**1. Introduction**

*Tetraclinis articulata* (Vahl) Masters (Cupressaceae) and *Cedrus atlantica* Manetti (Pinaceae) are threatened species [1] endemic to the western Mediterranean areas [2]. Moroccan *T. articulata* and *C. atlantica* populations occupy an area of about 500,000 and 130,000 ha, respectively, and satisfy many socioeconomic needs of the human riparian populations for various products. But in the last decades, forests of *T. articulata* were exposed to a significant degradation due to a strong demand by the craft sector for timbers [2, 3]. Even if *C. atlantica* forest provides approximately annually 90,000 m3 of softwood logs intended for sawing and veneer, they also suffer the same fate [4]. Both species are famous for their durable and noble timbers. *T. articulata* root burl provides good quality woody material (hard, homogeneous, and fine grained) with remarkable flecks and an aesthetic aspect very appreciated in cabinetry and marquetry uses [3].

Laboratory tests showed that *T. articulata* trunk wood and its root burl are durable against wood-decaying fungi [5, 6] as well as *C. atlantica* heartwood [6–8].

A lot of waste as slabs and sawdust results from wood processing of those species timbers. However, only sawdust accounts for about 8% of *C. atlantica* sawn timber that contains appreciable amounts of extractives [9–12]. Many recent works highlighted that essential oils (EOs) extracted from *T. articulata* and *C. atlantica* woods possess numerous biocidal activities [12–15]. Nevertheless, only few attempts to investigate the capability of EOs to protect woods against fungi decay have been previously undertaken [16–18]. The relationship between natural durability of *T. articulata* and *C. atlantica* woods and the bioactivity of their EOs was not yet established. Therefore, the present study is devoted to investigate this relationship.
