Evidence of rapid evolution of an invasive poaceae in response to salinity

• Published in: Aquatic sciences Vol. 82; no. 4
• Main Authors: Bora, Leticia Siman, Thomaz, Sidinei Magela, Padial, André Andrian
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-10-2020; Springer Nature B.V
• Subjects: Aquatic ecosystems; Aquatic habitats; Aquatic plants; Biological evolution; Biology; Biomedical and Life Sciences; Brackishwater environment; Ecology; Ecosystem management; Ecosystems; Environmental conditions; Environmental factors; Estuaries; Estuarine ecosystems; Estuarine environments; Evolution; Experiments; Freshwater; Freshwater & Marine Ecology; Freshwater ecosystems; Freshwater environments; Inland water environment; Invasive plants; Invasive species; Life Sciences; Macrophytes; Mangroves; Marine & Freshwater Sciences; Oceanography; Plant growth; Populations; Propagules; Research Article; Salinity; Salinity effects; Salinity gradients; Strategic management; Estuaries; Biological invasion; Plant physiology; Aquatic plants; Environmental filters; Salinity
• ISSN: 1015-1621; 1420-9055
• DOI: 10.1007/s00027-020-00750-y

Understanding how environmental factors and short-term evolution affect the growth of invasive plants is a central issue in Invasion Biology. For macrophytes, salinity is one of the main factors determining distribution along estuarine environments.
Urochola arrecta
is a Poaceae with high invasive potential in several freshwater and estuarine ecosystems. In South Brazilian estuaries, this species is found sparsely in mangroves, and invades successfully freshwaters and areas with low salinity. We experimentally described the
U. arrecta
tolerance to salt. Furthermore, we tested if the response to the saline gradient depends on the population origin, through an experiment with populations inhabiting estuarine and freshwater ecosystems. We designed the experiment with three populations of this species, expecting that estuarine populations were more resistant to salinity. Plants grew in a salinity gradient and after 40 days we measured macrophytes biomass and length. Salinity was highly stressful for
U. arrecta
independently of its origin. Even so, plant growth differed significantly among populations. Despite higher growth, the population originated from freshwater habitats presented the fastest decrease in performance indicators with increasing salinity. This result indicates short-term evolutionary changes because all populations grew common-garden conditions in our experiment. Furthermore, salinity did not prevent the full establishment of this plant, since almost all propagules developed roots even in the saline treatments. Differences among populations suggest that invasion potential of this species can be higher than predicted by the environmental conditions of current invaded sites. Constant monitoring in estuarine invaded ecosystems is central to manage invasions in critical ecosystems, such as mangroves areas.