Planting density and canopy interception relation
Canopy interception is the rainwater intercepted and absorbed by the leaves and branches. As for a rain event, the canopy interception increased with rainfall when the rainfall is smaller, the relationship between them is not a linear. Because there is a saturation value of the canopy interception, canopy interception cannot increase with rainfall when the canopy interception approximates the saturation value. Caragana is deciduous and the canopy interception can be ignored as the value is very small during the period of dormancy stage from October through December to April. So the canopy interception is mainly occurred during May to October. The canopy interception and interception rate in dense caragana shrublands with 87 shrubs per 100m2 is higher than that in low planting density in 2002. Under the same species, site, gradient, slope position and slope direction, the quantity of branches and leaves per unit ground area is also increased with an increasing plant density, and thus canopy interception is also increased. The relationship between canopy interception of a rain event in a plot (CI) and planting density (PD) was found to be (Guo & Shao, 2004,2013; Guo 2014,2020):
CI = 0.0158PD0.6601

Where, CI is canopy interception in mm and PD is planting density.