Local distribution patterns of harvestmen (Arachnida: Opiliones) in a Northern temperate Biosphere Reserve landscape: influence of orientation and soil richness

Abstract

The study at a local scale of the fauna in a natural mountain landscape provides insights regarding the patterns and the factors influencing distribution. We test if each type of natural forest and some open habitats in the Muniellos Biosphere Reserve have their own unique harvestmen assemblages. We further investigate the presence of groups of sites sharing harvestmen assemblages and the factors and indicator species involved. Nineteen sites with well-known phytosociological association were sampled during nine surveys from late 2001 to 2002 by means of three sampling protocols. The quality of the inventories was assessed via the corresponding species accumulation curves. The cluster analysis using the Bray Curtis similarity index showed the presence of two main distinct groups of sites. One group consisted of seven lower forest sites, while the second group contained samples from more open sites and lighter forests. IndVal analyses show the first group has six characteristic species and the second group has one. ANOSIM analyses revealed that the harvestmen community composition was significantly different between the two clusters. Orientation appears to be one main driver of harvestmen assemblages on Mount Muniellos: a clear distinction between the two clusters appears along the boundary of shady to sunny habitats. The vegetal associations that house the higher harvestmen species richness have the higher soil richness. Seven rare and infrequent species were found in forests with richer soil.

Environmental drivers of harvestmen assemblages (Arachnida: Opiliones) from Neotropical rainforest landscapes

“…Among invertebrates, harvestmen have recently gained attention in conservation studies (e.g., Bragagnolo et al 2007; Merino‐Sáinz & Anadón 2018; Tourinho et al 2020) due to their low dispersion capacity (Pinto‐da‐Rocha et al 2005) and responses to habitat changes and environmental gradients, such as temperature and humidity (e.g., Andrade et al 2009; Nogueira et al 2019; Piñeiro‐Passos et al 2016). It is important to note that environmental variables can easily be linked to the vegetation structure (Merino‐Sáinz & Anadón 2015; Proud et al 2011; Stasiov et al 2017). Thus, it is plausible to think of synergistic effects between different scales (e.g., landscape and habitat) modulating the assemblage of harvestmen.…”

The influence of stand density on the structure of harvestmen communities (Opiliones) in a submountain beech forest

“…The community structure and diversity in harvestmen is influenced by diverse environmental factors; however, temperature and humidity are considered as the most important (Todd, 1949;Branquart et al, 1995;Gava, 2004;Almeida-Neto et al, 2006). These factors are decisively determined, either directly or indirectly by the type, structure and composition of vegetation (Merino-Sáinz and Anadón, 2015;Proud et al, 2011;Stašiov et al, 2017). There are lacking studies dealing with the impact of stand density on the structure of harvestmen communities.…”