Agriculture Reference
In-Depth Information
Table 3.4 Postfire seeding woody genera in MTC crown fire regimes that depend entirely on seeding (obligate seeders)
or couple seeding with resprouting (facultative seeders)
Number of species
Resprouters
(facultative
seeders)
Species with
populations
of both
Obligate
seeders
Source
a
Mediterranean Basin
Cistus
Cistaceae
18
0
2
4
Erica
Ericaceae
1
11
0
4
Genista
Fabaceae
1
9
0
4
Ulex
Fabaceae
1
7
0
4
California
Arctostaphylos
Ericaceae
48
4
8
1
Ceanothus
Rhamnaceae
23
14
1
3
Chile
[none]
South Africa
Aspalathus
Fabaceae
81
11
1
6
b
Cliffortia
Rosaceae
60
60
-
Erica
Ericaceae
390
27
16
5
Leucadendron
Proteaceae
27
3
0
6
Leucospermum
Proteaceae
23
3
0
6
Podalyria
Fabaceae
4
12
2
6
Paranomus
Proteaceae
9
1
0
6
Protea
Proteaceae
28
15
0
6
Southwestern Australia
Adenanthos
Proteaceae
15
16
0
8
Banksia
Proteaceae
38
20
2
2
Grevillea
Proteaceae
138
62
0
8
Hakea
Proteaceae
77
38
0
7
a
(1) Parker
et al.
2010
; (2) Lamont & Markey
1995
; (3) Wilken
2010
; (4) Paula
et al.
2009
; (5) Ojeda
1998
; (6) Schutte
et al.
1995
; (7) Young
2006
; (8) Bell
2001
.
b
estimate.
Heat-stimulated seeds are known from temperate forests and grasslands, trop-
ical savannas, deserts, MTC shrublands and other ecosystems, in species of
Anacardiaceae, Apiaceae, Cistaceae, Convolvulaceae, Ericaceae, Fabaceae, Ger-
aniaceae, Hypericaceae, Lamiaceae, Malvaceae, Portulacaceae, Onagraceae, Res-
tionaceae, Rhamnaceae and Sterculiaceae (Keeley & Fotheringham
2000
). These
seeds typically exhibit exogenous dormancy imposed by a dense water-imperme-
able cutinized testa and dense palisade tissue that has led to the term
hardseeded
.
Fire disrupts the water-impermeable tissues, allowing imbibition, which typically
leads to germination. Hardseeded species with postfire seedling recruitment
appear to differ substantially in the intensity and duration of heat shock most
stimulatory to germination. Some exhibit optimal germination after brief bursts
of high temperatures (e.g. 5 minutes at 105
C) whereas others have higher
