When less means more: Reduction of both effort and survey methods boosts efficiency and diversity of harvestmen in a tropical forest

Marked compositional changes in harvestmen assemblages in Amazonian forest islands induced by a mega dam

“…Recent research also offered evidence for a relationship between number of palm trees and harvestmen assemblage composition in upland Amazonian forest (Tourinho et al, 2014;Colmenares et al, 2016;Porto et al, 2016). In previous studies in Amazon upland forests, most abundant harvestmen species were found mostly in trees (Colmenares Tourinho et al, 2014;Porto et al, 2016), being especially common in the accumulated litter at the base of the fronds in stemless and arborescent palms.…”

“…Recent research also offered evidence for a relationship between number of palm trees and harvestmen assemblage composition in upland Amazonian forest (Tourinho et al, 2014;Colmenares et al, 2016;Porto et al, 2016). In previous studies in Amazon upland forests, most abundant harvestmen species were found mostly in trees (Colmenares Tourinho et al, 2014;Porto et al, 2016), being especially common in the accumulated litter at the base of the fronds in stemless and arborescent palms. Fallen logs, roots, termite nests, and suspended litter at the base of trees and palm leaves are the habitats favored by harvestmen, providing ideal microclimatic conditions of humidity and temperature for their development (Mestre & Pinto-da-Rocha, 2004;Curtis & Machado, 2007;Curtis, 2007;Proud et al, 2012).…”

“…Between 2006 and 2008, we systematically sampled harvestmen assemblages (Fig. 2) using four 300-m 2 transects (30 m × 10 m) at each forest site, separated by 30 m, totalling 1,200 m 2 of transect area per site (see Tourinho et al, 2014, Porto et al, 2016. To avoid edge effects on islands, transects were established at least 250 m from the nearest forest edge.…”

“…Additionally, patterns of diversity in harvestmen assemblages are highly correlated with vegetation structure at meso and local scales, and are especially responsive to the presence of large old trees and palms in Amazonian forests (Colmenares et al, 2016;Tourinho et al, 2014, Porto et al, 2016. This occurs because palms increase habitat complexity at ground level, as a consequence of the fallen litter trapped within their leaves (Vasconcelos, 1990, Franken et al, 2013.…”

“…This occurs because palms increase habitat complexity at ground level, as a consequence of the fallen litter trapped within their leaves (Vasconcelos, 1990, Franken et al, 2013. Therefore, both palm and non-palm trees are directly responsible for the quality, depth and decomposition of the soil leaf-litter layer, which are a key microhabitat components affecting assemblages of small-bodied harvestmen species and other invertebrates (Tarli et al, 2014, Colmenares et al, 2016, Porto et al 2016.…”