Krashevska, V.; Maraun, M.; Rueß, L. & Scheu, S. (2010): <b>Carbon and nutrient limitation of soil microorganisms and microbial grazers in a tropical montane rain forest</b>. <i>Oikos</i> <b>119</b>, 1020-1028.
Resource Description
Title:
Carbon and nutrient limitation of soil microorganisms and microbial grazers in a tropical montane rain forest
FOR816dw ID:
1097
Publication Date:
2010-01-11
License and Usage Rights:
Resource Owner(s):
Individual:
Valentyna Krashevska
Contact:
email:
vkrashe <at> gwdg.de
Berliner Str. 28
37073 Göttingen
Germany
Individual:
Mark Maraun
Contact:
email:
mmaraun <at> gwdg.de
University of Göttingen
Institute of Zoology & Anthropology
Berliner Strasse 28
37073 Göttingen
Germany
Individual:
Liliane Rueß
Contact:
email:
webmaster <at> tropicalmountainforest.org
Individual:
Stefan Scheu
Contact:
email:
sscheu <at> gwdg.de
Untere Karspüle 2
University of Göttingen
J.F.B. Institute of Zoology and Anthropology
37073 Göttingen
Germany
Abstract:
We investigated the role of carbon, nitrogen and phosphorus as limiting factors of microorganisms and microbial grazers<br/>
(testate amoebae) in a montane tropical rain forest in southern Ecuador. Carbon (as glucose), nitrogen (as NH4NO3) and<br/>
phosphorus (as NaH2PO4) were added separately and in combination bimonthly to experimental plots for 20 months.<br/>
By adding glucose and nutrients we expected to increase the growth of microorganisms as the major food resource of<br/>
testate amoebae. Th e response of microorganisms to experimental treatments was determined by analysing microbial biomass<br/>
(SIR), fungal biomass and microbial community composition as measured by phospholipid fatty acids (PLFAs). We<br/>
hypothesized that the response of testate amoebae is closely linked to that of microorganisms. Carbon addition strongly<br/>
increased ergosterol concentration and, less pronounced, the amount of linoleic acid as fungal biomarker, suggesting that<br/>
saprotrophic fungi are limited by carbon. Microbial biomass and ergosterol concentrations reached a maximum in the<br/>
combined treatment with C, N and P indicating that both N and P also were in short supply. In contrast to saprotrophic<br/>
fungi and microorganisms in total, testate amoebae suff ered from the addition of C and reached maximum density by the<br/>
addition of N. Th e results indicate that saprotrophic fungi in tropical montane rain forests are mainly limited by carbon<br/>
whereas gram positive and negative bacteria benefi t from increased availability of P. Testate amoebae suff ered from increased<br/>
dominance of saprotrophic fungi in glucose treatments but benefi ted from increased supply of N. Th e results show that testate<br/>
amoebae of tropical montane rain forests are controlled by bottom?up forces relying on specifi c food resources rather<br/>
than the amount of bacterial biomass with saprotrophic fungi functioning as major antagonists. Compared to temperate<br/>
systems microbial food webs in tropical forests therefore may be much more complex than previously assumed with trophic<br/>
links being rather specifi c and antagonistic interactions overriding trophic interactions.
Literature type specific fields:
ARTICLE
Journal:
Oikos
Volume:
119
Page Range:
1020-1028
Metadata Provider:
Individual:
Valentyna Krashevska
Contact:
email:
vkrashe <at> gwdg.de
Berliner Str. 28
37073 Göttingen
Germany
