Growth Rates of Lymantria dispar Larvae and Quercus robur Seedlings at Elevated CO2 Concentration and Phytophthora plurivora Infection

Slobodan Milanović,Marija Popović,Alejandro Solla,Ivan Milenković,Jovan Dobrosavljević,Libor Jankovský,Michal Tomšovský

doi:10.3390/f11101059

Slobodan Milanović, Marija Popović + Show 5 more

Open Access

https://doi.org/10.3390/f11101059

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Abstract

Interactions between plants, insects and pathogens are complex and not sufficiently understood in the context of climate change. In this study, the impact of a root pathogen on a leaf-eating insect hosted by a tree species at elevated CO2 concentration is reported for the first time. The combined and isolated effects of CO2 and infection by the root pathogen Phytophthora plurivora on English oak (Quercus robur) seedlings were used to assess growth rates of plants and of gypsy moth (Lymantria dispar) larvae. For this purpose, two Q. robur provenances (Belgrade and Sombor) were used. At ambient CO2 concentration, the relative growth rates of larvae consuming leaves of plants infected by P. plurivora was higher than those consuming non-infected plants. However, at elevated CO2 concentration (1000 ppm) higher relative growth rates were detected in the larvae consuming the leaves of non-infected plants. At ambient CO2 concentration, lower growth rates were recorded in L. dispar larvae hosted in Q. robur from Belgrade in comparison to larvae hosted in Q. robur from Sombor. However, at elevated CO2 concentration, similar growth rates irrespective of the provenance were observed. Defoliation by the gypsy moth did not influence the growth of plants while P. plurivora infection significantly reduced tree height in seedlings from Belgrade. The results confirm that a rise of CO2 concentration in the atmosphere modifies the existing interactions between P. plurivora, Q. robur, and L. dispar. Moreover, the influence of the tree provenances on both herbivore and plant performance at elevated CO2 concentrations suggests a potential for increasing forest resilience through breeding.

Highlights

In recent decades, climate change has had a significant impact on all living organisms on Earth, including forests [1]
The results of the general linear mixed models showed a significant effect of CO2 concentration on both growth rate (GR) and relative growth rate (RGR) parameters of the gypsy moth larvae (Table 1)
Larvae consuming leaves from Q. robur plants exposed to ambient CO2 concentration gained

Summary

Introduction

Climate change has had a significant impact on all living organisms on Earth, including forests [1]. Climate change is mainly characterized by global warming and rising CO2 levels. Plants use sunlight and water to convert surplus CO2 into oxygen and carbohydrates, which form plant tissues, thereby increasing overall forest productivity [3]. Forests 2020, 11, 1059 levels, plants increase photosynthetic and water use efficiency by 30–50% [4]. The most rapid increase of CO2 concentration was recorded during the second half of the 20th century and the beginning of the 21st century, and according to the Intergovernmental Panel on Climate Change [5] the projected concentration of CO2 in 2100 will range from 540 to 970 ppm.

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