Assessing the biodiversity and the impact of pollinators on carob production

Carob pollination study Table 3 shows the results of the analysis on the effect of treatment, region and their interaction on the number of pods produced per inflorescence in the open and wind pollination. There was a significant effect of treatment applied (P < 0.001) and a weaker effect of region (P = 0.02), with no significant interaction between the treatment and the region. The median number of pods per inflorescence was higher in the open than in the wind pollination in all three regions and was higher in the NW Coast followed by the S. Plateau and the SE Lowlands (Fig 5A). Table 4 shows the results of the analysis of the effect of open vs wind pollination and region on carob pod weight (Fig 5B). The median weight per pod was higher in open than in wind pollination with the exception of pods from SE Lowlands in wind pollination, where only five pods were produced from three trees. Median pod weight in open pollination was highest for SE Lowlands, followed by S. Plateau and NW Coast (Fig 5B). A similar trend was observed for pod length, where median length was lowest for pods from NW Coast but the same for S. Pla- teau and SE Lowlands (Fig 5C), which was highly correlated with pod weight (r2 = 0.74). Pods in the open pollination contained more seeds than those in the wind pollination (Fig 5D). Fig 3. Wild bee presence in the 12 different carob plots sampled for the bee presence-absence study in 2016 and 2017 (S. Coast plots were sampled

only in 2016). The graphs show presence or absence of wild bees on four female (red color) and one male tree (cyan) per plot, during five weeks of sampling. All four sites of each tree were sampled, resulting in 20 samples per plot per sampling. Circles show absence of A. mellifera at the sampling tree site, while triangles show presence of A. mellifera. Consequently, a circle at y = 1 means that wild bees were present in the absence of A. mellifera. Horizontal and vertical jitter was added to allow visualization of all data points. See Materials and Methods for more details on sampling. https://doi.org/10.1371/journal.pone.0291431.g003 PLOS ONE Biodiversity and the impact of pollinators on carobs PLOS ONE | https://doi.org/10.1371/journal.pone.0291431 October 20, 2023 7 / 16