Priorities for Bark Anatomical Research: Study Venues and Open Questions

Abstract

The bark fulfils several essential functions in vascular plants and yields a wealth of raw materials, but the understanding of bark structure and function strongly lags behind our knowledge with respect to other plant tissues. The recent technological advances in sampling and preparation of barks for anatomical studies, along with the establishment of an agreed bark terminology, paved the way for more bark anatomical research. Whilst datasets reveal bark’s taxonomic and functional diversity in various ecosystems, a better understanding of the bark can advance the understanding of plants’ physiological and environmental challenges and solutions. We propose a set of priorities for understanding and further developing bark anatomical studies, including periderm structure in woody plants, phloem phenology, methods in bark anatomy research, bark functional ecology, relationships between bark macroscopic appearance, and its microscopic structure and discuss how to achieve these ambitious goals.

Temporal and spatial variability of phloem structure in Picea abies and Fagus sylvatica and its link to climate

“…Phloem plays a critical role in the long-distance transport and allocation of nutrients, resources and signals that are important for regulating organ growth, development and adaptation to stresses (Dinant & Lemoine, 2010). A fair amount of research has recently been published on phloem phenology and/or structure (e.g., Balzano et al, 2020;Dannoura et al, 2019;Jyske & Hölttä, 2015;Kiorapostolou et al, 2020;Savage & Chuine, 2021;Shtein et al, 2023) but few of these studies include multi-year data that provide insight into the impact of weather conditions on the seasonal development of the phloem growth ring (e.g., Prislan et al, 2013). Moreover, with few exceptions (Gri ar et al, 2014;Miller et al, 2020;Swidrak et al, 2014), comparison of seasonal trends in phloem between different locations and coexisting species is particularly understudied, although studying the weather-phloem interaction is necessary for better understanding tree physiological limits in terms of species-specific plasticity of phloem development and its connection to leaf and xylem growth (Savage, 2020).…”

“…With few exceptions, these studies must be performed on the youngest phloem increment, because age-related changes in bark tissue can greatly affect the morphology of phloem cells (Jyske et al, 2016). Significant improvements in sample preparation, the development of imaging techniques and the rate of knowledge and data exchange among different research laboratories (Shtein et al, 2023) are making a major contribution to improving our understanding of phloem phenology and anatomy.…”

Bark anatomy of lianescent Bignoniaceae: a generic synopsis

“…Bark is defined as all the tissues outside of the vascular cambium, encompassing two of the broadest and externalmost plant tissues: the secondary phloem (inner bark) and the periderm (outer bark) (Evert 2006; Angyalossy et al 2016; Shtein et al 2023). Both the phloem and the periderm are complex tissues, formed by more than one cell type, resulting from the activity of lateral meristems, the cambium, and the phellogen, respectively (Evert 2006).…”

“…Both the phloem and the periderm are complex tissues, formed by more than one cell type, resulting from the activity of lateral meristems, the cambium, and the phellogen, respectively (Evert 2006). The periderm includes the phelloderm, the phellogen, and the phellem; while the secondary phloem typically includes sieve elements, axial parenchyma, rays, and sclerenchyma (either fibers, sclereids or both) (Esau 1969; Roth 1981; Angyalossy et al 2016; Shtein et al 2023). Differences in cell type, abundance, morphology, and configuration within these two broad tissues constitute rich sources of characters for phylogenetic studies (Rosell & Olson 2014).…”

Comparative Analysis of Phytocompound Variations in Leaves, Bark and Roots of Allspice (Pimenta Dioica) Collections in Tanzania

“…Prominent phytocompounds found in the leaves were eugenol in 72.24% -73.91% of the total compounds detected. Bark was primarily composed of 1,8,3a. beta.,4.…”