scholarly journals Variations of net primary productivity and phytoplankton community composition in the Indian sector of the Southern Ocean as estimated from ocean color remote sensing data

2012 ◽  
Vol 9 (10) ◽  
pp. 3875-3890 ◽  
Author(s):  
S. Takao ◽  
T. Hirawake ◽  
S. W. Wright ◽  
K. Suzuki
Keyword(s):  
Southern Ocean ◽  
Community Composition ◽  
Primary Productivity ◽  
Phytoplankton Community ◽  
Net Primary Productivity ◽  
Austral Summer ◽  
Remote Sensing Data ◽  
The Past ◽  
Phytoplankton Community Composition ◽  
Indian Sector

Abstract. Phytoplankton population dynamics play an important role in biogeochemical cycles in the Southern Ocean during austral summer. Recent environmental changes such as a rise in sea surface temperature (SST) are likely to impact on net primary productivity (NPP) and phytoplankton community composition. However, their spatiotemporal relationships are still unclear in the Southern Ocean. Here we assessed the relationships between NPP, dominant phytoplankton groups, and SST in the Indian sector of the Southern Ocean over the past decade (1997–2007) using satellite remote sensing data. As a result, we found a statistically significant reduction in NPP in the polar frontal zone over the past decade during austral summer. Moreover, the decrease in NPP positively correlated with the dominance of diatoms (Kendall's rank correlation τ = 0.60) estimated by a phytoplankton community composition model, but not correlated with SST. In the seasonal ice zone, NPP correlated with not only the dominance of diatoms positively (τ = 0.56), but also the dominance of haptophytes (τ = −0.54) and SST (τ = −0.54) negatively. Our results suggested that summer NPP values were strongly affected by the phytoplankton community composition in the Indian sector of the Southern Ocean.

scholarly journals Variations of net primary productivity and phytoplankton community composition in the Southern Ocean as estimated from ocean-color remote sensing data

2012 ◽  
Vol 9 (4) ◽  
pp. 4361-4398 ◽  
Author(s):  
S. Takao ◽  
T. Hirawake ◽  
S. W. Wright ◽  
K. Suzuki
Keyword(s):  
Remote Sensing ◽  
Southern Ocean ◽  
Community Composition ◽  
Primary Productivity ◽  
Phytoplankton Community ◽  
Net Primary Productivity ◽  
Austral Summer ◽  
Remote Sensing Data ◽  
The Past ◽  
Phytoplankton Community Composition

Abstract. Phytoplankton population dynamics play an important role in biogeochemical cycles in the Southern Ocean during austral summer. Recent environmental changes such as a rise in sea surface temperature (SST) are likely to impact on net primary productivity (NPP) and phytoplankton community composition. However, their spatiotemporal relationships are still unclear in the Southern Ocean. Here we assessed the relationships between NPP, dominant phytoplankton groups, and SST in the Indian sector of the Southern Ocean over the past decade (1997–2007) using satellite remote sensing data. As a result, we found a statistically significant reduction in NPP in the polar frontal zone over the past decade during austral summer. Moreover, the decrease in NPP positively correlated with the dominance of diatoms (Kendall's rank correlation τ = 0.60) estimated by a phytoplankton community composition model, but not correlated with SST. In the seasonal ice zone, NPP correlated with not only the dominance of diatoms positively (τ = 0.56), but also the dominance of haptophytes (τ = −0.54) and SST (τ = −0.54) negatively. Our results suggested that summer NPP values were strongly affected by the phytoplankton community composition in the Southern Ocean.

Assessment on 2000-2010 Ecosystem Function Changes of Yiwulvshan National Nature Scenic Area

2014 ◽  
Vol 1051 ◽  
pp. 489-494
Author(s):  
Xiao Chen Wang ◽  
Jing Hai Zhu ◽  
Yuan Man Hu ◽  
Wei Ling Liu
Keyword(s):  
Remote Sensing ◽  
Ecosystem Function ◽  
Primary Productivity ◽  
Water Conservation ◽  
Net Primary Productivity ◽  
Remote Sensing Data ◽  
Vegetation Coverage ◽  
The Past ◽  
Remote Sensing Technology ◽  
Sensing Technology

Based on the remote-sensing data and ground data, this study is conducted on the ecosystem function of Yiwulvshan National Nature Scenic Area (hereinafter as “Yiwulvshan Scenic Area”) from 2000 to 2010 with the GIS (geographic information system) and RS (remote sensing) technology, so as to provide reference for better environmental protection of the scenic area. It is shown from the results that there is no obvious change of land use in Yiwulvshan Scenic Area; while the capacity for soil and water conservation is slightly improved mainly due to increase of vegetation coverage; the vegetation net primary productivity declines somewhat about 5.27% in past 10 years; and biodiversity is slightly increased. As a whole, the ecosystem function of Yiwulvshan Scenic Area basically kept stable in the past 10 years, which indicated that the existing regulations can effectively protect the ecological function of the Scenic Area.

Variability in primary productivity and bio-optical properties in the Indian sector of the Southern Ocean during an austral summer

Polar Biology ◽  
2020 ◽  
Vol 43 (10) ◽  
pp. 1469-1492
Author(s):  
Anvita U. Kerkar ◽  
S. C. Tripathy ◽  
P. Minu ◽  
N. Baranval ◽  
P. Sabu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Southern Ocean ◽  
Primary Productivity ◽  
Austral Summer ◽  
Indian Sector

scholarly journals Factors controlling coccolithophore biogeography in the Southern Ocean

2018 ◽  
Vol 15 (22) ◽  
pp. 6997-7024 ◽  
Author(s):  
Cara Nissen ◽  
Meike Vogt ◽  
Matthias Münnich ◽  
Nicolas Gruber ◽  
F. Alexander Haumann
Keyword(s):  
Southern Ocean ◽  
Phytoplankton Community ◽  
Net Primary Productivity ◽  
Austral Summer ◽  
Relative Importance ◽  
Biotic Factors ◽  
Top Down ◽  
Light Levels ◽  
Resolution Model ◽  
High Resolution Model

Abstract. The biogeography of Southern Ocean phytoplankton controls the local biogeochemistry and the export of macronutrients to lower latitudes and depth. Of particular relevance is the competitive interaction between coccolithophores and diatoms, with the former being prevalent along the “Great Calcite Belt” (40–60∘ S), while diatoms tend to dominate the regions south of 60∘ S. To address the factors controlling coccolithophore distribution and the competition between them and diatoms, we use a regional high-resolution model (ROMS–BEC) for the Southern Ocean (24–78∘ S) that has been extended to include an explicit representation of coccolithophores. We assess the relative importance of bottom-up (temperature, nutrients, light) and top-down (grazing by zooplankton) factors in controlling Southern Ocean coccolithophore biogeography over the course of the growing season. In our simulations, coccolithophores are an important member of the Southern Ocean phytoplankton community, contributing 17 % to annually integrated net primary productivity south of 30∘ S. Coccolithophore biomass is highest north of 50∘ S in late austral summer, when light levels are high and diatoms become limited by silicic acid. Furthermore, we find top-down factors to be a major control on the relative abundance of diatoms and coccolithophores in the Southern Ocean. Consequently, when assessing potential future changes in Southern Ocean coccolithophore abundance, both abiotic (temperature, light, and nutrients) and biotic factors (interaction with diatoms and zooplankton) need to be considered.

scholarly journals Factors controlling coccolithophore biogeography in the Southern Ocean

2018 ◽  
Author(s):  
Cara Nissen ◽  
Meike Vogt ◽  
Matthias Münnich ◽  
Nicolas Gruber ◽  
F. Alexander Haumann
Keyword(s):  
Southern Ocean ◽  
Phytoplankton Community ◽  
Net Primary Productivity ◽  
Austral Summer ◽  
Relative Importance ◽  
Biotic Factors ◽  
Top Down ◽  
Light Levels ◽  
Resolution Model ◽  
High Resolution Model

Abstract. The biogeography of Southern Ocean phytoplankton controls not only the local biogeochemistry, but also the export of macronutrients to lower latitudes and depth. Of particular relevance is the interaction between coccolithophores and diatoms, with the former being prevalent along the "Great Calcite Belt" (40–60° S), while diatoms tend to dominate the regions south of 60° S. To address the factors controlling coccolithophore distribution and the competition between them and diatoms, we use a regional high-resolution model (ROMS-BEC) for the Southern Ocean (24–78° S) that has been extended to include an explicit representation of coccolithophores. We assess the relative importance of bottom-up (temperature, nutrients, light) and top-down (grazing by zooplankton) factors in controlling Southern Ocean coccolithophore biogeography over the course of the growing season. In our simulations, coccolithophores are an important member of the Southern Ocean phytoplankton community, contributing 15 % to annually integrated net primary productivity south of 30° S. Coccolithophore biomass is highest north of 50° S in late austral summer, when light levels are high and diatoms become silicate limited. Furthermore, we find top-down factors to be a major control on the relative abundance of diatoms and coccolithophores in the Southern Ocean. Consequently, when assessing potential future changes in Southern Ocean coccolithophore abundance, both abiotic (temperature, light, nutrients, pH) and biotic factors (interaction with diatoms and zooplankton) need to be considered.

scholarly journals Impact of Icebergs on Net Primary Productivity in the Southern Ocean

2016 ◽  
Author(s):  
Shuang-Ye Wu ◽  
Shugui Hou
Keyword(s):  
Southern Ocean ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Positive Impact ◽  
Remote Sensing Data ◽  
Positive Influence ◽  
Small Scale ◽  
Linear Regression Models ◽  
Comparable Amount ◽  
Aeolian Dust

Abstract. Productivity in the Southern Ocean (SO) is iron-limited, and supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine environment. However, recent studies show that icebergs could provide comparable amount of bioavailable iron to the SO as aeolian dust. In addition, small scale areal studies suggest increased concentrations of chlorophyll, krill, and seabirds surrounding icebergs. Based on previous research, this study aims to examine whether iceberg occurrence has a significant impact on marine productivity for the entire SO (south of 40° S), using remote sensing data of monthly iceberg amount and monthly ocean net primary productivity (NPP) covering the period 2002–2014. Using global and geographically weighted multiple linear regression models, and controlling for temperature, our analyses show that iceberg presence has a small, yet statistically significant, positive impact on the SO NPP. NPP in the SO is largely influenced by temperature, which could explain 43 % of the total variance in NPP with the standardized coefficient of 0.68. However, in places with iceberg presence, temperature influence weakens, indicated by lower partial temperature R2 (0.19) and standardized coefficient (0.45). Meanwhile, iceberg probability could independently explain 2 % of the NPP variance with a standardized coefficient of 0.15. Although small, this influence is statistically significant at 0.01 level. The geographically weighted regression model reveals spatial variation of these relationships. The results suggest that as iceberg quantity increases, their positive influence on NPP also increases, as indicated by increasing iceberg partial R2 and standardized coefficient in the models.

Sign in / Sign up

Export Citation Format

Share Document