Аннотация:Plants colonizing 8‐ and 14‐year‐old lava flows, a 28‐year‐old cinder fall, a 137‐year‐old volcanic soil, and a geothermic volcanic soil were sampled for mycorrhizae. Vesicular arbuscular mycorrhizae were present in all sites, and the frequency of occurrence and intensity of root colonization increased with increasing age of the site. In the youngest site, 57% of the sampled species were mycorrhizal, and this increased to 84% in the cinder fall and 100% in the old soil. Orchid and ericoid mycorrhizae also were present in some sites. Native Hawaiian species tended to more frequently form mycorrhizae and have more intense mycorrhizal infection than did alien species. Plant succession on the Hawaiian volcanic sites differed somewhat from a predictive model in the lack of dominance by nonmycotrophic species in the early seral stages. The difference apparently results from 1) the arrival of mycorrhizal fungi soon after the volcanic substrates cool and 2) the paucity of nonmycotrophic species available to invade very recent volcanic sites.
