Data/hora: 10/06/2024 14:01:04

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 18/09/2008
Data da última atualização: | 18/09/2008
Autoria: | CALLAHAM JUNIOR, M. A.; O'BRIEN, J. J.; HENDRIX, P. F.; CAMP, D. L.; BENNETT, S. R.
Título: | Carbon and nitrogen dynamics in soils with native North American and introduced European earthworms determined with stable isotopes.
Ano de publicação: | 2008
Fonte/Imprenta: | In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.
Idioma: | Inglês

Conteúdo:

There is very little known about interactions between native and introduced earthworms in forested
soils of southeastern North America. We conducted a growth chamber study using 13C labeled
white oak (Quercus alba) seedlings and 15N labeled oak litter in mesocosms (10 cm dia., 20
cm depth) to examine the effects of native and exotic earthworms on plant growth, and C and N
dynamics. Three earthworm species with different ecological strategies and origins (Diplocardia
sylvicola, Octolasion tyrtaeum, and Lumbricus rubellus) were used in an incomplete factorial
experimental design to examine the dynamics of C and N in soil, plant and earthworm biomass
pools. Six experimental groupings were established: 1) Native endogeic alone; 2) Exotic
endogeic alone; 3) Exotic epigeic alone; 4) Native endogeic with exotic endogeic; 5) Native
endogeic, exotic endogeic, and exotic epigeic together; and 6) No earthworms (control). On
two sample dates (3 and 6 wk) mesocosms were destructively sampled for: soil 0-5 cm, soil 5-
20 cm, coarse root material, fine root material, leaves, stems, and earthworm tissue. Results
from the earthworm tissue analysis indicated no difference in the delta-13-C signatures of any
worms in any combination, but tissue analysis for delta-15-N signatures indicated strong
differences between species. In single species pots, Lumbricus rubellus exhibited the greatest
level of enrichment with delta-15-N signatures reaching nearly 200?. The pots with two endogeic
species together revealed a possibly competitive interaction between native and exotic endogees
with O. tyrtaeum having the largest delta-15-N signature (mean signature of 56? for O. tyrtaeum
vs. 30? for D. sylvicola). In the pots with the three species mix, the endogeic species (both
native and exotic) took up less 15N than when in competition with only one another, and L.
rubellus took up more 15N than when grown in isolation. Data from plant tissue and soil analysis
for? delta-13-C and delta-15-N will also be presented and discussed

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Registro original: | Embrapa Florestas (CNPF)
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