Related Experiment Video
Updated: Sep 10, 2025
11:14
Fatty Acid 13C Isotopologue Profiling Provides Insight into Trophic Carbon Transfer and Lipid Metabolism of Invertebrate Consumers
Published on: April 17, 2018
8.1K
Urbanisation is associated with changes in stable isotopes across multiple trophic levels.
Ana B Navarro1, Rona A R McGill2, Jason Newton2
1Seção de Aves, Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil.
Isotopes in Environmental and Health Studies
|August 19, 2025
Summary
Urbanisation impacts biodiversity by altering food webs and physiology across trophic levels. Studies show urban birds have narrower isotopic niches, indicating reduced food diversity in cities.
Area of Science:
- Ecology
- Urban Ecology
- Biodiversity Research
Background:
- Urbanisation poses significant threats to biodiversity, including habitat loss, reduced food availability, and increased pollution.
- Understanding how organisms at different trophic levels adapt to urban gradients is crucial for effective urban planning.
- Stable isotope analysis provides a powerful tool to trace energy flow and trophic relationships in ecosystems.
Purpose of the Study:
- To investigate the effects of urbanisation on carbon (δ13C) and nitrogen (δ15N) stable isotope values across a tri-trophic system.
- To assess how urbanisation influences the isotopic niche width of the blue tit (Cyanistes caeruleus) at different life stages.
- To explore the relationship between urbanisation, pollution, and physiological responses in plants and animals.
Main Methods:
- Carbon and nitrogen stable isotope analysis (δ13C and δ15N) was performed on trees, invertebrates, and blue tits.
- Isotopic niche width was measured for adult and nestling blue tits to assess urbanisation impacts.
- Data were analyzed across an urbanisation gradient to identify ecological shifts.
Main Results:
- All studied taxa exhibited higher δ15N values in urban areas, linked to air pollution (NOx).
- Urban trees and blue tit nestlings showed higher δ13C values, potentially due to soil water scarcity affecting plant physiology.
- Urban blue tits displayed significantly narrower isotopic niches (4.5-18 times smaller) compared to forest individuals, indicating reduced dietary breadth.
Conclusions:
- Urbanisation alters organismal physiology and trophic interactions across multiple levels, with consistent effects observed.
- Narrower isotopic niches in urban blue tits suggest a reduction in prey diversity and availability in urbanised environments.
- Findings highlight the pervasive impact of urbanisation on ecological processes and biodiversity, informing future urban planning strategies.
More Related Videos
12:10Stable Isotopic Profiling of Intermediary Metabolic Flux in Developing and Adult Stage Caenorhabditis elegans
Published on: February 27, 2011
13.6K
07:41A Method for Measuring Metabolism in Sorted Subpopulations of Complex Cell Communities Using Stable Isotope Tracing
Published on: February 4, 2017
8.5K
Related Concept Videos
00:46Trophic Efficiency
21.6K
Trophic level transfer efficiency (TLTE) is a measure of the total energy transfer from one trophic level to the next. Due to extensive energy loss as metabolic heat, an average of only 10% of the original energy obtained is passed on to the next level. This pattern of energy loss severely limits the possible number of trophic levels in a food chain.
21.6K
01:35Trophic Levels
31.8K
All organisms in an ecosystem occupy a trophic level in the food chain. The lowest level consists of primary producers, which synthesize their food from either solar or chemical energy. Each subsequent level obtains energy from the levels below. Detritivores can occupy any of the levels above primary producers.
31.8K
01:28Isotopes and Radioisotopes
10.0K
In the early 1900s, English chemist Frederick Soddy realized that an element could have atoms with different masses that were chemically indistinguishable. These different types are called isotopes — atoms of the same element that differ in mass. Isotopes differ in mass because they have different numbers of neutrons but are chemically identical because they have the same number of protons. Soddy was awarded the Nobel Prize in Chemistry in 1921 for this discovery.
An isotope containing...
An isotope containing...
10.0K
01:12Isotopes
59.9K
Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number of neutrons can vary for atoms of the same element. The sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are called isotopes. Elements can have multiple isotopes, for example, carbon-12, carbon-13, and carbon-14.
An element's atomic mass, or weight,...
An element's atomic mass, or weight,...
59.9K
01:13Mass Spectrometry: Isotope Effect
2.5K
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the difference between the molecular mass. Furthermore, the intensity of these signals is dependent on the...
2.5K
01:06Primary Production
23.9K
The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.
23.9K