NPP can be directly assessed by measuring plant traits or harvesting plant material on the ground, but across large areas remotely sensed images can be used to estimate NPP.. im trying to help
The asthenosphere lies 80-200km below the surface under the lithosphere. Convection also occurs in the asthenosphere. The asthenosphere is mostly made of up rock material (magnesium and iron silicates). The asthenosphere makes up 6% of the mantle and lets the lithosphere move.
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