Drought Legacy in Sub‐Seasonal Vegetation State and Sensitivity to Climate Over the Northern Hemisphere

Geophysical Research Letters, Год журнала: 2022, Номер 49(15)

Опубликована: Июль 19, 2022

Abstract Droughts affect ecosystems at multiple time scales, but their sub‐seasonal legacy effects on vegetation activity remain unclear. Combining the satellite‐based enhanced index MODIS EVI with a novel location‐specific definition of growing season, we quantify drought impacts and subsequent recovery in Northern Hemisphere. Drought are quantified as changes post‐drought greenness sensitivity to climate. We find that losses under severe partially compensated by ∼+5% greening within 2–6 growing‐season months following droughts, both woody herbaceous different timings. In addition, hydrological conditions increases noticeably high latitudes compared local normal conditions, regardless choice scales. general, larger than vegetation.

Язык: Английский

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Tree species growth response to climate in mixtures of Quercus robur/Quercus petraea and Pinus sylvestris across Europe - a dynamic, sensitive equilibrium

Forest Ecology and Management, Год журнала: 2022, Номер 530, С. 120753 - 120753

Опубликована: Дек. 29, 2022

Quercus robur/Quercus petraea and Pinus sylvestris are widely distributed economically important tree species in Europe co-occurring on mesotrophic, xeric mesic sites. Increasing dry conditions may reduce their growth, but growth reductions be modified by mixture, competition site conditions. The annual diameter monospecific mixed stands along an ecological gradient with mean temperatures ranging from 5.5 °C to 11.5 was investigated this study. On 36 triplets (108 plots), trees were cored the year-ring series cross-dated, resulting of 785 804 for Q. spp. P. sylvestris, respectively. A generalized additive model a logarithmic link fit data random effects intercept at triplet, year level slope covariate age each tree; Tweedie-distribution used. final explained 87 % total variation increment both species. Significant covariates age, climate variables (long-term mean, monthly), local variables, relative dbh, stand structure interactions thereof. Tree declined density increased social position. It positively influenced mixture structural diversity (Gini coefficient); significant only. influence potential evapotranspiration (PET) spring autumn positive non-linear, whereas sharply decreased increasing PET June, which proved most influential month whole gradient. Interactions position (relative dbh) July September April sylvestris. or not significant. Climatic found agree well previous results intra-annual studies indicate that captures causal factors well. Furthermore, interaction between dbh might longer duration higher classes. Analysis across time space showed highly dynamic patterns, competitive advantages changing annually spatial patterns showing no large-scale trends pointing prevalence factors. In mixed-species stands, have same competitivity long-term, is year. Climate warming will shift advantages, direction site-specific.

Язык: Английский

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Post-drought moisture condition determines tree growth recovery after extreme drought events in the Tianshan Mountains, northwestern China

Ecological Indicators, Год журнала: 2023, Номер 151, С. 110275 - 110275

Опубликована: Апрель 24, 2023

Recently, forests in the Tianshan Mountains have shown a marked decline growth and an increased mortality rate because of more frequent severe effects extreme drought, which threatens ecosystem services they provide. To achieve forest conservation sustainable development benefits, it is crucial to understand post-drought recovery trajectory tree its driving factors. In this study, we quantified performance dominant species after drought events determined influences climate factors on resilience using tree-ring proxy data. The results showed that moisture conditions may determine trees. for 1997 was higher than 1974, be attributed subsequent period experiencing very high precipitation, whereas year following 1974 dry (Standardized Precipitation Evapotranspiration Index < 0). Because favorable period, observed relationship between resistance closer fit hypothetical "line full resilience" sets constant value 1, allowing trees recover fully at any given resistance. Trees lower mean values index (RC) average (ARR) total reduction (TGR) (RE) event 1997. We distinguished relative influence temperature precipitation different phases Boosted Regression Tree (BRT) model. during variation were most influential variables recovery. Specifically, explained up 20 % variance RC, TGR, RE, ARR. These findings deepen our understanding impacts prolonged growth, could aid developing management strategies respond drought.

Язык: 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, Год журнала: 2023, Номер 334, С. 109435 - 109435

Опубликована: Март 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.

Язык: Английский

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An Overview of Extreme Years in Quercus sp. Tree Ring Records from the Northern Moldavian Plateau

Forests, Год журнала: 2023, Номер 14(5), С. 894 - 894

Опубликована: Апрель 26, 2023

In this study, we made use of a regional oak tree-ring network from six stands that cover the northern Moldavian Plateau (eastern Europe) to analyze how different tree ring parameters (i.e., early wood width, late and total width) Quercus sp. are influenced by occurrence extreme climatic events (e.g., long-lasting drought events). order explore influence hydroclimatic on have selected each most positive negative years growth addressed seasonal cycle in comparison with main parameters, then evaluated both current lagged consequences width capacity trees recover. Our results indicate variability is mainly availability water resources, an important limiting factor for events, e.g., at least two row severe conditions.

Язык: Английский

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