Related Experiment Video
Updated: Feb 3, 2026

Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis
Published on: August 15, 2018
Stable carbon and nitrogen isotopes in kukui (Aleurites moluccanus) endocarp along rainfall and elevation gradients:
Noa Kekuewa Lincoln1, Mark D McCoy2, Thegn N Ladefoged3,4
1Department of Tropical Plants and Soil Sciences, University of Hawai'i, Honolulu, Hawaii, United States of America.
Abstract:
Stable carbon and nitrogen isotopes are often used to make inferences of past environments and social patterns. We analyze δ 13C and δ 15N values in contemporary kukui (Aleurites moluccanus) endocarp to examine the effects of site environment. Results from across environmental transects on Hawai'i Island show strong patterns for both stable isotopes. For δ 13C a robust linear relationship with elevation is exhibited, strengthened by the inclusion of rainfall. This relationship breaks down at a minimum threshold of annual rainfall, possible relating to physiological responses to drought. For δ 15N, the only significant relationship observed pertains to substrate age. The endocarp from kukui is one of the most readily identified plant remains in the Pacific archaeological records and is often targeted for radiocarbon dating. We discuss the potential implications of our results regarding ancient climate, inferred diets, and habitat composition.
Related Concept Videos
Isotopes
An element's atomic mass, or weight,...
Elements: Chemical Symbols and Isotopes
Some symbols are derived from the common English name of the element; others are abbreviations of the name in another language — Latin, Greek or German. For example, the symbol for aluminum (common name)...
The Nitrogen Cycle
Freezing Point Depression and Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
What is an Electrochemical Gradient?
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...
The Carbon Cycle

