Fine-root morphological traits may improve understanding of the vulnerability of Fagus sylvatica natural forests to late-fall unusual wildfire

Abstract

<p>Extraordinary changes in alpine fire regimes have been often associated with heat waves, which are generally regarded as an indication of a changing climate that will lead to new fire regimes in the Alps. Fine roots function of absorbing water and nutrients is crucial to plant survival and their traits such as biomass, length, specific root length, production, death, and decomposition can inform how trees interact with their environments and provide ecological functions in response to exogenous stresses. After an unusual, late-fall wildfire in a European beech (<em>Fagus sylvatica</em> L.) forest in the pre-Alps of northern Italy, the response of fine roots (< 2 mm diameter) was analysed and appeared more evident when fine roots were further subdivided by diameter size and soil depth. The finest roots (0‒0.3 mm diameter) were generally the most responsive to fire, with the effect more pronounced at the shallowest soil depth. While roots 0.3‒1 mm in diameter had their length and biomass at the shallowest soil depth reduced by fire, fire stimulated more length and biomass at the deepest soil depth compared to the control. Fire elevated the total length of dead roots and their biomass immediately and this result persisted through the first spring, after which control and fire-impacted trees had similar fine root turnover. Our results add to the paucity of data concerning fire impacts on beech roots in a natural condition and provide the basis for understanding fine-root morphological traits approach to assess plant species vulnerability and resilience to unusual fire occurrence due to climate changes. Changes in disturbance regimes might be most realized by distribution of the finest of fine roots at differing soil depths, and the dynamics of these roots may provide the most resilience to disturbance.</p>

A systematic review of studies on fine and coarse root traits measurement: towards the enhancement of urban forests monitoring and management

“…Furthermore, a large part of the root studies do not focus on environmental or anthropogenic constraints, and they are mainly performed in natural sites that do not experience any urban stressors. In detail, among the 136 candidate plant species, F. sylvatica is a common target species in fine and coarse roots studies (Montagnoli et al, 2014;Weigt et al, 2015;Montagnoli et al, 2018;Nikolova et al, 2020) and specifically in those analyzing fine roots biomass (Braun et al, 2005;Konôpka and Lukac, 2013;Jagodzinski et al, 2016;Montagnoli et al, 2016;Geilfus et al, 2017;Konôpka et al, 2020;Montagnoli et al, 2023). In root turnover studies, species other than Temporal analysis per year of published papers present in our database (Source: PubMed, 1992-2023).…”

“…As reviewed by Freschét et al (2021b), root functional traits can be analyzed to obtain knowledge about resource acquisition, protection, and element cycling of plants. Additionally, the analysis of specific root functional traits can reveal plant resilience and adaptation mechanisms to disturbance (Montagnoli et al, 2023). Some of these traits are easily measurable and often vaguely related to a single or a few functions (i.e., "soft"), or difficult to measure and more often closely related to a precise function (i.e., "hard") (Bakker et al, 2019;Freschét et al, 2021b).…”