Drought alters carbon (C) allocation within trees, thereby impairing tree growth. Recovery of root and leaf functioning and prioritized C supply to sink tissues after drought may compensate for drought-induced reduction of assimilation and growth. It remains unclear if C allocation to sink tissues during and following drought is controlled by altered sink metabolic activities or by the availability of new assimilates. Understanding such mechanisms is required to predict forests’ resilience to a changing climate. We investigated the impact of drought and drought release on C allocation in a 100-y-old Scots pine forest. We applied 13CO2 pulse labeling to naturally dry control and long-term irrigated trees and tracked the fate of the label in above- and belowground C pools and fluxes. Allocation of new assimilates belowground was ca. 53% lower under nonirrigated conditions. A short rainfall event, which led to a temporary increase in the soil water content (SWC) in the topsoil, strongly increased the amounts of C transported belowground in the nonirrigated plots to values comparable to those in the irrigated plots. This switch in allocation patterns was congruent with a tipping point at around 15% SWC in the response of the respiratory activity of soil microbes. These results indicate that the metabolic sink activity in the rhizosphere and its modulation by soil moisture can drive C allocation within adult trees and ecosystems. Even a subtle increase in soil moisture can lead to a rapid recovery of belowground functions that in turn affects the direction of C transport in trees.

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<b><i>Background:</i></b> While videoconference cognitive behavioral therapy (V-CBT) has shown promising results in controlled studies, data from routine care are rare. We examined (1) changes in depressive symptoms and life satisfaction during V-CBT in German routine outpatient care for patients with depressive disorders, (2) the quality of the established working alliance, and (3) the influence of working alliance and the patients’ technology commitment on outcomes. <b><i>Patients and Methods:</i></b> Patients with primary diagnoses of depressive disorders were treated with V-CBT and concurrent internet-guided self-help via the MindDoc program, which operates within the regulations of the German health care system. The patients completed the 9-item Patient Health Questionnaire (PHQ-9) for depressive symptoms, an item on life satisfaction before and after treatment, the Working Alliance Inventory (WAI), and the Technology Commitment questionnaire for beliefs about handling technology. <b><i>Results:</i></b> Fifty-nine patients (71.2% female) with a mean age of 44.46 years (SD = 12.86) were included in the analyses. Longitudinal multilevel mixed models revealed improvements in depressive symptoms (Cohen’s <i>d</i> = 1.27) and life satisfaction (<i>d</i> = 0.80). The working alliance was good and showed a positive association with outcome, while technology commitment did not. <b><i>Conclusion:</i></b> V-CBT seems effective in reducing depressive symptoms, increasing life satisfaction, and establishing a good working alliance in routine care.

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