Ecological community description using the food web, species abundance, and body size

Food webs are the complex networks of trophic interactions that stoke the metabolic fires of life. To understand what structures these interactions in natural communities, ecologists have developed simple models to capture their main architectural features. However, apparently realistic food webs can be generated by models invoking either predator–prey body-size hierarchies or evolutionary constraints as structuring mechanisms. As a result, this approach has not conclusively revealed which factors are the most important. Here we cut to the heart of this debate by directly comparing the influence of phylogeny and body size on food web architecture. Using data from 13 food webs compiled by direct observation, we confirm the importance of both factors. Nevertheless, phylogeny dominates in most networks. Moreover, path analysis reveals that the size-independent direct effect of phylogeny on trophic structure typically outweighs the indirect effect that could be captured by considering body size alone. Furthermore, the phylogenetic signal is asymmetric: closely related species overlap in their set of consumers far more than in their set of resources. This is at odds with several food web models, which take only the view-point of consumers when assigning interactions. The echo of evolutionary history clearly resonates through current food webs, with implications for our theoretical models and conservation priorities.

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Responses of food web to hypolimnetic aeration in Lake Vesijärvi

Hydrobiologia ◽

10.1007/s10750-020-04319-6 ◽

2020 ◽

Vol 847 (21) ◽

pp. 4503-4523 ◽

Cited By ~ 3

Author(s):

Jukka Ruuhijärvi ◽

Tommi Malinen ◽

Kirsi Kuoppamäki ◽

Pasi Ala-Opas ◽

Mika Vinni

Keyword(s):

Body Size ◽

Food Web ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Perca Fluviatilis ◽

Fish Predation ◽

Filamentous Cyanobacteria ◽

Low Oxygen ◽

High Quality ◽

Oxygen Conditions

AbstractWe studied the responses of a food web, especially fish and zooplankton, to summertime aeration, pumping of oxygen-rich epilimnetic water to the hypolimnion in Lake Vesijärvi, southern Finland. The aim of hypolimnetic aeration was to reduce internal loading of phosphorus from sediment. The population of smelt (Osmerus eperlanus L.), the main planktivore of the pelagial area, collapsed during the two 1st years of aeration due to increased temperature and low oxygen concentrations in the hypolimnion. The population recovered after the 4th year of hypolimnetic aeration, when oxygen conditions were improved. Despite elevated hypolimnetic temperature, smelt reached exceptionally high abundance, which led to a significant reduction in cladoceran body size. The density of perch (Perca fluviatilis L.) increased at first, but then decreased when the proportion of smelt and cyprinids increased. Biomasses of Daphnia decreased probably as a result of the disappearance of dark, low-oxygen deep-water refuge against fish predation and low availability of nutritionally high-quality algae. Occasionally filamentous cyanobacteria, such as turbulence tolerant Planktothrix agardhii (Gomont), were abundant, suggesting deteriorated food resources for zooplankton. The responses of food web were controversial with respect to the aim of the management, which was to prevent the occurrence of harmful algal blooms.

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Using a Macroecological Approach to Study Geographic Range, Abundance and Body Size in the Fossil Record

The Paleontological Society Papers ◽

10.1017/s1089332600001844 ◽

2010 ◽

Vol 16 ◽

pp. 117-141 ◽

Cited By ~ 2

Author(s):

S. Kathleen Lyons ◽

Felisa A. Smith

Keyword(s):

Body Size ◽

Fossil Record ◽

Species Abundance ◽

Geographic Range ◽

Species Abundance Distribution ◽

Abundance Distribution ◽

Geographic Ranges ◽

Spatial And Temporal Scales ◽

Geographic Range Size ◽

Fossil Data

Macroecology is a rapidly growing sub-discipline within ecology that is concerned with characterizing statistical patterns of species' abundance, distribution and diversity at spatial and temporal scales typically ignored by traditional ecology. Both macroecology and paleoecology are concerned with answering similar questions (e.g., understanding the factors that influence geographic ranges, or the way that species assemble into communities). As such, macroecological methods easily lend themselves to many paleoecological questions. Moreover, it is possible to estimate the variables of interest to macroecologists (e.g., body size, geographic range size, abundance, diversity) using fossil data. Here we describe the measurement and estimation of the variables used in macroecological studies and potential biases introduced by using fossil data. Next we describe the methods used to analyze macroecological patterns and briefly discuss the current understanding of these patterns. This chapter is by no means an exhaustive review of macroecology and its methods. Instead, it is an introduction to macroecology that we hope will spur innovation in the application of macroecology to the study of the fossil record.

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