Abyssal food limitation, ecosystem structure and climate change

2008 ◽  
Vol 23 (9) ◽  
pp. 518-528 ◽  
Author(s):  
C SMITH ◽  
F DELEO ◽  
A BERNARDINO ◽  
A SWEETMAN ◽  
P ARBIZU
Keyword(s):  
Climate Change ◽  
Food Limitation ◽  
Ecosystem Structure

scholarly journals Latitudinal patterns in intertidal ecosystem structure in West Greenland suggest resilience to climate change

2021 ◽  
Author(s):  
Jakob Thyrring ◽  
Susse Wegeberg ◽  
Martin E Blicher ◽  
Dorte Krause-Jensen ◽  
Signe H&oslashgslund ◽  
...  
Keyword(s):  
Climate Change ◽  
Ascophyllum Nodosum ◽  
Tidal Range ◽  
Environmental Drivers ◽  
Small Scale ◽  
Ecosystem Structure ◽  
Assemblage Composition ◽  
West Greenland ◽  
Functional Changes ◽  
Time Substitution

Climate change has ecosystem-wide cascading effects. Little is known, however, about the resilience of Arctic marine ecosystems to environmental change. Here we quantify and compare large-scale patterns in rocky intertidal biomass, coverage and zonation in six regions along a north-south gradient of temperature and ice conditions in West Greenland (60-72°N). We related the level and variation in assemblage composition, biomass and coverage to latitudinal-scale environmental drivers. Across all latitudes, the intertidal assemblage was dominated by a core of stress-tolerant foundation species that constituted >95% of the biomass. Hence, canopy-forming macroalgae, represented by Fucus distichus subsp. evanescens and F. vesiculosus and, up to 69 °N, also Ascophyllum nodosum, together with Semibalanus balanoides, occupied >70% of the vertical tidal range in all regions. Thus, a similar functional assemblage composition occurred across regions, and no latitudinal depression was observed. The most conspicuous difference in species composition from south to north was that three common species (the macroalgae Ascophyllum nodosum, the amphipod Gammarus setosus and the gastropod Littorina obtusata) disappeared from the mid-intertidal, although at different latitudes. There were no significant relationships between assemblage metrics and air temperature or sea ice coverage as obtained from weather stations and satellites, respectively. Although the mean biomass decreased >50% from south to north, local biomass in excess of 10 000 g ww m-2 was found even at the northernmost site, demonstrating the patchiness of this habitat and the effect of small-scale variation in environmental characteristics. Hence, using the latitudinal gradient in a space-for-time substitution, our results suggest that while climate modification may lead to an overall increase in the intertidal biomass in north Greenland, it is unlikely to drive dramatic functional changes in ecosystem structure in the near future. Our dataset provides an important baseline for future studies to verify these predictions for Greenlands intertidal zone.

scholarly journals Cladoceran body size distributions along temperature and trophic gradients in the conterminous USA

2020 ◽  
Author(s):  
John R Beaver ◽  
Claudia E Tausz ◽  
Katherine M Black ◽  
Benjamin A Bolam
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Multiple Regression ◽  
Water Clarity ◽  
Total Biomass ◽  
Ecosystem Structure ◽  
Strong Positive Correlation ◽  
Size Distributions ◽  
Strong Negative Correlation ◽  
Lake Ecosystems

Abstract Body size is an important functional trait that can be indicative of ecosystem structure and constraints on growth. Both increasing temperatures and eutrophication of lakes have been associated with a shift toward smaller zooplankton taxa. This is important in the context of climate change, as most aquatic habitats are expected to warm over the coming decades. Our study uses data from over 1000 lakes surveyed across a range of latitudes (26–49°N) and surface temperatures (10–35°C) in the USA during the spring/summer of 2012 to characterize pelagic cladoceran body size distributions. We used univariate and multiple regression modeling to determine which environmental parameters were strongly correlated to cladoceran body size. A strong positive correlation was observed between cladoceran body size and latitude, while a strong negative correlation was observed between cladoceran body size and water temperature. The ratio of zooplankton to phytoplankton, as well as relative total biomass contributions by cladocerans, decreased as trophic state increased. Multiple regression identified temperature-related variables and water clarity as significantly affecting cladoceran body size. These observations demonstrate the dual threat of climate change and eutrophication on lake ecosystems and highlight potential changes in biogeographical patterns of zooplankton as lakes warm.

scholarly journals Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability

2007 ◽  
Vol 362 (1488) ◽  
pp. 2351-2365 ◽  
Author(s):  
P.N Trathan ◽  
J Forcada ◽  
E.J Murphy
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Food Webs ◽  
Time Scales ◽  
Trophic Level ◽  
Global Ocean ◽  
Ecosystem Structure ◽  
Marine Predator ◽  
Enso Events ◽  
Biological Responses

The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly in the high-latitude polar regions. In these regions, even small temperature changes can potentially lead to major environmental perturbations. Climate change is likely to be regional and may be expressed in various ways, including alterations to climate and weather patterns across a variety of time-scales that include changes to the long interdecadal background signals such as the development of the El Niño–Southern Oscillation (ENSO). Oscillating climate signals such as ENSO potentially provide a unique opportunity to explore how biological communities respond to change. This approach is based on the premise that biological responses to shorter-term sub-decadal climate variability signals are potentially the best predictor of biological responses over longer time-scales. Around the Southern Ocean, marine predator populations show periodicity in breeding performance and productivity, with relationships with the environment driven by physical forcing from the ENSO region in the Pacific. Wherever examined, these relationships are congruent with mid-trophic-level processes that are also correlated with environmental variability. The short-term changes to ecosystem structure and function observed during ENSO events herald potential long-term changes that may ensue following regional climate change. For example, in the South Atlantic, failure of Antarctic krill recruitment will inevitably foreshadow recruitment failures in a range of higher trophic-level marine predators. Where predator species are not able to accommodate by switching to other prey species, population-level changes will follow. The Southern Ocean, though oceanographically interconnected, is not a single ecosystem and different areas are dominated by different food webs. Where species occupy different positions in different regional food webs, there is the potential to make predictions about future change scenarios.

scholarly journals Geo-spatial Assessment of Flood Vulnerability Areas of the Gaza Strip Towards Preparedness and Humanitarian Response Planning

2021 ◽  
pp. 35-44
Keyword(s):  
Climate Change ◽  
Spatial Information ◽  
Social Issues ◽  
Flood Hazard ◽  
Gaza Strip ◽  
Negative Influence ◽  
Ecosystem Structure ◽  
Flood Vulnerability ◽  
Humanitarian Response ◽  
Response Planning

Nowadays, flood and drought will become more common as climate change causes. Due to climate change consequences, flood occurrence and its impact on Gaza people have been of great concern to the Palestinian water authority, as it has a negative influence on various humanitarian and social issues. The hazards and damages resulted by flooding cause loss of life, property, displacement of people and disruption of socioeconomic activities. This research focuses on assessing Gaza Strip vulnerability to flooding using analysis of GIS-based spatial information. Not only did it consider the physical-environmental flood vulnerability, it also investigated social flood vulnerability aspects e.g., population densities. Soil and slope were considered to have the highest weight in the vulnerability mapping, as they represent the main factors in urban hydro-ecosystem structure. The long term average rainfall, a climate function factor, has the lowest weight, because it could be considered as a threat factor in addition to a vulnerability factor. This research demonstrates that urban area and population density as strong factors influencing flood vulnerability for humanitarian and saving life purposes. The findings of Geospatial analysis were used to map vulnerable areas likely to be affected in the event of flood hazard and suggest future interventions and related adaptation strategies in Gaza areas for flood mitigation.

scholarly journals Projected decreases in future marine export production: the role of the carbon flux through the upper ocean ecosystem

2015 ◽  
Vol 12 (23) ◽  
pp. 19941-19998 ◽  
Author(s):  
C. Laufkötter ◽  
M. Vogt ◽  
N. Gruber ◽  
O. Aumont ◽  
L. Bopp ◽  
...  
Keyword(s):  
Climate Change ◽  
Net Primary Production ◽  
Marine Ecosystem ◽  
Upper Ocean ◽  
Ecosystem Structure ◽  
Relative Role ◽  
Ecosystem Models ◽  
Export Production ◽  
Wide Range

Abstract. Accurate projections of marine particle export production (EP) are crucial for predicting the response of the marine carbon cycle to climate change, yet models show a wide range in both global EP and their responses to climate change. This is, in part, due to EP being the net result of a series of processes, starting with net primary production (NPP) in the sunlit upper ocean, followed by the formation of particulate organic matter and the subsequent sinking and remineralization of these particles, with each of these processes responding differently to changes in environmental conditions. Here, we compare future projections in EP over the 21st century, generated by four marine ecosystem models under IPCC's high emission scenario RCP8.5, and determine the processes driving these changes. The models simulate small to modest decreases in global EP between −1 and −12 %. Models differ greatly with regard to the drivers causing these changes. Among them, the formation of particles is the most uncertain process with models not agreeing on either magnitude or the direction of change. The removal of the sinking particles by remineralization is simulated to increase in the low and intermediate latitudes in three models, driven by either warming-induced increases in remineralization or slower particle sinking, and show insignificant changes in the remaining model. Changes in ecosystem structure, particularly the relative role of diatoms matters as well, as diatoms produce larger and denser particles that sink faster and are partly protected from remineralization. Also this controlling factor is afflicted with high uncertainties, particularly since the models differ already substantially with regard to both the initial (present-day) distribution of diatoms (between 11–94 % in the Southern Ocean) and the diatom contribution to particle formation (0.6–3.8 times lower/higher than their contribution to biomass). As a consequence, changes in diatom concentration are a strong driver for EP changes in some models but of low significance in others. Observational and experimental constraints on ecosystem structure and how the fixed carbon is routed through the ecosystem to produce export production are urgently needed in order to improve current generation ecosystem models and their ability to project future changes.

Managerial perceptions and responses to climate change in Missouri state parks and historic sites

2019 ◽  
Author(s):  
◽  
Ojetunde Ayodeji Ojewola
Keyword(s):  
Climate Change ◽  
Risk Perceptions ◽  
Outdoor Recreation ◽  
Political Orientation ◽  
Extreme Weather Events ◽  
Ecosystem Structure ◽  
State Parks ◽  
Historic Sites ◽  
Audience Segmentation ◽  
Change Perceptions

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Climate change has been described as one of the greatest, long-term challenges facing modern society. Its impacts range from alteration of ecosystem structure and function to human health and welfare. Few studies have focused on the social aspects of climate change, and none on parks and protected areas, in the Midwest. The perceptions of park managers are an important, but overlooked dimension of climate change and outdoor recreation policy. This dissertation used a multi-method approach to examine, explore and explain the climate change perceptions of those employed at Missouri state parks and historic sites in year 2016. A total of 495 surveys were administered to MSP employees using online and mail methods, and 405 responded, yielding 82% response rate. A qualitative analysis was conducted with district park managers to gain a deeper understanding of system-wide responses to climate change. Spatial analysis was used to map the distribution of extreme weather events across Missouri in relation to vulnerability and resilience. This approach allowed for triangulation, thus increasing credibility. Findings from this study supported the hypothesized socio-demographic differences among climate change perceptions of park employees. Political orientation, gender, education and job title were significant with belief in climate change, concern about climate-related impacts, support for pro-environmental behavior and adaptation and trust in source of climate change information. Findings also revealed the influence of cognition, affect, concern, and other socio-cultural factors on climate change risk perceptions using hierarchical multiple regression analysis, accounting for 73% of the variance. This study identified and explained several important indicators for shaping personal, societal and place-based risk perceptions. Linear discriminant analysis was used for audience segmentation. This procedure resulted in six different groups (Alarmed, Concerned, Cautious, Disengaged, Doubtful, and Dismissive) characterized by their belief, behavior, policy preference, and issue engagement. Findings showed differences among park employees and highlighted the importance of audience segmentation for messaging climate change communication. Perceived vulnerability and resilience were collapsed into a 2X2 typology, and used to construct a 3-point continuum (1=high vulnerability / low resilience to 3=low vulnerability / high resilience). State park employees thought the system was more resilient and less vulnerable to climate change than what other indicators showed. A deductive qualitative approach was used to confirm and develop a conceptual climate change resilience model, linking theory with practice. The newly developed model described the process of recovery from climate-related impact within the state park system using resilience theory. Results of this study may be useful for environmental decision-making behavior, policy formation and adaptation strategy development within the park system, in addition to some important theoretical contributions.

scholarly journals Climate Change Effects on Aquatic Biota, Ecosystem Structure and Function

AMBIO ◽  
2006 ◽  
Vol 35 (7) ◽  
pp. 359-369 ◽  
Author(s):  
Frederick J. Wrona ◽  
Terry D. Prowse ◽  
James D. Reist ◽  
John E. Hobbie ◽  
Lucie M. J. Lévesque ◽  
...  
Keyword(s):  
Climate Change ◽  
Structure And Function ◽  
Ecosystem Structure ◽  
Aquatic Biota ◽  
Climate Change Effects ◽  
And Function ◽  
Ecosystem Structure And Function

The Impact of Climate Change on the River Jordan-Lake Kinneret (Israel) Ecosystem

2020 ◽  
pp. 1-12
Author(s):  
Moshe Gophen
Keyword(s):  
Climate Change ◽  
Lake Water ◽  
Regional Climate ◽  
Nitrogen Deficiency ◽  
Regional Climate Change ◽  
Lake Kinneret ◽  
Ecosystem Structure ◽  
Nutrient Inputs ◽  
Lake Water Level ◽  
The Impact

The long-term record of River Jordan-Lake Kinneret ecosystem indicates some significant climate condition changes: water temperature increase, decline in rainfall, and diminishing river discharges and lake water inflows accompanied by a reduction in nitrogen and a slight increase in phosphorus in the Lake upper layers (Epilimnion). Lake Water level decreased, Prolongation of Residence Time was documented, nutrient inputs and dynamics modifications resulting water quality deterioration. As a result of temperature elevation and nitrogen deficiency, the biomass of Peridinium spp significantly reduced and was replaced by Cyanobacterial biomass enhancement. Dryness trend expressed as enhanced frequency of drought seasons initiated an elevation of lake water salinity. It has been suggested that these changes in the phytoplankton community structure are caused by regional climate change. This study evaluates a multi-annual respective approach although the summer is the most critical. The objective of this research is evaluate the background of the ecosystem structure modification aimed at define future potential management design.

scholarly journals Projected decreases in future marine export production: the role of the carbon flux through the upper ocean ecosystem

2016 ◽  
Vol 13 (13) ◽  
pp. 4023-4047 ◽  
Author(s):  
Charlotte Laufkötter ◽  
Meike Vogt ◽  
Nicolas Gruber ◽  
Olivier Aumont ◽  
Laurent Bopp ◽  
...  
Keyword(s):  
Climate Change ◽  
Net Primary Production ◽  
Marine Ecosystem ◽  
Upper Ocean ◽  
Ecosystem Structure ◽  
Relative Role ◽  
Ecosystem Models ◽  
Export Production ◽  
Wide Range

Abstract. Accurate projections of marine particle export production (EP) are crucial for predicting the response of the marine carbon cycle to climate change, yet models show a wide range in both global EP and their responses to climate change. This is, in part, due to EP being the net result of a series of processes, starting with net primary production (NPP) in the sunlit upper ocean, followed by the formation of particulate organic matter and the subsequent sinking and remineralisation of these particles, with each of these processes responding differently to changes in environmental conditions. Here, we compare future projections in EP over the 21st century, generated by four marine ecosystem models under the high emission scenario Representative Concentration Pathways (RCP) 8.5 of the Intergovernmental Panel on Climate Change (IPCC), and determine the processes driving these changes. The models simulate small to modest decreases in global EP between −1 and −12 %. Models differ greatly with regard to the drivers causing these changes. Among them, the formation of particles is the most uncertain process with models not agreeing on either magnitude or the direction of change. The removal of the sinking particles by remineralisation is simulated to increase in the low and intermediate latitudes in three models, driven by either warming-induced increases in remineralisation or slower particle sinking, and show insignificant changes in the remaining model. Changes in ecosystem structure, particularly the relative role of diatoms matters as well, as diatoms produce larger and denser particles that sink faster and are partly protected from remineralisation. Also this controlling factor is afflicted with high uncertainties, particularly since the models differ already substantially with regard to both the initial (present-day) distribution of diatoms (between 11–94 % in the Southern Ocean) and the diatom contribution to particle formation (0.6–3.8 times higher than their contribution to biomass). As a consequence, changes in diatom concentration are a strong driver for EP changes in some models but of low significance in others. Observational and experimental constraints on ecosystem structure and how the fixed carbon is routed through the ecosystem to produce export production are urgently needed in order to improve current generation ecosystem models and their ability to project future changes.

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