Prepared by Dr. F. J. deNoyelles, University of Kansas (Department of Ecology and Evolutionary Biology, and Kansas Biological Survey)

Pond classifications: The pond types considered in this pilot project represent a variety of relationships between the aquatic and surrounding terrestrial environments. These relationships are important in terms of how each pond type influences terrestrial conditions or processes, both locally and collectively for a larger region. Influences include, but are not limited to: movement of nutrients and chemicals (nitrogen, phosphorus, carbon and pesticides); biocomplexity of the landscape; biodiversity across the landscape; and landscape-scale responses to climate or anthropogenic change. One of the objectives of this research project is to further clarify how the numbers, distributions, and characteristics of each pond type can affect local to regional conditions and processes, and thus to establish priorities for further study.

Four common types of artificial ponds are identified for this preliminary study, with characteristics summarized in Table X. These four types of ponds are distinguished by particular biological and ecological features with a strong relationship between pond condition and terrestrial condition, and by characteristics that can be distinguished by remote sensing over landscapes with high densities of ponds. The four types are identified on the basis of water column clarity and type/amount of aquatic vegetation: (1) low clarity, low vegetation, (2) high clarity, low vegetation, (3) high clarity, high vegetation as rooted or floating macrophytes, (4) high clarity, high vegetation as suspended or floating algae. These four conditions can be detected in ponds using various types of aerial remote sensing ranging from satellite based to low elevation aircraft, based on the reflectivity of the pond for particular wavelengths of light as influenced by clay/soil particles suspended in the water column or plant material of different structural types. If plant material dominates the reflectivity, its structure can be distinguished by the spatial pattern of reflectivity ranging from homogeneous over the pond surface for suspended microscopic algae to patchy for floating or emerging plants (either very coarse algal types or flowering plants). One of the objectives of this research is to determine how consistently these four pond types can be detected by remote sensing, based on ground‑truth verification.

Table X: Biological, Ecological, and Biogeochemical Pond Classifications
Type	Descriptive Characteristics	Functional Characteristics	Biodiversity & Biocomplexity
1	low water clarity, low vegetation,	Storage and throughput of allochthonous materials; sediment and C sink	low
2	high water clarity, low vegetation,	Minimal storage and throughput; effects on water cycle and terrestrial biota	low
3	high clarity, high vegetation (rooted/floating macrophytes)	Processing of C, N, P, chemicals; low sediment trapping, autochthonous C sink	moderate
4	high clarity, high vegetation (suspended/floating algae)	Highest processing of C, N, P, chemicals; low sed. trapping, autochthonous C sink	high

Type 1 ponds (low clarity, low vegetation) have greatly reduced sunlight for plant growth due to large amounts of particulate material suspended in the water column; they produce little vegetation, store some of the material entering, and pass through the rest with little biological processing or conversion. Type 2 ponds have adequate sunlight for plant growth but little growth; the movement of nutrients through the system must therefore be low, and the storage of biological carbon is minimal compared to type 3 and 4 ponds. Type 1 and 2 ponds also probably contribute less biodiversity to the landscape both directly (low internal species diversity) and indirectly (low external species moving through the system) compared to the type 3 and 4 ponds, unless their plant conditions were at the maximum (approaching a wetland condition).

Type 3 and 4 ponds contrast with type 1 and 2 ponds in terms of their influence on the landscape. Type 3 ponds must have both available sunlight and elevated nutrient inputs to support their biological activity, which will function to intercept and convert nutrients and organic compounds (e.g., pesticides) to other forms. They will contribute more to biodiversity and biocomplexity than type 1 and 2 ponds. Type 4 ponds are similar to type 3 ponds in having elevated plant growth, chemical conversions, and storage. However, the suspended or floating algae are more readily eaten by aquatic grazers, leading to more and faster conversions within the aquatic food chain, a more complex food chain, and the greatest biodiversity and biocomplexity. These preliminary and very general comparisons of the four pond types (summarized in Table X) are the conceptual starting point for further refining the influence of each of these pond types on the terrestrial landscape.

For some views of various types of ponds from multispectral aerial photography, click here.