The effect of mulching on some morphological and physiological seedling characteristics of Anatolian black pine (pinus nigra subsp. pallasiana) and taurus cedar (Cedrus libani A. Rich.) afforestation areas in Kırıkkale region

This study was conducted to determine the effects of different mulching methods (control, organic mulch, plastic mulch) on selected morphological and physiological characteristics of Anatolian black pine (Pinus nigra subsp. pallasiana) and Taurus cedar (Cedrus libani A. Rich.) seedlings in afforestation sites established in the Kırıkkale region. The evaluated morphological traits included seedling diameter, height, and survival rate, while the physiological traits comprised predawn water potential (Ψpd), midday water potential (Ψmd) and photosynthetic efficiency (Fv/Fm). The research was carried out during the 2023 growing season, and the meteorological data for the study year were compared with long-term averages. The findings demonstrated that mulching positively influenced seedling performance under arid and semi-arid conditions. In terms of morphological traits, no significant differences were observed among treatments for diameter and height in Anatolian black pine, whereas the highest survival rate (60.95%) was obtained under plastic mulch. In Taurus cedar, plastic and organic mulch significantly enhanced diameter growth, and survival exceeded 90% under both plastic and organic mulch treatments. Regarding physiological traits, predawn water potential (Ψpd) was positively affected by mulching in both species, with plastic mulch yielding higher values (–8.5 bar in black pine and –6.5 bar in teurus cedar). While midday water potential (Ψmd) showed no significant differences among treatments in pine, plastic mulch improved values in cedar during July, from –18 bar to –14.5 bar, thereby alleviating drought stress. For photosynthetic efficiency (Fv/Fm), plastic mulch raised the value to 0.720 in Anatolian black pine in August, while organic mulch provided the highest value 0.740 for Taurus cedar in July. In conclusion, mulching can be considered an effective practice in afforestation, particularly under arid and semi-arid conditions, as it enhances seedling survival and supports physiological resilience. Moreover, mulching represents a valuable silvicultural measure that contributes to the success of afforestation practices.