Climate controls on tree growth in the Western Mediterranean

Abstract

The first large-scale network of tree-ring chronologies from the western Mediterranean (WM; 32°N-43°N, 10°W-17°E) is described and analyzed to identify the seasonal climatic signal in indices of annual ring width. Correlation and rotated empirical orthogonal function analyses are applied to 85 treering series and corresponding gridded climate data to assess the climate signal embedded in the network. Chronologies range in length from 80 to 1129 years. Monthly correlations and partial correlations show overall positive associations for Pinus halepensis (PIHA) and Cedrus atlantica (CDAT) with winter (December-February) and spring (March-May) precipitation across this network. In both seasons, the precipitation correlation with PIHA is stronger, while CDAT chronologies tend to be longer. A combination of positive correlations between growth and winter-summer precipitation and negative partial correlations with growing season temperatures suggests that chronologies in at least part of the network reflect soil moisture and the integrated effects of precipitation and evapotranspiration signal. The range of climate response observed across this network reflects a combination of both species and geographic influences. Western Moroccan chronologies have the strongest association with the North Atlantic Oscillation.

Geographical adaptation prevails over species‐specific determinism in trees’ vulnerability to climate change at Mediterranean rear‐edge forests

“…Although precipitation is expected to increase globally, the Mediterranean Basin will likely experience drying due to the rise in temperature and changes in atmospheric circulation patterns (Collins et al, ). Specifically, precipitation over the Mediterranean Basin is known to be linked to changes in atmospheric circulation patterns such as the North Atlantic Oscillation (NAO; Fortuny, ; Kelley, Ting, Seager, & Kushnir, ; Kelley, Ting, Seager, & Kushnir,; Vicente‐Serrano et al, ), which has been demonstrated to influence forest growth in the Mediterranean region (Dorado‐Liñán, Zorita, et al, ; Piovesan & Schirone, ; Touchan et al, ). According to the information provided by instrumental records, the Mediterranean region has already been showing a significant increase in dryness over the last six decades (Hartmann et al, ) concurrent with an increase in the frequency of high NAO phases (Bladé, Liebmann, Fortuny, & Oldenborgh, ; Folland et al, ), and drying will likely continue during the next century (Gao & Giorgi, ; Ozturk, Ceber, Türkeş, & Kurnaz, ).…”

Stable carbon isotope analysis on fossil Cedrus pollen shows summer aridification in Morocco during the last 5000 years

“…Cheddadi et al, 1998;Campbell et al, 2017;Zielhofer et al, 2017aZielhofer et al, , 2019. However, other factors such as winter temperature (Touchan et al, 2017), or ecological and edaphic conditions could have also influenced Cedrus expansion. Indeed, C. atlantica is a drought-tolerant species (but is sensitive to extreme drought; Aussenac, 1984;Rhanem, 2011) and is found growing in semi-arid mountain areas across North Africa (Fig.…”

Structure, Tree Growth and Dynamics of <I>Cedrus atlantica</I> Manetti Forests in Theniet El Had National Park (N-W Algeria)

“…The Atlas cedar has an important place in the Mediterranean landscape in Algeria and Morocco [8]. Unfortunately, the status of Atlas cedar stands in Algeria indicates a strong degradation linked primarily to anthropogenic action and the unfavorable climatic conditions marked by persistent drought since the 1980s [9] [10]. This situation has led to a loss of vitality and the emergence of tree decline [11] [12].…”