Insect herbivory dampens Subarctic birch forest C sink response to warming

• DOI: 10.1038/s41467-020-16404-4
• Publication Date: 2020-05-21T10:03:14Z
• Authors: Tarja Silfver; Lauri Heiskanen; Mika Aurela; Kristiina Myller; Kristiina Karhu; Nele Meyer; Juha-Pekka Tuovinen; Elina Oksanen; Matti Rousi; Juha Mikola
• Keywords: Subarctic climate; Sink (geography)

Climate warming is anticipated to make high latitude ecosystems stronger C sinks through increasing plant production. This effect might, however, be dampened by insect herbivores whose damage plants at their background, non-outbreak densities may more than double under climate warming. Here, using an open-air experiment among Subarctic birch forest field layer vegetation, supplemented with plantlets, we show that a 2.3 °C air and 1.2 soil temperature increase can advance the growing season 1-4 days, enhance N availability, leaf chlorophyll concentrations growth up 400%, 160% 50% respectively, lead 122% greater ecosystem CO2 uptake potential. However, comparable positive effects are also found when herbivory reduced, of on sink potential intensified reduced herbivory. Our results confirm expected warming-induced in uptake, but reveal herbivorous insects significantly dampen strengthening