قارن الطرق

	كسر فجوة المظلة	مؤشر مساحة الورقة
المجال	علوم الغابات	علم المحاصيل
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1979	1947
صاحب الطريقة	John Norman	Donald J. Watson
النوع	measurement pipeline	Plant morphometric measurement
المصدر التأسيسي	Machado, J.-L., & Reich, P. B. (1999). Evaluation of several measures of canopy openness. Canadian Journal of Forest Research, 29(9), 1439–1444.	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.
الأسماء البديلة	gap fraction, canopy openness	LAI, Leaf area, Canopy structure
ذات صلة	2	3
الملخص	Canopy gap fraction quantifies the proportion of sky visible through the forest canopy, expressed as a percentage. Developed to measure light availability in the understory, it is a standard metric in forest ecology for characterizing canopy structure and microhabitat conditions. This measure is essential for understanding light-limited photosynthesis and seedling establishment in closed-canopy forests.	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.