Spatio-Temporal Connectivity of the Long-Term Dynamics of the Forest Phyllophagus Insects’ Abundance

Abstract

The study was conducted regarding the conjugation of the population dynamics of different forest insects species under different landscape conditions on the territory of the Krasnoturansky pine forest (South of the Krasnoyarsk Territory). The population dynamics conjugation indicates the presence of an ecological mechanism that leads to the coordination of the temporal series of different species’ population dynamics in one habitat or one species in different habitats. This means that using the conjugation indicators of insect dynamics one can indirectly assess the influence of various factors affecting these populations. To assess the spatio-temporal synchronization of the population dynamics of insects in different landscape conditions, the data of the phyllophagous insects counts for the period from 1979 to 2016 were used. According to the phases of dynamics, although the periods of cyclic fluctuations of phyllophages’ populations in different stows are close, the characteristics of the phyllophagous insects number dynamics still differ in both the absolute values and the phases of dynamics, even when the distance between the test sites is relatively small. The “memory” of the system, expressed in the order of the autoregressive model of the population dynamics, is fairly large for the studied complexes of phyllophagous species: the current value of the phyllophagous populations density can be influenced by the population density values from as far as four years before the counts. Such values of “memory” lead to an increase in the populations’ stability margin, and a decrease in the risks of developing insect outbreaks. The determination coefficients close to 1 for the phyllophages dynamics models in the stows of the Krasnoturansky pine forest indicate a weak influence of modifying factors (such as weather) on the population dynamics.