Robin Warne




In many ecosystems, seasonal shifts in temperature and precipitation induce pulses of primary productivity that vary in phenology, abundance and nutritional quality. Â Variation in these resource pulses could strongly influence community composition and ecosystem function, because these pervasive bottom-up forces play a primary role in determining the biomass, life cycles and interactions of organisms across trophic levels. Â The focus of this research is to understand how consumers across trophic levels alter resource use and assimilation over seasonal and inter-annual timescales in response to climatically driven changes in pulses of primary productivity. We measured the carbon isotope ratios (d13C) of plant, arthropod, and lizard tissues in the northern Chihuahuan Desert to quantify the relative importance of primary production from plants using C3 and C4 photosynthesis for consumers. Â Summer monsoonal rains on the Sevilleta LTER in New Mexico support a pulse of C4 plant production that have tissue d13C values distinct from C3 plants. Â During a year when precipitation patterns were relatively normal, d13C measurements showed that consumers used and assimilated significantly more C4 derived carbon over the course of a summer; tracking the seasonal increase in abundance of C4 plants. Â In the following spring, after a failure in winter precipitation and the associated failure of spring C3 plant growth, consumers showed elevated assimilation of C4 derived carbon relative to a normal rainfall regime. These findings provide insight into how climate, pulsed resources and temporal trophic dynamics may interact to shape semi-arid grasslands such as the Chihuahuan Desert in the present and future.


Other Identifier


Knowledge Network for Biocomplexity (KNB) Identifier


Document Type



This dataset was originally published on the Long Term Ecological Research (LTER) Network Data Portal,, and potentially via other repositories or portals as described. The Digital Object Identifier (DOI) of the source data package is doi:10.6073/pasta/6ce0459eb3c949d850b282974aced68f, and may be accessed at Metadata and files included in this record mirror as closely as possible the source data and documentation, with the provenance metadata and quality report generated by the LTER portal reproduced here as '*-provenance.xml' and *-report.html' files, respectively.


Data Policies: This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement of the Sevilleta LTER. Datasets must be cited as in the example provided. A copy of any publications using these data must be supplied to the Sevilleta LTER Information Manager. By downloading any data you implicitly acknowledge the LTER Data Policy (


Temporal coverage

2005-05-01 - 2006-10-01

Spatial coverage

The Five Points area emcompasses both the Five Points Black Grama and Five Points Creosote study sites. Five Points falls along the transition between the Chihuahuan Desert Scrub and Desert Grassland habitats. Both core sites are subject to intensive research activities, including NPP measurements, phenology observations, pollinator diversity studies, and ground dwelling arthropod and rodent population assessments. There are rain-out shelters for drought studies in both the Five Points Black Grama and Five Points Creosote sites.



Permanent URL

knb-lter-sev.270.3-metadata.html (71 kB)
Show full metadata

knb-lter-sev.270.3-provenance.xml (3 kB)
Show provenance metadata

knb-lter-sev.270.3-report.html (27 kB)
Show original LTER Network Data Portal ingest report

sev270_lizard_isotope_20140216.txt (15 kB)
Data in TXT format


Article Location