Phosphorus Cycling in a Mexican Tropical Dry Forest Ecosystem

• Published in: Biogeochemistry Vol. 53; no. 2; pp. 161 - 179
• Main Authors: Campo, Julio, Maass, Manuel, Jaramillo, Víctor J., Martínez-Yrízar, Angelina, Sarukhán, José
• Format: Journal Article
• Language: English
• Published: Heidelberg Kluwer Academic Publishers 01.04.2001; Springer; Springer Nature B.V
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Dry forests; Earth sciences; Earth, ocean, space; Exact sciences and technology; Forest ecosystems; Forest soils; Freshwater; Fundamental and applied biological sciences. Psychology; Geochemistry; Mexico; Mineralogy; Phosphorus; Phosphorus content; Phosphorus cycle; Plantae; Rain; Silicates; Soils; Stormwater; Surficial geology; Synecology; Terrestrial ecosystems; Tropical forests; Tropical soils; Water geochemistry; Watersheds; Mexico; Mexico, Jalisco, Chamela; atmosphere; particulate matters; rainfall; geochemical cycle; accumulation; streams; runoff; concentration; rain water; North America; forests; drainage basins; fallout; ecosystems; dissolved materials; residence time; statistical analysis; soils; phosphorus
• ISSN: 0168-2563; 1573-515X
• DOI: 10.1023/a:1010663516029

The study was conducted in five contiguous small watersheds (12-28 ha) gauged for long-term ecosystem research. Five 80 × 30 m plots were used for the study. We quantified inputs from the atmosphere, dissolved and particulate-bound losses, throughfall and litterfall fluxes, standing crop litter and soil available P pools. Mean P input and output for a six-year period was 0.16 and 0.06 kg·ha-1· yr-1, respectively. Phosphorus concentration increased as rainfall moved through the canopy. Annual P returns in litterfall (3.88 kg/ha) represented more than 90% of the total aboveground nutrient return to the forest floor. Phosphorus concentration in standing litter (0.08%) was lower than that in litterfall (0.11%). Phosphorus content in the litterfall was higher at Chamela than at other tropical dry forests. Mean residence time on the forest floor was 1.2 yr for P and 1.3 yr for organic matter. Together these results suggest that the forest at Chamela may not be limited by P availability and suggest a balance between P immobilization and uptake. Comparison of P losses in stream water with input rates from the atmosphere for the six-year period showed that inputs were higher than outputs. Balances calculated for a wet and a dry year indicated a small P accumulation in both years.