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Shorter food chain length in ancient lakes: evidence from a global synthesis.

Doi H, Vander Zanden MJ, Hillebrand H - PLoS ONE (2012)

Bottom Line: We examined historical effects on FCL in large lakes spanning >6 orders of magnitude in age.We found that food chains in the world's ancient lakes (n = 8) were significantly shorter than in recently formed lakes (n = 10) and reservoirs (n = 3), despite the fact that ancient lakes harbored much higher species richness, including many endemic species.Our results highlight a counter-intuitive and poorly-understood role of evolutionary history in shaping key food web properties such as FCL.

View Article: PubMed Central - PubMed

Affiliation: Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, Wilhelmshaven, Germany. doih@hiroshima-u.ac.jp

ABSTRACT
Food webs may be affected by evolutionary processes, and effective evolutionary time ultimately affects the probability of species evolving to fill the niche space. Thus, ecosystem history may set important evolutionary constraints on community composition and food web structure. Food chain length (FCL) has long been recognized as a fundamental ecosystem attribute. We examined historical effects on FCL in large lakes spanning >6 orders of magnitude in age. We found that food chains in the world's ancient lakes (n = 8) were significantly shorter than in recently formed lakes (n = 10) and reservoirs (n = 3), despite the fact that ancient lakes harbored much higher species richness, including many endemic species. One potential factor leading to shorter FCL in ancient lakes is an increasing diversity of trophic omnivores and herbivores. Speciation could simply broaden the number of species within a trophic group, particularly at lower trophic levels and could also lead to a greater degree of trophic omnivory. Our results highlight a counter-intuitive and poorly-understood role of evolutionary history in shaping key food web properties such as FCL.

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Correlations between food-chain length, latitude, log10 surface area (km2), log10 volume (km3), mean depth (m), log10 age of lake (year, the points of Lake Kyoga and Victoria were plotted as 400,000 year), and log10 (endemic species number +1).Symbols mean the origin of lakes as Fig.1A.
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pone-0037856-g002: Correlations between food-chain length, latitude, log10 surface area (km2), log10 volume (km3), mean depth (m), log10 age of lake (year, the points of Lake Kyoga and Victoria were plotted as 400,000 year), and log10 (endemic species number +1).Symbols mean the origin of lakes as Fig.1A.

Mentions: We found that FCL in ancient lakes was significantly shorter than glacial lakes and reservoirs (ANOVA, p<0.001, multiple comparison, p<0.001, Fig. 1A). The shortest food chains were consistently in the oldest lakes (Fig. 1B). FCL of reservoirs tended to be shorter than that of glacial lakes, although the difference was not significant (Fig. 1A). FCL was not correlated with lake area, lake volume, or mean depth (Pearson's correlation coefficient, /r/ <0.35, p>0.16, Fig. 2), but increased with latitude, as many ancient lakes are tropical (r = 0.60, p<0.05, Fig. 2). There was a strong positive relationship between lake age and number of endemic species (r = 0.81, p<0.001).


Shorter food chain length in ancient lakes: evidence from a global synthesis.

Doi H, Vander Zanden MJ, Hillebrand H - PLoS ONE (2012)

Correlations between food-chain length, latitude, log10 surface area (km2), log10 volume (km3), mean depth (m), log10 age of lake (year, the points of Lake Kyoga and Victoria were plotted as 400,000 year), and log10 (endemic species number +1).Symbols mean the origin of lakes as Fig.1A.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368915&req=5

pone-0037856-g002: Correlations between food-chain length, latitude, log10 surface area (km2), log10 volume (km3), mean depth (m), log10 age of lake (year, the points of Lake Kyoga and Victoria were plotted as 400,000 year), and log10 (endemic species number +1).Symbols mean the origin of lakes as Fig.1A.
Mentions: We found that FCL in ancient lakes was significantly shorter than glacial lakes and reservoirs (ANOVA, p<0.001, multiple comparison, p<0.001, Fig. 1A). The shortest food chains were consistently in the oldest lakes (Fig. 1B). FCL of reservoirs tended to be shorter than that of glacial lakes, although the difference was not significant (Fig. 1A). FCL was not correlated with lake area, lake volume, or mean depth (Pearson's correlation coefficient, /r/ <0.35, p>0.16, Fig. 2), but increased with latitude, as many ancient lakes are tropical (r = 0.60, p<0.05, Fig. 2). There was a strong positive relationship between lake age and number of endemic species (r = 0.81, p<0.001).

Bottom Line: We examined historical effects on FCL in large lakes spanning >6 orders of magnitude in age.We found that food chains in the world's ancient lakes (n = 8) were significantly shorter than in recently formed lakes (n = 10) and reservoirs (n = 3), despite the fact that ancient lakes harbored much higher species richness, including many endemic species.Our results highlight a counter-intuitive and poorly-understood role of evolutionary history in shaping key food web properties such as FCL.

View Article: PubMed Central - PubMed

Affiliation: Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, Wilhelmshaven, Germany. doih@hiroshima-u.ac.jp

ABSTRACT
Food webs may be affected by evolutionary processes, and effective evolutionary time ultimately affects the probability of species evolving to fill the niche space. Thus, ecosystem history may set important evolutionary constraints on community composition and food web structure. Food chain length (FCL) has long been recognized as a fundamental ecosystem attribute. We examined historical effects on FCL in large lakes spanning >6 orders of magnitude in age. We found that food chains in the world's ancient lakes (n = 8) were significantly shorter than in recently formed lakes (n = 10) and reservoirs (n = 3), despite the fact that ancient lakes harbored much higher species richness, including many endemic species. One potential factor leading to shorter FCL in ancient lakes is an increasing diversity of trophic omnivores and herbivores. Speciation could simply broaden the number of species within a trophic group, particularly at lower trophic levels and could also lead to a greater degree of trophic omnivory. Our results highlight a counter-intuitive and poorly-understood role of evolutionary history in shaping key food web properties such as FCL.

Show MeSH
Related in: MedlinePlus