10.3. M odel Results
201
tioning to the adult pool is inversely proportional to the stage duration:
1/ 80 of the Nepbtys and 1/4 of the Polydora in the juvenile immigrant pool
become adults each week.
Adults resulting from matured juvenile immigrants are treated identically
to adults resulting from mature larva-derived juveniles, with lags preventing
early senesce nt death in both cases. Some adults, however , colonize
patches directly through immigration and are not the result of in-patch maturation processes. These adults, similar to other life-stages in locations outside disturbed patches, are assumed to have a un iform age distribution.
Therefore, a proportion of adult immigrants is near the end of its lifespa n at
the time of patch recolonization and dies of old age immediately after occupying the patch. The flows N LIFESPAN ADT IMM and P LIFESPAN ADT
IMM in Figures 10.5 and 10.6 capture those deaths.
10.3. Model Results
For both polychaete species, increased advection of juvenile and adult lifestages from surrounding undisturbed sediments generally redu ces the time
of disturbed patch recovery (Table 10.1). When the advection of one lifestage is held constant, however, recovery time is not necessarily improved
T ABLE 10.1. General effect of background advection (defined as the proportion of
ambient adult or juve nile density transported a given distance per time-step; see text)
in medium-sized patches for (a) Nephtys incisa and (b) Polydora cornuta. Asterisks
(*) ind icate recovery time through larval co lonizatio n only, and represent maximal
recovery ti me produced by this model.
(a)
Advecti on of j uveni les
Advection of adults
Recovery tim e (wk)
0
0
83'
0.05
0.05
82
0.25
0.5
0.75
0.95
1
0.25
0.5
0.75
0.95
1
30
19
14
12
12
(b)
Advectio n of juveni les
Advection of adults
Recovery ti me (w k)
6'
6
6
6
5
4
4
0
0.05
0.25
0.5
0.75
0.95
1
0
0.05
0.25
0.5
0.75
0.95
1
201
tioning to the adult pool is inversely proportional to the stage duration:
1/ 80 of the Nepbtys and 1/4 of the Polydora in the juvenile immigrant pool
become adults each week.
Adults resulting from matured juvenile immigrants are treated identically
to adults resulting from mature larva-derived juveniles, with lags preventing
early senesce nt death in both cases. Some adults, however , colonize
patches directly through immigration and are not the result of in-patch maturation processes. These adults, similar to other life-stages in locations outside disturbed patches, are assumed to have a un iform age distribution.
Therefore, a proportion of adult immigrants is near the end of its lifespa n at
the time of patch recolonization and dies of old age immediately after occupying the patch. The flows N LIFESPAN ADT IMM and P LIFESPAN ADT
IMM in Figures 10.5 and 10.6 capture those deaths.
10.3. Model Results
For both polychaete species, increased advection of juvenile and adult lifestages from surrounding undisturbed sediments generally redu ces the time
of disturbed patch recovery (Table 10.1). When the advection of one lifestage is held constant, however, recovery time is not necessarily improved
T ABLE 10.1. General effect of background advection (defined as the proportion of
ambient adult or juve nile density transported a given distance per time-step; see text)
in medium-sized patches for (a) Nephtys incisa and (b) Polydora cornuta. Asterisks
(*) ind icate recovery time through larval co lonizatio n only, and represent maximal
recovery ti me produced by this model.
(a)
Advecti on of j uveni les
Advection of adults
Recovery tim e (wk)
0
0
83'
0.05
0.05
82
0.25
0.5
0.75
0.95
1
0.25
0.5
0.75
0.95
1
30
19
14
12
12
(b)
Advectio n of juveni les
Advection of adults
Recovery ti me (w k)
6'
6
6
6
5
4
4
0
0.05
0.25
0.5
0.75
0.95
1
0
0.05
0.25
0.5
0.75
0.95
1