MASTIF sites span the Pacific Border in coastal California to pinyon-juniper woodlands in southern Basin and Range of New Mexico and western Oklahoma. The Pacific Border, with its north-south trending mountains and lowlands, includes the UCSC site, collected by Greg Gilbert. Data from the Hastings Natural History Reservation (HNHR) come from Walt Koenig and Jean Knops.
Mountain ranges include the Rockies and Sierra Nevada, the latter being geologically young and active. Mesozoic granitic rocks uplifting throughout the last five million years dip westward to the Central Valley. In the Sierra Nevada Mountains SOAP is a NEON site. USGS sites (YOSE, SEQU) were organized for the MASTIF network by Emily Moran and Melaine Aubry-Kientz.
Basin and Range is characterized by rugged relief with low-lying desert basins. Miranda Redmond and colleagues generated the network of Pinus edulis sites in NM and OK. Data from the SEV site with Pinyon-juniper-oak vegetation come from Robert Parmenter and colleagues.
Large growing-season deficits are common throughout. Mediterranean climates dominate much of California and Oregon with warm-wet winters, falling as snow at high elevations. Winters are cold in the interior sites at mid to high elevation. Desert basins of Basin and Range generally do not support mast-bearing trees. However, semi-arid mid-elevations move to short-statured trees and shrubs in the genera Pinus, Quercus, and Juniperus, among others, that can generate large mast crops.
Vegetation is controlled by elevation-dependent gradients in precipitation and temperature, drainage, and soils. Strongly seasonal precipitation is characteristic throughout, but region-dependent. Coastal Pacific Border sites include giant redwoods and Douglas fir at UCSC and open oak woodland at HNHR. Mixed conifers and oak forests dominate the elevations of our Sierra Nevada sites (SEQU, SOAP, YOSE). Pinyon-oak-juniper are sampled across the southern Basin and Range.
Knops, J. M. H., and W. D. Koenig. 2012. Sex allocation in California oaks: trade-offs or resource tracking? PLoS One 7(8): e43492. doi:10.1371/journal.pone.0043492.
Redmond MD, Forcella F, and NN Barger. 2012. Declines in pinyon pine cone production associated with regional warming. Ecosphere 3: 120.