Bates et al. (2004) used canonical correspondence analysis (CCA) to develop a more rigorous approach to these relationships by sampling epiphytes along a transect across southern Britain from southwest to northeast. With climate, presence of water courses, and forest cover contributing to the analysis, they determined that Frullania tamarisci, Metzgeria temperata, Microlejeunea ulicina, Neckera pumila, and Hypnum andoi were restricted to habitats with high moisture availability.