Mountains and coasts, plains and islands, climates that change within just a few kilometers. Italy is an open-air mosaic of landscapes, trees, flowers, animals, villages, and cultures, and it is no surprise that it is one of the European countries with the greatest biodiversity richness [1].

A precious heritage ranging from the most common plant species (meaning easy to find and widespread) to endemic plants, which live only in a specific—and often very limited—area. A heritage that is, by its very nature, extremely fragile, threatened by external pressures and by changes that are difficult to control [1].

The term biodiversity—today often used rather lightly—is not synonymous with “many species,” but instead describes the variety of life in all its forms: genetic, species, ecosystem, and landscape diversity [2]. And “more species” does not always mean “better biodiversity”—quite the opposite! In recent decades, the number of plant species in Italy has indeed increased, but many of them are alien or invasive, often arriving from other continents and capable of overwhelming and displacing native ones [3].

An example of a delicate balance can be found in the mountains. The Alps and the Apennines host an extraordinary concentration of rare and endemic species (take a look at Primula recubariensis, range: 7 km² [4]) which here find unique habitats and microclimates. Yet, the abandonment of mountains, which began decades ago, has a double face. On the one hand, fewer human activities mean less disturbance and pressure; on the other, the disappearance of pastures and meadows created by humans has led to the loss of environments that for centuries supported numerous species [5].

The overall picture is not simple. For Italian flora, more than 16% of vascular plants are endemic, but only 43% enjoy a favorable conservation status. And the causes are well known: intensive agriculture, urban sprawl, invasive infrastructure, and hydrological alterations. In the mountains, overgrazing takes its toll, but so does the loss of traditional agricultural practices that once maintained specific habitats [3].

To make things more complicated, there are the so-called “neobiota”, alien species introduced intentionally or accidentally and often turning invasive [2] From the Asian hornet to the red swamp crayfish from Louisiana, from kudzu [6] to the tree of heaven, the list grows every year. These organisms arrive through global trade and travel, further aided by climate change. Once established, it is almost impossible to eradicate them completely. This is why strict regulations, monitoring, and—above all—citizen involvement are needed: recognizing an invasive species and reporting it can make a real difference.

Figure 1: Pueraria lobata (Kudzu). Invasive species native to East Asia. Roadside ditch in Valeggio sul Mincio (Verona, Italia). Photo: Author. 23.10.2020.