Food choice of the Neotropical harvestman Erginulus clavotibialis (Opiliones: Laniatores: Cosmetidae)

Volume: 41Start Page: 219End Page: 22

Unraveling the Effects of Hurricane Maria on the Abundance and Composition of Harvestmen (Arachnida: Opiliones) Species Along an Elevational Gradient in Puerto …

Harvestmen exhibit substantial responses to environmental conditions, disturbances, and modifications of their habitat. We examined the abundance and species distribution of harvestmen along an elevational gradient in the Luquillo Experimental Forest (LEF) on Puerto Rico 6–12 weeks before and 9–10 months after Hurricane Maria passed over the island in September, 2017. This provided a unique opportunity to examine the effects of a major storm on litter-dwelling arthropod populations, as the storm led to a much greater abundance of leaf litter and downed branches. The abundance of harvestmen was measured in quadrat samples from 300 to 1,000 m elevation using Winkler samplers. We observed greater harvestmen abundance post-storm, which was similar to the results for most other arthropod groups. Pre-storm, harvestmen showed greater abundance in palm habitat, as compared to forests that were a mix of broadleaf and palm vegetation. Across all sampling periods, harvestmen were most abundant at low to medium elevations (300–600 m), especially for the two dominant taxa (Stygnomma spinula and Metacynortoides obscura obscura). Our findings are similar to results obtained from manipulative studies in the LEF several years prior to the hurricane. A challenge for the future is to understand the ways that the projected increase in storm severity due to climate change can affect various invertebrate groups such as harvestmen, and how tropical forests can remain resilient to such disturbances

A global database of nitrogen and phosphorous excretion rates of aquatic animals

Animals can be important in modulating ecosystem-level nutrient cycling, although their importance varies greatly among species and ecosystems. Nutrient cycling rates of individual animals represent valuable data for testing the predictions of important frameworks such as the Metabolic Theory of Ecology (MTE) and ecological stoichiometry (ES). They also represent an important set of functional traits that may reflect both environmental and phylogenetic influences. Over the past two decades, studies of animal-mediated nutrient cycling have increased dramatically, especially in aquatic ecosystems. Here we present a global compilation of aquatic animal nutrient excretion rates. The dataset includes 10,534 observations from freshwater and marine animals of N and/or P excretion rates. These observations represent 491 species, including most aquatic phyla. Coverage varies greatly among phyla and other taxonomic levels. The dataset includes information on animal body size, ambient temperature, taxonomic affiliations, and animal body N:P. This data set was used to test predictions of MTE and ES, as described in Vanni and McIntyre (2016; Ecology DOI: 10.1002/ecy.1582). © 2017 Ecological Society of Americ