Neighboring species hinder the anatomical traits of a non-native and invasive aquatic grass in Pantanal.

Plant interactions significantly influence individual growth, with competition for resources being a key factor. However, it's still unclear if neighboring species affect the anatomical development of aquatic plants. This 60-day factorial experiment investigated the anatomical responses of three Pantanal macrophytes: the non-native Urochloa arrecta and native species Ipomoea carnea and Polygonum ferrugineum, grown alone and with neighbors. After the experiment, plants were analyzed anatomically using standard techniques, Image J, and a two-way ANOVA. Results showed that neighboring I. carnea and P. ferrugineum inhibited the formation of certain anatomical structures in U. arrecta, such as mesophyll and vascular bundles. This inhibition could reduce U. arrecta's success in the Pantanal, as these structures are vital for optimal plant development. Conversely, U. arrecta's cortex structures were stimulated by neighboring species, potentially enhancing its resistance and competitive ability. This finding aligns with previous studies showing that higher native species richness can inhibit the morphological development of non-native species, suggesting this relationship extends to anatomical structures as well.