The decline and conservation management of the threatened endemic palms of the Mascarene Islands

Abstract

The conservation status of the five genera and 11 species of palm endemic to the Mascarene Islands (Mauritius, La Réunion and Rodriques) are reviewed. All species are threatened with extinction; nine taxa are classified as Critically Endangered and four as Endangered on the 2000 IUCN Red List. Two taxa survive as single wild specimens (Hyophorbe amaricaulis and Dictyosperma album var. conjugatum); an additional seven taxa have wild populations of 100 or fewer. Although the historical phase of large-scale forest clearance has passed, the remaining palm populations in the Mascarenes are under threat from the effects of population fragmentation, invasive plants and animals, and high levels of seed predation that prevent natural regeneration. The advantages of in situ management for the recovery of these palm populations are discussed. Without a long-term conservation programme, utilising both in situ and ex situ management, extinction of wild populations will occur.

Low genetic diversity and recovery implications of the vulnerable Bankoualé Palm Livistona carinensis (Arecaceae), from North-eastern Africa and the Southern Arabian Peninsula

“…Their study recorded that seed predation, goat grazing, pig damage and human harvesting were contributing to the lack of regeneration (Chapin et al 2007). Maunder et al (2002) reported that high levels of seed predation of endangered Mascarene Island palms were preventing natural regeneration, and that active enhancement programs were needed to overcome this problem. Where there was grazing, Ford et al (2008) observed a lack of recruitment of seedlings to larger class sizes in L. carinensis.…”

“…For example, in a case study of threatened Pritchardia species in Hawaii, Chapin et al (2004) advocate conservation of existing populations, establishing ex situ populations and reintroducing plants into the wild. On the Mascarene Islands seven palm taxa have populations of 100 or fewer mature individuals in the wild and an active recovery involving both in-situ and exsitu approaches has been recommended to prevent extinction (Maunder et al 2002). Dowe et al (1997) also indicated that recovery of Carpoxylon macrospermum required active conservation programs to establish new populations containing the range of genetic diversity found in the species.…”

Importance of in vitro technology to future conservation programmes worldwide

“…& Drude var. conjugatum H. E. Moore & J. Guého); an additional seven taxa have wild populations of 100 or fewer (Maunder et al 2002). Some of these taxa have benefited from recent conservation efforts but a lot has to be done to save the rest of the species that are on the verge of extinction.…”

“…Eleven species of palms that are endemic to the Mascarenes are threatened according the IUCN statistics. All species are threatened with extinction; nine taxa are classified as CR and four as Endangered (EN) in the 2000 IUCN Red List (Maunder et al 2002). Two taxa survive as single wild specimens (Hyophorbe amaricaulis Mart.…”

Conservation genetics and ecology of an endemic montane palm on Lord Howe Island and its potential for resilience

“…Juvenile recruitment is thus severely impacted by seed predation in L. mooreana. Several species of palm have been reported to be threatened with extinction from lack of regeneration due to seed or seedling predation (Maunder et al 2002;Henderson et al 2006) and all palm species on LHI are affected. Despite the large numbers of seeds produced, heavy predation by rats will lead to reduced numbers for selection to act and a reduced capacity of L. mooreana to respond to episodic recruitment events.…”