caa a22 4500 469098961 CHVBK 20180323133039.0 cr unu---uuuuu 170328e19920501xx s 000 0 eng 10.1007/BF00317182 doi (NATIONALLICENCE)springer-10.1007/BF00317182 Crowley P. Evolutionary Ecology Research Group, T. H. Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA aut Density dependence, boundedness, and attraction: detecting stability in stochastic systems [Elektronische Daten] [P. Crowley] Summary: By analogy with deterministic stability, the stability of stochastic ecological systems can be viewed as a tendency for population densities to avoid dynamic boundaries (i.e. boundedness) or to approach a dynamic attractor (i.e. attraction). At the population level, these two views generate predictions consistent with density dependence. I therefore devised two new statistical tests of attraction, the "random-walk attraction test” and the "randomized attraction test”; I then used them successfully, along with randomization techniques that detect boundedness and two autocorrelation methods, to test for density dependence in published sequences of population densities. The attraction tests identify the apparent attractor, the band of densities toward which density tends to shift between generations. Locating the apparent attractor can generate a prediction of the next direction of density change; for data from a dragonfly assemblage, about 80% of these predictions were correct. From the single-population tests, I also developed two multispecies tests of attraction (the multispecies random-walk and randomized attraction tests) and two multispecies tests of boundedness (the multispecies permutation and randomization tests). These detected attraction and boundedness in the dragonfly assemblage and attraction in a collection of laboratory fruitfly populations. An evaluation of the statistical power of the new density attraction tests indicates a strong dependence on the sequence length n and on the number of populations m: power increases with n and particularly with m. Nevertheless, detecting attraction becomes likely even in populations with strong linear density-dependence only with n>30 or for shorter sequences in multispecies assemblages. Springer-Verlag, 1992 Randomization nationallicence Random walk nationallicence Statistical tests nationallicence Resilience nationallicence Population and community dynamics nationallicence Oecologia Springer-Verlag 90/2(1992-05-01), 246-254 0029-8549 90:2<246 1992 90 442 https://doi.org/10.1007/BF00317182 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317182 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Crowley P. Evolutionary Ecology Research Group, T. H. Morgan School of Biological Sciences, University of Kentucky, 40506, Lexington, KY, USA aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 90/2(1992-05-01), 246-254 0029-8549 90:2<246 1992 90 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer