Bark Anatomy, Chemistry, and Extractive Variation Among Forest Tree Species: Implications for Medicinal Applications, Industrial Utilization, and Sustainable Forest Management—A Systematic Review and Meta-Analysis

Tree bark is a structurally complex and chemically diverse component of woody plants that performs essential protective, physiological, and defensive functions while serving as an important reservoir of bioactive compounds with considerable medicinal and industrial value. Despite growing interest in bark as a renewable forest resource, information on its anatomical characteristics, chemical composition, extractive diversity, and utilization remains fragmented across forestry, wood science, plant anatomy, phytochemistry, pharmacology, and industrial processing literature. Consequently, a comprehensive synthesis of the available evidence is required to improve understanding of bark diversity and support sustainable resource utilization. This study systematically reviewed and quantitatively synthesized published literature on bark anatomy, chemical composition, extractive variation, medicinal properties, industrial applications, and implications for sustainable forest management among forest tree species. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines. Literature published between January 1980 and June 2026 was retrieved from major bibliographic databases, institutional repositories, and selected grey literature sources. Following systematic screening and eligibility assessment, 574 studies were included in the qualitative synthesis, while 311 studies provided sufficient quantitative data for random-effects meta-analysis. Standardized mean differences (Hedges' g ) were calculated, and heterogeneity among studies was evaluated using Cochran's Q statistic and the I² statistic. The findings revealed substantial interspecific variation in bark anatomical characteristics, including bark thickness, periderm development, secondary phloem organization, secretory structures, and rhytidome formation. Phenolic compounds, flavonoids, tannins, terpenoids, alkaloids, lignans, and suberin were the most frequently reported chemical groups, demonstrating significant variation among species and ecological regions. Meta-analysis showed consistently large and statistically significant pooled effect sizes for bark anatomical characteristics ( g  = 0.72–0.89), chemical constituents ( g  = 0.68–0.91), medicinal activities ( g  = 0.76–0.89), and industrial applications ( g  = 0.72–0.91) (all p  < 0.001). Bark-derived compounds exhibited considerable antioxidant, antimicrobial, anti-inflammatory, anticancer, and antidiabetic potential, while industrial applications extended to pharmaceuticals, nutraceuticals, leather tanning, wood adhesives, cosmetics, biopolymers, environmental remediation, and renewable bioenergy production. The review demonstrates that tree bark represents an underutilized but strategically important forest resource capable of supporting sustainable forest-based bioeconomies through the recovery of high-value phytochemicals and efficient biomass utilization. Integrating knowledge of bark anatomy, chemistry, and extractive diversity into forest management and industrial processing can enhance resource-use efficiency, promote value addition, reduce processing waste, and strengthen the transition toward circular bioeconomy systems. Future research should prioritize standardized analytical methodologies, greater representation of under-investigated indigenous tree species, long-term sustainability assessments, and the commercialization of bark-derived products to maximize the ecological and socio-economic benefits of forest resources.