Agriculture Reference
In-Depth Information
property of fynbos WUI fires probably owes much to the hard urban edges,
a legacy of past urban planning, and to the relatively manageable fuel loads in
typical fynbos (see
Table 2.1
). This fire though did initiate a renewed interest in
preventive measures for future fires that included control of alien plants and
improved management of the urban edge among others (Combrinck
et al.
2003
).
Conclusions
The South African MTC region is unusual in that shrublands dominate under
climate regimes that also support forests, and boundaries are determined by fire
history. Fynbos shrublands on nutrient-poor soils are extremely rich in species
and endemics, as are renosterveld shrublands on clay-rich substrates. The majority
of species in fynbos and many in renosterveld are fire dependent in one way or
another, which implies a long history of natural fires as a selective force. Most
fynbos stands burn at intervals of 10-30 yrs and few stands survive more than
40 yrs without burning. Most shrubs are postfire seeders. Some also resprout and
these facultative seeders sometimes have much lower postfire seedling recruitment
than obligate seeders that have no capacity for postfire resprouting. Dormant
seedbanks are maintained in the soil and in serotinous cones and the latter are
more sensitive to long fire intervals. Obligate resprouters regenerate after fire
solely by resprouting and do not recruit seedlings. Although this life history is
found in several evergreen sclerophyll shrubs widely distributed in fynbos and
renosterveld, it only becomes dominant in associated thicket, strandveld or forest
vegetation. When these other vegetation types burn, some woody species are
resprouters and others are non-resprouters, but none are postfire seeders.
Expanding urban development in the Cape region is creating increasing fire
problems. Fire suppression policy was begun more than 60 yrs ago and continues
to the present. In more remote areas of the Cape region, prescribed burning has
been replaced by natural fire zones in which attempts are made to suppress
anthropogenic fires while allowing naturally ignited
veld
fires to burn to their
full extent.
