Interannual variations in phosphorus content of semiarid grasslands over a long time period.
Mediterranean grasslands of the 'dehesa' ecosystem are characterized by strong annual and seasonal variations in biomass production and low fertility of the soil, particularly of phosphorus (P). Over a 19-year period (1987-2005), P content of 'dehesa' pastures in the province of Salamanca (westem Spain) was analysed. Herbage samples were collected from several sites along a topographic gradient that differentiated two types of herbaceous cornmunities on the upper and lower part of slopes. Phosphorus concentratíon in herbage ranged between 0.56-4.80 g kg'l DM in the upper zones, and between 0.56-3.50 g kg'\ DM in the lower ones. The mínimum mean P content was recorded in the lower zones in 1989 (1.42 g kg'\ DM), and the maxímum mean was recorded in the upper zone in 1988 (2.47 g kg'\ DM). Inter-annual variations in P content in herbage at different altitude ron paralleL Phosphorus content was significantly (P < 0.05) correlated with the proportion of botanical groups in the pasture but not with any climatic variable related to precipitation along the sampling years. Phosphorus in herbage was correlated with soíl characteristics in certain years.
| Main Authors: | , , , |
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| Format: | artículo biblioteca |
| Language: | English |
| Published: |
European Grassland Federation
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| Subjects: | Phosphorus, Long-term, Mediterranean pastures, Dehesa, |
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