Abstract
This study provides insight into the importance of top carnivores (top-down control) and nutrient inputs (bottom-up control) in structuring food chains in a terrestrial grassland system. Qualitative predictions about food chain structure are generated using 4 simple models, each differing in assumptions about some key component in the population dynamics of the herbivore trophic level. The four model systems can be classified broadly into two groups (1) those that assume plant resource intake by herbivores is limited by search rate and handling time as described by classic Lotka-Volterra models; and (2) those that assume plant resource intake by herbivores is limited externally by the supply rate of resources as described by alternatives to Lotka-Volterra formulations. The first class of models tends to ascribe greater importance to top-down control of food chain structure whereas the second class places greater weight on bottom-up control. I evaluated the model predictions using experimentally assembled grassland food chains in which I manipulated nutrient inputs and carnivore (wolf spider) abundance to determine the degree of top-down and bottom-up control of grassland plants and herbivores (grasshoppers). The experimental results were most consistent with predictions of the second class of models implying a predominance of bottom-up control of food chain structure.
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References
Abrams P (1987) Indirect interactions between species that share a common predator: varieties of indirect effects. In: Kerfoot WC, Sih A (eds) Predation: direct and indirect impacts on aquatic communities. University Press of New England, Hanover pp 38–54
Arditi R, Ginzburg LR (1989) Coupling in predator-prey dynamics: ratio-dependence. J Theor Biol 139:311–326
Belovsky GE (1986) Generalist herbivore foraging and its role in competitive interactions. Am Zool 26:51–69
Belovsky GE, Slade JB, Stockhoff BA (1990) Suceptibility to predation for different grasshoppers: an experimental study. Ecology 71:624–634
Carpenter SR, Kitchell JF, Hodgson JR (1985) Cascading trophic interactions and lake productivity. Bioscience 35:634–639
Caughley G, Lawton JH (1981) Plant-herbivore systems. In: May RM (ed) Theoretical Ecology. Sinauer Associates, Sunderland Massachusetts, pp 132–167
Fretwell SD (1977) The regulation of plant communities by the food chains exploiting them. Perspec Biol Med 20:169–185
Hagstrum DW (1970) Ecological energetics of the spider Tarentula kochi (Araneae: Lycosidae). Ann Ent Soc Am 63:1297–1304
Hairston NG, Smith FE, Slobodkin LB (1960) Community structure, population control and competition. Am Nat 94:421–425
Hardman JM, Turnbull AL (1974) The interaction of spatial heterogeneity, predator competition and the functional response to prey density in a lab system of wolf spiders and fruit flies. J Anim Ecol 43:155–171
Jager HI, Gardner RH (1988) A simulation experiment to investigate food web polarization. Ecol Mod 41:101–106
Kajak A, Andrzejewska L, Wojcik Z (1968) The role of spiders in the decrease of damage caused by Acridoidea on meadows-experimental investigations. Ekol Polska Ser A 16:755–764
Lawton JH (1989) Food webs. In: Cherett JM (ed) Ecological Concepts. Blackwell Scientific, Oxford, UK pp 43–78
Liebold MA (1989) Resource edibility and the effects of predators and productivity on the outcome of trophic interactions. Am Nat 134:922–949
Lomnicki A (1988) Population Ecology of Individuals, Princeton University Press, Princeton, NJ
McCauley E, Murdoch WW, Watson S (1988) Simple models of variation in plankton densities among lakes. Am Nat 132:383–403
McQueen DJ, Post JR, Mills EL (1986) Trophic relationships in freshwater pelagic ecosystems. Can J Fish Aquat Sci 43:1571–1581
Murdoch WW (1966) Community structure, population control and competition-a critique. Am Nat 100:219–226
Nakamura K (1974) A model of the functional response of a predator to prey density involving the hunger effect. Oecologia 16:265–278
Nakamura K (1977) A model of the functional response of a predator to varying prey densities based on the feeding ecology of wolf spiders. Bull Natl Inst Agric Sci Ser C 31:29–89
Oksanen L (1983) Trophic exploitation and arctic phytomass patterns. Am Nat 122:45–52
Oksanen L (1990) Predation, herbivory and plant strategies along gradients of primary productivity. In: Grace JP, Tilman D (eds) Perspectives on Plant Competition. Academic Press, New York, NY pp 445–474
Oksanen T (1990) Exploitation ecosystems in heterogenous habitat complexes. Evol Ecol 4:220–234
Oksanen L, Fretwell SD, Arruda J, Niemalä P (1981) Exploitation ecosystems in gradients of primary productivity. Am Nat 118:240–261
Price PW, Bouton CE, Gross PE, McPheron BA, Thompson JA, Weis EA (1980) Interactions among three trophic levels: influence of plants on interaction between insect herbivores and natural enemies. Ann Rev Ecol Syst 11:41–65
Ritchie ME, Tilman D (1992) Intraspecific competition among grasshoppers and their effects on plant abundance in experimental field environments. Oecologia 89:524–532
Rosenzweigh ML (1973) Exploitation in three trophic levels. Am Nat 107:275–294
Schmitz OJ (1992) Exploitation in model food chains with mechanistic consumer-resource dynamics. Theor Popul Biol 41:161–181
Schoener TW (1973) Population growth regulated by intraspecific competition for energy or time: some simple representations. Theor Popul Biol 4:56–84
Schoener TW (1978) Effects of density-restricted food encounter on some single-level competition models. Theor Popul Biol 13:365–381
Schoener TW (1983) Field experiments on interspecific competition. Am Nat 122:240–285
Schoener TW (1989) Food webs from the small to the large. Ecology 70:1559–1589
Sinclair ARE (1975) The resource limitation of trophic levels in tropical grassland ecosystems. J Anim Ecol 44:479–520
Sinclair ARE (1989) Population regulation in animals. In: Cherett JM (ed) Ecological Concepts. Blackwell Scientific, Oxford, UK, pp 43–78
Terry RA, Tilley JMA (1964) The digestibility of the leaves and stems of perennial ryegrass, cocksfoot, timothy, tall fescue, lucerne and sainfoin as measured by an in vitro procedure. J Br Grassl Soc 19:363–372
Tilman D (1988) Plant Strategies and the Structure and Dynamics of Plant Communities. Princeton Univ Press, Princeton, USA
Weis AE, Berenbaum MR (1989) Herbivorous insects and green plants. In Abrahamson WG (ed) Plantanimal interactions. McGraw-Hill Inc, NY, pp 123–162
White TCR (1978) The importance of a relative shortage of food in animal ecology. Oecologia 33:71–86
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Schmitz, O.J. Trophic exploitation in grassland food chains: simple models and a field experiment. Oecologia 93, 327–335 (1993). https://doi.org/10.1007/BF00317874
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DOI: https://doi.org/10.1007/BF00317874