Integrating climate, soil and stand structure into allometric models: An approach of site-effects on tree allometry in Atlantic Forest

Accuracy, realism and general applicability of European forest models

“…Moreover, the quantification of realism could be restricted to periods when one environmental driver (e.g., temperature, radiation or vapour pressure deficit) is driving the GPP response as to not confound interacting effects of different environmental drivers (e.g., Nadal-Sala et al, 2021). Additionally, models that assume identical allometric relationship for a single species regardless of environmental conditions, are expected to be less accurate than models accounting for site differences by different allometric coefficients or incorporating environmental drivers (Cysneiros et al, 2021).…”

“…Sala et al, 2021). Additionally, models that assume identical allometric relationship for a single species regardless of environmental conditions, are expected to be less accurate than models accounting for site differences by different allometric coefficients or incorporating environmental drivers(Cysneiros et al, 2021).…”

Functional evaluation of height–diameter relationships and tree development in an Australian subtropical rainforest

“…The most widely applied biophysical allometric relationship is the power equation, commonly expressed as a log-log relationship (Huxley 1924;Niklas 1995;Kooyman and Westoby 2009;Loubota Panzou et al 2021a). The structural characteristics of tree saplings are reflected in the initial value of the allometric proportionality factor, a, which varies among species in a particular environment with wood density (van Gelder et al 2006;Kooyman and Westoby 2009;Fournier et al 2013;Francis et al 2017), and among environments with different tree spacing (Hummel 2000;Vanclay 2009;del Río et al 2019) or site resource availability (Vanclay and Henry 1988;Lines et al 2012;Cysneiros et al 2021), and by external stresses such as wind (Jacobs 1954;King 1986;Thomas et al 2015). Changes in the H-D relationship with increasing organism size are described by the convexity factor, b, which appears as an exponent (Table 1, Eqn 2) and is related to species maximum dimensions, especially with the transition from early stage to late-stage successional species (Kohyama et al 2003;Poorter et al 2006;Martínez Cano et al 2019a).…”

“…The parameters of the NRH provide easily comprehended linear descriptions of three elements of tree growth in a specific environment, namely a, H a and b. Application of the NRH across different environments would require modifications, as have been made to power (Lines et al 2012;Zhao et al 2021), logarithmic (Feldpausch et al 2012;Chave et al 2014;Cysneiros et al 2021), Weibull and exponential (Banin et al 2012;Mensah et al 2018) models. An advantage of the NRH is that variations in environmental resource availability as reflected in forest type (Cysneiros et al 2020), site quality (Vanclay 2009) and tree density (Vanclay 1992;Deng et al 2019) may be identified and described quantitatively as factors independently altering a, b and H a , and other dependent parameters, including crown dimensions and biomass.…”

“…Advanced statistical techniques (Aertsen et al 2010;Cysneiros et al 2021;Loubota Panzou et al 2021a;Lu et al 2021) have been used, especially on large, aggregated datasets, to describe multiple functional relationships across different environments and their effects on structure and growth of trees (Falster et al 2018;Martínez Cano et al 2019a). Following Hunt (1979), the present study seeks to complement this computational sophistication with an analysis of biological bases and ease of interpretation of allometric relationships that underpin tree growth models applied to different species in a single environment.…”