Holocene environmental change in southern Spain deduced from the isotopic record of a high-elevation wetland in Sierra Nevada

2012 ◽  
Vol 48 (3) ◽  
pp. 471-484 ◽  
Author(s):  
Antonio García-Alix ◽  
Gonzalo Jiménez-Moreno ◽  
R. Scott Anderson ◽  
Francisco J. Jiménez Espejo ◽  
Antonio Delgado Huertas
Keyword(s):  
Environmental Change ◽  
Sierra Nevada ◽  
High Elevation ◽  
Southern Spain ◽  
Holocene Environmental Change

Holocene environmental change resets lichen surface dates on Recess Peak glacial deposits in the Sierra Nevada, California

2013 ◽  
Vol 80 (2) ◽  
pp. 180-188 ◽  
Author(s):  
Louis A. Scuderi ◽  
Peter J. Fawcett
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Sierra Nevada ◽  
Radiocarbon Dating ◽  
Late Holocene ◽  
Tree Line ◽  
Glacial Deposits ◽  
Present Evidence ◽  
Holocene Environmental Change ◽  
Age Estimates

Development of an accurate chronology for glacial deposits in the Sierra Nevada has long been problematic given the lack of suitable organic material for radiocarbon dating. Lichenometry initially appeared promising as ages showed an increase from cirque headwalls to down-canyon moraines. However, while Recess Peak lichen age estimates range from 2 to 3 ka, recent work shows these deposits to be at least 10 ka older. Here, we present evidence for a late Holocene reset of Recess Peak lichen ages by significant post-depositional climate change. Following late-Pleistocene deposition of Recess Peak moraines, warming through the mid-Holocene allowed forests to advance into shallow basins eliminating local inverted tree lines. This produced a partial canopy where shading killed the original post-Pleistocene crustose lichen colonies. Late-Holocene cooling resulted in forest retreat from these basins as alpine tree line fell. Lichens then recolonized the re-exposed Recess Peak deposits. We conclude that while Recess Peak lichen ages are accurate to within the dating uncertainty of the technique, existing lichen ages actually date the timing of post-mid-Holocene cooling and recolonization, and not the original emplacement of these deposits. Thus, applications of Lichenometry should consider post-depositional environmental change when interpreting the meaning of these dates.

Holocene vegetation and climate change recorded in alpine bog sediments from the Borreguiles de la Virgen, Sierra Nevada, southern Spain

2012 ◽  
Vol 77 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Gonzalo Jiménez-Moreno ◽  
R. Scott Anderson
Keyword(s):  
Climate Change ◽  
Magnetic Susceptibility ◽  
High Resolution ◽  
Sierra Nevada ◽  
High Elevation ◽  
High Impact ◽  
Southern Spain ◽  
Pollen Record ◽  
Arboreal Pollen ◽  
Vegetation And Climate

High-resolution pollen and magnetic susceptibility (MS) analyses have been carried out on a sediment core taken from a high-elevation alpine bog area located in Sierra Nevada, southern Spain. The earliest part of the record, from 8200 to about 7000 cal yr BP, is characterized by the highest abundance of arboreal pollen andPediastrum, indicating the warmest and wettest conditions in the area at that time. The pollen record shows a progressive aridification since 7000 cal yr BP that occurred in two steps, first shown by a decrease inPinus, replaced by Poaceae from 7000 to 4600 cal yr BP and then by Cyperaceae,Artemisiaand Amaranthaceae from 4600 to 1200 cal yr BP.Pediastrumalso decreased progressively and totally disappeared at ca. 3000 yr ago. The progressive aridification is punctuated by periodically enhanced drought at ca. 6500, 5200 and 4000 cal yr BP that coincide in timing and duration with well-known dry events in the Mediterranean and other areas. Since 1200 cal yr BP, several changes are observed in the vegetation that probably indicate the high-impact of humans in the Sierra Nevada, with pasturing leading to nutrient enrichment and eutrophication of the bog,Pinusreforestation andOleacultivation at lower elevations.

A multiproxy evaluation of Holocene environmental change from Lake Igaliku, South Greenland

2012 ◽  
Vol 48 (1) ◽  
pp. 241-258 ◽  
Author(s):  
Charly Massa ◽  
Bianca B. Perren ◽  
Émilie Gauthier ◽  
Vincent Bichet ◽  
Christophe Petit ◽  
...  
Keyword(s):  
Environmental Change ◽  
Holocene Environmental Change

scholarly journals Holocene environmental change in Kamchatka: A synopsis

2015 ◽  
Vol 134 ◽  
pp. 166-174 ◽  
Author(s):  
S.J. Brooks ◽  
B. Diekmann ◽  
V.J. Jones ◽  
D. Hammarlund
Keyword(s):  
Environmental Change ◽  
Holocene Environmental Change

Holocene environmental change and its impact on sediment dynamics in the Eastern Mediterranean

2011 ◽  
Vol 108 (3-4) ◽  
pp. 137-157 ◽  
Author(s):  
Bert Dusar ◽  
Gert Verstraeten ◽  
Bastiaan Notebaert ◽  
Johan Bakker
Keyword(s):  
Environmental Change ◽  
Eastern Mediterranean ◽  
Sediment Dynamics ◽  
Holocene Environmental Change

Response of high-elevation limber pine (Pinus flexilis) to multiyear droughts and 20th-century warming, Sierra Nevada, California, USA

2007 ◽  
Vol 37 (12) ◽  
pp. 2508-2520 ◽  
Author(s):  
Constance I. Millar ◽  
Robert D. Westfall ◽  
Diane L. Delany
Keyword(s):  
20Th Century ◽  
Sierra Nevada ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
High Elevation ◽  
Dwarf Mistletoe ◽  
Lower Growth ◽  
Pinus Flexilis ◽  
Limber Pine ◽  
Temperature And Precipitation

Limber pine ( Pinus flexilis James) stands along the eastern escarpment of the Sierra Nevada, California, experienced significant mortality from 1985 to 1995 during a period of sustained low precipitation and high temperature. The stands differ from old-growth limber pine forests in being dense, young, more even-aged, and located in warmer, drier microclimates. Tree growth showed high interannual variability. Relative to live trees, dead trees over their lifetimes had higher series sensitivity, grew more variably, and had lower growth. Although droughts recurred during the 20th century, tree mortality occurred only in the late 1980s. Significant correlations and interactions of growth and mortality dates with temperature and precipitation indicate that conditions of warmth plus sustained drought increased the likelihood of mortality in the 1985–1995 interval. This resembles a global-change-type drought, where warming combined with drought was an initial stress, trees were further weakened by dwarf mistletoe ( Arceuthobium cyanocarpum (A. Nels. ex Rydb.) A. Nels.), and proximally killed by mountain pine beetle ( Dendroctonus ponderosae Hopkins). However, the thinning effect of the drought-related mortality appears to have promoted resilience and improved near-term health of these stands, which suffered no additional mortality in the subsequent 1999–2004 drought.

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