Distribution of throughfall and stemflow in multi-strata agroforestry, perennial monoculture, fallow and primary forest in central Amazonia, Brazil

Abstract

The partitioning of rain water into throughfall, stem¯ow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of dierent plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes in¯uence not only the water availability for the plants, but also water in®ltration and nutrient leaching, the understanding of plant eects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stem¯ow in a perennial polyculture (multi-strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuacË u (Theobroma grandi¯orum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The eect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stem¯ow, diered signi®cantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was signi®cantly higher than the open-area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with signi®cantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6 . 4% in the polyculture, 13 . 9 and 12 . 3% in the peach palm monocultures for fruit and for palmito, respectively, 0 . 5% in the cupuacË u monoculture and 3 . 1% in the fallow. With more than 20% of the open-area rainfall, the highest stem¯ow contributions to the water input into the soil were measured in the palm monocultures and in the fallow.

Energy dynamics and modeled evapotranspiration from a wet tropical forest in Costa Rica

“…The stemflow component of interception was ignored because it was assumed to be a small volumetric flux, i.e. !2% of rain (Schroth et al, 1999;Neal et al, 1993). The canopy conditions were modeled as either completely wet or completely dry for any 30 min period .…”

Variability of throughfall volume and solute inputs in wooded ecosystems

“…Hydrologists have demonstrated that species composition does have a detectable and substantial impact on throughfall amounts (Mahendrappa, 1989;Brown and Iles, 1991;Cape et al, 1991;Thimonier, 1998;Schroth et al, 1999;Lilienfein and Wilcke, 2004). At Devilla Forest, in northern Britain, Cape et al (1991) found that throughfall varied substantially between Pinus sylvestris L. (Scots pine) and Larix decidua L. (larch) over two successive years of measurement using a series of fixed gauges.…”

Rainfall interception and spatial distribution of throughfall in a pine forest planted in an arid zone

“…stem diameter, crown geometry). We are therefore forced to ascribe, as were Schroth et al, 1999Schroth et al, ,2001 the difference in stemflow yields among trees to undefined structural variables in the canopy.…”