Ecological Modeling of the Potential Distribution of the Mistletoe Phoradendron nervosum (Viscaceae) Parasitism in Ecuador

This study characterizes Phoradendron nervosum, a hemiparasitic mistletoe species prevalent in Ecuador, using morphological, molecular, and ecological modeling approaches. Morphological analysis revealed that P. nervosum possesses green-yellowish cylindrical stems, lanceolate leaves with entire margins, and berry-like fruits with mucilaginous pulp. DNA sequencing of the internal transcribed spacer (ITS) region confirmed a 99.43% identity with P. nervosum (GenBank: AH009776.2), supporting the taxonomic classification. A maximum entropy (MaxEnt version 3.4.4) model was developed using 36 occurrence points and 19 bioclimatic variables to assess potential distribution across the Tumbaco region in Ecuador. Key environmental factors influencing the species’ distribution were precipitation during the warmest quarter (BIO_18), temperature seasonality (BIO_4), and mean diurnal temperature range (BIO_2). The model showed good predictive performance (AUC = 0.736), identifying areas with high suitability for P. nervosum, particularly in habitats with adequate water availability and thermal stability. Findings suggest that this mistletoe parasitizes both native and exotic tree species, potentially impacting biodiversity and forest health. This research provides a baseline for monitoring mistletoe spread under climate change scenarios and emphasizes the need for management strategies in agroforestry systems where host trees are vulnerable.