Heathlands Functioning in a Perspective of Climate Warming: Estimation of Parameters, Elements for Discrete Event Simulation

• Published in: Plant ecology 2000-07, Vol.149 (1), p.107-118
• Main Authors: Coquillard, P., Gueugnot, J., Michalet, R., Carnat, A.-P., L'Homme, G.
• Format: Article
• Language: English
• Subjects: Altitude; Annuals; Biomass; Biomass production; Calluna vulgaris; Climate change; Climate models; France; Germination; Global warming; Heathlands; Nitrogen; Plant ecology; Plants; Seedlings; Survival
• ISSN: 1385-0237; 1573-5052
• DOI: 10.1023/A:1009805112857

Three Calluna vulgaris (L.) Hull heathlands (1100, 1500 and 1780 m altitude) are studied in order to establish and estimate parameters which will be integrated in a discrete event stimulation of heathland functioning in the case of a 2 °C climate warming. The sites, situated in the Chaîne des Puys and the Massif du Sancy (France), present similar conditions for Calluna growth: bedrock (trachyt), exposure and slope, so that they can be compared on a climatic basis. Main parameters sampled are: age distributions, life expectancies, layering probabilities, annual growths, biomasses (standing crop), C/N rates and potential respiratory of soils. In addition, experiments were carried out on germination, hypocotyle elongation and growth of mycorrhizal fungi in order to estimate the inhibitory-to-growth action against the substitution process. On one stand (exhibiting gaps) the patch structure of Calluna plants was recorded and mapped. The rising of biomass expected is calculated according to the Aerts's model, as a function of nitrogen availability which would increase under a scenario of climate warming. From a similar point of view, layering probabilities, life expectancies and inhibition of seedlings survival modelling -- under a linear model assumption -- are proposed.