Ligustrum robustum (L.)

Ligustrum robustum is a small tree which can reach up to 5 m in height. In its native range it occurs up to 1,500m in wet and intermediate low montane regions (in ) and in the sub- montane forest (in ) at an altitude of between 725m and 1,650m. There are at least three subspecies of L. robustum ssp. robustum is from northeastern India, ssp. perrottetii is from southern India and ssp. walkeri is from Sri Lanka. It is L. robustum ssp. walkeri which has been introduced to the Mascarene Archipelago and become invasive in natural areas. Its invasiveness is partly attributable to its dense foliage, the regeneration of light-demanding. The may alter the structurewhich reduces and composition light reaching of the theforest forest by affecting floor and nutrient prevents and water cycling, and may compete with native species for space and nutrients, displacing them and affecting successional patterns. L. robustum is capable of invading primary forests which poses Photo credit: Sténio Félix [link] punctatus), the cuckoo-shrike (Coracina typica) and the highly threatened by this aggressive species. Mauritius black bulbul (Hypsipetes olivaceus), and the Mascarene L.a seriousrobustum threat is one to of native the worst ecosystems. plant pests Native in the floral Mauritian diversity wet is Terpsiphone bourbonnensis, race desolata) forests along with Psidium cattleianum and Rubus alceifolius. are negatively affected by the expansion of exotic such as L. Threatened native birds, such as the ‘Critically Endangered robustumparadise . flycatcher ( (CR)’ Mauritius olive white-eye (Zosterops chloronothus); the L. robustum is one of the main threats to the 47 native plants present ‘Endangered (EN)’ pink pigeon (Nesoenas mayeri =(Columba in the highland areas of Reunion infested with the plant. Its seeds mayeri)), (Psittacula eques) and Mauritius fody (Foudia rubra); the ‘Vulnerable (VU)’ Mauritius kestrel (Falco which threatens the regeneration of native species. have a higher germination rate on the forest floor than native seeds

References: Global Invasive Species Database (GISD), 2011. Ligustrum robustrum (L.) Lavergne, C., Rameau, J. and Figier, J. 1999. The invasive woody weed Ligustrum robustum subsp. walkeri threatens native forests on La Réunion, Biological Invasions 1: 377–392.

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