

1981 ◽  
Vol 59 (12) ◽  
pp. 2635-2649 ◽  
Author(s):  
Charles C. Grier ◽  
T. M. Ballard
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Net Primary Production ◽  
Yukon Territory ◽  
Nutrient Concentrations ◽  
Aboveground Net Primary Production ◽  
Matter Distribution ◽  
Nutrient Distribution ◽  
Alpine Zone ◽  
Temperature Regimes

Biomass and nutrient distribution and aboveground net primary production were determined for two communities growing at 1600 m elevation and five communities growing at about 2000 m elevation in the alpine zone of the Kluane Ranges, Yukon Territory, Canada. Living biomass accumulations ranged from 183 to 1350 g/m2, whereas total organic matter accumulations ranged from 2126 to 51120 g/m2. Nutrient distribution in general reflected organic matter distribution. Highest nutrient concentrations were in leaves and fine roots. Aboveground net primary production ranged from 18.3 to 185.5 g/m2. Primary production appeared to be related most to moisture during the growing season and temperature regimes.

Simulation of Mediterranean forest carbon pools under expected environmental scenarios

2010 ◽  
Vol 40 (5) ◽  
pp. 850-860 ◽  
Author(s):  
M. Chiesi ◽  
M. Moriondo ◽  
F. Maselli ◽  
L. Gardin ◽  
L. Fibbi ◽  
...  
Keyword(s):  
Primary Production ◽  
Environmental Changes ◽  
Net Primary Production ◽  
Gross Primary Production ◽  
Central Italy ◽  
Forest Carbon ◽  
Simulation Approach ◽  
Two Factors ◽  
Vegetation Carbon ◽  
The Impact

Simulating the effects of possible environmental changes on the forest carbon budget requires the use of calibrated and tested models of ecosystem processes. A recently proposed simulation approach based on the use of the BIOME-BGC model was applied to yield estimates of present carbon fluxes and pools in Tuscany forests (central Italy). After the validation of these estimates against existing ground data, the simulation approach was used to assess the impact of plausible climate changes (+2 °C and increased CO2 concentration) on forest carbon dynamics (gross primary production (GPP), net primary production (NPP), and relevant allocations). The results indicate that the temperature change tends to inhibit all production and allocation processes, which are instead enhanced by the CO2 concentration rise. The combination of the two factors leads to a general increase in both GPP and NPP that is higher for deciduous oaks and chestnut (+30% and 24% for GPP and +42% and 31% for NPP, respectively). Additionally, vegetation carbon is slightly increased, while total soil carbon remains almost unchanged with respect to the present conditions. These findings are analyzed with reference to the Tuscany forest situation and previous studies on the subject.

scholarly journals Diatoms Si Uptake Capacity Drives Carbon Export In Coastal Upwelling Systems

2016 ◽  
Author(s):  
F. Abrantes ◽  
P. Cermeño ◽  
C. Lopes ◽  
O. Romero ◽  
L. Matos ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Coastal Upwelling ◽  
Net Primary Production ◽  
Regional Scale ◽  
Global Scale ◽  
Global Ocean ◽  
Nutrient Concentrations ◽  
Organic Carbon Content ◽  
Organic Carbon Burial

Abstract. Coastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica–precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia-Canary, Benguela, Peru-Humboldt, California and Somalia-Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. At the global-scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.

scholarly journals The ecological module of BOATS-1.0: a bioenergetically-constrained model of marine upper trophic levels suitable for studies of fisheries and ocean biogeochemistry

2015 ◽  
Vol 8 (12) ◽  
pp. 10145-10197
Author(s):  
D. A. Carozza ◽  
D. Bianchi ◽  
E. D. Galbraith
Keyword(s):  
Primary Production ◽  
Biomass Production ◽  
Net Primary Production ◽  
Global Scale ◽  
Trophic Levels ◽  
Fish Biomass ◽  
Earth System ◽  
Computationally Efficient ◽  
Ocean Biogeochemistry ◽  
Empirical Size

Abstract. Environmental change and the exploitation of marine resources have had profound impacts on marine communities, with potential implications for ocean biogeochemistry and food security. In order to study such global-scale problems, it is helpful to have computationally efficient numerical models that predict the first-order features of fish biomass production as a function of the environment, based on empirical and mechanistic understandings of marine ecosystems. Here we describe the ecological module of the BiOeconomic mArine Trophic Size-spectrum (BOATS) model, which takes an Earth-system approach to modeling fish biomass at the global scale. The ecological model is designed to be used on an Earth System model grid, and determines size spectra of fish biomass by explicitly resolving life history as a function of local temperature and net primary production. Biomass production is limited by the availability of photosynthetic energy to upper trophic levels, following empirical trophic efficiency scalings, and by well-established empirical temperature-dependent growth rates. Natural mortality is calculated using an empirical size-based relationship, while reproduction and recruitment depend on both the food availability to larvae from net primary production and the production of eggs by mature adult fish. We describe predicted biomass spectra and compare them to observations, and conduct a sensitivity study to determine how the change as a function of net primary production and temperature. The model relies on a limited number of parameters compared to similar modeling efforts, while retaining realistic representations of biological and ecological processes, and is computationally efficient, allowing extensive parameter-space analyses even when implemented globally. As such, it enables the exploration of the linkages between ocean biogeochemistry, climate, and upper trophic levels at the global scale, as well as a representation of fish biomass for idealized studies of fisheries.

Quantitative Assessment of the Impact of Human Activities on Terrestrial Net Primary Productivity in the Yangtze River Delta

2020 ◽  
Vol 12 (4) ◽  
pp. 1697
Author(s):  
Qing Huang ◽  
Fangyi Zhang ◽  
Qian Zhang ◽  
Hui Ou ◽  
Yunxiang Jin
Keyword(s):  
Primary Production ◽  
Human Activities ◽  
Yangtze River ◽  
Net Primary Production ◽  
Yangtze River Delta ◽  
River Delta ◽  
The Yangtze River ◽  
Continuous Growth ◽  
The Impact ◽  
The Yangtze River Delta

The continuous growth of the economy and population have promoted increasing consumption of natural resources, and raised concerns regarding the upper limits of the terrestrial ecosystems with biomass accessible for humanity. Here, human appropriation of net primary production (HANPP) was employed to assess the influence of human activities on terrestrial net primary production (NPP), and a detailed method was introduced to simulate the magnitude and trends of HANPP in the Yangtze River Delta. The results showed that the total HANPP of the Yangtze River Delta increased from 102.3 Tg C yr−1 to 142.2 Tg C yr−1, during 2005–2015, with an average of 121.3 Tg C yr−1. NPP changes induced by harvest (HANPPharv) made the dominant contribution of 79.9% to the total HANPP, and the increase of HANPPharv in cropland was the main driver of total HANPP growth, which was significantly correlated with the improvement in agricultural production conditions, such as total agricultural machinery power and effective irrigation area. The proportion of HANPP ranged from 59.3% to 72.4% of potential NPP during 2005–2015 in the Yangtze River Delta, and distinguishable differences in the proportions were found among the four provinces in the Yangtze River Delta. Shanghai had the largest proportion of 84.3%, while Zhejiang had the lowest proportion of 32.0%.

scholarly journals Diatoms Si uptake capacity drives carbon export in coastal upwelling systems

2016 ◽  
Vol 13 (14) ◽  
pp. 4099-4109 ◽  
Author(s):  
Fatima Abrantes ◽  
Pedro Cermeno ◽  
Cristina Lopes ◽  
Oscar Romero ◽  
Lélia Matos ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Coastal Upwelling ◽  
Net Primary Production ◽  
Regional Scale ◽  
Global Scale ◽  
Global Ocean ◽  
Nutrient Concentrations ◽  
Organic Carbon Content ◽  
Organic Carbon Burial

Abstract. Coastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica-precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia–Canary, Benguela, Peru–Humboldt, California, and Somalia–Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production, and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. On the global scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.

scholarly journals A comprehensive benchmarking system for evaluating global vegetation models

2013 ◽  
Vol 10 (5) ◽  
pp. 3313-3340 ◽  
Author(s):  
D. I. Kelley ◽  
I. C. Prentice ◽  
S. P. Harrison ◽  
H. Wang ◽  
M. Simard ◽  
...  
Keyword(s):  
Primary Production ◽  
Seasonal Cycle ◽  
Fire Regime ◽  
Net Primary Production ◽  
Annual Variability ◽  
Benchmark System ◽  
Vegetation Models ◽  
Global Vegetation ◽  
The Impact ◽  
Benchmarking System

Abstract. We present a benchmark system for global vegetation models. This system provides a quantitative evaluation of multiple simulated vegetation properties, including primary production; seasonal net ecosystem production; vegetation cover; composition and height; fire regime; and runoff. The benchmarks are derived from remotely sensed gridded datasets and site-based observations. The datasets allow comparisons of annual average conditions and seasonal and inter-annual variability, and they allow the impact of spatial and temporal biases in means and variability to be assessed separately. Specifically designed metrics quantify model performance for each process, and are compared to scores based on the temporal or spatial mean value of the observations and a "random" model produced by bootstrap resampling of the observations. The benchmark system is applied to three models: a simple light-use efficiency and water-balance model (the Simple Diagnostic Biosphere Model: SDBM), the Lund-Potsdam-Jena (LPJ) and Land Processes and eXchanges (LPX) dynamic global vegetation models (DGVMs). In general, the SDBM performs better than either of the DGVMs. It reproduces independent measurements of net primary production (NPP) but underestimates the amplitude of the observed CO2 seasonal cycle. The two DGVMs show little difference for most benchmarks (including the inter-annual variability in the growth rate and seasonal cycle of atmospheric CO2), but LPX represents burnt fraction demonstrably more accurately. Benchmarking also identified several weaknesses common to both DGVMs. The benchmarking system provides a quantitative approach for evaluating how adequately processes are represented in a model, identifying errors and biases, tracking improvements in performance through model development, and discriminating among models. Adoption of such a system would do much to improve confidence in terrestrial model predictions of climate change impacts and feedbacks.

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