Invasive species and renewable energy

One of the biggest threats to biodiversity are exotic or invasive species. The globalization process is favoring the dispersion of propagules and favors the expansion of exotic or invasive species.

The International Union for Conservation of Nature defines:

• “Exotic species” (non-native, non-native, foreign): the species, subspecies or lower taxon that occurs outside its natural range (past or current) and of potential dispersion (e.g. outside the area it naturally occupies or that it could not occupy without direct or indirect human introduction or care) and includes any part, gamete or propagule of that species that can survive and reproduce.
• “Invasive alien species”: an exotic species that is established in a natural or semi-natural ecosystem or habitat; it is an agent of change and threatens native biological diversity.

A Silent Invasion

This process is happening before our eyes many times without us realizing it. In general, more attention is paid to invasive fauna and less to plants. However, the effects of plants can also be very serious.

The process of expansion of some species is certainly familiar to us and yet we have not paid attention. For about 10 years it has been spreading through the ditches of all of Spain. Dittricha viscosa. From the ditches, it has spread to anthropized areas, abandoned crops, urban areas, etc. Places modified by human action. These environments are what favor the presence of these species, who desire places with resources and without competition. D. viscose It would not be exotic in many places in the Iberian Peninsula, but it is an invasive one since it is expanding at an alarming rate, especially taking advantage of the ecological vacuum that has been generated in ditches and slopes of roads and railway tracks. And from there it jumps into the environment: abandoned crops, land under construction, etc. In addition, it is likely that climate change is favoring its expansion.

Other cases of species that are expanding at high speed are several species of the genus Conyza sp. (=Erigeon sp.) or Aster squamatus. These species also extend through ditches and wastelands and become very abundant in cereal crops, stubble and fallow land. Its expansion is more recent, but it is also very fast. Just like Dittricha viscosa they are composite, generating enormous quantities of seeds, dispersed by wind and which take root in land where there is no competition.

A case in which a recent expansion can be seen is that of estramonium Datura stramonium. It is a species always linked to nitrified terrain, widely distributed, but confined to very localized environments. However, for a few years now, it has been proliferating in a very remarkable way on cultivated land, especially irrigated land. Probably the dispersing agent is agricultural machinery.

Photovoltaic installations or wind farms can be the perfect place for the establishment of invasive species. Areas where earthworks, slopes, and clearing take place can become rapidly occupied areas. It is very important that soil movement and clearing are limited to the technically essential minimum, avoiding soil alteration is the best way to prevent the entry of these species. In addition, the risks of the appearance of these species must be assessed in environmental impact studies.

What to do to prevent the spread of invasive alien species

To avoid the implantation of invasive alien species (EEI), an effective strategy is to encourage the entry of native invaders. It is necessary to facilitate the implantation of native species that proliferate rapidly and compete with exotic ones (Ernst, A.R.. et al. 2023). For example, Dittrichia viscosa can carry out a first occupation of altered surfaces. A mixture of legumes and cultivated cereals, yeros, peas with barley or rye can also be sown, so that dense vegetation is established quickly and is then colonized by the annuals associated with these crops. In this way, ecological succession can be directed towards situations in which EEI have more difficulty establishing themselves.

Once established, immediate action to prevent the spread of seeds and propagules is the most effective. It is essential that the environmental monitoring plans for facilities take into account the ISS. Environmental monitoring tasks require qualified personnel capable of detecting ESI in the early stages of their establishment. There must be an action plan in case of detection, including information procedures and coordination with administrations. Protocols and resources must be established for the immediate eradication of the detected species, as well as the form of destruction or destination of the generated remains.

Bibliography

IUCN—the World Conservation Union. 2000. IUCN GUIDELINES FOR THE PREVENTION OF BIODIVERSITY LOSS DUE TO BIOLOGICAL INVASION (approved by the IUCN Council, February, 2000).
Ernst, A.R., Barak, R.S., Glasenhardt, M.-C., Kramer, A.T., Larkin, D.J., Marx, H.E., Kamakura, R.P., & Hipp, A.L. (2023). Dominant species establishment may influence invasion resistance more than phylogenetic or functional diversity. Journal of Applied Ecology, 60, 2652—2664. https://doi.org/10.1111/1365-2664.14534

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