Altered performance of forest pests under atmospheres enriched by CO2 and O3

Abstract

Human activity causes increasing background concentrations of the greenhouse gases CO2 and O3. Increased levels of CO2 can be found in all terrestrial ecosystems. Damaging O3 concentrations currently occur over 29% of the world's temperate and subpolar forests but are predicted to affect fully 60% by 2100 (ref. 3). Although individual effects of CO2 and O3 on vegetation have been widely investigated, very little is known about their interaction, and long-term studies on mature trees and higher trophic levels are extremely rare. Here we present evidence from the most widely distributed North American tree species, Populus tremuloides, showing that CO2 and O3, singly and in combination, affected productivity, physical and chemical leaf defences and, because of changes in plant quality, insect and disease populations. Our data show that feedbacks to plant growth from changes induced by CO2 and O3 in plant quality and pest performance are likely. Assessments of global change effects on forest ecosystems must therefore consider the interacting effects of CO2 and O3 on plant performance, as well as the implications of increased pest activity.

Olfaction in vector-host interactions

“…As well as contributing to effects of temperature, and the aforementioned effects on insects, these increasing levels of CO 2 and O 3 affect plants considerably. Elevated concentrations of these gases alter the nutritional and defensive characteristics of plants, and subsequently these effects can cascade through ecosystems and in turn impact upon higher trophic levels, such as insect herbivores and their natural enemies (Percy et al 2002). All these changes may help create novel vector species by removing some of the barriers that render many Culicoides species refractory to infection.…”

Selection of air pollution tolerant plants through the 20-years-long transplanting experiment in the Yeocheon industrial area, southern Korea

“…Reduced photosynthesis and visible damage, such as chlorosis, lesions, and abscission, are preludes to growth inhibition and to mortality of the more sensitive plants, leading to alteration of vegetation structure (Hällgren 1978;You et al 1998;Luttermann & Freedman 2000;Winterhalder 2000; Lee et al 2004Lee et al , 2007. In addition, vegetation is also influenced by changes in reproductive capacity due to air pollution and acid rain (Kramer & Kozlowski 1980;Cox 1984) and by their interactions with plant diseases and insects (Treshow 1975;Chakraborty et al 2000;Percy et al 2002).…”

New Phytotron for Studying the Effect of Climate Change on Plant Pathogens

“…Despite the paramount importance of plant disease for agricultural and natural ecosystems, little is known of how plant interactions with pathogens will change under future climatic conditions [McElrone 2005;Runion 2003;Percy 2002;Chakraborty 2000;Coakley 1999] The expression of disease symptoms is influenced by three main components: (1) host, (2) pathogen, and (3) environmental conditions. Because plant predisposition to disease is altered by abiotic factors, changes in environmental variables such as elevated CO 2 will also likely affect the severity and range of pathogens [Salinari 2006].…”