| 292 | | Describes r6908. '''Longevity_leaf''' is a prescribed parameter for the longevity of a typical leaf/needle at the average temperature for that PFT. For PFTs where a large range in longevity has been observed, this is accounted for in the calculation of '''leaf_age_crit'''. Leaf_age_crit is thus the location-specific longevity. It the age of a leaf/needle exceeds half the value for crit_leaf_age, leaf, root and sapwood turnover will start. Because of the way leaf_age_crit is calculated the simulated longevity differs from the prescribed longevity. For example, longevity_leaf = 220, leaf_age_crit = 165 at 25C, 220 at 15C and 330 at 5C. Note that turnover starts when leaf age is half this value. Thus at 110 days in the temperate zone which is within the observations. |
| | 292 | Describes r7767. '''Longevity_leaf''' is a prescribed parameter for the longevity of a typical leaf/needle at the average temperature for that PFT. For PFTs where a large range in longevity has been observed, this is accounted for in the calculation of '''leaf_age_crit'''. Leaf_age_crit is thus a location-specific critical age of a leaf. For example, longevity_leaf = 220, leaf_age_crit = 165 at 25C, 220 at 15C and 330 at 5C. If the age of a leaf/needle exceeds half the value for leaf_age_crit, leaf, root and sapwood turnover will start (Thus at 110 days in example for the temperate zone, which is within the observations). Leaf growth may continue at the same time as leaf turnover. The mean leaf age is the outcome of the interplay of the leaf longevity and the leaf growth. |
| | 293 | |
| | 294 | +++SL CONTINUE+++ |
| | 295 | For evergreen PFTs, the control of leaf_age_crit on the simulated longevity (reflected in the mean leaf age) is straightforward. Because of the way leaf_age_crit is calculated the simulated longevity differs from the prescribed longevity. |
| | 296 | |
| | 297 | Because of the way leaf_age_crit is calculated the simulated longevity differs from the prescribed longevity. |
| | 298 | ++++++++++++++++++ |
