SPECIES COMPOSITION OF ROOT-FEEDING MACROARTHROPODS IN A SUB-ALPINE GRASSLAND ASSOCIATED WITH PINE FOREST IN MEXICO

Below-ground herbivores have been poorly studied regardless of their i mportance for the establishment and composition of plant communities. In a subalpine grassland associated with a 3200-m-elevation pine fores t in central Mexico, the composition and vertical and horizontal distr ibution of the macroarthropod root-feeding community was studied for 1 4 months. The root-feeding community included six species of Coleopter a and one species of Diptera. The dominant species were Phyllophaga sp p, (subgenus Phytallus, ''macrophylla'' group) and Trachyploeomimus af f, spurcus Champion. Mean density and biomass of this community were 1 01 individuals and 3 g per square metre, respectively. These values we re low when compared with those reported for other communities. Specie s were most abundant in the first 10 cm of the soil all year around. D ominant species showed a clumped horizontal distribution most of the y ear.