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About La Selva Biological Station
Nematode Survey
Maps of the region
Sampling Protocols
Sampling was done one time, during the late dry- early wet season at La Selva Biological Station, Costa Rica. Samples were taken along the ALAS transect.
At each sampling point, nematodes were collected at four vertical positions: soil, litter, subcanopy (5 cm to 2.5 m, ground vegetation, shrubs and short trees and their epiphytes) and arboreal (>2.5 m, including epiphytes). Within each site, sampling was done within an area circumscribed by four canopy and four subcanopy or understory trees that were dominant or typical of the forest type. 
Soil sample: a composite sample made up of eight subsamples of mineral soil (0-20 cm) collected with a narrow shovel near and between each tree base. The composite sample was mixed thoroughly and a portion removed for soil chemical analysis.
soil sample collection
Litter sample: a composite sample made up of eight subsamples collected using a similar approach, incorporating the entire depth of duff. 

Subcanopy sample: a composite sample including a mixture of subsamples from three height catagories (bottom, middle and top one-third) in each tree habitat. 

Canopy sample: each canopy sample is based on collection of all vascular and non-vascular plants and plant debris inside a 15 x 15 cm frame. 

  Insect sample:The order Isoptera (termites) was chosen as a focal group for assessing nematode diversity in association with invertebrates. “Time trial sampling” was done by two scientists with a 20 minute timed harvest of termite colonies within each of four 5-m-radius sampling areas per transect point. Cockroaches were also sampled for nematode associates at each of the sites along the transect. In addition, Ficus species (figs) at the La Selva station were sampled for nematodes associated with their Agaonidae (fig wasp) pollinators. Live nematodes were collected for DNA samples for genotyping. Voucher insects were retained for identification. 
insect trap
Entompathogenic nematode baiting: Soil, litter, and subcanopy subsamples were used for a standard Galleria (waxmoth) bioassay to recover and identify entomopathogenic nematodes from these substrates.