Definition of quadrat in US English:



  • 1Each of a number of small areas of habitat, typically of one square meter, selected at random to act as samples for assessing the local distribution of plants or animals.

    • ‘Territory quadrats were the vegetation quadrats sampled at the center of each of 88 territories.’
    • ‘For every nightly census, a minimum of three and a maximum of 21 quadrats were sampled.’
    • ‘Nonuse quadrats were the 413 vegetation quadrats that fell outside of territories.’
    • ‘Forest quadrats showed a less pronounced seasonal decline in light availability.’
    • ‘A total of 199 quadrats were sampled in closed canopy areas.’
    1. 1.1 A portable frame, typically with an internal grid, used to mark out a quadrat.
      • ‘Canopy cover was dominated by Quercus macrocarpa with a relative frequency of 63% of quadrats with a wooded canopy.’
      • ‘Percent cover of each species in the herb stratum was estimated visually using a portable 1 X 1 m quadrat with 1 dm graduations.’
      • ‘A plastic grid with 25 small quadrats (each corresponding to 4% of the total cover) was used.’


Early 20th century: variant of quadrate.