Forests provide a wide range of ecosystem services to humans, such as carbon capture. They have proved to be resilient to climate change for 400 million years. However, because of variations in biodiversity and ecosystem functions due to the increase of forest management, fragmentation and degradation, forests become less resilient to climate change. Therefore, Hernández-Agüero and his fellow researchers studied the effect of forest management on ecosystems functioning across the world. Their study was published in Global Ecology and Conservation.
Herbivory and predation
They estimated herbivory by insects and predation by birds in four regions belonging to five countries: Argentina, Finland, Peru, Spain and Russia. Two types of forest management were used: the first one was heavily managed or plantation forests, and the other one forests inside or nearby cities. To test the effect of the management, they selected pristine forests near the managed ones, as a reference forest. In total, 1600 model caterpillars and 280,000 leaves were used to establish predation and herbivory pressure.
Stable
The scientists concluded that ecosystems in forests remain stable though time, despite being disturbed by forest management. Only forests inside or nearby cities differ from others (pristine or managed). Bird predation is higher in urban forests while herbivory is generally lower. The variations observed can be attributed to the rise in resource availability during winters, and the increased abundance of generalist predators resulting from higher temperatures (the urban heat effect). This is particularly notable in regions where winter temperatures might otherwise pose a limiting factor.
Ecosystem services
According to Hernández-Agüero, cities are a valuable context for studying the potential negative consequences of climate change on ecosystems in the future: ‘This is particularly interesting given the ecosystem services, such as pest regulation through bird predation, that cities provide.’ He uses the results of this study to start a line of research on the effects of urbanization on ecosystem functioning at the Institute of Environmental Studies (IVM).
