Woody Invasive Species: A Regional Assessment - IUCN Invasive ...

Kueffer & Vos Woody Invasive Species: A Regional Assessment
• Phase 1: Before 1760, First settlements. Limited impact, introduction of alien
animals.
• Phase 2: 1760-1830, Permanent settlements. Main introductions of alien plant
species, destruction of lowland habitats.
• Phase 3: 1830-1960s, Fast population & economic growth. Main habitat
destruction
• Phase 4: After 1960s, Post-colonial phase. Mainly accidental introductions, and
propagation of exotic ornamentals
Main invasive species
The invasive species compiled in the report were categorized into three groups:
i) main invasives, ii) non-consensus species, and iii) potentially new invasives. Main
invasive species were mentioned by most of the experts consulted and in the literature.
Non-consensus species were rated as invasive only by a sub-set of the experts consulted
and literature. Potentially invasive species show a tendency to naturalize in the country
and proved to be invasive in other countries of the tropics. The main invasive species
were further rated as either a.) most problematic or b.) problematic. The species that are
most problematic in at least one country of the region are compiled in table 2.
Species
Acacia mangium
Acacia auriculiformis
Alstonia macrophylla
Comoros La
Arch. Réunion
**
** (*)
Mauritius
Seychelles Tropics
**
Ardisia crenata * ** * 1
Casuarina equisetifolia (*) ** (*) ** 3
Cinnamomum verum * (*) (*) ** 2
Clidemia hirta ** ** * * 3
Hiptage benghalensis ** ** 2
Lantana camara ** ** ** * 3
Ligustrum robustum ** ** 3
Litsea glutinosa ** * (*) (*) 3
Paraserianthes falcataria ** 2
Psidium cattleianum ** ** ** ** 3
Ravenala
(*) ** (*) 3
madagascariensis
Rubus alceifolius (*) ** ** 3
Schinus terebinthifolius * ** 3
Solanum mauritianum (*) ** (*) 3
Spathodea campanulata
Syzigium jambos
**
**
(*)
**
(*)
**
(*)
**
2
2
Ulex europeaus ** (*) 3
Table 2. The woody invasive species that are very problematic in at least one country of
the Western Indian Ocean region. (*): potentially invasive or non-consensus, *: main
invasive, **: most problematic invasive. 1: potentially invasive; 2: moderately invasive;
3: highly invasive according to Binggeli et al. (1998).
(*)
3
25