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

Ecography ◽  
2021 ◽  
Author(s):  
Jakob Thyrring ◽  
Susse Wegeberg ◽  
Martin E. Blicher ◽  
Dorte Krause‐Jensen ◽  
Signe Høgslund ◽  
...  

2021 ◽  
Author(s):  
Jakob Thyrring ◽  
Susse Wegeberg ◽  
Martin E Blicher ◽  
Dorte Krause-Jensen ◽  
Signe H&oslashgslund ◽  
...  

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.



2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.





2008 ◽  
Vol 23 (9) ◽  
pp. 518-528 ◽  
Author(s):  
C SMITH ◽  
F DELEO ◽  
A BERNARDINO ◽  
A SWEETMAN ◽  
P ARBIZU


Author(s):  
John R Beaver ◽  
Claudia E Tausz ◽  
Katherine M Black ◽  
Benjamin A Bolam

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.



2014 ◽  
Vol 119 (12) ◽  
pp. 2619-2634 ◽  
Author(s):  
Jerome R. Mayaud ◽  
Alison F. Banwell ◽  
Neil S. Arnold ◽  
Ian C. Willis


2007 ◽  
Vol 362 (1488) ◽  
pp. 2351-2365 ◽  
Author(s):  
P.N Trathan ◽  
J Forcada ◽  
E.J Murphy

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.



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.



2015 ◽  
Vol 12 (23) ◽  
pp. 19941-19998 ◽  
Author(s):  
C. Laufkötter ◽  
M. Vogt ◽  
N. Gruber ◽  
O. Aumont ◽  
L. Bopp ◽  
...  

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.



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