Fire-related Plant Traits - Fire in Mediterranean Ecosystems - page 59

Table 3.1 Widespread postfire obligate resprouting shrubs in mediterranean-type climate regions
These taxa are resilient to fire by vegetative resprouting but have not modified their reproductive cycle to
delay reproduction to postfire conditions, rather seedlings recruit sporadically during the fire-free
interval.

Mediterranean California Chile South Africa Australia

Arbutus Cercocarpus Colliguaya Diospyros

Daphne Comarostaphylos Kageneckia Heeria

Lonicera Heteromeles Lithraea Maytenus

Myrtus Prunus Quillaja Myrsine

Phillyrea Rhamnus Schinus Rhus

Pistacia Rhus

Quercus Quercus

Rhamnus Styrax

Ruscus Sambucus

Styrax Xylococcus

Viburnum

sprouting , which refers to initiation of new shoots throughout the life cycle of a
plant. Resprouting from vegetative structures that survive fire may occur on
aboveground stems known as epicormic resprouts , from basal resprouts on basal
burls or lignotubers (see below), bulbs, corms, rhizomes or roots. In some
rhizomatous species, resprouting may be coupled with vegetative spread as in
most species of Rosa and Rubus or in some species of Eucalyptus (Lacey 1974 ).
Basal resprouting is a nearly universal trait in perennial dicotyledonous (dicot)
plants (Wells 1969 ), although in broadleaf trees it is often restricted to the sapling
stage (Del Tredici 2001 ; Bond & Midgley 2003 ).
Resprouting is perhaps a near universal recovery mechanism following top-kill
from fire. However, it is also of adaptive value following other disturbances such
as freezing, wind, drought and browsing and has led to the conclusion that even on
fire-prone landscapes it is not an adaptation to fire per se (Wells 1969 ; Axelrod
1973 ; Mooney 1977b ; Keeley 1981 ; Lloret et al. 1999a ). However, in light of the
evidence for fire as a potential selective agent throughout the evolutionary history
of land plants, this conclusion is likely not true for all lineages with resprouting
taxa (see Chapter 9 ).
On fire-prone landscapes many species regenerate after fire from resprouting as
well as recruiting seedlings in a single postfire pulse of seed germination, and
these are termed facultative seeders . Obligate seeders are woody species that lack
resprouting capacity and are dependent entirely on postfire seedling recruitment.
Obligate resprouters are species that are present in the first growing season after
fire solely as vegetative resprouts with no seedling recruitment at that time. Such
obligate resprouters are rare in some MTC ecosystems such as kwongan in
Western Australia but very common in the Mediterranean Basin, Californian
and Chilean shrublands ( Table 3.1 ). Obligate resprouting is a highly conserved
trait at the generic level.