Pathogens threatening Czech Republic forest ecosystems - a review

In recent years, European forests have been endangered by rising temperatures and more frequent weather extremes. In the Czech Republic, the warm and dry period between 2015 and 2019 led to the weakening of many trees and activation of harmful biotic agents, including fungal and other pathogens. These factors led to the death and decline of many trees and forest stands. The most important pathogens of forest trees in the Czech Republic are Armillaria ostoyae (Romagn.) Herink; A. gallica Marxm. & Romagn.; A. cepistipes Velen.; A. mellea (Vahl) P. Kumm; Heterobasidion annosum (Fr.) Bref.; H. parviporum Niemela & Korhonen; H. abietinum Niemela & Korhonen; Ophiostoma novo-ulmi Brasier; Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz & Hosoya; Cryptostroma corticale (Ellis & Everh.) P.H. Greg. & S. Waller; Eutypella parasitica R.W. Davidson & R.C. Lorenz; Cucurbitaria piceae Borthw.; Phytophthora alni species complex; P cactorum (Lebert & Cohn) J. Schrot; P cambivora (Petri) Buisman; P cinnamomi Rands.; P. plurivora T. Jung & T.I. Burgess and P. ramorum Werres, De Cock & Man in 't Veld. Other important forest tree pathogens with potential for spreading in the Czech Republic in the coming years are Neonectria coccinea (Pers.) Rossman & Samuels; Inonotus spp.; Sphaeropsis sapinea (Fr.) Dyko & B. Sutton; Cenangium ferruginosum Fr. and Lecanosticta acicola (Thum.) Syd. The effects of most of the above-mentioned pathogens are expected to be similar or greater in the future. Moreover, the introduction of new invasive pathogens cannot be neglected. Measures against dangerous fungal and fungal-like infections should include long-lasting management decisions. It is crucial to strengthen the overall resilience of forest stands by increasing their species, age and spatial diversities; planting site-suitable tree species and focusing on timely interventions against pathogens and the prevention of their spread, all in relation to the integrated pest management plans.