Millennial-scale climate variability and ecosystem response at the Jornada LTER site

TitleMillennial-scale climate variability and ecosystem response at the Jornada LTER site
Publication TypeBook Chapter
Year of Publication2003
AuthorsH. Monger C
EditorGreenland D, Goodin DG, Smith RC(eds.)
Book TitleClimate variability and ecosystem response at long-term ecological research sites
PublisherOxford University Press
CityNew York
Accession NumberJRN00390
Call Number00818
Keywordsbook, books, carbon isotope ratios, chapter, chapters, climate change, ecosystem response, climate variability, ecosystem response, climate variability, fossil pollen, Jornada LTER, LTER site, packrat middens, pedogenic carbonates, report, reports, soil, geomorphology, vegetation change
AbstractThe Jornada Long-Term Ecological Research (JRN LTER) program consists of studies superimposed on three research entities, the Jornada Experimental Range, the Chihuahuan Desert Rangeland Research Center, and the Desert Soil-Geomorphology project. The JRN site is in the northern part of the Chihuahuan Desert and represents, for the LTER network, the desert shrubland and desert grassland ecosystems of the southwestern United States. Climate data at the Jornada site and surrounding area span the last 110 years. Ecological data span the last 144 years. Jornada LTER researchers still struggle to understand how ecosystems respond to climate variability. Human land use (including cattle grazing, brush control, and habitat fractionation) is an important factor that complicates this question and produces external pressure on Jornada ecosystems. The cause-and-effect relationship between climate and ecosystems in prehistoric times is even more uncertain. Here evidence is limited to indicators, such as former lake shorelines, plant fossils in packrat middens, fossil pollen, 13C/12C rations in paleosols, and erosion rates. When some indicators are used by themselves, circularity arises if a conclusion about ecosystem response to climate change is based on an inference about climate change, which is based, in turn, on ecosystem change. For example, grasslands increased at the end of the middle Holocene as the result of increased rainfall, where the interpretation of increased rainfall is based on increased grass pollen in the middle Holocene sediments. Also focusing on millennial-scale climate and ecosystem variability, this chapter briefly discusses historic variability for comparison and as a means for describing the setting. The historic-prehistoric boundary for the Jornada area has been set at A.D. 1850.
Reprint EditionIn File (11/21/2003)