What term describes a square frame of known area used for sampling the abundance of slow or non-moving organisms?

The term that describes a square frame of known area used for sampling the abundance of slow or non-moving organisms is a quadrat. Quadrats are commonly employed in ecological studies to estimate the distribution and abundance of species in a particular area. By placing these frames on the ground and counting the organisms within them, researchers can gather quantitative data about various species and their habitats. This method is particularly effective for studying plants and stationary animals, where movement doesn't complicate the data collection process.

Other potential terms like transect, sample plot, or sampling frame refer to different methods or concepts in ecological research. For example, a transect is a straight line or path along which ecological measurements are taken, focusing on observing changes in species composition over a distance. A sample plot could suggest a temporary area for studying a larger plot but isn't specifically defined as a square frame. A sampling frame typically refers more broadly to a defined area for selecting samples rather than the specific square frame utilized in quadrat sampling. Thus, quadrat is the most precise term for this method of ecological sampling.