Comparer des méthodes

	Indice de Surface Foliaire	Fluorescence de la chlorophylle
Domaine	Agronomie	Agronomie
Famille	Process / pipeline	Process / pipeline
Année d'origine	1947	1931-2004
Auteur d'origine	Donald J. Watson	Hans Kautsky, Ulrich Schreiber, Reto J. Strasser
Type	Plant morphometric measurement	Non-invasive photosynthetic measurement
Source fondatrice	Watson, D. J. (1947). Comparative physiological studies on the growth of field crops: I. Variation in net assimilation rate and leaf area between species and varieties, and within and between years. Annals of Botany, 11(43), 375-407.	Kautsky, H., & Hirsch, A. (1931). Neue Versuche zur Klärung der Assimilationstätigkeit. Naturwissenschaften, 19(48), 964-964.
Alias	LAI, Leaf area, Canopy structure	Fluorescence, Fv/Fm, OJIP curve, PAM fluorometry
Apparentées	3	3
Résumé	Leaf Area Index (LAI) is a dimensionless quantity that measures the total one-sided area of leaves per unit ground area covered by a canopy. It quantifies canopy density and structure: LAI = 0 for bare soil, LAI = 1 for a thin crop, LAI = 3-6 for dense cereal or grass canopies, and LAI > 8 for dense forest. LAI is a key variable in crop growth models, evapotranspiration estimation, and remote sensing because it directly controls light interception, photosynthesis, and water loss from vegetation.	Chlorophyll fluorescence is a non-invasive optical measurement of how efficiently the photosynthetic machinery converts absorbed light into chemical energy (photosynthesis) or heat and light (fluorescence). When photosynthesis is inhibited by stress (drought, cold, salt, pests), chlorophyll fluorescence increases because excitation energy cannot be used for photosynthesis and must be released as light or heat. Fluorescence parameters (Fv/Fm, OJIP curves) act as sensitive, rapid indicators of photosynthetic stress, enabling early detection of plant dysfunction before visible symptoms appear.