2026-10-06T06:17:54Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34038693 2026-10-01T04:37:01Z category_1311 portal_316 item_type_3 month_year_10_2026

Data Sheet 1_Four decades of drought impacts on Swiss protective forests: a vanishing altitudinal gradient.pdf Estelle Noyer (11597151) Luuk Dorren (25152219) Barbara Allgaier Leuch (16363392) Christine Moos (11040534) Forestry Management and Environment climate vulnerability ecosystem services elevation gradient growth dominance coefficient NDMI stand basal area stem density tree growth <p>Swiss protective forests are distributed along a wide altitudinal gradient, where many are already facing the deleterious impacts of repeated drought episodes. How intensifying drought will influence forest structure and, ultimately, their protective effect is still an open question. In this study, we investigated the temporal evolution of forest demographic traits and canopy moisture resilience over four decades, using National Forest Inventories (NFI) and satellite-derived vegetation index (NDMI), examining both growing and declining forest stands across five altitude belts. Our results reveal a general decline in forest stability and productivity in growing stands, evidenced by decreasing stand basal area increment driven by accelerating stem density losses rather than a reduction in average individual tree growth. Declining stands were consistently exposed to higher drought stress, particularly during the two most recent NFI periods. A critical finding is the vanishing influence of the altitudinal gradient on forest canopy resilience components, indicating a convergence of drought acclimation levels across the gradient. In declining stands, fundamental resilience thresholds appear to be exceeded independently of altitude, while the specific resilience component signaling decline shifted from resistance to recovery over time, suggesting a progressive compositional adaptation that nonetheless proved insufficient to prevent continued decline. Drought stress reshaped individual tree growth drivers before inducing stand-scale reorganization. The vulnerability of large, dominant individuals to drought were observed broadly across most periods, although a structural shift in stand growth partitioning toward smaller trees was detectable only in declining stands at the highest altitude and only in the most recent periods, alongside with higher average tree growth rates in that belt. These findings emphasize the urgent need for adaptive management strategies that promote structural heterogeneity, sufficient stem density, and the transition toward drought-tolerant tree cohorts to sustain the forest protective function under intensifying drought.</p> 2026-10-01T04:37:01Z Dataset Dataset 10.3389/ffgc.2026.1933304.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Four_decades_of_drought_impacts_on_Swiss_protective_forests_a_vanishing_altitudinal_gradient_pdf/34038693 CC BY 4.0