Burrows might interact with physical and
chemical conditions of different habitat types,
which affected the nutrient concentrations of soil
transported. Soil in Phragmites and Spartina marshes
had higher water content and lower bulk density
than those in mudflats (Figure 4D, E), although
there were no significant differences in soil grain
size and salinity among the habitats (Figure 3A, B).
Soil in Phragmites and Spartina marshes had significantly
higher TN, TC and TOC, and TOC/TC ratios,
and hence, lower C/N ratios compared to those in
590 J. Q. Wang and others
mudflats (Figure 3C–G). Moreover, the interaction
between habitat type and soil source was significant
(Table A3 Supplemental Material). NH4-N and
TIN concentrations of surface soil in Phragmites
marshes were significantly higher than those in
both Spartina marsh and mudflats, but NO3-N
concentration was not different among the three
habitats (Figure 4A–C, Table A4).
(A)
(B)
(C)
(D)
Figure 1. The effects of
burrow or burrow mimic
opening size on the four
parameters reflecting crab
excavation and burrow
mimic deposition in
Phragmites and Spartina
marshes and mudflats
over a 5-d sampling
period. (A) Excavating
rate by crabs (g d-1); (B)
deposition rate per
burrow mimics (g d-1);
(C) deposition efficiency
(g d-1 cm-3); (D) net
transport to the marsh
surface (g d-1). The data
are separately presented
for small (diameter: 0–
15 mm), medium
(diameter: 15–30 mm)
and large (diameter:
>30 mm) crab burrows.
(A) (B)