quadrat

noun
  1. A square or rectangular plot of ground used as a unit of measurement in surveying or mapping, often for sampling or study purposes. noun
    The ecologists set up several quadrats to assess plant diversity in the meadow.
    Each quadrat measured 1 meter by 1 meter and was used to estimate the density of the grass species.
  2. A square or rectangular area marked out for scientific sampling or experimental purposes, especially in ecology or biology. noun
    Researchers placed quadrats randomly across the beach to study the distribution of shellfish.
    The biologist used a quadrat to count the number of insects on the plants within that designated area.