Late Pleistocene Piñon Pines in the Chihuahuan Desert

Abstract

Examination of late Pleistocene packrat middens from the northern and central Chihuahuan Desert disclosed macrofossils of Colorado piñon (Pinus edulis) and Texas piñon (P. remota). Radiocarbon dating indicates that Texas piñon was widespread in Trans-Pecos Texas and northeastern Mexico between 30,000 and 11,000 yr B.P. Today it is found in small refugia east of its former range. In the late Pleistocene Colorado piñon occurred at lower elevations on the northern edge of the Chihuahuan Desert. Both species occurred in the Hueco Mountains, near El Paso, Texas. No clear evidence was found of the presence of Mexican piñon (P. cembroides), though today it is abundant in the Davis and Chisos Mountains. A paleoclimate is postulated that had the following characteristics: increased winter precipitation from Pacific frontal sources, reduced summer temperatures and precipitation, and milder winter temperatures due to a reduced frequency of Arctic airmass incursion. Winter precipitation appears to have decreased from north to south, while winter temperatures, and, possibly, summer precipitation, increased from north to south. During the late Pleistocene, the northern Chihuahuan Desert was dominated by woodlands of piñon pines, junipers, and oaks. The desert-scrub communities that characterize the area today are a Holocene phenomenon.

Neogene and Pleistocene history of Agave lechuguilla in the Chihuahuan Desert

“…Another small area north of Big Bend National Park, USA, was found to be a refugium during the LIG and current times. All these areas have been previously identified as having high species diversity and endemism (Hernández et al ., ) and as possible refugia for high‐latitude species (Lanner & Van Devender, ; Van Devender & Burgess, ; Castoe et al ., ; Sosa et al ., ; Rebernig et al ., ; Wilson & Pitts, ).…”

Ecological niches as stable distributional constraints on mammal species, with implications for Pleistocene extinctions and climate change projections for biodiversity

“…Species’ responses to global climate change provide a direct test of these hypotheses of niche conservatism. Both in past (Lanner & van Devender, 1981; Thompson & Mead, 1982; Wells, 1983) and ongoing (Parmesan, 1996; Parmesan et al ., 1999; Walther et al ., 2002; Parmesan & Yohe, 2003) climate change events, shifts in geographical distributions of species have been observed. Particularly dramatic climate change occurred since the Last Glacial Maximum ( c .…”

Species’ Geographic Distributions Through Time: Playing Catch-up with Changing Climates

“…The Pleistocene-covering approximately the past 2.5 million years-was characterized by dramatic shifts from conditions rather similar to those of the present day (Otto-Bliesner et al 2006) to much colder conditions (Dansgaard et al 1993). The effect of these fluctuations on biodiversity began to be appreciated thanks to the detailed documentation of past vegetation types provided by Neotoma packrat middens (Lanner and Van Devender 1981;Wells 1983). Pleistocene climatic shifts also figured very prominently in theories for the diversification of the Amazon Basin (Haffer 1974), and these ideas have been adopted quite broadly (e.g., Church et al 2003), although they have also been controversial (Bush 1994).…”