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Titre du document / Document title

Field validation and sensitivity analysis of a mechanistic model for tree seed dispersal by wind

Auteur(s) / Author(s)

NATHAN Ran (1) ; SAFRIEL Uriel N. (1) ; NOY-MEIR Imanuel (1) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Department of Evolution, Systematics and Ecology, The Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 91904, ISRAEL

Résumé / Abstract

We present a temporally and spatially explicit mechanistic model of tree seed dispersal by wind, incorporating full stochasticity based on natural variation. The model simulates the dispersal of each individual seed by integrating the temporal effects of climatic conditions on the rate of seed release, and the spatial effects of wind direction and horizontal and vertical velocities, the terminal velocity of seeds (i.e., the constant descent velocity in calm air), and the height of seed release, partitioned into tree height and the distribution of seeds with tree height. The model was tested for two Pinus halepensis stands within the Mediterranean region of Israel, in which seed dispersal has been extensively monitored by seed traps. The predicted dispersal curve verified expectations of a positively skewed leptokurtic distribution and of peak location at some distance from a point source and at zero distance from an area source. Long-distance dispersal events occurred with very low frequency, but given the large seed crop in P. halepensis, even a small fraction should result in a considerable number of seeds dispersed far from their source. The model reliably simulates the observed dispersal pattern in a spatial resolution of 1 m2 (R2 between 60% and 90%), as revealed from comparisons of the predicted and observed proportions of seed dispersed to seed traps. A sensitivity analysis using Latin hypercube sampling along with stepwise multiple rank regression showed that the effects of the horizontal and vertical wind velocities on the dispersal distance override those of the biotic factors. This suggests that the synchronization of seed release with favorable winds is the most effective plant-controlled mechanism to increase the distance of dispersal in wind-dispersed species such as P. halepensis.

Revue / Journal Title

Ecology    ISSN  0012-9658   CODEN ECGYAQ 

Source / Source

2001, vol. 82, no2, pp. 374-388 (2 p.1/2)

Langue / Language

Anglais

Editeur / Publisher

Ecological Society of America, Washington, DC, ETATS-UNIS  (1920) (Revue)

Mots-clés anglais / English Keywords

Dispersion

;

Seeds

;

Distance

;

Wind

;

Wind effect

;

Wind velocity

;

Climatic condition

;

Environmental factor

;

Models

;

Mediterranean region

;

Israel

;

Pinus halepensis

;

Anemochory

;

Mechanistic model

;

Asia

;

Coniferales

;

Gymnospermae

;

Spermatophyta

;

Softwood forest tree

;

Mots-clés français / French Keywords

Dispersion

;

Graine

;

Distance

;

Vent

;

Action vent

;

Vitesse vent

;

Condition climatique

;

Facteur milieu

;

Modèle

;

Région méditerranéenne

;

Israël

;

Pinus halepensis

;

Anémochorie

;

Modèle mécaniste

;

Asie

;

Coniferales

;

Gymnospermae

;

Spermatophyta

;

Arbre forestier résineux

;

Mots-clés espagnols / Spanish Keywords

Dispersión

;

Semillas

;

Distancia

;

Viento

;

Acción viento

;

Velocidad viento

;

Condición climática

;

Factor medio

;

Modelo

;

Región mediterránea

;

Israel

;

Pinus halepensis

;

Asia

;

Coniferales

;

Gymnospermae

;

Spermatophyta

;

Arbol forestal resinoso

;

Localisation / Location

INIST-CNRS, Cote INIST : 3018, 35400009794364.0070

Nº notice refdoc (ud4) : 1028917



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