The Rare, Old-aged Conifers of the Malpais; Their Role in Understanding Climatic Change in the American Southwest
Grissino-Mayer HD, Swetnam TW, Adams RK. 1997. The Rare, Old-aged Conifers of the Malpais; Their Role in Understanding Climatic Change in the American Southwest. Tucson, AZ
Trees of great age growing on the malpais volcanic area of El Malpais National Monument provide an opportunity to investigate past climate. The age of some of the oldest trees had to be determined through chronologies from other areas, yielding dates older than any previously known from New Mexico (as early as 200 B.C.). Climate analysis based on tree-ring samples indicate alternations over the past 2100 years between long-term periods of above-normal and below-normal rainfall. The authors corroborate earlier studies by Lindsey that lava flows support flora which would otherwise require a more humid climate, apparently through an ability to retain moisture. The concluding section emphasizes the uniqueness of the information preserved in the wood of the malpais, and urges that none of the living trees or remnant wood would be used for fuelwood or other forms of consumption, or destroyed in construction projects. This is the only area in the Southwest with the potential for developing a chronology as long as 3,000 years, and the authors hope to use Rocky Mountain Junipers to extend the climate sequence. With tables, photographs, and a 2200-year precipitation graph. Bibliography pages 13-14.