Publications des scientifiques de l'IRD

Enright N.J., Miller B.P., Perry G.L.W., Goldblum D., Jaffré Tanguy. (2014). Stress-tolerator leaf traits determine population dynamics in the endangered New Caledonian conifer Araucaria muelleri. Austral Ecology, 39 (1), p. 60-71. ISSN 1442-9985.

Titre du document
Stress-tolerator leaf traits determine population dynamics in the endangered New Caledonian conifer Araucaria muelleri
Année de publication
2014
Type de document
Article
Auteurs
Enright N.J., Miller B.P., Perry G.L.W., Goldblum D., Jaffré Tanguy
Source
Austral Ecology, 2014, 39 (1), p. 60-71 ISSN 1442-9985
Demographic and ecophysiological data for the endangered New Caledonian conifer, Araucaria muelleri (Araucariaceae), were analysed to: (i) evaluate population viability in relation to site conditions and human impacts; and (ii) advance our understanding of how stress-tolerator plant functional traits affect the population dynamic behaviour and conservation requirements of long-lived tree species. Growth, survivorship and recruitment in four A. muelleri populations were monitored across 9 years. Demographic rates were analysed using stage-based transition matrices. Leaf δ13C, %N and photosystem II stress (Fv/Fm) were measured for seedlings, saplings and trees, and leaf mass per area (LMA) for trees, and correlations among ecophysiological and demographic variables explored. Seedling, sapling and tree stem growth were among the slowest, and annual survivorship among the highest, reported for any tree. Transition matrix analyses yielded stable estimated population growth rates, λ, not significantly different from 1.0 for all populations. Leaf δ13C was positively correlated with seedling and sapling height growth, while daytime photosystem II stress (Fv/Fm) was high in seedlings, but low in saplings and trees. Ecophysiological measures suggest that individuals transition from moisture-limited growth at the seedling stage to nutrient-limited growth as adults. High levels of environmental stress result in slow stand dynamics, characterized by low recruitment and growth rates counterbalanced by equally low mortality rates. These dynamics result in populations with limited capacity to increase in size quickly, but potentially highly vulnerable to decline should the rate of adult mortality increase. This combination of traits is likely typical of extreme stress-tolerator woody species and suggests a conservation focus on the preservation of mature individuals.
Plan de classement
Croissance et développement [076PHYBIO05] ; Formations végétales [082VEGET02]
Descripteurs
PHYTOECOLOGIE ; ARBRE ; ESPECE MENACEE ; ECOPHYSIOLOGIE ; ANALYSE DE DONNEES ; DYNAMIQUE DE VEGETATION ; TOLERANCE AU STRESS ; CONIFERE ; CARBONE 13
Description Géographique
NOUVELLE CALEDONIE
Localisation
Fonds IRD [F B010060318] ; Nouméa
Identifiant IRD
fdi:010060318
Contact