EcoDiv Lab

About the lab

Featured projects (3)

We aim to investigate invasive predator effects on emerging belowground arthropods in forest remnants of differing sizes and the resulting influence on recruitment of belowground arthropods to soil communities in adjacent pasture. In this vein, we will quantify the top-down control of invasive predators on insectivorous birds and the cascading effects on belowground arthropods (both emerging from soil and living in the litter layer), as well as the direct top-down effects of invasive predators on belowground arthropods. Moreover, we will assess the indirect effects of mammalian predators in forest reserves on belowground ecosystem processes provided by soil food webs, both within forest remnants and in directly adjacent pasture.
The Jena Experiment is one of the longest-running biodiversity experiments in Europe. We have been studying biodiversity effects in experimental grassland communities for more than 10 years. This coordinated investigation of above-ground and below-ground consumers and processes, includes a full quantification of the most important element cycles, which will be used to unravel the mechanisms underlying biodiversity effects on ecosystem functioning.

Featured research (21)

Arthropod herbivores cause substantial economic costs that drive an increasing need to develop environmentally sustainable approaches to herbivore control. Increasing plant diversity is expected to limit herbivory by altering plant-herbivore and predator-herbivore interactions, but the simultaneous influence of these interactions on herbivore impacts remains unexplored. We compiled 487 arthropod food webs in two long-running grassland biodiversity experiments in Europe and North America to investigate whether and how increasing plant diversity can reduce the impacts of herbivores on plants. We show that plants lose just under half as much energy to arthropod herbivores when in high-diversity mixtures versus monocultures and reveal that plant diversity decreases effects of herbivores on plants by simultaneously benefiting predators and reducing average herbivore food quality. These findings demonstrate that conserving plant diversity is crucial for maintaining interactions in food webs that provide natural control of herbivore pests.
Seven species of springtail (Collembola) are present in Victoria Land, Antarctica and all have now been sequenced at the DNA barcoding region of the mitochondrial cytochrome c oxidase subunit I gene (COI). Here, we review these sequence data (n = 930) from the GenBank and Barcode of Life Datasystems (BOLD) online databases and provide additional, previously unpublished sequences (n = 392) to assess the geographic distribution of COI variants across all species. Four species (Kaylathalia klovstadi, Cryptopygus cisantarcticus, Friesea grisea, and Cryptopygus terranovus) are restricted to northern Victoria Land and three (Antarcticinella monoculata, Cryptopygus nivicolus, and Gomphiocephalus hodgsoni) are found only in southern Victoria Land, the two biogeographic zones which are separated by the vicinity of the Drygalski Ice Tongue. We found highly divergent lineages within all seven species (range 1.7–14.7%) corresponding to different geographic locations. Levels of genetic divergence for the southern Victoria Land species G. hodgsoni, the most widespread species (~27,000 km2), ranged from 5.9 to 7.3% divergence at sites located within 30 km, but separated by glaciers. We also found that the spatial patterns of genetic divergence differed between species. For example, levels of divergence were much higher for C. terranovus (>10%) than for F. grisea (<0.2%) that had been collected from the same sites in northern Victoria Land. Glaciers have been suggested to be major barriers to dispersal and two species (C. cisantarcticus and F. grisea) showed highly divergent (>5%) populations and over 87% of the total genetic variation (based on AMOVA) on either side of a single, 16 km width glacier. Collectively, these data provide evidence for limited dispersal opportunities among populations of springtails due to geological and glaciological barriers (e.g., glaciers and ice tongues). Some locations harbored highly genetically divergent populations and these areas are highlighted from a conservation perspective such as avoidance of human-mediated transport between sites. We conclude that species-specific spatial and temporal scales need to be considered when addressing ecological and physiological questions as well as conservation strategies for Antarctic Collembola.
The ecological implications of body size extend from the biology of individual organisms to ecosystem-level processes. Measuring body mass for high numbers of invertebrates can be logistically challenging, making length-mass regressions useful for predicting body mass with minimal effort. However, standardized sets of scaling relationships covering a large range in body length, taxonomic groups, and multiple geographical regions are scarce. We collected 6,212 arthropods from 19 higher-level taxa in both temperate and tropical locations to compile a comprehensive set of linear models relating live body mass to a range of predictor variables. We measured live weight (hereafter, body mass), body length and width of each individual and conducted linear regressions to predict body mass using body length, body width, taxo-nomic group, and geographic region. Additionally, we quantified prediction discrepancy when using parameters from arthropods of a different geographic region. Incorporating body width into taxon-and region-specific length-mass regressions yielded the highest prediction accuracy for body mass. Using regression parameters from a different geographic region increased prediction discrepancy, causing over-or underestimation of body mass depending on geographical origin and whether body width was included. We present a comprehensive range of parameters for predicting arthropod body mass and provide guidance for selecting optimal scaling relationships. Given the importance of body mass for functional invertebrate ecology and the paucity of adequate regressions to predict arthropod body mass from different geographical regions, our study provides a long-needed resource for quantifying live body mass in invertebrate ecology research. K E Y W O R D S allometric scaling, body size, insects, invertebrates, length-mass regression

Lab head

Andrew D. Barnes
About Andrew D. Barnes
  • I am broadly interested in the impacts of global change drivers on natural systems and the resulting functional consequences. In particular, my research is aimed at exploring how environmental changes can alter the seemingly complex relationships between biodiversity, the structure of communities, biotic interactions, and ecosystem functioning.

Members (4)

Fevziye Hasan
  • The University of Waikato
Nigel Binks
  • The University of Waikato
Rene Devenish
  • The University of Waikato
Grace Mitchell
  • The University of Waikato