RESOURCE LIMITATION IN A STREAM COMMUNITY: PHOSPHORUS ENRICHMENT EFFECTS ON PERIPHYTON AND GRAZERS'

A field experiment was used to test whether stream periphyton was nutrient limited, and if so, whether the grazing insects that consumed this resource were food limited. Eight replicate wooden flumes were placed in an unshaded riffle in Augusta Creek, a third- order, hardwater trout stream in southwestern Michigan (USA). Phosphorus, in the form of Ca(H2PO4)2, was added to four of these flumes for 105 d. The average concentration of soluble reactive phosphorus (SRP) maintained in P-enriched flumes (85 ,g/L) was >5 times as great as in control flumes (15 jug/L). After 77 d of nutrient enrichment, periphyton biomass per unit area on substrates with reduced grazer densities was 1.8 x as great in P-enriched flumes as in control flumes. The larvae of two species of grazing caddisflies (Leucotrichia pictipes and Psychomyia flavida) in P-enriched flumes also had higher individual mass, developmental rates, and population densities. These responses resulted in standing crops of final-instar larvae in P-enriched flumes that were 2.1 x and 1.5 x as great as those in control flumes for Psy- chomyia and Leucotrichia, respectively. This demonstration of food limitation supplements previous behavioral studies showing that both grazer species aggressively defend feeding territories, and contributes to a growing body of evidence suggesting that resource limitation is more important in some stream food webs than previously recognized. Resource limitation of these grazer populations may be due in part to the rarity of catastrophic flooding and drying in Augusta Creek. Such stable flows could permit consumer populations to reach higher densities than in frequently disturbed streams.

[1]  S. Fretwell,et al.  The Regulation of Plant Communities by the Food Chains Exploiting Them , 2015 .

[2]  N. LeRoy Poff,et al.  Implications of Streamflow Variability and Predictability for Lotic Community Structure: A Regional Analysis of Streamflow Patterns , 1989 .

[3]  Arthur V. Brown,et al.  The Role of Disturbance in Stream Ecology , 1988, Journal of the North American Benthological Society.

[4]  A. Hershey,et al.  Nutrient Incluence on a Stream Grazer: Orthocladius Microcommunities Respond to Nutrient Input , 1988 .

[5]  W. Hill,et al.  Experimental Analysis of the Grazing Interaction Between a Mayfly and Stream Algae. , 1987, Ecology.

[6]  R. Wetzel,et al.  Boundary-layer and internal diffusion effects on phosphorus fluxes in lake periphyton1 , 1987 .

[7]  G. Minshall,et al.  Effects of Disturbance Frequency on Stream Benthic Community Structure in Relation to Canopy Cover and Season , 1986, Journal of the North American Benthological Society.

[8]  J. Webster,et al.  Periphyton Response to Nutrient Manipulation in Streams Draining Clearcut and Forested Watersheds , 1986, Journal of the North American Benthological Society.

[9]  S. D. Cooper,et al.  Effects of Macroalgae on a Stream Invertebrate Community , 1986, Journal of the North American Benthological Society.

[10]  S. Fisher,et al.  Nitrogen Limitation in a Sonoran Desert Stream , 1986, Journal of the North American Benthological Society.

[11]  A. Hershey,et al.  Transformation of a Tundra River from Heterotrophy to Autotrophy by Addition of Phosphorus , 1985, Science.

[12]  M. Bothwell.  Phosphorus limitation of lotic periphyton growth rates: An intersite comparison using continuous‐flow troughs (Thompson River system, British Columbia)1 , 1985 .

[13]  D. Hart.  Grazing insects mediate algal interactions in a stream benthic community , 1985 .

[14]  D. Strong.  3. Exorcising the Ghost of Competition Past: Phytophagous Insects , 1984 .

[15]  J. McAuliffe.  Competition for Space, Disturbance, and the Structure of a Benthic Stream Community , 1984 .

[16]  J. McAuliffe.  Resource depression by a stream herbivore: effects on distributions and abundances of other grazers , 1984 .

[17]  S. Hurlbert.  Pseudoreplication and the Design of Ecological Field Experiments , 1984 .

[18]  S. Mckinnell,et al.  Responses of stream zoobenthos to enrichment of gravel substrates with cereal grain and soybean , 1983 .

[19]  J. Hobbie,et al.  A continuous‐flow periphyton bioassay: Tests of nutrient limitation in a tundra stream1 , 1983 .

[20]  T. Schoener.  The Controversy over Interspecific Competition , 1982 .

[21]  S. R. Reice.  Interspecific Associations in a Woodland Stream , 1981 .

[22]  W. K. Kellogg,et al.  Foraging and resource patchiness: field experiments with a grazing stream insect , 1981 .

[23]  S. L. Loeb.  An in situ method for measuring the primary productivity and standing crop of the epilithic periphyton community in lentic systems1 , 1981 .

[24]  J. Newbold,et al.  The Limiting Role of Phosphorus in a Woodland Stream Ecosystem: Effects of P Enrichment on Leaf Decomposition and Primary Producers , 1981 .

[25]  Martin L. Cody,et al.  Habitat Selection in Birds: The Roles of Vegetation Structure, Competitors, and Productivity , 1981 .

[26]  G. Rhee,et al.  OPTIMUM N:P RATIOS AND COEXISTENCE OF PLANKTONIC ALGAE 1 , 1980 .

[27]  J. Thomson.  Implications of Different Sorts of Evidence for Competition , 1980, The American Naturalist.

[28]  M. Lock,et al.  The effect of flow patterns on uptake of phosphorus by river periphyton , 1979 .

[29]  J. Diamond.  Niche Shifts and the Rediscovery of Interspecific Competition , 1978 .

[30]  B. Menge,et al.  Species Diversity Gradients: Synthesis of the Roles of Predation, Competition, and Temporal Heterogeneity , 1976, The American Naturalist.

[31]  Robert K. Colwell,et al.  PREDICTABILITY, CONSTANCY, AND CONTINGENCY OF PERIODIC PHENOMENA' , 1974 .

[32]  B. Manny,et al.  Diurnal changes in dissolved organic and inorganic carbon and nitrogen in a hardwater stream , 1973 .

[33]  H. B. N. Hynes,et al.  The Ecology of Running Waters , 1971 .

[34]  S. Fretwell,et al.  On territorial behavior and other factors influencing habitat distribution in birds , 1969 .

[35]  L. Slobodkin,et al.  Community Structure, Population Control, and Competition , 1960, The American Naturalist.

[36]  L. Birch,et al.  The Meanings of Competition , 1957, The American Naturalist.

[37]  A. G. Huntsman.  Fertility and Fertilization of Streams , 1948 .

[38]  W. Hill,et al.  Concurrent grazing effects of two stream insects on periphyton1 , 1988 .

[39]  J. McAuliffe.  Competition, Colonization Patterns, and Disturbance in Stream Benthic Communities , 1983 .

[40]  W. Dixon,et al.  BMDP statistical software , 1983 .

[41]  T. Zaret.  Predation and freshwater communities , 1980 .

[42]  M. Klug,et al.  Feeding Ecology of Stream Invertebrates , 1979 .

[43]  M. Stainton,et al.  The Chemical Analysis of Fresh Water , 1977 .

[44]  W. Murdoch,et al.  Predation and Population Stability , 1975 .

[45]  W. Murdoch.  The Developmental Response of Predators to Changes in Prey Density , 1971 .

[46]  A. C. Redfield.  The biological control of chemical factors in the environment. , 1960, Science progress.

[47]  D. Lack.  The natural regulation of animal numbers , 1954 .

[48]  H. G. Andrewartha,et al.  The distribution and abundance of animals. , 1954 .