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Nutrient limitations to bacterial and fungal growth during cellulose decomposition in tropical forest soils

Nottingham, Andrew T.; Hicks, Lettice C. LU ; Ccahuana, Adan J.Q.; Salinas, Norma; Bååth, Erland LU and Meir, Patrick (2018) In Biology and Fertility of Soils 54(2). p.219-228
Abstract

Nutrients constrain the soil carbon cycle in tropical forests, but we lack knowledge on how these constraints vary within the soil microbial community. Here, we used in situ fertilization in a montane tropical forest and in two lowland tropical forests on contrasting soil types to test the principal hypothesis that there are different nutrient constraints to different groups of microorganisms during the decomposition of cellulose. We also tested the hypotheses that decomposers shift from nitrogen to phosphorus constraints from montane to lowland forests, respectively, and are further constrained by potassium and sodium deficiency in the western Amazon. Cellulose and nutrients (nitrogen, phosphorus, potassium, sodium, and combined) were... (More)

Nutrients constrain the soil carbon cycle in tropical forests, but we lack knowledge on how these constraints vary within the soil microbial community. Here, we used in situ fertilization in a montane tropical forest and in two lowland tropical forests on contrasting soil types to test the principal hypothesis that there are different nutrient constraints to different groups of microorganisms during the decomposition of cellulose. We also tested the hypotheses that decomposers shift from nitrogen to phosphorus constraints from montane to lowland forests, respectively, and are further constrained by potassium and sodium deficiency in the western Amazon. Cellulose and nutrients (nitrogen, phosphorus, potassium, sodium, and combined) were added to soils in situ, and microbial growth on cellulose (phospholipid fatty acids and ergosterol) and respiration were measured. Microbial growth on cellulose after single nutrient additions was highest following nitrogen addition for fungi, suggesting nitrogen as the primary limiting nutrient for cellulose decomposition. This was observed at all sites, with no clear shift in nutrient constraints to decomposition between lowland and montane sites. We also observed positive respiration and fungal growth responses to sodium and potassium addition at one of the lowland sites. However, when phosphorus was added, and especially when added in combination with other nutrients, bacterial growth was highest, suggesting that bacteria out-compete fungi for nitrogen where phosphorus is abundant. In summary, nitrogen constrains fungal growth and cellulose decomposition in both lowland and montane tropical forest soils, but additional nutrients may also be of critical importance in determining the balance between fungal and bacterial decomposition of cellulose.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Decomposition, Ecological stoichiometry, Phospholipid fatty acids, Soil carbon, Soil microorganisms, Tropical lowland forest, Tropical montane forest
in
Biology and Fertility of Soils
volume
54
issue
2
pages
219 - 228
publisher
Springer
external identifiers
  • scopus:85033376857
ISSN
0178-2762
DOI
10.1007/s00374-017-1247-4
language
English
LU publication?
yes
id
499f9be6-06e1-4b71-a179-944b4e8fd320
date added to LUP
2017-11-20 10:37:55
date last changed
2018-02-19 01:00:44
@article{499f9be6-06e1-4b71-a179-944b4e8fd320,
  abstract     = {<p>Nutrients constrain the soil carbon cycle in tropical forests, but we lack knowledge on how these constraints vary within the soil microbial community. Here, we used in situ fertilization in a montane tropical forest and in two lowland tropical forests on contrasting soil types to test the principal hypothesis that there are different nutrient constraints to different groups of microorganisms during the decomposition of cellulose. We also tested the hypotheses that decomposers shift from nitrogen to phosphorus constraints from montane to lowland forests, respectively, and are further constrained by potassium and sodium deficiency in the western Amazon. Cellulose and nutrients (nitrogen, phosphorus, potassium, sodium, and combined) were added to soils in situ, and microbial growth on cellulose (phospholipid fatty acids and ergosterol) and respiration were measured. Microbial growth on cellulose after single nutrient additions was highest following nitrogen addition for fungi, suggesting nitrogen as the primary limiting nutrient for cellulose decomposition. This was observed at all sites, with no clear shift in nutrient constraints to decomposition between lowland and montane sites. We also observed positive respiration and fungal growth responses to sodium and potassium addition at one of the lowland sites. However, when phosphorus was added, and especially when added in combination with other nutrients, bacterial growth was highest, suggesting that bacteria out-compete fungi for nitrogen where phosphorus is abundant. In summary, nitrogen constrains fungal growth and cellulose decomposition in both lowland and montane tropical forest soils, but additional nutrients may also be of critical importance in determining the balance between fungal and bacterial decomposition of cellulose.</p>},
  author       = {Nottingham, Andrew T. and Hicks, Lettice C. and Ccahuana, Adan J.Q. and Salinas, Norma and Bååth, Erland and Meir, Patrick},
  issn         = {0178-2762},
  keyword      = {Decomposition,Ecological stoichiometry,Phospholipid fatty acids,Soil carbon,Soil microorganisms,Tropical lowland forest,Tropical montane forest},
  language     = {eng},
  number       = {2},
  pages        = {219--228},
  publisher    = {Springer},
  series       = {Biology and Fertility of Soils},
  title        = {Nutrient limitations to bacterial and fungal growth during cellulose decomposition in tropical forest soils},
  url          = {http://dx.doi.org/10.1007/s00374-017-1247-4},
  volume       = {54},
  year         = {2018},
}