Jk. Whalen et Rw. Parmelee, Growth of Aporrectodea tuberculata (Eisen) and Lumbricus terrestris L. under laboratory and field conditions, PEDOBIOLOG, 43(1), 1999, pp. 1-10
The growth of juvenile A. tuberculata and L. terrestris under different con
ditions of soil temperature (10 degrees C and 18 degrees C) and moisture (2
0 %, 25 % and 30 % (w/w) soil moisture content) was determined in a laborat
ory experiment. The instantaneous growth rates (IGR) of A. tuberculata were
between 10.8 x 10(-3) d(-1) and 18.7 x 10(-3) d(-1) and the IGR was lowest
when A. tuberculata was placed in soil at 10 degrees C and 30 % (w/w) soil
moisture content. The growth of L,. terrestris tended to be lower than tha
t of A. tuberculata, and the IGR of L. terrestris ranged from 7.1 x 10(-3)
d(-1) to 13.9 x 10(-3) d(-1) under laboratory conditions. L. terrestris gro
wth was greatest in soil maintained at 10 degrees C and 20 % (w/w) soil moi
sture content. The growth of juveniles of A. tuberculata and L. terrestris
was also examined in the field in large cores containing soil from long-ter
m manure-amended and inorganic fertilizer-treated plots during the spring a
nd autumn of 1995 and 1996. The IGR of A. tuberculata in the field ranged f
rom 7.5 x 10(-3) d(-1) to 14.6 x 10(-3) d(-1) when soil temperatures were b
etween 10 degrees C and 18 degrees C, and was comparable to the IGR of A. t
uberculata under similar environmental conditions in the laboratory. The gr
owth of L. terrestris in the field was much lower than L. terrestris growth
in the laboratory under similar environmental conditions, and the IGR of L
. terrestris in the field ranged from -1.0 x 10(-3) d(-1) to 5.3 x 10(-3) d
(-1) when soil temperatures were between 10 degrees C and 18 degrees C. The
growth of A. tuberculata and L. terrestris was not significantly different
for individuals placed in cores containing soil from either manure-amended
or inorganic fertilizer-treated plots. While there appeared to be adequate
soil organic substrates for A. tuberculata growth in the field, L. terrest
ris growth was probably limited by the absence of sufficient surface organi
c residues. The IGR equation can be used to predict the nonlinear growth of
earthworms under laboratory and field conditions.