Red List Status -Critically Endangered (CR) , assessed in 24/07/2015
Protected species -in Northern Province , in Northern Province
Pittosporum tanianum is an endemic shrub of New Caledonia known exclusively on île Léprédour, located on the west coast of Grande Terre. Epithet tanianum is coming from the name Tani corresponding at île Leprédour in Kanak language. Strongly threatened by invasive species, population of P. tanianum is only composed by 2 individuals. Under pressure of rusa rusa deer (Rusa timorensis) (Rusa timorensis) and feral rabbit, a continuous decline of number of individuals and habitat quality is observed. This species was the object of numerous conservation plans, which fail to contain the decline of individual numbers. Using criteria B, C and D, P. tanianum qualifies as Critically Endangered (CR) B1ab(iii,v)+2ab(iii,v);C2a(i);D.
P. tanianum is an endemic shrub of New Caledonia exclusively known on île Léprédour, located on west coast of Grande Terre.
From current field observations, only one male and one female individual remain from natural population on îlot Leprédour. On in situ plantations done by CEN, it would remain only 50% individuals. Concerning ex situ population located in parc zoologique et forestier, there is no evidence of mortality.
P. tanianum occurs in low-altitude strongly damaged sclerophyllous forest on calcareous soil.
P. tanianum is strongly threatened by invasive animal species. Introduced in the 1880's for rusa rusa deer (Rusa timorensis) (Rusa timorensis) and at the end of 1970's for rabbit, those two species are the cause of strong damages on environment (erosion...) as well as loss of mature individuals and problem of seedling regeneration.
Protected species by legislation in Province Nord and Province Sud, two natural mature individuals remain in réserve naturelle de l’Ile Leprédour. Propagation in nursery keep going and population control of invasive species inside the protected area are being organized. On 300 plants produced as a part of conservation of P. tanianum, 100 plants have been planted on île Leprédour and 100 plants in parc zoologique et forestier. Parc zoologique population shows good results while in situ plantation recorded 50% of mortality (com. pers. 2015). First generation comes from germination. Next generations were propagated by taking cuttings. On intra-genus crossings tried, only crossing with P. coccineum and P. croceum worked well. Urgent situation of P. tanianum justifies to extend prospection to nearby areas where vegetation is similar, such as presqu'île Montagnès, Perceval, îlot Moro and îlot Page.
Bouchet, P.; Jaffré, T. and Veillon J.-M. 1995. Plant extinction in New Caledonia: protection of sclerophyll forest urgently needed. Biodiversity and Conservation(4) , p.415-428.
Tirel Ch.; Veillon J.-M. 2002. Flore de la Nouvelle-Calédonie, tome 24. Pittosporaceae.
Morat, P.; Jaffré, T.; Tronchet, F.; Munzinger, J.; Pillon, Y.; Veillon, J.-M. and Chalopin, M. 2012. The taxonomic database « FLORICAL » and characteristics of the indigenous flora of New Caledonia. Adansonia(334) , p.177-219.
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
Assessor(s): Gemmill, C., Veillon, J., Amice, R., Cazé, H., Dumontet, V., Fleurot, D., Garnier, D., Gâteblé, G., Letocart, I., Letocart, D., Maggia, L., Pain, A.
Reviewer(s): Tanguy, V.
Contributor(s): Plouzennec, P.
Facilitator(s): Chanfreau, S.