Pollen indices of Cedrus atlantica Manetti populations vary with geographical localities in the Moroccan Atlas Mountains

Abstract

North Africa’s forests of Cedrus atlantica Manetti have declined drastically, by more than 58% in the last 130 years, and many stands are likely to disappear entirely in the coming decades. This study on the interactions between C. atlantica pollen characters (production, germination, and pollen tube length) and locality characters in Morocco, using seventy individuals from seven geographically distant populations, showed that pollen indices varied according to station. Pollen production was high in the populations of the Moudemam-1 and Seheb stations, intermediate in the Ait Oufella and Ait Ayach stations, and low in the Zerrouka, Ras Elma and Moudemam-2 stations. Pollen germination was very low for the populations in the Seheb and Moudemam-1 stations but high in the other stations. On the other hand, the longest pollen tubes were recorded in the Moudemam-1 population, while those in the other stations were shorter. These results show an inverse variation between the pollen indices characterizing the populations of the stations studied. The shortest pollen tube length classes [0-100] to [300-400] accounted for 85.98% of all classes and were assessed for the Zerrouka, Ait Oufella and Ait Ayach stations. The other classes were more represented or exclusive to the population of the Moudemam-1 station. These results could have implications not only for assessing pollen variations according to geographical localities but also for optimizing fertilization in cedar forests by selecting the best clones for this species.