• UNDERSTAND

    Trophic Positions

  • UNDERSTAND

    Animal Migration Patterns

  • UNDERSTAND

    Soil Microbial Ecology

Ökologie

Die Stabilisotopenanalyse einer Vielzahl von Materialien im Bereich der Ökologie erlaubt es Forschern, Informationen zu gewinnen, die mit anderen analytischen Methoden nicht erzielt werden können. Stabile Isotope werden von Ökologen häufig als Tracer in biologischen Systemen eingesetzt, um Elementkreisläufe in einem Ökosystem nachzuvollziehen. Variationen in der Isotopensignatur in unterschiedlichen geographischen Regionen erlauben es, Isotopen als Tracer für Migration zu nutzen, während mit Hilfe des Prinzips der Isotopenfraktionierung biogeochemische Prozesse in einer solchen Detailgenauikgeit analysiert werden können, die von der Betrachtung der Elementzusammensetzung alleine nicht erreicht werden kann.

So können z.B. Kohlenstoffisotope genutzt werden, um die Primärenergiequelle in einem Ökosystem zu bestimmen, wohingegen Stickstoffisotope nützlich sind, um die trophische Ebene eines Organismus zu identifizieren. Schwefelisotope können benthische Produzenten von pelagischen unterscheiden, ebenso wie Sumpfpflanzen von Phytoplanktonproduzenten.

Die Entwicklung unseres Verständnisses dieser immanenten Beziehungen zwischen lebenden Organismen und ihrer Umgebung durch die Stabilisotopenanalyse unterstützt unseren sorgfältigen Umgang mit der natürlichen Welt um zu gewährleisten, dass künftige Generationen die gleichen Wunder erleben wie wir heute.

Publikationen zum Thema Ökologie mit unseren Geräten

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155 Ergebnisse:

Feeding behaviour, predatory functional responses and trophic interactions of the invasive Chinese mitten crab ( Eriocheir sinensis ) and signal crayfish ( Pacifastacus leniusculus )
Freshwater Biology (2016)
Paula J Rosewarne, Robert J.G. Mortimer, Robert J. Newton, Christopher Grocock, Christopher D. Wing, Alison M. Dunn

Freshwaters are subject to particularly high rates of species introductions; hence, invaders increasingly co-occur and may interact to enhance impacts on ecosystem structure and function. As trophic interactions are a key mechanism by which invaders influence communities, we used a combination of approaches to investigate the feeding preferences and community impacts of two globally invasive large benthic decapods that co-occur in freshwaters: the signal crayfish (Pacifastacus leniusculus) and Chinese mitten crab (Eriocheir sinensis).
Schlagworte: carbon , nitrogen , ecol , elem

δ13C and Water Use Efficiency in the Glucose of Annual Pine Tree Rings as Ecological Indicators of the Forests in the Most Industrialized Part of Poland
Water, Air, & Soil Pollution (2016)
Barbara M. Sensuła

In this study, stable carbon isotope ratios in the glucose samples were extracted from annual pine tree rings as bio-indicators of contemporary environmental changes in heavily urbanized areas. The sampling sites were located in close proximity to point source pollution emitters, such as a heat and power plant “Łaziska” and steelworks “Huta Katowice” in Silesia (Poland). The analysed samples covered the time span from 1975 to 2012 AD, the time period of the development of industrialization and the modernization in the industrial sector in Poland, similarly as in Eastern Europe. This modernization was connected with EU legislation and the implementation of restrictive governmental regulations on emissions. The carbon isotope discrimination has been proposed as a method for evaluating water use efficiency. The measurements of carbon isotopes were carried out using the continuous flow isotope ratio mass spectrometer coupled to the elemental analyser. The δ13C values were calibrated relative to the C-3 and C-5 international standards. Diffuse air pollution caused the variation in δ13C and iWUE (the ratio between CO2 assimilation and stomatal conductance) dependency on the type of emitter and some local effects of other human activities. In this study, the first results of water use efficiency in glucose are presented. In the period of time from 1975 to 2012, the water use efficiency values increased from 98 to 122 μmol/mol.

Pan-Arctic concentrations of mercury and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in marine zooplankton.
The Science of the total environment (2016)
Corinne Pomerleau, Gary A Stern, Monika Pućko, Karen L Foster, Robie W Macdonald, Louis Fortier

Zooplankton play a central role in marine food webs, dictating the quantity and quality of energy available to upper trophic levels. They act as "keystone" species in transfer of mercury (Hg) up through the marine food chain. Here, we present the first Pan-Arctic overview of total and monomethylmercury concentrations (THg and MMHg) and stable isotope ratios of carbon (δ(13)C) and nitrogen (δ(15)N) in selected zooplankton species by assembling data collected between 1998 and 2012 from six arctic regions (Laptev Sea, Chukchi Sea, southeastern Beaufort Sea, Canadian Arctic Archipelago, Hudson Bay and northern Baffin Bay). MMHg concentrations in Calanus spp., Themisto spp. and Paraeuchaeta spp. were found to increase with higher δ(15)N and lower δ(13)C. The southern Beaufort Sea exhibited both the highest THg and MMHg concentrations. Biomagnification of MMHg between Calanus spp. and two of its known predators, Themisto spp. and Paraeuchaeta spp., was greatest in the southern Beaufort Sea. Our results show large geographical variations in Hg concentrations and isotopic signatures for individual species related to regional ecosystem features, such as varying water masses and freshwater inputs, and highlight the increased exposure to Hg in the marine food chain of the southern Beaufort Sea.
Schlagworte: carbon , nitrogen , ecol , ocea , poll , elem

Latitudinal variation in ecological opportunity and intraspecific competition indicates differences in niche variability and diet specialization of Arctic marine predators
Ecology and Evolution (2016)
David J. Yurkowski, Steve Ferguson, Emily S. Choy, Lisa L. Loseto, Tanya M. Brown, Derek C. G. Muir, Christina A. D. Semeniuk, Aaron T. Fisk

Individual specialization (IS), where individuals within populations irrespective of age, sex, and body size are either specialized or generalized in terms of resource use, has implications on ecological niches and food web structure. Niche size and degree of IS of near-top trophic-level marine predators have been little studied in polar regions or with latitude. We quantified the large-scale latitudinal variation of population- and individual-level niche size and IS in ringed seals (Pusa hispida) and beluga whales (Delphinapterus leucas) using stable carbon and nitrogen isotope analysis on 379 paired ringed seal liver and muscle samples and 124 paired beluga skin and muscle samples from eight locations ranging from the low to high Arctic. We characterized both within- and between-individual variation in predator niche size at each location as well as accounting for spatial differences in the isotopic ranges of potential prey. Total isotopic niche width (TINW) for populations of ringed seals and beluga decreased with increasing latitude. Higher TINW values were associated with greater ecological opportunity (i.e., prey diversity) in the prey fish community which mainly consists of Capelin (Mallotus villosus) and Sand lance (Ammodytes sp.) at lower latitudes and Arctic cod (Boreogadus saida) at high latitudes. In beluga, their dietary consistency between tissues also known as the within-individual component (WIC) increased in a near 1:1 ratio with TINW (slope = 0.84), suggesting dietary generalization, whereas the slope (0.18) of WIC relative to TINW in ringed seals indicated a high degree of individual specialization in ringed seal populations with higher TINWs. Our findings highlight the differences in TINW and level of IS for ringed seals and beluga relative to latitude as a likely response to large-scale spatial variation in ecological opportunity, suggesting species-specific variation in dietary plasticity to spatial differences in prey resources and environmental conditions in a rapidly changing ecosystem.
Schlagworte: carbon , nitrogen , ecol , elem

Specialized morphology corresponds to a generalist diet: linking form and function in smashing mantis shrimp crustaceans
Oecologia (2016)
Maya S. deVries, Brian C. Stock, John H. Christy, Gregory R. Goldsmith, Todd E. Dawson

Schlagworte: carbon , nitrogen , ecol , elem

Effects of lipid extraction and ultrafiltration on stable carbon and nitrogen isotopic compositions of fish bone collagen
Rapid Communications in Mass Spectrometry (2016)
Eric J. Guiry, Paul Szpak, Michael P. Richards

Rationale Fish bone collagen isotopic measurements are increasingly important in palaeodietary and paleoenvironmental studies yet differences in the chemical and physical properties of fish relative to other vertebrate bones are rarely considered. Lipid content in fish bone, which can exceed 50%, may underlie the poor collagen integrity criteria typically observed in archaeological studies. Methods We compare stable carbon and nitrogen isotopic and elemental compositions of bone collagen prepared using four different methods from a wide range of modern fish species to: (1) assess the extent to which lipid content influences bone collagen δ13C and δ15N values, and (2) evaluate the relative efficacy of chemical (2:1 chloroform/methanol) and physical (30 kDa ultrafilters) methods for removing lipids from bones. Results Lower δ13C values were observed when the lipid content exceeded 5% of the initial bone mass. The lipid content did not influence the δ15N values. 30 kDa ultrafiltration, a common pretreatment for purifying archaeological collagen, removed fewer lipids and was associated with reduced collagen yields (37% loss) as well as altered amino acid compositions. In contrast, collagen prepared using a 2:1 chloroform/methanol lipid extraction step resulted in significantly improved collagen yields, elemental compositions, and isotopic measurements relative to a control treatment. Conclusions The chemical lipid extraction method (2:1 chloroform/methanol) performed significantly better than the physical lipid extraction method (30 kDa ultrafilters). Given the high quantities of lipids in fish bones we recommend the inclusion of a chemical lipid extraction step when isolating collagen from modern and archaeological fish bones.
Schlagworte: carbon , nitrogen , arch , ecol , elem

Determining the geographical origin of Asian longhorn beetle (Anoplophora glabripennis) specimens using stable isotope and trace element analyses
Pest Management Science (2016)
Katharina Heinrich, Larissa Collins

BACKGROUND An outbreak of EU quarantine listed pest Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambicidae), Asian Longhorn Beetle, in Kent (UK) resulted in environmentally and financially costly eradication action being taken. In this study the potential of using multi-element stable isotope or trace element analyses to determine the geographical origin of individual specimens has been investigated. RESULTS The isotope ratios of A. glabripennis individuals for hydrogen varied within and across 5 locations. Carbonisotope ratios fell within the expected values for C3 plants (trees using the photosynthetic pathway common for moderate climates). Nitrogen isotope ratios indicated separation of UK laboratory from American (New York, Ohio, Massachusetts) beetles; whilst sulfur isotope ratios distinguished beetles from New York against the other 4 locations. Three trace elements (TEs) separated UK laboratory-reared beetles from American beetles (Ohio and New York) with ~ 68% confidence. CONCLUSIONS Stable isotope and TE analyses show potential to differentiate between newly arrived A. glabripennis individuals and those from previously undetected in-country populations, which would be of immediate practical benefit in making appropriate strategic decisions on surveillance and eradication. Analyses of additional samples (i) from the same populations, (ii) different locations and (iii) variety of host trees will enhance the overall picture.
Schlagworte: carbon , nitrogen , ecol , elem

Beyond Zar: the use and abuse of classification statistics for otolith chemistry
Journal of Fish Biology (2016)
C. M. Jones, M. Palmer, J. J. Schaffler

Classification method performance was evaluated using otolith chemistry of juvenile Atlantic menhaden Brevoortia tyrannus when assumptions of data normality were met and were violated. Four methods were tested [linear discriminant function analysis (LDFA), quadratic discriminant function analysis (QDFA), random forest (RF) and artificial neural networks (ANN)] using computer simulation to determine their performance when variable-group means ranged from small to large and their performance under conditions of typical skewness to double the amount of skewness typically observed. Using the kappa index, the parametric methods performed best after applying appropriate data transformation, gaining 2% better performance with LDFA performing slightly better than QDFA. RF performed as well as QDFA and showed no difference in performance between raw and transformed data while the performance of ANN was the poorest and worse with raw data. All methods performed well when group differences were large, but parametric methods outperformed machine-learning methods. When data were skewed the performance of all methods declined and worsened with greater skewness, but RF performed consistently as well or better than the other methods in the presence of skewness. The parametric methods were found to be more powerful when assumptions of normality can be met and can be used confidently when skewness and kurtosis are minimized. When these assumptions cannot be minimized, then machine-algorithm methods should also be tried.
Schlagworte: carbon , oxygen , ecol , gashead

Seasonal migration distance varies with natal dispersal and predicts parasitic infection in song sparrows
Behavioral Ecology and Sociobiology (2016)
Tosha R. Kelly, Heather L. MacGillivray, Yanina Sarquis-Adamson, Matthew J. Watson, Keith A. Hobson, Elizabeth A. MacDougall-Shackleton

Seasonal migration and natal dispersal represent the major large-scale movements in the lives of animals. Individuals that are relatively prone to movement and exploration might thus be more likely to disperse and also to migrate farther. Such movement might be either negatively associated with parasitic infection (if infection prevents hosts from successful long-distance migration) or positively associated (e.g. if longer-distance migrants encounter more abundant or more diverse parasites). We examined whether natal dispersal tendency predicts seasonal migration distance in song sparrows (Melospiza melodia) and whether migration distance predicts infection with bloodborne parasites upon arrival at the breeding grounds. Migration distance, inferred from stable hydrogen isotope analysis (δ2H) of winter-grown tissue, was repeatable (repeatability = 0.41) over years. Birds that were more likely to have immigrated from outside the breeding grounds, as inferred from genetic assignment tests, also overwintered farther south, as inferred from stable isotope analysis. The finding that individuals more prone to movement in the context of natal dispersal also tended to travel farther, on average, in the context of seasonal migration suggests consistent individual variation in large-scale movements across these two contexts. Although statistically significant, this effect was modest in scope and subtle relative to sex differences in inferred migration distance. Among after-second-year individuals, but not yearlings, longer-distance migrants were more likely, on average, to be infected with bloodborne parasites. Individual variation in propensity to long-distance movement may interact with age-related variation in exposure or susceptibility to parasites, to shape the role of animal migration in transporting infectious disease.
Schlagworte: hydrogen , ecol , elem

Evaluando los niveles tróficos de dos tiburones oceánicos del Océano Pacífico suroriental
Latin american journal of aquatic research (2016)
Sebastian A Klarian, Augusto Cornejo, Pauline Sallaberry-Pincheira, Patricio Barría, Roberto Meléndez

Stable isotope analyses for shortfin mako (Isums oxyrinchus) and blue sharks (Prionace glauca) were conducted to assess their trophic position in two periods of time (before 1980 and after 2000) in the Southeastern Pacific waters (SEP). Both sharks showed that their trophic position decreased over time (P < 0.05). Many factors could be involved in this change such as dietary shifts, prey availability, or indirect fishing effects in SEP waters.
Schlagworte: carbon , nitrogen , ecol , elem