Document: JAV-3-99-125

Understorey palm stemflow and throughfall in a Mexican Rainforest.

ALVAREZ-SÁNCHEZ, J.* and R.LEÓN-RICO

Universidad Nacional Autónoma de México 04510 México ¹

Abstract:
We partitioned rainfall received through canopy in a small plot in a mexican rainforest at the coast of the Gulf of Mexico to measure canopy throughfall and stemflow received. We randomly selected thirty two palms and the same quantity of places out of the palm cover under the forest canopy. Canopy throughfall was intercepted by the foliage of an abundant and efficient litter capturing understorey palm (Astrocaryum mexicanum Liebm, Arecaceae). Stemflow was measured by harness belts put around palm stems which finished in a bottle to capture stemflow. In in every plot we put one funnel with its bottle for canopy throughfall capture. Likewise, we put funnels in a gap to measure the total rainfall. Up to 25% of total rainfall was harnessed by the forest canopy. While in the palm areas, almost 30% of throughfall was concentrated by the funnel foliage. Under the palm cover, more than 45% of the gross precipitation was retained or deviate . We measured the nitrate, ammonium and phosphate content of this water flows. We found similar quantities of phosphate and ammonium content in both stemflow and throughfall, however, in stemflow water the nitrate content was higher than in throughfall water. Decomposition and mineralization that occurred over litter intercepted by the palm foliage increased significantly - the content of nitrate, and leaching by the water harnessing into the stemflow. Ammonium and phosphate solved in the rain partitions measured were produced by the rain deposition from the atmosphere.

Keywords: Mexican Rainforest

This abstract is being presented at: 8:15 AM in session:
Oral Session #41: N Dynamics: Additions, Retention and Transformations.