There are, of course, exceptions to these general patterns. For example, some epiphytic chlorolichens (e.g., Hypogymnia duplicata) are restricted to coastal rainforests ( McCune 1997), and some epiphytic bryophytes (e.g., Porella platyphylla) are very tolerant of desiccation ( Marschall and Proctor 1999). However, the typical abundance sequence (bryophytes—cyanolichens—chlorolichens) recurs along gradients of decreasing moisture availability at multiple spatial scales.