KELIMPAHAN DAN BIOMASSA CACING TANAH PADA LAHAN RUANG TERBUKA HIJAU (RTH) DALAM KAMPUS UNIVERSITAS RIAU, PEKANBARU

Abstract

The campus of Riau University is one of the most important green open spaces (“RTH”) in Pekanbaru. There are four different cover vegetation types in the campus:grass, shrub, single tree and trees. The purposes of this study were to examine the effect of different cover vegetation types on earthworm abundance and biomass and to analyze how underground factors influenced earthworm abundance and biomass in green open space. This study had been conducted from March-June 2013 within the campus of Riau University. Earthworm sampling was taken in 20 randomly-selected plots under each type of cover vegetation using a steel frame measuring 25 cm x 25 cm x 15 cm to a depth of 30 cm below the soil surface. The earthworms were counted and weighed alive. Environmental conditions in each plot were characterized by measuring soil temperature, soil water content, soil bulk density, root biomass, soil pH and soil texture. Results showed that cover vegetation type significantly influenced earthworms abundance and biomass (P<0.05). Earthworms were most abundant and had the largest biomass under trees (141.65 individuals/m2 and 40.99 g/m2). They were least abundant under shrub (75.20 individuals/m2) and had the smallest biomass under grass (12.83 g/m2). Results of principal component analysis (PCA) showed that soil pH gave the strongest influence on earthworm abundance and biomass compared to other underground factors under consideration in the campus of Riau University.