Table 16.2
Widespread, locally severe, or rapidly spreading invasive alien plant species in South African rangelands
a
Species
Growth form
QDGCs occupied
(%) in 2000
QDGCs occupied
(%) by 2016
Increase (%) in QDGCs
occupied 2000–2016
Affected
biomes
b
Affected habitat
(riparian, dryland)
Biological
control
c
Acacia baileyana
Medium tree
4.4
5.2
16.5
G
Both
Negligible
Acacia cyclops
Medium tree
8.4
8.9
5.4
AT, SK
Both
Substantial
Acacia dealbata
Medium tree 13.0
15.4
18.0
G
Both
Negligible
Acacia decurrens
Medium tree
5.1
6.4
24.8
G, IOCB
Both
Negligible
Acacia longifolia
Medium tree
4.8
4.9
2.1
AT, IOCB,
NK, Sv
Both
Substantial
Acacia mearnsii
Medium tree 21.8
23.6
8.2
AT, G, IOCB,
Sv
Both
Substantial
Acacia melanoxylon
Tall tree
6.8
8.7
27.6
G
Both
Substantial
Acacia saligna
Medium tree
8.0
8.5
6.3
AT, SK
Both
Substantial
Achyranthes aspera
Perennial herb 3.9
5.0
22.2
G, IOCB, Sv Dryland
None
Agave americana
Succulent
shrub
21.9
26.9
22.7
AT, G, NK,
SK, Sv
Dryland
None
Ageratum conyzoides
Annual herb
1.9
2.2
18.9
G, IOCB, Sv Riparian
None
Araujia sericifera
Woody
climber
1.8
2.8
52.8
G, Sv
Riparian
None
Arundo donax
Tall grass
18.9
23.1
22.4
G, IOCB, NK,
SK, Sv
Riparian
Under
investigation
Atriplex inflata
Low shrub
8.3
9.9
18.9
NK, SK
Dryland
None
Atriplex nummularia
Low shrub
8.7
12.1
37.8
NK, SK
Both
None
Caesalpinia
decapetala
Shrub
6.5
7.4
15.0
IOCB, Sv
Both
Negligible
Campuloclinium
macrocephalum
Perennial herb 0.7
5.5
671.4
G, IOCB
Dryland
Not determined
Cardiospermum
grandiflorum
Woody
climber
2.2
3.1
41.9
G, IOCB, Sv Riparian
Not determined
Cereus jamacaru
Succulent tree 6.3
10.1
60.5
AT, IOCB, Sv Dryland
Complete
Cestrum laevigatum
Shrub
3.6
3.6
0.0
AT, IOCB, Sv Both
Under
investigation
Chromolaena odorata
Shrub
4.7
6.1
28.0
G, IOCB, Sv Both
Not determined
Cosmos bipinnatus
Annual herb
2.4
7.0
185.4
G
Riparian
None
0.05
0.9
1700.0
Sv
Riparian
None
468
T. G. O’Connor and B. W. van Wilgen
Widespread, locally severe, or rapidly spreading invasive alien plant species in South African rangelands
a
Species
Growth form
QDGCs occupied
(%) in 2000
QDGCs occupied
(%) by 2016
Increase (%) in QDGCs
occupied 2000–2016
Affected
biomes
b
Affected habitat
(riparian, dryland)
Biological
control
c
Acacia baileyana
Medium tree
4.4
5.2
16.5
G
Both
Negligible
Acacia cyclops
Medium tree
8.4
8.9
5.4
AT, SK
Both
Substantial
Acacia dealbata
Medium tree 13.0
15.4
18.0
G
Both
Negligible
Acacia decurrens
Medium tree
5.1
6.4
24.8
G, IOCB
Both
Negligible
Acacia longifolia
Medium tree
4.8
4.9
2.1
AT, IOCB,
NK, Sv
Both
Substantial
Acacia mearnsii
Medium tree 21.8
23.6
8.2
AT, G, IOCB,
Sv
Both
Substantial
Acacia melanoxylon
Tall tree
6.8
8.7
27.6
G
Both
Substantial
Acacia saligna
Medium tree
8.0
8.5
6.3
AT, SK
Both
Substantial
Achyranthes aspera
Perennial herb 3.9
5.0
22.2
G, IOCB, Sv Dryland
None
Agave americana
Succulent
shrub
21.9
26.9
22.7
AT, G, NK,
SK, Sv
Dryland
None
Ageratum conyzoides
Annual herb
1.9
2.2
18.9
G, IOCB, Sv Riparian
None
Araujia sericifera
Woody
climber
1.8
2.8
52.8
G, Sv
Riparian
None
Arundo donax
Tall grass
18.9
23.1
22.4
G, IOCB, NK,
SK, Sv
Riparian
Under
investigation
Atriplex inflata
Low shrub
8.3
9.9
18.9
NK, SK
Dryland
None
Atriplex nummularia
Low shrub
8.7
12.1
37.8
NK, SK
Both
None
Caesalpinia
decapetala
Shrub
6.5
7.4
15.0
IOCB, Sv
Both
Negligible
Campuloclinium
macrocephalum
Perennial herb 0.7
5.5
671.4
G, IOCB
Dryland
Not determined
Cardiospermum
grandiflorum
Woody
climber
2.2
3.1
41.9
G, IOCB, Sv Riparian
Not determined
Cereus jamacaru
Succulent tree 6.3
10.1
60.5
AT, IOCB, Sv Dryland
Complete
Cestrum laevigatum
Shrub
3.6
3.6
0.0
AT, IOCB, Sv Both
Under
investigation
Chromolaena odorata
Shrub
4.7
6.1
28.0
G, IOCB, Sv Both
Not determined
Cosmos bipinnatus
Annual herb
2.4
7.0
185.4
G
Riparian
None
0.05
0.9
1700.0
Sv
Riparian
None
468
T. G. O’Connor and B. W. van Wilgen