Achieving Bio-Protection in New Zealand Ecosystems mesocosm data

We established 160 experimental ecosystems (mesocosms), manipulated
interactions between plants, soil biota and invertebrate herbivores in a
fully factorial design. Each mesocosm was grown in a 125 L pot (575 mm
diameter, Fig. 1B), and comprised one of 20 unique, eight-species plant
communities varying orthogonally in the proportion of exotic and woody
shrub/tree species (0-100% and 0-63%, respectively). These plants were
taken from a pool of 20 exotic and 19 native/endemic New Zealand plant
species. Soil biota were manipulated using a modified plant-soil feedback
approach, where each plant species was grown in monoculture in 10 L pots
containing field-collected soil for 9-10 months, allowing the conditioning
of typical associated soil biota for each of the plant species. We created
‘home’ soils by taking the conditioned soil from each of the eight
representative species in a mesocosm and mixing it together to create a
single inoculum. Each ‘home’ soil mixture was also used as an ‘away soil’
in a different mesocosm that did not contain any of the representative
plants in that inoculum. These soils were intended to increase the
relative biomass in inocula of specialized and preferred interaction
partners of the resident (or non-resident) plant species. Invertebrate
insect herbivore populations were added into half of the mesocosms with
home soils and half with away soils. Thirteen invertebrate herbivore
species introduced into the mesocosms successfully established, along with
seven self-colonizing species, totaling 20 species in all. All mesocosms
were sealed with mesh cages (15% shade factor) designed to retain added
herbivores and exclude others from entering. In each mesocosm, we measured
distinct ecosystem properties and processes that are relevant to carbon
cycling dynamics: above and belowground biomass; total in situ soil
respiration; basal respiration; microbial biomass (measured as
substrate-induced respiration); decomposition (rate of standardized
substrate mass loss); soil organic matter; nitrogen availability;
herbivore biomass; arbuscular mycorrhizal and other fungal biomass (using
neutral- and phospho-lipid fatty acid [NLFA and PLFA] biomarkers,
respectively); and bacterial biomass (PLFA).