Cotorras, siluros, carpas, chinches, diferentes tipos de plantas… Hemos normalizado la presencia de distintas especies invasoras en las ciudades -incluida Córdoba– que, sin darnos cuenta, afectan a nuestro entorno. Algunas acaban o reducen la población de nuestras especies autóctonas, mientras que otras tienen incidencias directas en nuestro día a día: favorecen la aparición de alergias, dificultan la visibilidad en las carreteras, incrementan el riesgo de incendios o afectan al ruido de la ciudad. Un riesgo del que los ciudadanos son cada vez más conscientes, aunque «no lo suficiente», y que, sobre todo, resulta muy difícil de frenar.
Son las principales conclusiones que resalta el investigador de la Universidad de Córdoba ( UCO ) y experto en especies invasoras, Pablo González. Para él, el principal riesgo que enfrenta Córdoba en este ámbito se encuentra en las plantas, algunas de las cuales llevan más de diez siglos en la ciudad. Tanto, que incluso podrían no considerarse especies invasoras, aunque también existen casos de peces, animales vertebrados e invertebrados.
In the case of plants, the expert points out that Córdoba has a critically important number of them, including the ailanto (Ailanthus altissima), foxtail grass (Cenchrus setaceus or previously Pennisetum), reed (Arundo donax), and Spanish flag (Lantana camara). The first two species arrived in Córdoba recently. The ailanto was introduced because it was used to stabilize road slopes. Its expansion has been “very rapid” and causes road safety problems, González points out.”It is present mainly on the highway, but we also see it in many abandoned plots in the city and in the river area.” These are very fast-growing trees.
The impact of these species goes beyond eliminating native populations, as they also increase the risk of fire or accidents, promote a resurgence of allergies, damage the vegetation in the area, and can affect the natural course of rivers.
Other species, such as foxtail grass, increase the probability of fires, the researcher points out. This plant is especially present in the area of Rabanales 21 and the Las Quemadas industrial estate,although he warns of its expansion to other points in the capital. In addition, it is a species that “covers and leaves a very large impact on plant biodiversity,” he points out. While foxtail grass promotes a resurgence of grass allergies.
The Battle for the Guadalquivir: Córdoba fights Invasive species
The Guadalquivir River, a vital artery flowing through Córdoba, Spain, is facing a growing threat: invasive species. These non-native plants and animals are disrupting the delicate balance of the river’s ecosystem, impacting biodiversity and even posing risks to local infrastructure. A concerted effort is underway to combat this ecological challenge and restore the river to its former health.
One of the most visible invaders is the giant reed (Arundo donax), which aggressively colonizes the riverbanks, forming dense thickets. These reeds outcompete native vegetation,reducing habitat for local wildlife and increasing the risk of flooding by narrowing the river channel. The Sotos de la Albolafia, a protected natural area along the Guadalquivir in Córdoba, is especially affected.
Beyond the giant reed, other invasive plants like the water hyacinth and various species of Salvinia pose similar problems, clogging waterways and hindering navigation. Animal invaders also present a challenge.The red swamp crayfish, for example, preys on native fish and amphibians, while certain bird species compete with local populations for resources.
The fight against these invaders is multifaceted. Authorities are employing mechanical removal methods, physically extracting invasive plants from the riverbanks. Though, this is frequently enough a temporary solution, as the plants readily regenerate. Chemical control, using herbicides, is used cautiously and strategically to minimize environmental impact.
Perhaps the most promising approach lies in biological control – introducing natural enemies of the invasive species. Research is ongoing to identify suitable biocontrol agents that can effectively manage the invaders without harming native species.
Local authorities,environmental organizations,and citizen groups are collaborating to raise awareness about the issue and encourage responsible practices. This includes preventing the introduction of new invasive species through measures like stricter regulations on ballast water discharge from ships and educating the public about the dangers of releasing exotic pets into the wild.
The battle for the Guadalquivir is far from over, but the ongoing efforts offer a glimmer of hope. Protecting this iconic river requires a long-term commitment to monitoring, prevention, and innovative control strategies. the health of the Guadalquivir is not just an environmental concern; it’s crucial for the economic and social well-being of Córdoba and the surrounding region.
Regarding vertebrate animals, the most striking case is the…