scholarly journals Late Quaternary chironomid community structure shaped by rate and magnitude of climate change

2021 ◽  
Author(s):  
Roseanna J. Mayfield ◽  
Peter G. Langdon ◽  
C. Patrick Doncaster ◽  
John A. Dearing ◽  
Rong Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Late Quaternary ◽  
Chironomid Community

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

scholarly journals Response of ocean phytoplankton community structure to climate change over the 21st century: partitioning the effects of nutrients, temperature and light

2010 ◽  
Vol 7 (12) ◽  
pp. 3941-3959 ◽  
Author(s):  
I. Marinov ◽  
S. C. Doney ◽  
I. D. Lima
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Sea Ice ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Vertical Mixing ◽  
Phytoplankton Community Structure ◽  
Marginal Sea ◽  
Small Phytoplankton ◽  
The Impact

Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.

Quaternary Mammal Communities: Relevance of the Individualistic Response and Non-Analogue Faunas

2005 ◽  
Vol 11 ◽  
pp. 141-158 ◽  
Author(s):  
Russell W. Graham
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Natural Experiment ◽  
Late Quaternary ◽  
Global Climate ◽  
Land Use Management ◽  
Change Analysis ◽  
Climate Fluctuations ◽  
Core Species ◽  
Mammal Communities

Frequent and repeated climate fluctuations of the late Quaternary serve as a “natural experiment” for the response of species to environmental change. Analysis of the FAUNMAP database documents individualistic shifts in the geographic distributions for late Quaternary mammals. However, because the individualistic response is not necessarily random and because many species share similar niche parameters, it is possible that some species appear to form coherent groups of core species. In reality their dispersals are individualistic with regard to rate and timing. The individualistic response of mammals, as well as that of other organisms, has created late Quaternary communities without modern analogues. This concept has profound implications for the design of biological reserves and for land use management with respect to future global climate change. However, the relevance of non-analogue mammal communities has been challenged by Alroy (1999), who claims that non-analogue associations were not common in the Quaternary and that they appeared to occur in both the Pleistocene and Holocene. Reexamination of his analysis shows that he employed a different definition for non-analogue faunas and that his methods of analyses created artificially low counts of non-analogue communities and consequently an underestimate of their importance.

scholarly journals Late Quaternary climate change in the north-eastern highlands of Ethiopia: A high resolution 15,600 year diatom and pigment record from Lake Hayk

2018 ◽  
Vol 202 ◽  
pp. 166-181 ◽  
Author(s):  
Katie L. Loakes ◽  
David B. Ryves ◽  
Henry F. Lamb ◽  
Frank Schäbitz ◽  
Michael Dee ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Late Quaternary ◽  
The North ◽  
Quaternary Climate ◽  
North Eastern ◽  
Eastern Highlands

Climate change effects on soil microarthropod abundance and community structure

2011 ◽  
Vol 47 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Paul Kardol ◽  
W. Nicholas Reynolds ◽  
Richard J. Norby ◽  
Aimée T. Classen
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Climate Change Effects ◽  
Soil Microarthropod

scholarly journals Climate change in the recent geological past and the near future. Predicting its impacts: a Review

2019 ◽  
Vol 55 (1) ◽  
pp. 260
Author(s):  
Constantinos Perisoratis
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Climatic Change ◽  
Sea Level ◽  
Scientific Community ◽  
Climate Changes ◽  
Late Quaternary ◽  
The Earth ◽  
Geological Past ◽  
Near Future

The climate changes are necessarily related to the increase of the Earth’s temperature, resulting in a sea level rise. Such continuous events, were taking place with minor and greater intensity, during the alternation of warm and cool periods in the Earth during the Late Quaternary and the Holocene periods. However, a particularly significant awareness has taken place in the scientific community, and consequently in the greater public, in the last decades: that a climatic change will take place soon, or it is on-going, and that therefore it is important to undertake drastic actions. However, such a climatic change has not been recorded yet, and hence the necessary actions are not required, for the time being.

scholarly journals Plant genotype controls wetland soil microbial functioning in response to sea-level rise

2021 ◽  
Vol 18 (23) ◽  
pp. 6133-6146
Author(s):  
Hao Tang ◽  
Susanne Liebner ◽  
Svenja Reents ◽  
Stefanie Nolte ◽  
Kai Jensen ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Microbial Community ◽  
Sea Level Rise ◽  
Sea Level ◽  
Microbial Community Structure ◽  
Soil Microbial Communities ◽  
Litter Breakdown ◽  
Plant Genotype ◽  
Soil Microbial

Abstract. Climate change can strongly alter soil microbial functioning via plant–microbe interactions, often with important consequences for ecosystem carbon and nutrient cycling. Given the high degree of intraspecific trait variability in plants, it has been hypothesized that genetic shifts within plant species yield a large potential to control the response of plant–microbe interactions to climate change. Here we examined if sea-level rise and plant genotype interact to affect soil microbial communities in an experimental coastal wetland system, using two known genotypes of the dominant salt-marsh grass Elymus athericus characterized by differences in their sensitivity to flooding stress – i.e., a tolerant genotype from low-marsh environments and an intolerant genotype from high-marsh environments. Plants were exposed to a large range of flooding frequencies in a factorial mesocosm experiment, and soil microbial activity parameters (exo-enzyme activity and litter breakdown) and microbial community structure were assessed. Plant genotype mediated the effect of flooding on soil microbial community structure and determined the presence of flooding effects on exo-enzyme activities and belowground litter breakdown. Larger variability in microbial community structure, enzyme activities, and litter breakdown in soils planted with the intolerant plant genotype supported our general hypothesis that effects of climate change on soil microbial activity and community structure can depend on plant intraspecific genetic variation. In conclusion, our data suggest that adaptive genetic variation in plants could suppress or facilitate the effects of sea-level rise on soil microbial communities. If this finding applies more generally to coastal wetlands, it yields important implications for our understanding of ecosystem–climate feedbacks in the coastal zone.

Sign in / Sign up

Export Citation Format

Share Document