Meiofauna in intermittent streams differ among watersheds subjected to five methods of timber harvest

Abstract

Meiofauna were collected from the pools of small (0 order) streams in the Ouachita National Forest, Arkansas to examine the impact of forest harvest methods. The study streams and their watersheds (2–6 ha) were located in 14–16 ha forest stands that were selected based on comparability of stands. Five treatment stands were paired with adjacent undisturbed reference stands (10 total). Treatment stands were subjected to one of five harvest methods, listed in order of decreasing severity of harvest disturbance to the stands: (1) clearcut; (2) pine seed-tree; (3) pine shelterwood; (4) pine-hardwood group selection; and (5) pine single-tree selection. Although the mean density of meiofauna collected in 22 l samples pumped from pools was low (1 No. l −1), significant differences were identified. Densities of total meiofauna, harpacticoid copepods, nauplii, ostracods and `other' meiofauna varied significantly by site and treatment (forest harvest). The highest densities of these taxa occurred at the single-tree treatment sites. Greater densities of meiofauna corresponded to greater diversity. The mean number of taxa per site was 11 with a range of 5–24. Rotifers, copepods, nematodes, ostracods and `other' meiofauna taxa were collected. The pattern of diversity of meiofauna at treatment sites from the least intensive (single-tree) to most intensive (clearcut) suggests a curve related to disturbance intensity.