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Trees that survive disturbances are important biological legacies that facilitate forests' recovery and enhance their structural and species diversity, substantially contributing to the resilience of these ecosystems. The dynamic pattern of legacy syndromes sets the understudied aspects of survivors of wind disturbance into focus. Several factors at tree, stand, and landscape scales alter the susceptibility of the remnant trees, and affect their potential to recover and survive subsequent disturbances. The characteristics of the survivors interact with direct stress and mortality drivers such as changed environmental conditions and pressure by pests and pathogens. Climate change further enhances the post-storm vulnerability of the remaining stand. This literature review analyzes the impact of disturbance parameters (e.g., severity, seasonal timing) and characteristics of the affected forest (e.g., tree species composition, successional stage of a forest stand) on the conditions of survivors through post-windthrow stand development. We attempted to reveal the main agents and processes driving the fate of remnant trees and linked delayed mortality patterns to the main standscale wind disturbance regimes in Eurasian and North American boreal and temperate forests: (1) stand-replacing, (2) partially stand-replacing, and (3) finescale gap disturbance. We found that after stand-replacing wind disturbance, the spatial location of the remaining trees largely determines their onward fate, whereas these survivors are generally more susceptible to subsequent mortality compared to trees that survived less severe events. After partially stand-replacing wind disturbance, the structure of the remnant stand as well as characteristics of the individual remnant trees (e.g., species, age, size) largely determine their survival probability. Following a fine-scale gap disturbance, the trees at the gap edge are more likely to die, compared to the trees situated in the stand interior, but the mortality-causing processes usually operate on a longer time scale. Our findings contribute to the current knowledge on postwindthrow stand development and offer insights into temporal stability of these increasingly important biological legacies. [ABSTRACT FROM AUTHOR]

A generic regression model for above-ground biomass of forest stands was constructed based on published data (R2 = 0.88, RSE = 32.8 t/ha). The model was used 1) to verify two allometric regression models of trees from Scandinavia applied to repeated measurements of 275 sample plots from database of Estonian Network of Forest Research (FGN) in Estonia, 2) to analyse impact of between-tree competition on biomass, and 3) compare biomass estimates made with different European biomass models applied on standardized forest structures. The model was verified with biomass measurements from hemiboreal and tropical forests. The analysis of two Scandinavian models showed that older allometric regression models may give biased estimates due to changed growth conditions. More biomass can be stored in forest stands where competition between trees is stronger. The tree biomass calculation methods used in different countries have also substantial influence on the estimates at stand-level. A common database of forest biomass measurements from Europe in similar to pan-tropical tree measurement data may be helpful to harmonise carbon accounting methods.

: Live vegetation carbon (C) pool dynamics are central to understanding C sequestration of forest ecosystems. Despite its importance, how aboveground live C pools change with stand development in boreal mixedwoods is poorly understood. We quantified aboveground live C pools (i.e., trees, > 4 m in height; saplings and shrubs, 1.3-4 m in height; and understory plants, Resume: La dynamique des reservoirs de carbone (C) que constitue la vegetation vivante est primordiale pour comprendre la sequestration de C dans les ecosyste`mes forestiers. Malgre son importance, la fac on dont les reservoirs de C constitue s de la partie aerienne de la vegetation vivante changent en fonction du developpement des peuplements dans les forets boreales mixtes est mal comprise. Nous avons quantifieles reservoirs de C constitues de la partie aerienne de la vegetation vivante, c.-a-d. les arbres (hauteur > 4 m), les gaules et les arbustes (hauteur de 1,3 a 4 m) et les plantes de sous-bois (hauteur < 1,3 m) pour une chronosequence issue de feux allant de 1 a 203 ans et pour une chronosequence issue de coupes allant de 1 a 27 ans dans les forets boreales mixtes du centre du Canada. Le reservoir de C dans les arbres des peuplements issus de feux augmentait de 0 a 109,2 Mg/ha de 1 a 92 ans apres un feu et diminuait par la suite a environ 70 Mg/ha dans les peuplements ages de 140 a 203 ans. Les reservoirs de C dans les gaules, les arbustes et la vegetation du sousbois ont aussi changes selon le developpement et l'origine du peuplement. Parmi les trois classes d'age qui ont ete comparees, il y avait significativement plus de C dans la vegetation des peuplements issus de coupes que dans les peuplements issus de feux 1 et 27 ans apres la perturbation mais il n'y avait pas de difference dans les peuplements ages de neuf ans. Les valeurs plus elevees de C dans la vegetation vivante des peuplements issus de coupes ont ete attribuees aux arbres vivants laisses debout apres la coupe et aux traitements sylvicoles qui ont favorise l'etablissement des arbres pendant l'initiation du peuplement. [Traduit par la Redaction], Introduction Carbon (C) dynamics of northern forests are largely driven by disturbances and subsequent stand development (Pregitzer and Euskirchen 2004; Bond-Lamberty et al. 2007; Magnani et al. 2007; Luyssaert et [...]

Litterfall is a fundamental process in the nutrient cycle of forest ecosystems and a major component of annual net primary production (NPP). Despite its importance for understanding ecosystem energetics and carbon accounting, the dynamics of litterfall production following disturbance and throughout succession remain poorly understood in boreal forest ecosystems. Using a replicated chronosequence spanning 209 years following fire and 33 years following logging in Ontario, Canada, we examined the dynamics of litterfall production associated with stand development, overstory composition type (broadleaf, mixedwood, and conifer), and disturbance origin. We found that total annual litterfall production increased with stand age following fire and logging, plateauing in post-fire stands approximately 98 years after fire. Neither total annual litterfall production nor any of its constituents differed between young fire- or logging-originated stands. Litterfall production was generally higher in broadleaf stands compared with mixedwood and conifer stands, but varied seasonally, with foliar litterfall highest in broadleaf stands in autumn, and epiphytic lichen litterfall highest in conifer stands in spring. Contrary to previous assumptions, we found that the contribution of litterfall production to net primary production increased with stand age, highlighting the need for modeling studies of net primary productivity to account for the effects of stand age on litterfall dynamics. [ABSTRACT FROM AUTHOR]