scholarly journals Jeffrey Pine Seed Dispersal in the Sierra San Pedro Mártir, Baja California, Mexico

2012 ◽  
Vol 72 (4) ◽  
pp. 534-542 ◽  
Author(s):  
Stephen B. Vander Wall ◽  
Mark S. Enders ◽  
Sarah Barga ◽  
Christopher Moore ◽  
Amy Seaman ◽  
...  
Check List ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 1649 ◽  
Author(s):  
Jorge Heriberto Valdez-Villavicencio ◽  
Anny Peralta-Garcia ◽  
Bradford Damion Hollingsworth

We found a new population of Ensatina klauberi in San Quintín volcanic field, Baja California. It represents the first coastal population of this species. This record extends the species range ca. 71 km southwest of the southernmost record of E. klauberi in the Sierra San Pedro Mártir and represents the first population discovered outside of coniferous and pine-oak woodlands.


2011 ◽  
Vol 75 (3) ◽  
pp. 647-657 ◽  
Author(s):  
Camille A. Holmgren ◽  
Julio L. Betancourt ◽  
Kate A. Rylander

AbstractPlant macrofossils from 38 packrat middens spanning the last ~ 33,000 cal yr BP record vegetation between ~ 650 and 900 m elevation along the eastern escarpment of the Sierra San Pedro Mártir, northern Baja California. The middens span most of the Holocene, with a gap between ~ 4600 and 1800 cal yr BP, but coverage in the Pleistocene is uneven with a larger hiatus between 23,100 and 14,400 cal yr BP. The midden flora is relatively stable from the Pleistocene to Holocene. Exceptions include Pinus californiarum, Juniperus californica and other chaparral elements that were most abundant > 23,100 cal yr BP and declined after 14,400 cal yr BP. Despite being near the chaparral/woodland-desertscrub ecotone during glacial times, the midden assemblages reflect none of the climatic reversals evident in the glacial or marine record, and this is corroborated by a nearby semi-continuous pollen stratigraphy from lake sediments. Regular appearance of C4 grasses and summer-flowering annuals since 13,600 cal yr BP indicates occurrence of summer rainfall equivalent to modern (JAS average of ~ 80–90 mm). This casts doubt on the claim, based on temperature proxies from marine sediments in the Guaymas Basin, that monsoonal development in the northern Gulf and Arizona was delayed until after 6200 cal yr BP.


2007 ◽  
Vol 37 (2) ◽  
pp. 318-330 ◽  
Author(s):  
Rand R. Evett ◽  
Ernesto Franco-Vizcaino ◽  
Scott L. Stephens

Fire histories of Jeffrey pine ( Pinus jeffreyi Grev. & Balf.) – mixed conifer forests in the Sierra San Pedro Mártir, Baja California, Mexico, recently described through analysis of 300 years of tree-ring fire-scars, indicate there have been four distinct fire-regime periods based on fire frequency and size. We used modern lightning and fire data to assess whether the current lightning regime could have supported the prehistoric fire regime. Although there are several sources of uncertainty, the present lightning regime, concentrated in the summer with little spring activity, may be insufficient to support the high number and spring seasonality of fires recorded during some periods in the past. Changes in the ignition regime recorded during the past 300 years could have been due to anthropogenic and (or) climatic factors; available evidence suggests periods of frequent fire were dominated by anthropogenic ignitions.


2013 ◽  
Vol 118 (4) ◽  
pp. 1660-1673 ◽  
Author(s):  
D. M. Meko ◽  
R. Touchan ◽  
J. Villanueva Díaz ◽  
D. Griffin ◽  
C. A. Woodhouse ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7220 ◽  
Author(s):  
Víctor M. Aguilera-Molina ◽  
Khutzy K. Munguía-Ortega ◽  
Eulogio López-Reyes ◽  
Andrés Martínez-Aquino ◽  
F. Sara Ceccarelli

The imminent threat of climate change lies in its potential to disrupt the balance of ecosystems, particularly vulnerable areas such as mountain-top remnant forests. An example of such a fragile ecosystem is the Sierra San Pedro Mártir (SSPM) National Park of Mexico’s Baja California state, where high levels of endemism can be found, and which is home to one of the country’s few populations of the emblematic Jeffrey pine (Pinus jeffreyi). Recent outbreaks of pine-feeding sawfly larvae in SSPM increase the vulnerability of this forest ecosystem, calling for immediate assessments of the severity of this threat. Here, we present a thorough study of the sawfly’s biology and distribution, carrying out molecular and morphology-based identification of the species and creating model-based predictions of the species distribution in the area. The sawfly was found to belong to an undescribed species of the genus Zadiprion (family Diprionidae) with a one-year life-cycle. The distribution of this species appears to be restricted to the SSPM national park and it will probably persist for at least another 50 years, even considering the effects of climate change.


Author(s):  
R. Gordon Gastil ◽  
David L. Kimbrough ◽  
Joan M. Kimbrough ◽  
Marty Grove ◽  
Masaaki Shimizu

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