The role of clumped defecation in the spatial distribution of soil nutrients and the availability of nutrients for plant uptake.

摘要

In this study, soil nutrient content and nutrient availability were determined along two transects located on small (<=1 ha) land-bridge islands in Lake Guri, Venezuela, each of which crossed an established latrine of howler monkeys (Alouatta seniculus). Fine root biomass along the two transects was also determined to determine if plants are in fact utilizing the nutrients made available through the latrine piles. It was found that the concentration of both total N and bicarbonate extractable P in the clay-rich Oxisols underlying the two latrines was substantially higher than in the soil collected at other sample sites. In addition to high soil nutrient concentrations under the latrines, high levels in the availability of N and P for plant uptake were also observed. Finally, results indicate that fine-root biomass responds to the high concentrations of soil nutrients in the howler monkey latrines. In one of the transects, the mass of fine roots was 1.3 times greater in the latrine than in the other sample sites; in the other transect, fine root biomass in the latrine was almost twice than that found outside of the latrine (1.8 times greater). While the findings of this preliminary study are based on a very small sample size, the results clearly support the hypothesis that habitual latrine sites are associated with localized soil nutrient enrichment..