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Community- and population-level changes in diatom size structure in a subarctic lake over the last two centuries.

Kerrigan EA, Irwin AJ, Finkel ZV - PeerJ (2015)

Bottom Line: Climate change over the last two centuries has been associated with significant shifts in diatom community structure in lakes from the high arctic to temperate latitudes.To test the hypotheses that recent climate warming selects for species of smaller size within communities and a decrease in the average size of species within populations, we quantified the size of individual diatom valves from 10 depths in a sediment core covering the last ∼200 years from a pristine subarctic lake.In the surface sediments that correspond to the recent decades when air temperatures have warmed, the mean size of valves in the diatom community has significantly decreased due to an increase in the proportion of smaller-sized planktonic diatom species.

View Article: PubMed Central - HTML - PubMed

Affiliation: Environmental Science Program, Mount Allison University , Sackville, New Brunswick , Canada.

ABSTRACT
Climate change over the last two centuries has been associated with significant shifts in diatom community structure in lakes from the high arctic to temperate latitudes. To test the hypotheses that recent climate warming selects for species of smaller size within communities and a decrease in the average size of species within populations, we quantified the size of individual diatom valves from 10 depths in a sediment core covering the last ∼200 years from a pristine subarctic lake. Over the last ∼200 years, changes in the relative abundance of species of different average size and changes in the average valve size of populations of species contribute equally to the changes in community size structure, but are often opposite in sign, compensating for one another and moderating temporal changes in community size structure. In the surface sediments that correspond to the recent decades when air temperatures have warmed, the mean size of valves in the diatom community has significantly decreased due to an increase in the proportion of smaller-sized planktonic diatom species.

No MeSH data available.


Map showing the location of Slipper Lake in the tundra of the Northwest Territories in Canada.
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fig-1: Map showing the location of Slipper Lake in the tundra of the Northwest Territories in Canada.

Mentions: Slipper Lake (110°W, 64°N; 460 m above sea level) is a remote, tundra lake, located approximately 50 km north of the current tree line in Canada’s Northwest Territories, 300 km from Yellowknife (Fig. 1). At the time of sampling, 1997, the lake had no history of human settlement or disturbance. The lake is 17.0 m deep, has a surface area of 1.9 km2 and a pH of 6.4. Climate in this region normally consists of short, cool summers and long, cold winters with a mean annual temperature of −10.5 °C (Rühland & Smol, 2005).


Community- and population-level changes in diatom size structure in a subarctic lake over the last two centuries.

Kerrigan EA, Irwin AJ, Finkel ZV - PeerJ (2015)

Map showing the location of Slipper Lake in the tundra of the Northwest Territories in Canada.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493642&req=5

fig-1: Map showing the location of Slipper Lake in the tundra of the Northwest Territories in Canada.
Mentions: Slipper Lake (110°W, 64°N; 460 m above sea level) is a remote, tundra lake, located approximately 50 km north of the current tree line in Canada’s Northwest Territories, 300 km from Yellowknife (Fig. 1). At the time of sampling, 1997, the lake had no history of human settlement or disturbance. The lake is 17.0 m deep, has a surface area of 1.9 km2 and a pH of 6.4. Climate in this region normally consists of short, cool summers and long, cold winters with a mean annual temperature of −10.5 °C (Rühland & Smol, 2005).

Bottom Line: Climate change over the last two centuries has been associated with significant shifts in diatom community structure in lakes from the high arctic to temperate latitudes.To test the hypotheses that recent climate warming selects for species of smaller size within communities and a decrease in the average size of species within populations, we quantified the size of individual diatom valves from 10 depths in a sediment core covering the last ∼200 years from a pristine subarctic lake.In the surface sediments that correspond to the recent decades when air temperatures have warmed, the mean size of valves in the diatom community has significantly decreased due to an increase in the proportion of smaller-sized planktonic diatom species.

View Article: PubMed Central - HTML - PubMed

Affiliation: Environmental Science Program, Mount Allison University , Sackville, New Brunswick , Canada.

ABSTRACT
Climate change over the last two centuries has been associated with significant shifts in diatom community structure in lakes from the high arctic to temperate latitudes. To test the hypotheses that recent climate warming selects for species of smaller size within communities and a decrease in the average size of species within populations, we quantified the size of individual diatom valves from 10 depths in a sediment core covering the last ∼200 years from a pristine subarctic lake. Over the last ∼200 years, changes in the relative abundance of species of different average size and changes in the average valve size of populations of species contribute equally to the changes in community size structure, but are often opposite in sign, compensating for one another and moderating temporal changes in community size structure. In the surface sediments that correspond to the recent decades when air temperatures have warmed, the mean size of valves in the diatom community has significantly decreased due to an increase in the proportion of smaller-sized planktonic diatom species.

No MeSH data available.