Rapid beech decline under recurrent drought stress: Individual neighborhood structure and soil properties matter

Forest Ecology and Management, Journal Year: 2023, Volume and Issue: 545, P. 121305 - 121305

Published: July 29, 2023

During the summer of 2022, an acute drought once more afflicted central and southern Europe. This marked third episode (after 2015 2018) severe aridity in large parts Germany within last decade, leading to increased soil water depletion. Consequently, from July 2022 onward, European beech trees (Fagus sylvatica L.) exhibited early withering pronounced premature defoliation. Nevertheless, crown defoliation substantial variation among same forest stands, prompting questions regarding causal factors. In our study, we scrutinized twelve mature drought-impacted, beech-dominated stands northern Bavaria, arranged along a gradient different nutrient regime levels (base-rich, intermediate, base-poor), with co-occurring vital (≤40% defoliation) declining (≥60% trees. Within each stand, selected equal number trees, culminating total 332 target Dendrochronological patterns were analyzed identify potential timing growth separation between vitality classes. Moreover, used Bayesian modelling framework discern whether disparities tree hinged on competition, structure, small-scale differences plant-available capacity, spatial clustering competitors. We further explored factors influencing magnitude decline post-2018 how these modulated by site's regime. Our study unveiled that (i) low competition size diversity bolstered vitality; (ii) spatially aggregated; (iii) strikingly similar trajectories past, which underwent drastic shift following 2018, indicating for rapid under recurrent stress; (iv) capacity emerged as crucial determinant subsequent 2018; (v) was most at base-poor intermediate sites. findings underscore importance accommodating stand characteristics advocate silvicultural guidance towards reduced densities combination heterogenous structure mitigate dieback drought-prone stands.

Language: Английский

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Nutritional changes in trees during drought‐induced mortality: A comprehensive meta‐analysis and a field study

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(1)

Published: Jan. 1, 2024

Abstract Both macronutrients and micronutrients are essential for tree growth development through participating in various ecophysiological processes. However, the impact of nutritional status trees on their ability to withstand drought‐induced mortality remains inconclusive. We thus conducted a comprehensive meta‐analysis, compiling data 11 nutrients from 44 publications (493 independent observations). Additionally, field study was Pinus sylvestris L. with varying vitality loss “Visp” forest southern Switzerland. No consistent decline observed during mortality. The meta‐analysis revealed significantly lower leaf potassium (K), iron (Fe), copper (Cu) concentrations showed no causal relationships between levels trees. This discrepancy is mainly attributed intrinsic differences two types experimental designs ontogenetic stages target Nutrient reductions preceding were predominantly non‐field conditions, where seedlings saplings underdeveloped root systems. It limits nutrient uptake capacity these young drought. Furthermore, responses also influenced by many variables. Specifically, (a) more susceptible drought stress than other organs; (b) reduced prevalent evergreen species mortality; (c) all biomes, Mediterranean forests most vulnerable deficiencies; (d) soil affect direction extent responses. identified factors that influence relationship survival, proposed potential early‐warning indicators impending mortality, example, decreased K declining vitality. These findings contribute our understanding provide practical implications management strategies context global change.

Language: Английский

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Exploring the connection between climatic conditions and genetic properties of Abies alba Mill., including warm and summer-dry Mediterranean environments

The Science of The Total Environment, Journal Year: 2025, Volume and Issue: 964, P. 178559 - 178559

Published: Jan. 23, 2025

Abies alba Mill. is a prominent European tree species predominantly inhabiting cool and humid montane environments. However, paleoecological evidence reveals that during the Eemian mid-Holocene, A. thrived in much warmer drier climates. This capacity nowadays reflected cryptic meso- sub-Mediterranean lowland populations. To link populations across diverse climates spanning from Mediterranean lowlands to Alpine timberline, we genotyped 421 specimens Italy Switzerland at 190 single-nucleotide polymorphisms (SNPs). Population genetic structure analyses indicate isolated Tuscany Ticino align genetically with higher elevation each region, suggesting their thrive warmer, conditions cannot be attributed plantations planting stock originating different or occurrence of single warm-adapted lineage showing disjunct distribution, unless migration between stands occurred. Genotype-environment associations reveal temperature seasonality, precipitation critical seasons, relative humidity are important for explaining species' variation. With genotype-environment genotype-phenotype associations, identified candidate adaptive genes potentially linked climatic drought response. While certain alleles may have spread Southern could explained by shared ancestry Tuscan populations, local adaptation occurred specific loci. These findings underscore importance considering hitherto overlooked better understand niche its potential forest conservation management under global warming.

Language: Английский

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The role of nutritional impairment in carbon‐water balance of silver fir drought‐induced dieback

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(14), P. 4439 - 4458

Published: March 23, 2022

Rear-edge populations at the xeric distribution limit of tree species are particularly vulnerable to forest dieback triggered by drought. This is case silver fir (Abies alba) forests located in Southwestern Europe. While drought-induced patterns have been previously explored, information on role played nutritional impairment lacking despite its potential interactions with carbon-water balances. We performed a comparative analysis radial growth, intrinsic water-use efficiency (iWUE), oxygen isotopes (δ18 O) and nutrient concentrations leaves declining (DD) non-declining (ND) trees four Spanish Pyrenees. also evaluated relationships among predisposition, intraspecific trait variation (wood density leaf traits) rhizosphere soil physical-chemical properties. The onset growth decline DD occurred more than two decades ago, they subsequently showed low resilience against droughts. presented consistently lower foliar nutrients such as P, K, Cu Ni ND trees. strong effects status indices support key mineral nutrition functioning before, during after In contrast, variability wood morphological traits, well properties, weak drought performance. At elevation, warmer sites, stronger climate-growth δ18 O uncoupling between iWUE O, together positive correlations P K point deeper soil/bedrock water sources vertical decoupling uptake study provides novel insights into mechanisms driving highlights need incorporate studies.Las poblaciones del límite xérico de distribución las especies árboles son particularmente vulnerables al decaimiento forestal inducido por sequía. Este es el caso los bosques abeto situados en suroeste Europa. Si bien patrones provocado sequía se han explorado previamente, falta información sobre papel que desempeña deterioro nutricional pesar sus interacciones potenciales con balances agua y carbono árboles. En este estudio, hemos realizado un análisis comparativo crecimiento radial, la eficiencia intrínseca uso isótopos oxígeno (δ18O) concentraciones nutrientes hojas decaídos no cuatro abetares Pirineos españoles. También evaluamos relaciones entre predisposición decaimiento, variación rasgos intraespecíficos (densidad madera hojas) propiedades físico-químicas rizosfera. El inicio disminución ocurrió hace más dos décadas posteriormente mostraron una baja resiliencia frente sequías. Los presentaron foliares consistentemente bajas como ND. fuertes efectos estado índices respaldan clave nutrición funcionamiento antes, durante después contraste, variabilidad densidad morfológicos hojas, así suelo, relación débil respuesta sitios cálidos elevación, clima-crecimiento bajo desacoplamiento junto correlaciones positivas apuntan fuentes profundas suelo/lecho rocoso absorción DD. estudio proporciona novedosa mecanismos impulsan destaca necesidad incorporar estudios muerte regresiva bosque.

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Delineating vulnerability to drought using a process-based growth model in Pyrenean silver fir forests

Forest Ecology and Management, Journal Year: 2023, Volume and Issue: 541, P. 121069 - 121069

Published: May 10, 2023

Assessing tree growth patterns and deviations from expected climate baselines across wide environmental gradients is fundamental to determine forest vulnerability drought. This need particularly compelling for the southernmost limit of species distribution where hot droughts often trigger dieback processes. case some silver fir (Abies alba) populations located in southwestern Europe (Spanish Pyrenees) which present ongoing processes since 1980s. We sampled 21 stands showing different intensity, assessed using defoliation levels, quantified their characterized responses climate. Then, we climatic predictions process-based Vaganov-Shashkin (VS) model. The forests most intense dieback, i.e. highest were mainly low-elevation sites western Pyrenees. Trees these displayed lowest rates year-to-year variability was limited by late-summer evaporative demand. In eastern central Pyrenees, detected a mild limitation low soil moisture during late growing season positive recovery recent years with respect baseline. Decreasing trajectories common pattern, while rising trends Our results portend systematic spatial Pyrenean forming south-western Europe. Decoupling between observed decades suggests contrasting change, more importantly, decoupling clusters could be used as an early-warning signal impending dieback. Consequently, foresee future events have detrimental effects compared

Language: Английский

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Drought legacies in mixed Mediterranean forests: Analysing the effects of structural overshoot, functional traits and site factors

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 927, P. 172166 - 172166

Published: April 3, 2024

Previous favorable climate conditions stimulate tree growth making some forests more vulnerable to hotter droughts. This so-called structural overshoot may contribute forest dieback, but there is little evidence on its relative importance depending site and species because of limited field data. Here, we analyzed remote sensing (NDVI) tree-ring width data evaluate the impacts 2017 drought canopy cover in mixed Mediterranean (Fraxinus ornus, Quercus pubescens, Acer monspessulanum, Pinus pinaster) located southern Italy. Legacy effects were assessed by calculating differences between observed predicted basal area increment (BAI). Overall, response study stands was contingent characteristics. Most sites presented BAI reductions during drought. Growth decline followed a quick recovery positive legacy effects, particularly case F. ornus. However, found negative legacies (e.g., Q. A. monspessulanum) sites. In those showing legacies, high rates prior previous wet winter-spring have predisposed trees damage. Vice versa, ornus linked post-drought release due pubescens dieback mortality. Therefore, evidences overshoot, it restricted specific species. Our findings highlight considering settings such as stand composition, pre-drought different when studying overshoot. Droughts modify composition dynamics forests.

Language: Английский

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Drought constrains acorn production and tree growth in the Mediterranean holm oak and triggers weak legacy effects

Agricultural and Forest Meteorology, Journal Year: 2023, Volume and Issue: 334, P. 109435 - 109435

Published: March 22, 2023

Droughts are becoming more frequent in the Mediterranean basin due to warmer conditions. negatively impact forests growth for several years, often generating negative legacies or carryover effects. However, these differ among tree species, sites and drought characteristics have been mainly studied considering canopy greenness, but ignoring reproductive phenomena. Here, we compare legacy effects of on acorn male inflorescence production radial by using a 19-year series 150 Quercus ilex individuals three stands located north-eastern Spain. We evaluate relationships between monthly climate variables, tree-ring width, production. For two driest years considered (2005 2012), when very few acorns were produced, did not find following droughts. The inflorescences show any significant after drought, although its annual variation was related climatic conditions year before ripening. Acorn higher than expected some apparently pattern recovery with certain lag. This compensatory response differed analysed droughts, accordance different timing post-drought Even though found, confirmed effect stress production, linked dry winter Our findings confirm that features (timing, duration, intensity) influence reproduction legacies.

Language: Английский

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Higher risk of hydraulic dysfunction and carbohydrate depletion of declining Larix principis-rupprechtii trees

Ecological Processes, Journal Year: 2025, Volume and Issue: 14(1)

Published: Jan. 2, 2025

Abstract Background Climate change associated with droughts has led to widespread forest decline. Hydraulic and carbon-related performances are key physiological processes for the tolerance of trees environmental changes, yet our current understanding such decline is still limited. Here, we investigated hydraulic carbohydrate healthy declining (canopy dieback) in temperate larch ( Larix principis-rupprechtii ) plantations. Results Relative trees, higher native percentage loss xylem conductivity lower indicated a deterioration integrity system trees. Additionally, comparable Huber value, intrinsic water-use efficiency, leaf mass per area between suggest relatively profligate strategy by Declining had nonstructural concentrations leaves, branches, twigs but soluble sugars concentration fine roots than conspecific Conclusions Overall, plantations would be more vulnerable drought due risk dysfunction depletion.

Language: Английский

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Climate and Biological Factors Co-Regulate the Drought Resilience of Pinus Tabulaeformis

Published: Jan. 1, 2025

Severe drought can threaten the structure and function of forest ecosystems by profoundly altering plant growth mortality. Identifying drivers influencing resilience is essential for understanding global warming effect on ecosystem. However, direct indirect impacts multiple climate biological factors remain unquantified, a potential mechanistic pathway remains unexplored. Here, we aimed to quantify resistance, recovery, Pinus tabulaeformis using basal area increment. We showed that Palmer Drought Severity Index had significant positive impact negative but non-significant resilience. Tree age pre-drought increments (preBAI) effects recovery resilience, while only preBAI significantly affected resistance. Additionally, competition index relatively minor exerted influence limiting diameter at breast height (DBH). This research suggests co-regulate in this region. findings are helpful comprehending ecological ecosystem stability, provide useful insights effective management under future change.

Language: Английский

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Die-off after an extreme hot drought affects trees with physiological performance constrained by a more stressful abiotic niche

Agricultural and Forest Meteorology, Journal Year: 2025, Volume and Issue: 363, P. 110430 - 110430

Published: Feb. 7, 2025

Language: Английский

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