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Background and Aims: There is evidence that some species can withstand a stress event better when experienced previously. This capacity could help to increase stress tolerance and resilience under recurrent stresses. To test the effect of a previous season drought imprint on the tolerance to a subsequent drought event, we compared the growth and physiological performance of young cv. Cabernet Sauvignon grapevines growing in a semi‐arid zone in Chile. Methods and Results: Treatments were single drought (SD; stressed during the second season) and double drought (DD; stressed during the first and second season). During the second season, DD vines budburst earlier, and leaves were smaller. During the drought period, DD showed a higher rate of photosynthesis despite a similar reduction in the stem water potential and stomatal conductance compared to that of SD. Such difference was associated to a higher maximum Rubisco carboxylation rate observed in DD. Conclusions: Our results suggest that grapevines exposed to drought are primed for an upcoming second drought event, the priming lasting from one season to the next, involving contrasting growth and physiological performance. Significance of the Study: Our study results contribute information to the emerging debate regarding drought‐priming effects on the tolerance of grapevines to recurrent drought events. [ABSTRACT FROM AUTHOR]

Abstract: We studied the effects of afforestation on soil respiration (R s) in an arid shrubland in northern Chile. We sampled R s monthly for three years in two adjacent plots, one left as control in natural condition, and one afforested with Acacia saligna. Sampling occurred 3–6 years after afforestation. Soil temperature (T s) was a good predictor of R s on certain periods of the year, although we could not relate this to specific levels of soil moisture (θ). Seasonal R s variation related more to θ than to T s, which could be explained by extremely low annual precipitation (138mm), concentrated during winter months. The correlation between T s and R s was higher when measured under plants compared to bare ground. The afforested site had in average 17% lower annual R s (p =0.06) than the control site. During some months of the third year of measurements, the afforested site showed greater R s than the control, suggesting that in the near future, R s might be higher for the afforested site than for the natural condition, depending on the effect that trees may have on soil carbon stability, temperature and hydrological conditions. [Copyright &y& Elsevier]

Abstract: The pattern of carbon (C) allocation among the different pools is an important ecosystem structural feature, which can be modified as a result of changes in environmental conditions that can occur gradually (e.g., climatic change) or abruptly (e.g., management practices). This study quantified the C pools of plant biomass, litter and soil in an arid shrubland in Chile, comparing the natural condition (moderately disturbed by grazing) vs. the afforested condition (two-year-old plantation with Acacia saligna (Labill.) H.L. Wendl.), each represented by a 60 ha plot. To estimate plant biomass, allometric functions were constructed for the four dominant woody species, based on the volume according to their shape, which showed high correlation (R 2 > 0.73). The soil was the largest C pool in both natural and afforested conditions (89% and 94%, respectively) and was significantly lower in the afforested than natural condition at all five soil depths. The natural condition had in total 36.5 ton (t) C ha−1 compared to 21.1 t C ha−1 in the afforested condition, mainly due to C loss during soil preparation, prior to plantation of A. saligna. These measurements serve as an important baseline to assess long-term effects of afforestation on ecosystem C pools. [ABSTRACT FROM AUTHOR]