Prey Predator Relationships

The effects of global climate change have also affected ecosystem interactions, altering prey-predator and parasite-host relationships. In temperate regions, the photoperiod is the cue for seasonal synchrony: the interaction between temperature and photoperiod determine the phenology. In The Netherlands, studies have demonstrated the shift in synchrony between plants and plant feeders, which has had serious consequences for functioning of the ecosystem due to the tight multitrophic interactions involved in the timing of reproduction and growth. Visser and Holleman (2001) highlighted that in an ecological system that evolved with strong selection on synchronization, such as with the winter moth's (Operophtera brumata) egg hatching and the oak's (Quercus robur) bud burst, there was poor synchrony in recent springs due to an increase in spring temperatures without a decrease in the incidences of freezing spells during the winter. The timing of egg hatching in relation to bud burst has had major health consequences for caterpillars. If the eggs hatch prior to bud burst the caterpillars starve, whereas if hatching occurs after bud burst the caterpillars have to eat less digestible leaves due to the increased tannin concentrations. This may lead to lower weight at pupation or to a longer larval period, resulting in a higher probability of being preyed upon or parasitized.

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