Competition-based mortality and tree losses. An essential component of net primary productivity

Forest Ecology and Management, Journal Year: 2023, Volume and Issue: 544, P. 121204 - 121204

Published: June 22, 2023

Even-aged stands can regenerate with many thousand seedlings per hectare before the density declines to just a few hundred trees 100 years later; management practices lead even lower tree numbers due quality selection and thinning. In other words, during development of unmanaged stands, majority individuals die naturally competition. Despite far-reaching consequences for structural genetic diversity, dead wood fuel accumulation, we have only limited quantitative knowledge about continuous mortality volume loss over longer timespans. For this study, used unique set 476 unmanaged, monospecific experimental plots Norway spruce (Picea abies (L.) H. Karst.), silver fir (Abies alba Mill.), Scots pine (Pinus sylvestris L.), European larch (Larix decidua Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)), beech (Fagus sylvatica oak (Quercus robur L. Quercus petraea (Matt.) Liebl.) throughout Europe analyze competition-based its dependency on age site conditions. First, show that total stem production, standing stock, were continuously increasing until an 100–150 years. The accumulated competition-caused at amounted 500–1000 m3 ha−1. Second, net growth (share is in stock) strongly decreased when gross was still high. proportion versus regardless quality. Third, degressive decrease annual relative number rates from 0.05 0.20 young down 0.01–0.02 mature stands. some species, found these be dependent different directions effect. interplay decreasing average resulted unimodal curves time mortality, peaking 3–12 ha−1 yr−1 ages 75–150 Over whole rotation, biomass ranged between 0.8 2.1 t carbon content 0.4–1.1 C yr−1. We discuss relevance results measuring, understanding, modelling, managing forest Our reveal withdrawal setting aside (previously managed) forests rotation means one third production would flow debris pool rather than being exploited sequestration related emission savings harvested products. fractions above ground quantified study indicate trade-off allow deadwood accumulation associate changes biodiversity.

Language: Английский

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Evaluating the Development and Application of Stand Density Index for the Management of Complex and Adaptive Forests

Current Forestry Reports, Journal Year: 2024, Volume and Issue: 10(2), P. 133 - 152

Published: Feb. 8, 2024

Language: Английский

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Mapping mortality rates in boreal mixedwood forest using airborne laser scanning and permanent plot data

Forestry An International Journal of Forest Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 17, 2025

Abstract Accurate and spatially explicit predictions of tree mortality are critical for understanding forest dynamics guiding management practices. Airborne Laser Scanning (ALS) can cover large spatial areas, allowing the estimation attributes characterization canopy vertical structure gaps over various environments. This study integrated field measurements from permanent growth yield plots with ALS-derived to develop zero-inflated beta regression models estimating basal area rates. Specifically, we combined a set related complexity derived ALS data predict map (20 m pixel resolution) rates boreal mixedwood in northern Ontario, Canada. We evaluated how vary depending on stand-level factors, such as stand age type defined by species composition proportions. Our findings demonstrate that structural significantly In particular, found higher associated more complex structures larger gaps. However, magnitude varied composition. The resulting probability rate maps showed highly variable across types attributes, offering possibility analyzing correlation occurrence other variables like soil climate attributes. results support using Enhanced Forest Inventory systems precise timely interventions operational silvicultural planning.

Language: Английский

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Decaimiento en bosques mediterráneos: desentrañando amenazas y abordando retos para su gestión y conservación

Cuadernos de la Sociedad Española de Ciencias Forestales, Journal Year: 2025, Volume and Issue: 51(1), P. 21 - 48

Published: March 12, 2025

El término decaimiento se viene aplicando de forma genérica a aquellos procesos pérdida progresiva y prematura del vigor en sistemas forestales. La generalización este tipo está determinando la selvicultura que aplica muchos forestales, ha abierto un debate sobre las opciones selvícolas pueden usar para paliar o revertir estos procesos. Si bien idea una “selvicultura decaimiento” es muy atractiva investigadores, aún no dispone datos empíricos los posibles efectos tratamientos propuestos aspectos claves masas como son cambios estructura dinámica especies regeneración, cuando comparan con propios (ej., claras). En trabajo revisan algunos conceptos importantes relacionados bosques, el posible impacto selvicultura, potenciales alternativas gestión pinar afectadas por mortalidad Andalucía.

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Mortality reduces overyielding in mixed Scots pine and European beech stands along a precipitation gradient in Europe

Forest Ecology and Management, Journal Year: 2023, Volume and Issue: 539, P. 121008 - 121008

Published: April 14, 2023

Many studies show that mixed species stands can have higher gross growth, or so-called overyielding, compared with monocultures. However, much less is known about mortality in stands. Knowledge lacking, for example, of how the growth retained standing stock and lost due to mortality. Here, we addressed this knowledge gap stand dynamics by evaluating 23 middle-aged, unthinned triplets monospecific plots Scots pine (Pinus sylvestris L.) European beech (Fagus sylvatica repeatedly surveyed over 6–8 years throughout Europe. For explanation technical terms abstract see Box 1. First, produced more (+10%) but net (−28%) weighted mean In stands, 73% was accumulated stock, whereas only 48% The overyielding (2%) lower than (18%). still 10%, low dropout caused a substantial reduction from growth. Second, rates, self- alien-thinning strength, stem volume were main reason survival pine, persisted similarly Third, found 10% density at first survey. This superiority decreased 5% second Fourth, mixing proportion 46% 44% between doubling segregation index (S) calculated Pielou (S increased 0.2 0.5), indicated strong tendency towards demixing pine. Fifth, showed increasing water supply fraction mixture slightly strongly beech, also as whole. We discuss inter-specific competition thinning may enable continuous benefit diversity beech.

Language: Английский

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Structural and compositional acclimation of forests to extended drought: results of the KROOF throughfall exclusion experiment in Norway spruce and European beech

Trees, Journal Year: 2023, Volume and Issue: 37(5), P. 1443 - 1463

Published: July 31, 2023

Abstract Drought effects on tree growth and mortality are widely studied, but scant knowledge exists its impact stand density, size variation, or mixing proportions. Grasping drought's influence structural compositional diversity is crucial for dynamics, ecosystem services, silvicultural adaptation. We relied KROOF, a 5-year throughfall exclusion experiment in mature Norway spruce ( Picea abies ) European beech Fagus sylvatica stand, to analyze attributes, including Stand Density Index (SDI), Growth Dominance Coefficient (GDC), species proportion. Our study demonstrates that drought-induced reduction loss decreased SDI by 27%, proportion 41% at spruce’s expense, homogenized structure. Furthermore, we reveal proportion, were more affected spruce, stabilizing the level. Extended drought significantly altered partitioning favor of smaller trees, with 70% growth-size relationship slope 157% decrease GDC. Species-level analysis indicated stronger shift towards particularly spruce. discuss longer periods may trigger acclimation levels, potentially underestimated when based solely individual years. Sustained stress could induce across various from cohort, tree, organ. Maintaining mitigate future growth, mortality, structure, as exemplified extended experimental drought. suggest approaches better attuned natural processes amid climate change.

Language: Английский

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Investigating the Spatial Pattern of White Oak (Quercus alba L.) Mortality across the Eastern United States

Published: Aug. 28, 2024

White oak mortality is a significant concern in forest ecosystems due to its impact on biodiversity and ecosystem functions. Understanding the factors influencing white crucial for effective management conservation efforts. In this study, we aimed investigate spatial pattern of rates at different locations eastern US explore underlying processes involved with distribution patterns. Multicycle Forest Inventory Analysis data were compiled capture plots across US. collected plot systems that utilized Diameter Breast Height between two periods. Ripley’s K function was used study rate. Results found clustered patterns both local broad scales random only southern northern regions. However, central region indicated scale only. We uniform all Our findings demonstrated importance rate associated it. This research can inform practices populations varying scales. Future needed comprehensive assessment biotic abiotic strategies various mitigating mortality.

Language: Английский

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Integration of tree hydraulic processes and functional impairment to capture the drought resilience of a semiarid pine forest

Biogeosciences, Journal Year: 2024, Volume and Issue: 21(12), P. 2973 - 2994

Published: June 20, 2024

Abstract. Drought stress causes multiple feedback responses in plants. These span from stomata closure and enzymatic downregulation of photosynthetic activity to structural adjustments xylem biomass leaf area. Some these processes are not easily reversible may persist long after the has ended. Despite a multitude hydraulic model approaches, simulation models still widely lack an integrative mechanistic description how this sequence physiological tree be realized that is also simple enough generally applicable. Here, we suggest integrative, sequential approach simulate drought responses. First, decreasing plant water potential triggers stomatal alongside performance, thereby effectively slowing down further desiccation. A second protective mechanism introduced by increasing soil–root resistance, represented disconnection fine roots threshold soil been reached. Further decreases due residual transpiration loss internal stem storage consistently lead functioning, which reflected sapwood foliage senescence. This new functionality used investigate hydraulics, carbon uptake, atmospheric extremely dry Aleppo pine (Pinus halepensis Mill.) plantation. Using hypothesis triggering stress-mitigating responses, was able reflect uptake patterns under varying supply demand conditions – especially during summer respond realistically regarding medium-term such as We could show observed avoidance strategy only achieved when accounted for very early photosynthesis downregulation, relatively high measured potentials were well reproduced with root–soil started before major conductance losses occurred. Residual canopy found pivotal explaining dehydration summer, but it disclosed fact balance driest periods requires deep layers. In agreement resistance at site, our indicated little functioning pine, despite intensive seasonal drought.

Language: Английский

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Integration of tree hydraulic processes and functional impairment to capture the drought resilience of a semi-arid pine forest

Published: Sept. 5, 2023

Abstract. Drought stress is imposing multiple feedback responses in plants. These span from stomata closure and enzymatic downregulation of photosynthetic activity to structural adjustments leaf area. Some these processes are not easily reversible may persist long after the ended. Unfortunately, simulation models widely lack an integrative mechanistic description on how this sequence tree physiological occur. Here, we suggest approach simulate drought responses. Firstly, a decreasing plant water potential triggers stomatal alongside performance. This followed by disconnection roots soil reliance internal stem storage or uptake deep layers. Consistently, loss hydraulic functioning reflected sapwood functionality foliage senescence. new model has been used investigate hydraulics, carbon transpiration soil- atmospheric extremely dry Aleppo pine (Pinus halepensis L.) plantation. Using hypothesis sequential triggering stress-mitigating responses, was able reflect patterns under varying supply demand – especially during summer responded realistically regarding medium-term such as In agreement with high resistance observed at site our indicated little pine, despite intensive seasonal drought.

Language: Английский

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Norway spruce productivity in southern Sweden is equally limited by nitrogen and phosphorous

Forest Ecology and Management, Journal Year: 2024, Volume and Issue: 572, P. 122192 - 122192

Published: Sept. 12, 2024

Language: Английский

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