Which estimate method uses nested grids for sampling immobile species?
Quadrat sampling estimates abundance or density by placing frames or grid cells of known area and counting organisms within them. It is especially appropriate for immobile or slow-moving species such as plants, corals, barnacles, and many soil organisms because individuals remain associated with a sampling unit during observation. Nested quadrats place progressively larger frames around the same point or subdivide a larger grid, allowing investigators to examine species–area relationships, choose an efficient quadrat size, or measure pattern at multiple scales. A line transect records organism
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 9
