Psidium cattleianum (tree, shrub)

Ecology Distribution Management Info Impact Info References and Links Contacts

General Impact P. cattleianum is a habitat-altering weed that poses a major threat to endemic flora by competing for light and soil nutrients. Today the most serious threat to Seychelles forests is the low regeneration of native trees caused by the invasion of alien plant species such as P. cattleianum (Fleischmann, 1997, 1999, in Fleischmann et al. 2006).          Location Specific Impacts: French Polynesia (Polynésie Française)     Threat to endangered species: Psidium cattleianum has invaded all the moist forest of Tubuia (Austral Islands), where it forms dense monospecific stands and threatens the rare species Charpenteria australis and the critically endangered Meryta brachypoda in IUCN Red List of Threatened Species (Meyer, 2004). Mauritius   Competition Reunion (La Réunion)   Competition: Psidium competes with native plants for light, space and nutrients. Monospecific thickets are rapidly formed under which no native regeneration is possible. Modification of hydrology: Psidium is not nearly so resistant to cyclones as Mauritian native species. After the passage of a cyclone a great deal of knock down and defoliation of Psidium occurs, which leaves the land vulnerable to landslides and floods. Seychelles   Competition Modification of successional patterns: Today the most serious threats to the forests are low regeneration of native trees and invasion by alien species (Fleischmann, 1997, 1999). Hawaii (United States (USA))   Habitat alteration: Tetraplasandra lydgatei is a distinct species inhabiting the mesic Hawaiian forest remnants of the southeastern Ko‘olau Mountains. The mesic forest habitat of T. lydgatei, unfortunately, is now dominated by two invasive weed species, strawberry guava and Schinus terebinthifolius (Christmas berry), which form dense stands that prevent native species from flourishing and shade and inhibit understory species from sprouting (Motley 2005). Interaction with other invasive species: Wild pigs (Sus scrofa) create soil disturbances that may enhance the spread of P. cattleianum (Huenneke Vitousek 1990).