With a surface area of up to 100 km², the diversity of small permanent lakes, ponds and pools depends on their size, depth and connectivity. Littoral vegetation and benthic energy pathways are critical to productivity and food web complexity. Deep lakes have plankton, supporting fish, birds and frogs, in different habitats of the lake. Shallow lakes are often more productive, providing breeding habitat for birds, frogs and reptiles, but limited buffering against nutrient inputs may result in regime shifts between alternative stable states dominated either by large aquatic plants or phytoplankton.