Equations for Soil Microbial Biovolume and Carbon Calculation

VARIATE:

DEFINITION AND EQUATION:

s:

Mass of soil per image(µg)

where
x = 512 * 0.089(µm),
y = 768 * 0.089 (µm) for bacterial images;
x = 512 * 1.0 (µm),
y = 768 * 1.0 (µm) for fungal hyphal images;
%H₂O = water content of soil sample.

bv:

Volume of each bacterial cell (µm³ )

d = small diameter of cell

l= long diameter of cell

The volume (bv) of each bacteria is calculated from measurements of the large,
l, and small,
d, diameters of each cell by assuming that the cells are
prolate spheroids.

BAC_NUM:

Total bacteria (cells g^-1soil)

BAC_NUM = count per image / S

BAC_VOL:

Bacterial biovolume (µm³g^-1 soil)

BAC_VOL =

BAC_C:

Bacterial biomass C (µgC g^-1soil)

BAC_C = BAC_VOL * 0.2

The factor 0.2 used to convert
bacterial biovolume to carbon © is thought to be the
best available based on a range of estimates available in
the literature.

hv:

Volume of each hyphal fragment (µm³)

d = hyphal diameter

l = hyphal length

Hyphal volume for each fragment is calculated assuming
the hyphae are simple cylinders of length
l and diameter
d.

HYP_LEN:

Total fungal hyphal length (m g^-1
soil)

HYP_LEN = *10^-6

l = hyphal length

HYP_DIAM:

Mean fungal hyphal diameter (µm)

HYP_VOL:

Fungal hyphal biovolume (µm³ g^-1 soil)

HYP_VOL =

HYP_C:

Fungal hyphal biomass C (µgC g^-1 soil)

HYP_C = HYP_VOL * 0.15

The factor 0.15 used to convert fungal
biovolumes to carbon © is thought to be the best
available based on a range of estimates available in the
literature.

DMC_C:

Total microscopic biomass C (µgC g^-1 soil)

DMC_C = BAC_C + HYP_C