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9. Modeling Eelgrass (Zostera marina L.) Distributions in Great Bay
As stated, the ultimate goal for the development of the plant model is to"
scale up " to the next level in the hierarchical scheme, to the ecosystem
level (Figure 3). As such, the dynamics of epiphytes, algae, herbivores ,
water quality, and the hydrology of Great Bay would combine to further influence eelgrass bed formation and provide a more complete understanding of the causes of eelgrass bed decline .
9.6. Questions and Tasks
1. What is, in the model, the minimum light requirement to support eelgrass shoot growth?
2. Explore the mechanisms by which new leaves are produced. You can do
so by experimenting in the model with different plastochrone intervals.
3. Research eelgrass seed germination and incorporate the production of
new plants through reproductive processes.
4. Research has shown that estuarine eutrophication can have a highly negative impact on eelgrass survival (Twilley et al. 1985). Currently in the
model, plant production is limited only by light attenuation in the water
column . Add a nutrient limitation on plant production perhaps using an
available dataset to test production responses to nutrient overload .
5. In conjunction with task #4, add an epiphyte sector to the model to further illustrate the effects both light reduction and nutrient loading have
on eelgrass. Epiphytes attach to the eelgrass leaves and in the presence
of nutrients , can bloom and shade the leaves. References to help develop the epiphytes sectors include : Twilley et al. 1985, Bach, H.K. 1993,
Short, F.T. et al. 1995, Kemp et al. 1983, and Sand-Jensen 1977.
6. Visit the web site (
) to download a full ecosystem model , and to learn more about the model in a larger-landscape
context.
EELGRASS DYNAMICS
Plant Density Sector
Nr_of_leaves(t) = Nr_of_leaves(t-dt) + (New_leavesloss_of_leaves) * dt
INIT Nr_of_leaves = 30
INFLOWS:
New_leaves
oPer_of_max_Light*«oratio*Nr_of_shoots) /PI_Model)
OUTFLOWS :
9. Modeling Eelgrass (Zostera marina L.) Distributions in Great Bay
As stated, the ultimate goal for the development of the plant model is to"
scale up " to the next level in the hierarchical scheme, to the ecosystem
level (Figure 3). As such, the dynamics of epiphytes, algae, herbivores ,
water quality, and the hydrology of Great Bay would combine to further influence eelgrass bed formation and provide a more complete understanding of the causes of eelgrass bed decline .
9.6. Questions and Tasks
1. What is, in the model, the minimum light requirement to support eelgrass shoot growth?
2. Explore the mechanisms by which new leaves are produced. You can do
so by experimenting in the model with different plastochrone intervals.
3. Research eelgrass seed germination and incorporate the production of
new plants through reproductive processes.
4. Research has shown that estuarine eutrophication can have a highly negative impact on eelgrass survival (Twilley et al. 1985). Currently in the
model, plant production is limited only by light attenuation in the water
column . Add a nutrient limitation on plant production perhaps using an
available dataset to test production responses to nutrient overload .
5. In conjunction with task #4, add an epiphyte sector to the model to further illustrate the effects both light reduction and nutrient loading have
on eelgrass. Epiphytes attach to the eelgrass leaves and in the presence
of nutrients , can bloom and shade the leaves. References to help develop the epiphytes sectors include : Twilley et al. 1985, Bach, H.K. 1993,
Short, F.T. et al. 1995, Kemp et al. 1983, and Sand-Jensen 1977.
6. Visit the web site (
) to download a full ecosystem model , and to learn more about the model in a larger-landscape
context.
EELGRASS DYNAMICS
Plant Density Sector
Nr_of_leaves(t) = Nr_of_leaves(t-dt) + (New_leavesloss_of_leaves) * dt
INIT Nr_of_leaves = 30
INFLOWS:
New_leaves
oPer_of_max_Light*«oratio*Nr_of_shoots) /PI_Model)
OUTFLOWS :