Testing the role of body size and litter depth on invertebrate diversity across six forests in North America

Abstract

Ecologists search for rules by which traits dictate the abundance and distribution of species. Here we search for rules that apply across three common taxa of litter invertebrates in six North American forests from Panama to Oregon. We use image analysis to quantify the abundance and body size distributions of mites, springtails, and spiders in 21 1-m 2 plots per forest. We contrast three hypotheses: two of which focus on trait-abundance relationships and a third linking abundance to species richness. Despite three orders of magnitude variation in size, the predicted negative relationship between mean body size and abundance per area occurred in only 18% of cases, never for large bodied taxa like spiders. We likewise found only 18% of tests supported our prediction that increasing litter depth allows for high abundance; two-thirds of which occurred at a single deciduous forest in Massachusetts. In contrast, invertebrate abundance constrained species richness 76% of the time. Our results suggest that body size and habitat volume in brown food webs are rarely good predictors of variation in abundance, but that variation in diversity is generally well predicted by abundance.

Community Structure of Epilithic Moss Mites and Their Response to Environmental Factors in Different Grades of Rocky Desertification Habitats

“…Scientific studies on mites first began in the late 19th and early 20th centuries and domestic studies in China began in the 1950s [12]. The study sites include North America [13], South America [14], Europe [15], Australia [16], South Africa [17], Russia [18] and China [19]. These study environments include broad-leaved forests [20], grasslands [21], deserts [22], farmlands [23], parks [24] and dwellings [25]; the study contents include mite community structure [26], species diversity and their interactions with habitat types [27], soil physical and chemical properties [28], climatic factors [29], heavy metal pollution [30] and land use practices [31].…”