## 3 Discussion  
The chemical composition of the liquid and vapor phases of two EOs obtained from leaves of _J. communis_ var. _saxatilis_ and _L. decidua_ was determined by SPME-GC/MS analyses. Gymosperms and, in particular, confers produce EOs characterized by compounds belonging to the family of terpen such as monoterpenes, sesquiterpenes, and their derivatives [18]. In agreement with previous works [19; 20; 21; 22], our results showed monoterpenes prevail over sesquiterpenes. In particular, the two major components of _J. communis_ and _L. decidua_ EOs were \(\alpha\)-pinene or sabinene, which were also found in other _Juniperus_[23; 24] and _Larix_ species [17; 25; 26]. Nevertheless, qualitative and/or quantitative differences in the chemical composition can be found, especially for minor compounds [27; 28; 29; 30; 31]. This is due to the different genotype or species [32; 33], environmental conditions and soil composition [34; 35], geographical area of origin [36] and harvesting period, in addition to different extraction methods and plant parts [37; 38]. It is known that monoterpenes possess phytotoxic effects capable of leading to anatomical and physiological changes in plant seedlings, probably due to the inhibition of DNA synthesis or the rupture of mitochondrial membranes [39; 40]. In particular, it was reported that \(\alpha\)-pinene strongly inhibited mitochondrial ATP production [41] and root growth, also causing oxidative damage [42]. Furthermore, several monoterpenes, including \(\alpha\)-pinene, have been shown to have inhibiting abilities on germination and radicle elongation of _Raphanus sativus_ L. and _Lepidium sativum_ L. [43]. Regarding sabinene, some studies documented the phytotoxicity of different EOs having this compound among the main constituents [44; 45; 46]. For example, a sabinene chemotype identified for EO from _Ravensara aromatic_ Sonn. showed strong toxicity against _Oryza sativa_ L. and _Lepidium sativum_ L. [44]. Nonetheless, the higher percentage of \(\alpha\)-pinene in our _L. decidua_ EO may justify its greater effectiveness compared to the _J. communis_ EO, in which sabinene was the most abundant. However, it is highly probable that the herbicidal activity of both EOs found in this work cannot be exclusively attributed to \(\alpha\)-pinene and/or sabinene, but to the combined effect (synergistic or additive) of several molecules, including the minor ones. Indeed, as has been recently confirmed, mixtures of compounds are much more active and trigger different and more drastic responses [47]. EOs from conifer leaves have been reported to have high therapeutic potential [48] and, therefore, they are widely used in the treatment of infections and inflammatory phenomena [49]. Several studies demonstrated their biological properties [20; 50; 51; 52; 53; 54; 55; 56; 57], including allebotatic effects [10; 11]. Nevertheless, EOs obtained from _Juniperus_ and _Larix_ species have been rather neglected from this point of view. Recently, [PERSON] and co-authors [58] investigated the allebotatic activity of _J. [PERSON]_ L. and _J. excelsa_ Bieb. EOs, reporting different inhibitory actions depending on the target species, the type of used EO, and the relative concentrations. Previously, [PERSON] et al. [14] documented the phytotoxic potential of EO obtained from the leaves of _J. polycarpos_ var. _tromcanica_ ([PERSON].) [PERSON]. [PERSON] against three species of weeds, namely, _Portulaca olerca_ L., _Amaranthus retroflexus_ L., and _Datura_