Strange plants and the weirding climate: parasitic plant physiology under climate change

Parasitic flowering plants are often seen as keystone species due to the broad influence they exert on communities worldwide. Positive and negative effects associated with parasitic plant infestation have been documented for a variety of species in multiple locations and under different experimental conditions. However, the impact of the different drivers of climate change on these plants has only recently begun to be analyzed in more detail. In this context, most studies have dealt with modelling future distribution ranges of parasite species and assessing potential ecological impacts. Building on this work, this review discusses studies that have employed a more mechanistic approach to investigate different aspects of parasitic plant physiology under climate change. Considering results obtained for both hemi- and holo-parasites, I hypothesize that, in the presence of conditions that improve parasite performance, such as reduced intraspecific competition or increased diversity of host species, elevated levels of atmospheric CO2 can partially alleviate the negative impact of parasitism on host growth. However, this reduction of negative impacts is potentially hampered by other drivers of climate change, such as extreme high temperatures and severe drought events. Future research should strive to analyze the combined impact of different components of climate change simultaneously, preferably considering a wider diversity of parasitic plant species.