Vegetation succession on 4 recent (1852-1942) montane lava Rows on Mau
na Loa, Hawaii, was remeasured 22 years after the first measurement in
1967. Colonisation patterns of vascular plant species were observed o
n a new lava flow (1984) which overwhelmed part of the earlier studied
1852 flow. An influx of adventive species, positively correlated with
flow age, was noted at the remeasured sites; most were herbs and gras
ses that do not appear to interfere with the succession to Metrosidero
s-dominated forest. Some indigenous species important in older forest,
e.g., Cibotium glaucum, had apparently colonised all four remeasured
flows regardless of flow age. Densities and total basal area of Metros
ideros polymorpha increased on all flows, but a closed-canopy forest h
ad not yet developed. Vascular plant aggregations comprising a mixture
of adventive and indigenous species were found on the 1984 flow assoc
iated with soil or logs of the overwhelmed forest. This phenomenon may
allow rare individual Metrosideros trees to be in place on a new flow
within 10 years of its formation. A closed-canopy, self-thinned Metro
sideros forest can develop within 400 years but dieback of colonising
Metrosideros individuals and/or invasion of adventive species capable
of altering ecosystem processes can delay this process.