Khalid Benarchid*, Mohammed Khatori, and Said Hilali

Laboratory Eco-Design, Energy, Environment and Innovation.

Faculty of Science and Technology, Hassan Premier University, Settat – Morocco

(*)Corresponding author: k.benarchid@uhp.ac.ma

The purpose of this study is to determine the effect of the reforestation of Pinus halepensis on the plant biomass and morphological characteristics of native species in the Beni Sohane forest. Plant biomass of the herbaceous layer was harvested on randomly selected 2 m2 quadrats in reforested plots of ± 12, ± 25, and ± 45 -year-old, and native forest controls. The internode length and leaves dimensions (length and width) were measured on plants randomly selected belonging to four native species Quercus ilex L., Pistacia lentiscus L., Phillyrea augustifolia L., and Cistus creticus L. The results showed that Pinus halepensis reforestation did not affect the above-ground biomass and the leaves and internodes dimensions for the young plantation ±12-year-old. However, it has a negative effect on aboveground biomass, which is exacerbated by the age of planting. The average weight of dry matter was significantly reduced for ± 25-year-old and ± 45-year-old (P < 0.001) compared with the native forest. This has led to the abandonment of pastors of important pastures previously exploited by cattle. Moreover, the raising of Pinus halepensis trees which forms a canopy above all indigenous species leads to changes in the dimensions of internodes and leaves. In fact, for the two oldest plantations, the internodes length, leaf width, and length of the 4 species have been significantly increased. However, their ratio length/width has been significantly decreased. Regular thinning of the P. halepensis trees would be necessary to restore the balance of these ecosystems.

Keywords: Reforestation; Pinus halepensis ; Phytomass ; Exotic species.