The Relationship in Lake Communities Between Primary Productivity and Species Richness

Abstract

An understanding of the relationship between species richness and productivity is crucial to understanding biodiversity in lakes. We investigated the relationship between the primary productivity of lake ecosystems and the number of species for lacustrine phytoplankton, rotifers, cladocerans, copepods, macrophytes, and fish. Our study includes two parts: (1) a survey of 33 well‐studied lakes for which data on six major taxonomic groups were available; and (2) a comparison of the effects of short‐ and long‐term whole‐lake nutrient addition on primary productivity and planktonic species richness. In the survey, species richness of all six taxa showed a significant quadratic response to increased annual primary productivity (14C estimate, g C·m−2·yr−1) when lake area is taken into account. However, the richness–productivity relationship for phytoplankton and fish was strongly dependent on lake area. The relationship for phytoplankton, rotifers, cladocerans, copepods, and macrophytes was significantly unimodal. Species richness generally peaked at levels of primary productivity in the range of 30–300 g C·m−2·yr−1. For the average lake size, the highest biodiversity tended to occur in lakes with relatively low primary productivity, such as those found in the Northern Temperate Lakes Long‐Term Ecological Research (LTER) site in the upper Midwest (United States) and in the Experimental Lakes Area of Ontario (Canada). Based on short‐term (3 yr) and long‐term (21–24 yr) experiments, we tested whether individual lakes respond to whole‐lake enrichment experiments in the manner suggested by analyses of survey data. Experimental addition of nutrients produced varied and unpredictable responses in species richness, probably due to transient dynamics and time lags. Responses to nutrient addition were taxon and lake specific. Phytoplankton showed a variety of relationships between species richness and pelagic primary productivity (PPR), depending on the history of enrichment and recovery. No significant effect of primary productivity on rotifer richness occurred in any of the experimental lakes, whereas richness of crustacean zooplankton was negatively correlated with primary productivity in both the short‐ and long‐term experiments.

Interactive effects of chemical and biological controls on food-web composition in saline prairie lakes

“…Interestingly, greater species richness and population abundances were observed in lakes of lower nutrient levels but higher Chl a concentrations, whereby Chl a and nutrients were generally uncorrelated among lakes (except the positive association of TKN and Chl a , see above). This finding contrasts with prior research suggesting maximum species richness at intermediate productivity [71]. Furthermore, the previous survey by [13] identified a negative association between zooplankton richness and Chl a .…”

Estimating the effects of excess nutrients on stream invertebrates from observational data

“…Long-term nitrogen loading decreases plant species richness (Tilman 1987) and insect richness (Haddad et al 2000) in grasslands. In lakes, a unimodal relationship is often observed between primary productivity and species richness (Dodson et al 2000), and differences in nutrient availability may cause many of these variations in primary productivity (Smith 1979). In estuaries, increased nutrient loading has also been associated with decreased benthic invertebrate richness (Valiela et al 1992).…”

“…For example, in grasslands, long-term nutrient enrichment can reduce plant and insect richness (Tilman 1987, Haddad et al 2000. Similarly, manipulations of nutrient concentrations in lakes have revealed negative associations between nutrient concentrations and phytoplankton richness (Dodson et al 2000).…”

“…Human activities have greatly intensified the release of nitrogen and phosphorus in the environment (Vitousek et al 1997, Smil 2000, Bennett et al 2001, and these nutrients have altered species richness in many ecosystems (Tilman 1987, Valiela 1992, Dodson et al 2000. In streams and rivers increased nutrients have markedly changed stream biological community structure and function.…”

The Response of Zooplankton Communities in Montane Lakes of Different Fish Stocking Histories to Atmospheric Nitrogen Deposition Simulations

“…Zooplankton richness has been previously shown to increase in response to nutrients in low productivity systems, which shift to an intermediate level of productivity when more resources are added to the system (Dodson et al 2000). Both H. gibberum and H.…”