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Zineb Choury Tatiana A. Shestakova Hocine Himrane Ramzi Touchan Dalila Kherchouche J. Julio Camarero Jordi Voltas 《European Journal of Forest Research》2017,136(1):139-152
The Algerian Green Barrier, mainly composed of native and artificial Aleppo pine forests, spreads along the pre-Saharan steppes and is threatened by anthropogenic and natural disturbances, including climate change. We hypothesized that the ecophysiological functioning of this conifer has been substantially modified in reaction to recent warming and drought much beyond the expected effect of CO2 fertilization. Our aim was to characterize the long-term performance (1925–2013) of native Aleppo pines thriving at their southernmost distribution. We used tree-ring width (TRW) and carbon isotope discrimination (Δ13C) to characterize basal area increment (BAI) and intrinsic water-use efficiency (WUEi) at three sites. BAI remained stable or slightly increased over time, with mean values ranging between 4.0 and 6.3 cm2 year?1. Conversely, site-Δ13C decreased from ?0.022 to ?0.014‰ year?1 along time, which translated into WUEi increases of ca. 39%. This strong physiological reaction indicated that pines were responding simultaneously to rising CO2 and drier conditions, inducing a progressively tighter stomatal control of water losses. However, WUEi increments were essentially unrelated to BAI and did not affect carbon reserves, which suggests a high resilience to climate change. This finding could be due to shifts in growing season towards earlier months in winter–spring, as suggested by temporal changes in climate factors underlying Δ13C and TRW. Our study highlights the substantial plasticity of Aleppo pine, but this species is unlikely to follow a similar pace of ecophysiological adjustments according to unprecedented low Δ13C records and lack of WUEi stimulation observed from 2000 onwards. 相似文献
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Anne C. RICHER-de-FORGES Dominique ARROUAYS Laura POGGIO Songchao CHEN Marine LACOSTE Budiman MINASNY Zamir LIBOHOVA Pierre ROUDIER Vera L. MULDER Herv&#; N&#;D&#;LEC Guillaume MARTELET Blandine LEMERCIER Philippe LAGACHERIE Hocine BOURENNANE 《土壤圈》2023,33(5):731-743
Digital maps of soil properties are now widely available. End-users now can access several digital soil mapping (DSM) products of soil properties, produced using different models, calibration/training data, and covariates at various spatial scales from global to local. Therefore, there is an urgent need to provide easy-to-understand tools to communicate map uncertainty and help end-users assess the reliability of DSM products for use at local scales. In this study, we used a large amount of hand-feel soil texture (HFST) data to assess the performance of various published DSM products on the prediction of soil particle size distribution in Central France. We tested four DSM products for soil texture prediction developed at various scales (global, continental, national, and regional) by comparing their predictions with approximately 3 200 HFST observations realized on a 1:50 000 soil survey conducted after release of these DSM products. We used both visual comparisons and quantitative indicators to match the DSM predictions and HFST observations. The comparison between the low-cost HFST observations and DSM predictions clearly showed the applicability of various DSM products, with the prediction accuracy increasing from global to regional predictions. This simple evaluation can determine which products can be used at the local scale and if more accurate DSM products are required. 相似文献
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