Climatic Conditions Drive the Abundance and Diversity of Spiders Community in an Atlantic Forest Fragment

Abstract

Spiders are very sensitive to variations in abiotic conditions. Here, we evaluated to what extent the variation in monthly rainfall and mean temperature can affect spiders community attributes. To this aim, we conducted an inventory of spiders species in a mixed ombrophilous forest fragment, using three different methods (beating tray, nocturnal manual collection and pitfall traps) over July 2010 and June 2011. The influence of monthly rainfall and mean temperature in spiders richness and abundance were evaluated using linear mixed models. We sampled 5,416 spiders belonging to 142 morphospecies and 28 families. These values were higher than those found in other studies conducted in temperate regions, and similar to those values found in tropical regions. Monthly mean temperature positively affected abundance and richness of adults, and negatively affected the abudance of immature spiders. Monthly rainfaill was negatively related to abundance of immature individuals. Species composition also differed between the hottest and coldest months. Our study helps us to understand the role of climatic conditions on spiders communities, and highlights that even small variations in these conditions can directly affect richness, abundance and species composition of spiders.

Flutuação populacional de aranhas na cultura da canola, em Passo Fundo, Rio Grande do Sul, Brasil

“…A comunidade de aranhas teve uma tendência de aumento populacional à medida que também houve uma tendência no aumento da temperatura (Figura 2). Semelhantemente ao encontrado no presente estudo, Pitilin et al (2019) constataram que, ao longo do período avaliado, o aumento gradativo da temperatura média mensal afetou positivamente a abundância de aranhas adultas coletadas. As precipitações, mesmo no mês mais chuvoso, não influenciaram na população das aranhas coletadas (Figura 2).…”

Seasonal changes in spider diversity in subtropical riparian forests: what drives the seasonality of the araneofauna?

“…Spiders are considered very sensitive to variations in abiotic conditions (Pitilin et al 2019; Baldissera et al 2020). However, we failed to find a clear pattern between spider diversity and abiotic conditions such as extreme (max and min) temperatures and rainfall.…”

“…Spiders play important ecological roles in a variety of terrestrial ecosystems, for example acting as predators, assuming the important function of maintaining population balance for a series of prey invertebrates (New 1999). Spiders in subtropical regions are recorded at all seasons and present high abundance throughout the year (Indrusiak & Kotzian 1998; Rodrigues 2005; Podgaiski et al 2007; Rinaldi & Trinca 2008; Campuzano et al 2019; Pitilin et al 2019; Baldissera et al 2020). However, they are thought to be more abundant during warmer periods of the year, when they would hunt most actively, avoiding adverse conditions of the colder periods (Arango et al 2000; Avalos et al 2007).…”

Drivers of the beta diversity of spider assemblages in southern Brazilian temporary wetlands

“…(), we selected two incidence‐based estimators with the best performances: Jackknife1 (first‐order) and Bootstrap. Taking into account the fact that many spider species can have seasonal patterns of distribution in subtropical and temperate regions (Baldissera et al ., ; Podgaiski et al ., ; Villanueva‐Bonilla et al ., ; Pitilin et al ., ), the outputs of the richness estimators should help us to assess the reliability of the sampling effort concentrated within a single season. The level of ‘completeness’ of the sampling effort was achieved by dividing the observed number of taxa by the estimated values calculated by the estimators.…”