caa a22 4500 469060905 CHVBK 20180323132856.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF01200564 doi (NATIONALLICENCE)springer-10.1007/BF01200564 Local and global cycles in an acarine predator-prey system: a frequency domain analysis [Elektronische Daten] [Robert Lingeman, Gerrit van de Klashorst] Techniques of time series analysis are applied to the dynamics of the phytophagous miteTetranychus urticae Koch and its predatorTyphlodromus occidentalis Nesbitt in six experimental mini-orchards, sampled weekly during two years (van de Klashorst et al., 1992). Autocovariance and crosscovariance functions characterize local and global behaviour in the time domain. Spectral density function and cross amplitude spectrum provide important information of the system's behaviour in the frequency domain. Because of a strikingly different behaviour, the total record was cut into two distinct periods. During the first period, all local systems oscillate with a frequency of four cycles per year and all in phase, resulting in a strongly periodical global behaviour at a high mean level. Since the mean local power spectra coincide with the global power spectrum over a wide range of frequencies, it is concluded that the total system of six orchards is homogeneous. During the second period, all local power spectra are mutually different, more or less smoothed with no apparent peak pointing to a periodical component. The resulting global power spectrum is almost flat at a low mean level. The system is heterogeneous with a quasi-stable global behaviour. From the cross-amplitude spectrum it became clear that the dynamics of the two species within the orchards remained strongly coupled over a wide range of frequencies. Since the experimental circumstances had not been intentionally changed, the origin of the drastic change in behaviour could not be identified. If high rates of dispersal have been the synchronizer during the first period, it is not clear why asynchrony suddenly occured in the second period. A comparison of the overall record with the results of Nachman's (1987) stochastic simulation model suggests that the change could possibly be of stochastic origin. Elsevier Science Publishers B.V., 1992 Lingeman Robert Department of Pure and Applied Ecology, University of Amsterdam, Amsterdam, Netherlands aut van de Klashorst Gerrit Department of Pure and Applied Ecology, University of Amsterdam, Amsterdam, Netherlands aut Experimental & Applied Acarology Kluwer Academic Publishers 14/3-4(1992-06-01), 201-214 0168-8162 14:3-4<201 1992 14 10493 https://doi.org/10.1007/BF01200564 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01200564 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lingeman Robert Department of Pure and Applied Ecology, University of Amsterdam, Amsterdam, Netherlands aut NATIONALLICENCE 700 1- van de Klashorst Gerrit Department of Pure and Applied Ecology, University of Amsterdam, Amsterdam, Netherlands aut NATIONALLICENCE 773 0- Experimental & Applied Acarology Kluwer Academic Publishers 14/3-4(1992-06-01), 201-214 0168-8162 14:3-4<201 1992 14 10493 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer