Identification, abundance, and origin of moss, liverwort, and algal contaminants in greenhouses of containerized forest nurseries

Five containerized forest nurseries in British Columbia were surveyed for cryptogam (moss, liverwort, and algal) contamination. Fourteen cryptogam species (five bryophyte and nine algal species) were identified from contaminated styroblock containers. No cryptogams were cultured from the peat and soil mix samples and no mosses or liverworts were detected in the water samples. Algae were found in water samples of two of the five nurseries, but only one of these had species similar to those contaminating the styroblocks. Air samples contained moss, liverwort, and six of the nine algal contaminant species. The relative abundance and distribution of cryptogams at each nursery is given and data are presented which indicate an airborne mode of contamination. The results are discussed with respect to the nature of the contamination and possible control of cryptogam pests in greenhouses of containerized forest nurseries.