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Unexprected changes in soil phosphorus dynamics following tropical deforestation to cattle pasture
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Asner, Gregory P. Bustamante, Mercedes M. C. Townsend, Alan R. Lefer, Margaret E. Cleveland, Cory C. |
| Copyright Year | 2001 |
| Description | Phosphorus (P) is widely believed to limit plant growth and organic matter storage in a large fraction of the world's lowland tropical rainforests. We investigated how the most common land use change in such forests, conversion to cattle pasture, affects soil P fractions along forest to pasture chronosequences in the central Brazilian Amazon and in southwestern Costa Rica. Our sites represent a broad range in rainfall, soil type, management strategies, and total soil P (45.2 - 1228.0 microng P / g soil), yet we found some unexpected and at times strikingly similar changes in soil P in all sites. In the Brazilian sites, where rainfall is relatively low and pasture management is more intense than in the Costa Rican sites, significant losses in total soil P and soil organic carbon (SOC) were seen with pasture age on both fine-textured oxisol and highly sandy entisol soils. However, P losses were largely from occluded, inorganic soil P fractions, while organic forms of soil P remained constant or increased with pasture age, despite the declines in SOC. In Costa Rica, SOC remained constant across the oxisol sites and increased from forest to pasture on the mollisols, while total soil P increased with pasture age in both sequences. The increases in total soil P were largely due to changes in organic P; occluded soil P increased only slightly in the mollisols, and remained unchanged in the older oxisols. We suggest that changes in the composition and/or the primary limiting resources of the soil microbial community may drive the changes in organic P. We also present a new conceptual model for changes in soil P following deforestation to cattle pasture. |
| File Size | 1249709 |
| Page Count | 46 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20010048006 |
| Archival Resource Key | ark:/13960/t3cz85g21 |
| Language | English |
| Publisher Date | 2001-01-01 |
| Access Restriction | Open |
| Subject Keyword | Environment Pollution Deforestation Amazon Region South America Grasslands Forests Organic Materials Phosphorus Carbon Land Use Tropical Regions Microorganisms Cattle Chronology Costa Rica Sequencing Rain Forests Vegetation Growth Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
