Soil microarthropods in reforested area of dipterocarpus seedlings at different stages

Abstract

The diversity and abundance of soil microarthropods and physical and biological factors had been evaluated in 1-year and 2-year reforested areas planted with dipterocarpus seedlings inoculated with ectomycorrhizae and a non-reforested area at Chulalongkorn University Area, Saraburi Province, Thailand. Soil microarthropods were extracted with Berlese-Tullgren funnels from monthly collected soil samples from October 2014 to October 2015. The total abundance of soil microarthropods was highest in the 2-year dipterocarpus reforestation area (3,596 ± 227 ind./m2), followed by the 1-year reforestation area (2,989 ± 334 ind./m2) and the non-reforested area (2,496 ± 361 ind./m2), respectively (F = 1.988, df = 2, 73, p = 0.051). Mites (74-83%) and collembolans (15-21%) were the most abundant groups from the nine groups of collected soil microarthropods in all three areas. Symphylans, spirobilids, geophilomorphs and proturans were more abundant in the reforestation areas than the non-reforested area, while pseudoscorpions were most abundant in the non-reforested area. Detrito-fungivorous microarthropods were the most abundant guild in all three areas, followed by predatory arthropods and detritivore microarthropods. Diversity index of soil microarthropods at morphospecies level was lowest in the non-reforested area (H/ = 0.85) when compared to the 1-year reforestation area (H/ = 0.92) and the 2-year reforestation area (H/ = 0.93). Soil moisture was significantly different in three areas (F = 93.602, df = 2, 33, p < 0.001), and was highest in the 2-year dipterocarpus reforestation area, followed by the 1-year reforestation area and the non-reforested area, respectively. However, soil microarthropods were positively correlated with soil moisture only in the non-reforested area (r = 0.752, p = 0.003). This study shows that increasing age progression of seedling affected several environmental factors, particularly soil moisture, which in turn relate to an increasing trend of the diversity and abundance of soil microarthropods.