เปรียบเทียบวิธี

	การวิเคราะห์การเลือกปฏิบัติของคาร์บอน-13	ดัชนีพื้นที่ใบ
สาขาวิชา	พืชไร่	พืชไร่
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1982–1989	1947
ผู้ริเริ่ม	Graham D. Farquhar and collaborators	Donald J. Watson
ประเภท	Isotopic measurement and analysis technique	Plant morphometric measurement
แหล่งต้นตำรับ	Farquhar, G. D., Ehleringer, J. R., & Hubick, K. T. (1989). Carbon isotope discrimination and photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology, 40, 503–537.	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.
ชื่อเรียกอื่น	delta-13C analysis, carbon isotope discrimination, 13C discrimination, isotopic discrimination analysis	LAI, Leaf area, Canopy structure
ที่เกี่ยวข้อง	1	3
สรุป	Carbon-13 Discrimination Analysis quantifies the degree to which C3 plants preferentially fix the lighter carbon isotope (12C) over the heavier 13C during photosynthesis. The resulting discrimination value (Delta) is closely linked to the ratio of internal to ambient CO2 concentration, making it a reliable, integrative proxy for intrinsic water-use efficiency across the growing season. The technique is widely used in agronomy, plant physiology, and crop breeding.	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.