In the temperate rainforests of southern Chile, scientists have uncovered a fascinating relationship between mistletoes and lianas (woody vines). A recent study published in Ecology reveals that these parasitic plants thrive on lianas, possibly as a survival strategy against drought and a clever way to spread their seeds. Mistletoes, which depend on host plants for water and nutrients, are rarely documented growing on lianas. However, researchers observed that nearly half of the mistletoes (Tristerix corymbosus) in the study area were parasitizing lianas like Boquila trifoliolata and Cissus striata. This was surprising because these vines aren’t the most abundant plants in the forest, suggesting mistletoes might prefer them for specific reasons.
One key factor is the role of the arboreal marsupial Dromiciops gliroides, the mistletoe’s sole seed disperser. Camera traps recorded these small mammals using lianas as highways to move through the canopy, leaving feces containing mistletoe seeds. This behavior helps the plants colonize new hosts. Additionally, lianas may act as drought-safe havens for mistletoes. Unlike trees, lianas have efficient water transport systems, allowing them to stay hydrated during dry spells. As climate change brings hotter, drier summers to the region, mistletoes on lianas showed fewer signs of stress than those on trees.
Nacho’s study highlights the overlooked importance of lianas in forest ecosystems—not just as structural supports, but as critical partners for both plants and animals. By understanding these interactions, scientists can better predict how climate change might reshape these unique rainforests.
For more details, the full study is available in Ecology: https://doi.org/10.1002/ecy.4479