Ecological response of Cedrus atlantica to climate variability in the Massif of Guetiane (Algeria)

Abstract

Aim of the study: The study analyzes the long-term response of Atlas cedar, Cedrus atlantica (Manneti), to climate variability.Area of study: Atlas cedar forest of Guetiane (Batna, Algeria). Material and methods:The dendrochronological approach was adopted. An Atlas cedar tree-ring chronology was established from twenty trees. The response of the species to climate variability was assessed through the pointer years (PYs), the common climate signal among the individual chronologies, expressed by the first component (PC1), the mean sensitivity (ms x ), and response function and correlations analysis involving the tree-ring index and climate data (monthly mean temperature and total precipitation).Results: The highest growth variability was registered from the second half of the 20 th century. The lower than the mean PYs, the PC1, and the ms x increased markedly during the studied period. Dramatic increases in the PC1 and ms x were detected at the end of the 1970s, reflecting a shift towards drier conditions enhancing an increasing trend towards more synchronous response of trees to climate conditions. The response function and correlations analysis showed that tree growth was mainly influenced by precipitation variability.Research highlights: Our findings provide baseline knowledge concerning the ecological response of Atlas cedar to climate variability in in its southern distribution limit, where a high level of tree mortality has been observed during recent decades, coinciding with the driest period Algeria has ever experienced. This information is vital to support ongoing ecosystem management efforts in the region.

Mediterranean forests, land use and climate change: a social-ecological perspective

“…This suggests climate conditions more limiting to tree growth and drought-sensitive species geographical distribution, especially for those at the edge of their range. This event triggered substantial mortality in Cedrus atlantica forests where, in some areas, stands disappeared completely (Zine El Abidine 2003; Linares et al 2011;Kherchouche et al 2012Kherchouche et al , 2013Slimani et al 2014), and even in other tree species reputed for their drought hardiness, including Pinus halepensis, Quercus ilex, Quercus suber and Juniperus thurifera (Allen et al 2010). …”

“…Concerning changes in forest vegetation over the last few decades, recent studies in northwestern Africa reported recurrent drought events from the second half of the twentieth century (Touchan et al 2010;Linares et al 2011;Kherchouche et al 2012Kherchouche et al , 2013Slimani 2014). Touchan et al (2008) showed that the 1999-2002 severe drought appears to be the worst in northwestern Africa since the middle of the fifteenth century.…”

Climate controls on tree growth in the Western Mediterranean

“…Previous analyses have shown that tree growth in the WM is controlled by soil moisture and precipitation (Aloui, 1982;Aloui and Serre-Bachet, 1987;Camarero et al, 2013;Chbouki, 1992;Chbouki et al, 1995;Esper et al, 2007;Linares et al, 2011;Messaoudene and Tessier, 1997;Safar et al, 1992;Serre-Bachet, 1969;Slimani et al, 2014;Tessier et al, 1994;Till and Guiot, 1990;Touchan et al, 2008aTouchan et al, , 2008bTouchan et al, , 2011. We compared our chronology network against the gridded, self-calibrating, Penman-Monteith Palmer Drought Severity Index (PDSI; Van der Schrier et al, 2013) covering 1901-2009 and 1.0° gridded monthly precipitation data from the Global Precipitation Climatology Centre (GPCC; version 6) dataset covering 1901-2010 (Becker et al, 2013;Schneider et al, 2011Schneider et al, , 2013.…”

Historical droughts recorded in extended Juniperus procera ring-width chronologies from the Ethiopian Highlands

“…This could reflect a lag in the negative effect of drought on tree growth which was supported by the relatively high autocorrelation in the site chronologies (Matisons et al 2013). It has been demonstrated that J. procera is sensitive to climatic variability (Wils et al 2010), and such trees show more pointer years than other tree species in the same area (Slimani et al 2014).…”