Faculty Opinions recommendation of Biodiversity enhances ecosystem multifunctionality across trophic levels and habitats.

AbstractHigher levels of diversity within trophic levels are necessary to sustain multiple ecosystem functions, but this diversity-multifunctionality relationship peaks at intermediate percent-function thresholds. The presence of multiple trophic levels, or trophic complexity, affects ecosystem multifunctionality but its effect on the diversity-multifunctionality relationship has not been experimentally tested. To test the sensitivity of the diversity-multifunctionality relationship to trophic complexity, we simultaneously manipulated plant diversity and trophic complexity in a multifactorial tall-grass prairie mesocosm experiment at Cedar Creek, Minnesota, USA. Trophic complexity altered the diversity-multifunctionality relationship, by lowering the height of the peak as well as by shifting to a negative effect at lower thresholds. These outcomes are consistent with decreases in both the “jack-of-all-trades” effect and complementarity among plant species. Our findings suggest that trophic complexity, which is experiencing widespread declines on a global scale, is important for sustaining ecosystem multifunctionality in the face of equally widespread declines in biodiversity.

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Relationship between morphometrics and trophic levels in deep-sea fishes

Marine Ecology Progress Series ◽

10.3354/meps13243 ◽

2020 ◽

Vol 637 ◽

pp. 225-235 ◽

Cited By ~ 1

Author(s):

MA Ladds ◽

MH Pinkerton ◽

E Jones ◽

LM Durante ◽

MR Dunn

Keyword(s):

Stable Isotopes ◽

Trophic Level ◽

Deep Sea ◽

Strong Relationship ◽

Ecosystem Model ◽

Trophic Levels ◽

Fish Size ◽

Wide Range ◽

Gape Size ◽

Morphological Variables

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.

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Faculty Opinions recommendation of Light, nutrients, and food-chain length constrain planktonic energy transfer efficiency across multiple trophic levels.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1131968.589080 ◽

2008 ◽

Author(s):

Robert Sterner

Keyword(s):

Energy Transfer ◽

Chain Length ◽

Food Chain ◽

Energy Transfer Efficiency ◽

Trophic Levels ◽

Transfer Efficiency ◽

Food Chain Length

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ENERGY TRANSFER EFFICIENCIES ON LOWER TROPHIC LEVELS WITH INTENSIVE OYSTER FARMING IN HIROSHIMA BAY, JAPAN

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.21610/conferencearticle_58b43169dc569 ◽

2017 ◽

Author(s):

Akira Umehara ◽

Satoshi Asaoka ◽

Naoki Fujii ◽

...

Keyword(s):

Energy Transfer ◽

Primary Production ◽

Skeletonema Costatum ◽

Warm Season ◽

Nutrient Supply ◽

Trophic Levels ◽

Phytoplankton Primary Production ◽

Mean Values ◽

Hiroshima Prefecture ◽

Study Species

In enclosed water areas, organic matters are actively produced by phytoplankton due to abundant nutrient supply from the rivers. In our study area of the semi-enclosed Hiroshima Bay, oyster farming consuming high primary production has been developed since the 1950s, and the oyster production of Hiroshima prefecture have had the largest market share (ca. 60%) in Japan. In this study, species composition of phytoplankton, primary production, and secondary production of net zooplanktons and oysters were determined seasonally at seven stations in the bay between November 2014 and August 2015. In the bay, diatoms including Skeletonema costatum dominated during the period of the study. The primary productions markedly increased during summer (August), and its mean values in the northern part of the bay (NB) and the southern part (SB) were 530 and 313 mgC/m2/d, respectively. The productions of net zooplankton and oyster increased during the warm season, and its mean values in the NB were 14 and 1.2 mgC/m2/d, and in SB were 28 and 0.9 mgC/m2/d, respectively. The energy transfer efficiencies from the primary producers to the secondary producers in the NB and SB were 2.8% and 9.1%, respectively. However, the transfer efficiency to the oysters was approximately 0.3% in the bay. This study clearly showed the spatial difference of the productions and transfer efficiencies, and the low contribution of the production of oysters in secondary productions in Hiroshima Bay.

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Evaluation and Avoidance of False Alarm by Controlling Rhine Water with Continuously Working Biotests

Water Science & Technology ◽

10.2166/wst.1994.0102 ◽

1994 ◽

Vol 29 (3) ◽

pp. 207-209 ◽

Cited By ~ 6

Author(s):

H. Puzicha

Keyword(s):

Warning System ◽

Point Sources ◽

Trophic Levels ◽

River Rhine ◽

Wide Range ◽

River Test ◽

Continuous Working ◽

Range Of Variation ◽

Contaminant Load ◽

Rhine Water

Effluents from point sources (industries, communities) and diffuse inputs introduce pollutants into the water of the river Rhine and cause a basic contaminant load. The aim is to establish a biological warning system to detect increased toxicity in addition to the already existing chemical-physical monitoring system. To cover a wide range of biocides, continuous working biotests at different trophic levels (bacteria, algae, mussels, water fleas, fishes) have been developed and proved. These are checked out for sensitivity against toxicants, reaction time, validity of data and practical handling under field conditions at the river. Test-specific appropriate methods are found to differentiate between the normal range of variation and true alarm signals.

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Trophic Cascades in Grasslands

10.1093/oso/9780198744511.003.0005 ◽

2018 ◽

Author(s):

Brian J. Wilsey

Keyword(s):

Indirect Effects ◽

Prey Species ◽

Trophic Levels ◽

Herbaceous Plant ◽

Direct Effects ◽

Temperate Grasslands ◽

Cascading Effect ◽

Top Predators ◽

Invertebrate Predators ◽

Ecology Of Fear

Top predators have effects that can ‘cascade down’ on lower trophic levels. Because of this cascading effect, it matters how many trophic levels are present. Predators are either ‘sit and wait’ or ‘active’. Wolves are top predators in temperate grasslands and can alter species composition of smaller-sized predators, prey, and woody and herbaceous plant species, either through direct effects or indirect effects (‘Ecology of Fear’). In human derived grasslands, invertebrate predators fill a similar ecological role as wolves. Migrating populations of herbivores tend to be more limited by food than non-migratory populations. The phenology and synchrony of births vary among prey species in a way that is consistent with an adaptation to predation. Precocious species have highly synchronous birth dates to satiate predators. Non-precocious species (‘hiders’) have asynchronous births. Results from studies that manipulate both predators and food support the hypothesis that bottom-up and top-down effects interact.

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