Change search
ReferencesLink to record
Permanent link

Direct link
Microbial responses to P addition in six South African forest soils
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
Department of Forest and Wood Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
Umeå University, Faculty of Science and Technology, Department of Chemistry.
Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden.
Show others and affiliations
2010 (English)In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 329, no 1/2, 209-225 p.Article in journal (Refereed) Published
Abstract [en]

Forests growing on highly weathered soils are often phosphorus (P) limited and competition between geochemical and biological sinks affects their soil P dynamics. In an attempt to elucidate the factors controlling the relative importance of these two sinks, we investigated the relationship of between soil microbial growth kinetics and soil chemical properties following amendments with C, N and P in six South African forest soils. Microbial growth kinetics were determined from respiration curves derived from measurements of CO2 effluxes from soil samples in laboratory incubations. We found that microbial growth rates after C + N additions were positively related to NaOH-extractable P and decreased with soil depth, whereas the lag time (the time between substrate addition and exponential growth) was negatively related to extractable P. However, the growth rate and lag time were unrelated to the soil’s sorption properties or Al and Fe contents. Our results indicate that at least some of the NaOH-extractable inorganic P may be biologically available within a relatively short time (days to weeks) and might be more labile than previously thought. Our results also show that microbial utilization of C + N only seemed to be constrained by P in the deeper part of the soil profiles.

Place, publisher, year, edition, pages
Springer , 2010. Vol. 329, no 1/2, 209-225 p.
Keyword [en]
Phosphorus availability, Microbial bioassay, Weathered soils, Soil respiration, Microbial growth rate, Hedley fractionation
National Category
Biological Sciences
URN: urn:nbn:se:umu:diva-33733DOI: 10.1007/s11104-009-0146-3ISI: 000275543300016OAI: diva2:317682
Available from: 2010-05-04 Created: 2010-05-04 Last updated: 2012-10-02Bibliographically approved
In thesis
1. Phosphorus availability and microbial respiration across biomes:  from plantation forest to tundra
Open this publication in new window or tab >>Phosphorus availability and microbial respiration across biomes:  from plantation forest to tundra
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Phosphorus is the main limiting nutrient for plant growth in large areas of the world and the availability of phosphorus to plants and microbes can be strongly affected by soil properties. Even though the phosphorus cycle has been studied extensively, much remains unknown about the key processes governing phosphorus availability in different environments.

In this thesis the complex dynamics of soil phosphorus and its availability were studied by relating various phosphorus fractions and soil characteristics to microbial respiration kinetics. The soils used represent a range of aluminium, iron, carbon and total phosphorus content, and were located in four different biomes: subtropical forest, warm temperate forest, boreal forest and tundra.

The results showed that NaOH extractable phosphorus, a fraction previously considered to be available to plants only over long time scales, can be accessed by microbes in days or weeks. Microbial phosphorus availability was not related to aluminium or iron content in any of the studied systems, not even in highly weathered soils with high aluminium and iron content. This is in contrast with other studies of soils with high sorption capacity and shows the variability of factors that govern phosphorus availability in different environments.

In the boreal forest chronosequence, no difference could be seen with age in total phosphorus content or concentrations of occluded phosphorus forms. However, there were lower concentrations of labile phosphorus forms in older systems, which were correlated with a decrease in microbial respiration. This was most likely related to organic matter quality in the system, and not to geochemical factors.

Phosphorus availability was linked to differences in topography (water regime) and vegetation in the tundra ecosystems. The results suggest that the availability of phosphorus, both for microbes and plants, was lower on the meadow vegetation sites compared to the two types of heath vegetation.

Many factors are important for phosphorus availability in soils, but these results suggest that microbes can access less available phosphorus if not restricted by carbon, and this may be important in regard to forest management practices as well as effects of environmental change.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2010. 32 + 4 papers p.
phosphorus availability, microbial bioassay, soil respiration, microbial growth rate, Hedley fractionation, soil sorption, weathered soils, boreal forest, subarctic and tundra
urn:nbn:se:umu:diva-33732 (URN)978-91-7264-989-1 (ISBN)
Public defence
2010-05-27, Institutet för Rymdfysik, Aulan, Rymdcampus 1, Kiruna, 09:00 (English)
Available from: 2010-05-06 Created: 2010-05-04 Last updated: 2010-05-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Esberg, CamillaOlsson, RickardGiesler, Reiner
By organisation
Department of Ecology and Environmental SciencesDepartment of Chemistry
In the same journal
Plant and Soil
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 113 hits
ReferencesLink to record
Permanent link

Direct link