We studied a type of Californian ultramafic
chaparral to determine functional groups which can help
reduce the complexity of ecosystem management. The
study was realized in McLaughlin Reserve, State of
California, USA. We analysed the species of a serpentine
plant association previously phytosociologically described in the area: Ceanotho albiflori-Quercetum duratae
for their functional traits and functional groups. Traits
per species were measured building a trait database. We
used Principal Component Analysis to identify the
combination of functional traits with major weight and
a neighbor-joining clustering to define functional groups
for this vegetation association. Our results indicated that
the studied association is dominated by phanerophytes,
with low degree of spinescence. Leaves were mainly
malacophyllous with high degree of tomentosity, reduced size and a partial shedding of leaves was observed
during summer. We considered six functional groups as
the optimum number of clusters in a total of 18 species.
The two first functional groups were composed of
chamaephytes with brachyblasts and dolichoblasts with
differences in the degree of tomentosity. The rest of the
functional groups were composed of phanerophytes
where the differences between them were based on traits
in relation to the branches, leaf size and the horizontal
development of the root system. The functional groups
obtained show that this serpentine chaparral is composed of species with a wide range of functional traits.
The study of other Mediterranean serpentine ecosystems
in California and elsewhere could contribute to create
new perspectives of functional ecology and help in the
management of these valuable ecosystems.
