Is the reverse J-shaped diameter distribution universally applicable in European virgin beech forests?

Westphal, Christina; Tremer, Nils; Oheimb, Goddert von; Hansen, Jan Holmegaard; Gadow, Klaus von; Härdtle, Werner

doi:10.1016/j.foreco.2005.10.057

Cited by 151 publications

(132 citation statements)

References 21 publications

(36 reference statements)

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“…This phase is characterized by significant vertical layering, and, according to some authors, can be stable for decades or even hundreds of years (see Rubin et al, 2006;Westphal et al, 2006;Král et al, 2010b). Dying individuals in the canopy layer gradually release the lower tree layer, which is indicated in radial growth as a (weak) release (see Šamonil et al, 2013a).…”

Section: Discussionmentioning

confidence: 99%

Disturbances can control fine-scale pedodiversity in old-growth forests: is the soil evolution theory disturbed as well?

et al. 2014

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Abstract. Biota–soil interactions in natural ecosystems are the subject of considerable research. Our hypothesis is that individual trees play a significant role through biomechanical and biochemical disturbances affecting soil formation in temperate forests, resulting in a complex spatial pattern of disturbance regimes and a close relationship between disturbance histories and soil units. In Žofínský Prales (Czech Republic) – the fourth oldest, continuously protected reserve in Europe and the first site of global research network SIGEO (Smithsonian Institution Global Earth Observatories) in continental Europe – we compared extensive dendrochronological, soil and pit–mound microtopography data both temporally and spatially from an area of anthropogenically unaffected 42 ha collected from 2008–2012. These data sets differ in terms of information complexity and length of memory: tree cores contain complex information about the disturbance history of the past 350 years, footprints of disturbances from the uprooting of a specific tree can persist 1700 years, and soils represent an extensive composite phenotype that has been developing for at least the entire postglacial period (10 500 years). On average, 6.18–13.41% of the canopy on individual soil units was disturbed per decade. Even though the "backbone" of key events in the development of the forest ecosystem remained the same (e.g. the 1870s, 1880s and 1980s), the internal structure of disturbance history often differed among soil units; the most exceptional were Gleysols and Histosols, where important feedback from soil to trees was expected. However, the characteristics of treethrow dynamics as well as the frequencies of stronger releases in core series also significantly differed along a gradient of terrestrial soil weathering and leaching (Haplic Cambisols – Dystric Cambisols – Entic Podzols – Albic Podzols). These results suggest the existence of several disturbance regimes within the forest, controlling fine-scale pedodiversity.

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Section: Discussionmentioning

confidence: 99%

Disturbances can control fine-scale pedodiversity in old-growth forests: is the soil evolution theory disturbed as well?

et al. 2014

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“…3A). This shape is often thought to be characteristic of the diameter class distributions of mature stands that have reached an equilibrium state (Westphal et al 2006). If diameter distributions are an operational goal for hardwood stands, it may be necessary to either combine multiple small field plots to capture the complete distribution or to collect field data from larger plots.…”

Section: Discussionmentioning

confidence: 99%

LiDAR and Weibull modeling of diameter and basal area

Thomas¹,

Oliver²,

Lim³

et al. 2008

The Forestry Chronicle

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This study investigates the ability to predict forest diameter distributions from light detection and ranging (LiDAR) data using Weibull modelling for forest stands in central Ontario. Results suggest that the unimodal 2-parameter Weibull model is a promising technique for the prediction of diameter class distributions, with strong relationships evident for several subgroups (at 95% confidence, r 2 adj =0.83, 0.78, 0.88, 0.80, 0.83, and 0.65, with validation RMSE of 4.09 m 2 /ha, 0.61 stems/ha, 6.05, 0.64, 4.73, and 0.09 for basal area, stem density, and the Weibull a and b parameters for basal area and stem density, respectively). The unimodal models were found to be least effective for the irregularly shaped diameter distributions, particularly for low-density coniferous plots that have undergone shelterwood treatment. A significant improvement in results for these irregular plots was found with a finite mixture modelling approach, suggesting that finite mixture models may extend our ability to predict diameter distributions over large portions of the landscape.Key words: LiDAR, Weibull, finite mixture modeling, diameter class distributions, multiple linear regression RÉSUMÉCette étude porte sur la capacité de prédiction de la distribution des diamètres d'arbres à partir de données de détection de la lumière et de calcul de la distance (LiDAR) utilisées dans un modèle Weibull pour des peuplements forestiers du centre de l'Ontario. Les résultats laissent entendre que le modèle Weibull unimodal à 2 paramètres constitue une technique prometteuse de la prédiction de la distribution des classes de diamètre comportant de fortes corrélations évidentes pour certains sous-groupes (à un niveau de confiance 95%, r 2 adj =0.83, 0.78, 0.88, 0.80, 0.83 et 0.65, une variance de 4,09 m 2 /ha, 0,61 tiges/ha, 6,05, 0,64, 4,73 et de 0,09 respectivement pour la surface terrière, le nombre de tige par hectare et pour les paramètres a et b de Weibull portant sur la surface terrière et le nombre de tige). Les modèles unimodaux se sont avérés être moins efficaces dans le cas des distributions de forme irrégulière des diamètres, particulièrement dans le cas de parcelles de faible densité de résineux ayant subi des traitements de coupe progressive. Une amélioration significative des résultats de ces parcelles irrégulières est apparue à la suite d'une approche de modélisation pour peuplement mélangé spécifique, laissant entendre que les modèles pour peuplement mélangé spécifique pourrait accroître notre capacité de prédire la distribution des diamètres pour de grandes portions de l' écosystème.Mots clés : LiDAR, Weibull, modélisation de peuplement mélangé spécifique, distributions des classes de diamètre, régression linéaire multiple

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“…The large proportion of large individuals in groups 3 and 4, due to the persistence of an old cohort of the pioneers N. nitida and W. trichosperma and the more shade-tolerant S. conspicua (group 4) that can achieve giant sizes due to its ability to persist with adventitious roots generated within hollow logs [36], would explain that these groups present diameter structures most similar to the rotated S-shape rather that the reverse J-shape (Figures 4 and 5). The rotated S-shape diameter structures are common in forests with composite structures that include successional and pioneer species, as reported for south central Chile [37] and for old-growth temperate forests of the Northern Hemisphere [35,[38][39][40].…”

Section: Forest Groups In the Evergreen Forests Of Southern Chiloémentioning

confidence: 91%

Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile)

Bannister

Donoso

2013

Forests

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Is the reverse J-shaped diameter distribution universally applicable in European virgin beech forests?

Cited by 151 publications

References 21 publications

Disturbances can control fine-scale pedodiversity in old-growth forests: is the soil evolution theory disturbed as well?

Disturbances can control fine-scale pedodiversity in old-growth forests: is the soil evolution theory disturbed as well?

LiDAR and Weibull modeling of diameter and basal area

Forest Typification to Characterize the Structure and Composition of Old-growth Evergreen Forests on Chiloe Island, North Patagonia (Chile)

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