Journal Article

Reorganization of an arid ecosystem in response to recent climate change

Valone, T.J, Curtin, C.G, Brown, J.H

1997

Overview

Natural ecosystems contain many individuals and species interacting with each other and with their abiotic environment. Such systems can be expected to exhibit complex dynamics in which small perturbations can be amplified to cause large changes. Here, we document the reorganization of an arid ecosystem that has occurred since the late 1970s. The density of woody shrubs increased 3-fold. Several previously common animal species went locally extinct, while other previously rare species increased. While these changes are symptomatic of desertification, they were not caused by livestock grazing or drought, the principal causes of historical desertification. The changes apparently were caused by a shift in regional climate: since 1977 winter precipitation throughout the region was substantially higher than average for this century. These changes illustrate the kinds of large, unexpected responses of complex natural ecosystems that can occur in response to both natural perturbations and human activities.

• Publisher: National Academy of Sciences of the United States of America,National Acad Sciences,National Academy of Sciences,The National Academy of Sciences of the USA
• Subject: Ants / ARBUSTE / ARBUSTOS / ARID CLIMATE / ARID GRASSLANDS / arid zones / ARIZONA / Biological Sciences / CAMBIO CLIMATICO / CHANGEMENT CLIMATIQUE / CLIMA ARIDO / CLIMAT ARIDE / Climate / Climate change / Climate models / CLIMATIC CHANGE / COMMUNITY ECOLOGY / DENSIDAD DE LA POBLACION / DENSITE DE POPULATION / DESERT / DESERTS / DESIERTOS / ECOLOGIA / ECOLOGIE / ECOLOGY / Ecosystems / FORMICIDAE / GRASSLANDS / HERBAGE / Insect colonies / Livestock / LLUVIA / plant ecology / PLANTAS LENOSAS / PLANTE LIGNEUSE / PLUIE / POPULATION DENSITY / POPULATION ECOLOGY / PRADERAS / RAIN / SHRUBLAND / SHRUBS / Terrestrial ecosystems / VEGETACION / VEGETATION / vegetation types / Winter / WOODY PLANTS