Abstract
Ecological disturbance is inherently a multi-faceted phenomenon; disturbance events can differ in distinct quantifiable aspects, such as intensity, duration, spatial extent, and time since last disturbance. Though effects of disturbance timing (specifically, time within a season) have been investigated empirically, theoretical work is lacking, in part because effects of disturbance may depend on the timing relative to the life cycle of the species in question. To demonstrate a theoretical basis for the effects of timing, we develop a model of annual plants subject to soil disturbance. We show that timing of disturbance can have significant effects on community composition. In addition, we quantify the mechanisms of coexistence acting under different timing regimes and show that differences in timing lead to different coexistence mechanisms. Specifically, we find that early disturbance (which enhances germination from the seed bank) generates the storage effect, whereas coexistence under late disturbance (which reduces adult fecundity and contributions to the soil seed bank) depends more on relative nonlinearity of competition. We discuss these two distinct mechanisms within the context of the underlying ecological processes, and we also briefly consider the broader implications of our analyses for disturbance timing in real communities. Our findings extend ecological disturbance theory by linking timing to specific competitive outcomes and can be applied to a wide range of disturbance-prone communities. Because we identify the underlying mechanisms resulting from different disturbance timings, our results can potentially inform theory for conservation and invasive species management practice.
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References
Alexander H, Schrag A (2003) Role of soil seed banks and newly dispersed seeds in population dynamics of the annual sunflower, Helianthus annuus. J Ecol 91(6):987–998
Armstrong R, McGehee R (1980) Competitive exclusion. Am Nat 115(2):151–170
Chesson P (1985) Coexistence of competitors in spatially and temporally varying environments: a look at the combined effects of different sorts of variability. Theor Popul Biol 28(3):263–287
Chesson P (1994) Multispecies competition in variable environments. Theor Popul Biol 45:227–276
Chesson P (2008) Quantifying and testing species coexistence mechanisms. In: Unity in diversity: reflections on ecology after the legacy of Ramon Margalef, pp 119–164
Chesson P, Ellner S (1989) Invasibility and stochastic boundedness in monotonic competition models. J Math Biol 27(2):117–138
Chesson P, Huntly N (1997) The roles of harsh and fluctuating conditions in the dynamics of ecological communities. Am Nat 150(5):519–553
Connell J (1978) Diversity in tropical rain forests and coral reefs. Science 199(4335):1302–1310
Crawley M (2004) Timing of disturbance and coexistence in a species-rich ruderal plant community. Ecology 85(12):3277–3288
Drew T, Flewelling J (1977) Some recent Japanese theories of yield-density relationships and their application to Monterey pine plantations. For Sci (Bethesda, Md) 23(4):517–534
Ellner S (1985) ESS germination strategies in randomly varying environments. II. Reciprocal yield-law models. Theor Popul Biol 28(1):80–116
Ellner S (1987) Alternate plant life history strategies and coexistence in randomly varying environments. Plant Ecol 69(1):199–208
Froud-Williams R, Chancellor R, Drennan D (1984) The effects of seed burial and soil disturbance on emergence and survival of arable weeds in relation to minimal cultivation. J Appl Ecol 21(2):629–641
Gallagher R, Cardina J (1998) Phytochrome-mediated Amaranthus germination I: effect of seed burial and germination temperature. Weed Sci 46(1):48–52
Grime J (1977) Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. Am Nat 111(982):1169
Haddad N, Holyoak M, Mata T, Davies K, Melbourne B, Preston K (2008) Species’ traits predict the effects of disturbance and productivity on diversity. Ecol Lett 11(4):348–356
Hobbs R, Mooney H (1985) Community and population dynamics of serpentine grassland annuals in relation to gopher disturbance. Oecologia 67(3):342–351
Humphrey L, Pyke D (1998) Demographic and growth responses of a guerrilla and a phalanx perennial grass in competitive mixtures. J Ecol 86(5):854–865
Kotanen P (1996) Revegetation following soil disturbance in a California meadow: the role of propagule supply. Oecologia 108(4):652–662
Li X, Jia X, Long L, Zerbe S (2005) Effects of biological soil crusts on seed bank, germination and establishment of two annual plant species in the Tengger Desert (N China). Plant Soil 277(1):375–385
Miller A, Chesson P (2009) Coexistence in disturbance prone communities: how a resistance–resilience trade-off generates coexistence via the storage effect. Am Nat 173(2):E30–E43
Miller A, Roxburgh S, Shea K (2011) How frequency and intensity shape diversity–disturbance relationships. Proc Natl Acad Sci 108(14):5643
Pickett S, White P (1985) The ecology of natural disturbance and patch dynamics. Academic, New York
Pickett S, Collins S, Armesto J (1987) A hierarchical consideration of causes and mechanisms of succession. Plant Ecol 69(1):109–114
Roxburgh S, Shea K, Wilson J (2004) The intermediate disturbance hypothesis: patch dynamics and mechanisms of species coexistence. Ecology 85(2):359–371
Ruel J, Ayres M (1999) Jensen’s inequality predicts effects of environmental variation. Trends Ecol Evol 14(9):361–366
Shea K, Roxburgh S, Rauschert E (2004) Moving from pattern to process: coexistence mechanisms under intermediate disturbance regimes. Ecol Lett 7(6):491–508
Shinozaki K, Kira T (1956) Intraspecific competition among higher plants VII. Logistic theory of the CD effect. J Inst Polytech Osaka City Univ Ser D 7:35–72
Smith R (2006) Timing of tillage is an important filter on the assembly of weed communities. Weed Sci 54(4):705–712
Sousa W (1984) The role of disturbance in natural communities. Annu Rev Ecol Syst 15(1):353–391
Acknowledgements
This work was supported by NSF grant DEB-0815373. The Shea Lab was very helpful and encouraging in their support of this work, and additionally, the authors would like to thank Robin Snyder for her comments and discussion.
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Miller, A.D., Roxburgh, S.H. & Shea, K. Timing of disturbance alters competitive outcomes and mechanisms of coexistence in an annual plant model. Theor Ecol 5, 419–432 (2012). https://doi.org/10.1007/s12080-011-0133-1
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DOI: https://doi.org/10.1007/s12080-011-0133-1