Decline
-t.atuude
168
9. Mode ling Eel grass (Zostera marina L.) Distributions in Great Bay
Global Input
Dispersion
Aeproductives
Surface light
F,GURE 9.4
state variable represents the resulting sum of the biomass of all leaves in the
population as well as the amount of suga r residing in the leaves:
shoot =CHO_shoot + you ngestl eaves + you ngleaues
+ medium_leaves + old_leaves + older_leaves + oldestleaues.
( 1)
The total shoot popul ation increases through primary production and
sugar flow from roo ts and rhizome s. Shoot biomass decreases through leaf
loss, material transfer to reproductives, and sugar flow to roots. Primary
production is limited by light and shoot density :
shootJrom_PSP =
(0 .4*Light/4.OYLeaLarea*((Max_ShooCdensityWr_oLshoots-Leafarea)
/ Max_Shoocdensity Wr_oLshootsYO.OOOOOOOl8.
(2)
Where:
shootJro m_PSP = net produ ction (grams/ day)
0.4 = maximum amount of light that reaches eelgrass
(u n itless)
Light = light available to shoots (microe insteins)