Trophic niche but not abundance of Collembola and Oribatida changes with drought and farming system

Higher frequencies of summer droughts are predicted to change soil conditions in the future affecting soil fauna communities and their biotic interactions. In agroecosystems drought effects on soil biota may be modulated by different management practices that alter the availability of different food resources. Recent studies on the effect of drought on soil microarthropods focused on measures of abundance and diversity. We here additionally investigated shifts in trophic niches of Collembola and Oribatida as indicated by stable isotope analysis (13C and 15N). We simulated short-term summer drought by excluding 65% of the ambient precipitation in conventionally and organically managed winter wheat fields on the DOK trial in Switzerland. Stable isotope values suggest that plant litter and root exudates were the most important resources for Collembola (Isotoma caerulea, Isotomurus maculatus and Orchesella villosa) and older plant material and microorganisms for Oribatida (Scheloribates laevigatus and Tectocepheus sarekensis). Drought treatment and farming systems did not affect abundances of the studied species. However, isotope values of some species increased in organically managed fields indicating a higher proportion of microorganisms in their diet. Trophic niche size, a measure of both isotope values combined, decreased with drought and under organic farming in some species presumably due to favored use of plants as basal resource instead of algae and microorganisms. Overall, our results suggest that the flexible usage of resources may buffer effects of drought and management practices on the abundance of microarthropods in agricultural systems.

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Trophic ecology of sea urchins in coral-rocky reef systems, Ecuador

PeerJ ◽

10.7717/peerj.1578 ◽

2016 ◽

Vol 4 ◽

pp. e1578 ◽

Cited By ~ 8

Author(s):

Nancy Cabanillas-Terán ◽

Peggy Loor-Andrade ◽

Ruber Rodríguez-Barreras ◽

Jorge Cortés

Keyword(s):

Stable Isotope ◽

Trophic Ecology ◽

Habitat Degradation ◽

Sea Urchins ◽

Relative Proportion ◽

Isotope Analysis ◽

Niche Overlap ◽

Trophic Niche ◽

Rocky Reef ◽

Trophic Overlap

Sea urchins are important grazers and influence reef development in the Eastern Tropical Pacific (ETP).Diadema mexicanumandEucidaris thouarsiiare the most important sea urchins on the Ecuadorian coastal reefs. This study provided a trophic scenario for these two species of echinoids in the coral-rocky reef bottoms of the Ecuadorian coast, using stable isotopes. We evaluated the relative proportion of algal resources assimilated, and trophic niche of the two sea urchins in the most southern coral-rocky reefs of the ETP in two sites with different disturbance level. Bayesian models were used to estimate the contribution of algal sources, niche breadth, and trophic overlap between the two species. The sea urchins behaved as opportunistic feeders, although they showed differential resource assimilation.Eucidaris thouarsiiis the dominant species in disturbed environments; likewise, their niche amplitude was broader than that ofD. mexicanumwhen conditions were not optimal. However, there was no niche overlap between the species. The Stable Isotope Analysis in R (SIAR) indicated that both sea urchins shared limiting resources in the disturbed area, mainlyDictyotaspp. (contributions of up to 85% forD. mexicanumand up to 75% forE. thouarsii). The Stable Isotope Bayesian Ellipses in R (SIBER) analysis results indicated less interspecific competition in the undisturbed site. Our results suggested a trophic niche partitioning between sympatric sea urchin species in coastal areas of the ETP, but the limitation of resources could lead to trophic overlap and stronger habitat degradation.

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Stable isotope analysis of trophic niche in two co-occurring native and invasive terrapins, Emys orbicularis and Trachemys scripta elegans

Biological Invasions ◽

10.1007/s10530-016-1251-x ◽

2016 ◽

Vol 18 (12) ◽

pp. 3611-3621 ◽

Cited By ~ 10

Author(s):

Paride Balzani ◽

Salvatrice Vizzini ◽

Giacomo Santini ◽

Alberto Masoni ◽

Claudio Ciofi ◽

...

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Trophic Niche ◽

Trachemys Scripta ◽

Trachemys Scripta Elegans ◽

Emys Orbicularis

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Stable isotope analysis reveals variation in trophic niche depending on altitude in an endemic alpine gecko

Basic and Applied Ecology ◽

10.1016/j.baae.2014.05.005 ◽

2014 ◽

Vol 15 (4) ◽

pp. 362-369 ◽

Cited By ~ 11

Author(s):

Mar Comas ◽

Daniel Escoriza ◽

Gregorio Moreno-Rueda

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Trophic Niche

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Stable isotope analysis indicates resource partitioning and trophic niche overlap in larvae of four tuna species in the Gulf of Mexico

Marine Ecology Progress Series ◽

10.3354/meps12958 ◽

2019 ◽

Vol 619 ◽

pp. 53-68 ◽

Cited By ~ 3

Author(s):

R Laiz-Carrión ◽

T Gerard ◽

JJ Suca ◽

E Malca ◽

A Uriarte ◽

...

Keyword(s):

Stable Isotope ◽

Gulf Of Mexico ◽

Stable Isotope Analysis ◽

Resource Partitioning ◽

Isotope Analysis ◽

Niche Overlap ◽

Trophic Niche

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Trophic niche partitioning and diet composition of sympatric fin (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae) in the Gulf of Alaska revealed through stable isotope analysis

Marine Mammal Science ◽

10.1111/mms.12333 ◽

2016 ◽

Vol 32 (4) ◽

pp. 1319-1339 ◽

Cited By ~ 11

Author(s):

Briana H. Witteveen ◽

Kate M. Wynne

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Diet Composition ◽

Isotope Analysis ◽

Niche Partitioning ◽

Gulf Of Alaska ◽

Trophic Niche ◽

Megaptera Novaeangliae ◽

Humpback Whales ◽

Balaenoptera Physalus

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Stable isotope analyses identify trophic niche partitioning between sympatric terrestrial vertebrates in coastal saltmarshes with differing oiling histories

PeerJ ◽

10.7717/peerj.11392 ◽

2021 ◽

Vol 9 ◽

pp. e11392

Author(s):

Sydney Moyo ◽

Hayat Bennadji ◽

Danielle Laguaite ◽

Anna A. Pérez-Umphrey ◽

Allison M. Snider ◽

...

Keyword(s):

Stable Isotope ◽

Oil Spills ◽

Foraging Ecology ◽

Isotope Analysis ◽

Niche Partitioning ◽

Trophic Niche ◽

Bioindicator Species ◽

Terrestrial Vertebrates ◽

Oryzomys Palustris ◽

Trophic Niches

Bioindicator species are commonly used as proxies to help identify the ecological effects of oil spills and other stressors. However, the utility of taxa as bioindicators is dependent on understanding their trophic niche and life history characteristics, as these factors mediate their ecological responses. Seaside sparrows (Ammospiza maritima) and marsh rice rats (Oryzomys palustris) are two ubiquitous terrestrial vertebrates that are thought to be bioindicators of oil spills in saltmarsh ecosystems. To improve the utility of these omnivorous taxa as bioindicators, we used carbon and nitrogen stable isotope analysis to quantify their trophic niches at saltmarshes in coastal Louisiana with differing oiling histories. We found that rats generally had lower trophic positions and incorporated more aquatic prey relative to seaside sparrows. The range of resources used (i.e.,trophic niche width) varied based on oiling history. Seaside sparrows had wider trophic niches than marsh rice rats at unoiled sites, but not at oiled sites. Trophic niche widths of conspecifics were less consistent at oiled sites, although marsh rice rats at oiled sites had wider trophic niches than rats at unoiled sites. These results suggest that past oiling histories may have imparted subtle, yet differing effects on the foraging ecology of these two co-occurring species. However, the temporal lag between initial oiling and our study makes identifying the ultimate drivers of differences between oiled and unoiled sites challenging. Even so, our findings provide a baseline quantification of the trophic niches of sympatric seaside sparrows and marsh rice rats that will aid in the use of these species as indicators of oiling and other environmental stressors in saltmarsh ecosystems.

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The Ontogenetically Variable Trophic Niche of a Praying Mantid Revealed by Stable Isotope Analysis

Environmental Entomology ◽

10.1093/ee/nvv004 ◽

2015 ◽

Vol 44 (2) ◽

pp. 239-245 ◽

Cited By ~ 8

Author(s):

L. E. Hurd ◽

P. A. P. Dehart ◽

J. M. Taylor ◽

M. C. Campbell ◽

M. M. Shearer

Keyword(s):

Stable Isotope ◽

Stable Isotope Analysis ◽

Isotope Analysis ◽

Trophic Niche ◽

Praying Mantid

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Trophic ecology of the seagrass-inhabiting footballer demoiselle Chrysiptera annulata (Peters, 1855); comparison with three other reef-associated damselfishes

Belgian Journal of Zoology ◽

10.26496/bjz.2016.36 ◽

2020 ◽

Vol 146 (1) ◽

Author(s):

Gilles Lepoint ◽

Loïc N. Michel ◽

Eric Parmentier ◽

Bruno Frédérich

Keyword(s):

Stable Isotope ◽

Trophic Ecology ◽

Close Association ◽

Isotope Analysis ◽

Niche Overlap ◽

Trophic Niche ◽

Isotopic Niche ◽

Seagrass Meadows ◽

Turf Algae ◽

Herbivorous Species

Many damselfishes (Pomacentridae) are herbivorous or omnivorous with an important contribution from different kinds of algae in their diet. They display different levels of territoriality and farming behavior, from almost non territorial to monoculture farmers. In addition, a few species inhabit seagrass meadows but, presently, none can be considered as seagrass-eating specialists. The footballer demoiselle, Chrysiptera annulata, is found in the seagrass meadows on the reef flat of the Great Reef of Toliara (Madagascar, Mozambique Channel). In the light of this unusual habitat for a pomacentrid, this study aimed to answer three questions: 1) What is the diet of C. annulata? 2) Do the resources supporting this diet include seagrass? 3) Does its trophic niche overlap those of other sympatric damselfishes (Pomacentrus trilineatus, Chrysiptera unimaculata and Plectroglyphidodon lacrymatus) living in close association with macrophytes or eating algae? Stomach content examination and stable isotope analysis showed that the footballer demoiselle is not a seagrass consumer but is an omnivorous/herbivorous species heavily relying on algal resources and small invertebrates. SIAR, a stable isotope mixing model, indicated it assimilated large amounts of turf algae, and various benthic or planktonic invertebrates in lower proportions. SIBER metrics revealed that the isotopic niche of the footballer demoiselle partly overlaps that of its congener, C. unimaculata, but not those of P. trilineatus and P. lacrymatus. Trophic strategies of C. annulata differed both from farming species such as P. lacrymatus and from less territorial herbivores such as P. trilineatus. Its seagrass meadow habitat on the Great Reef of Toliara allows the conquest of an unusual habitat for damselfishes and could limit competition with C. unimaculata, a species displaying the same territorial behavior and the same isotopic niche but living on the reef itself.

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