Due to the increasing globalization and climate change in recent years, invasive alien species with their harmful and adverse effects on biodiversity have become a global threat to ecosystems. Several organizations are showing an intense concern for the growing menace with multiple international initiatives and educational guidelines.
A study published in Global Change Biology indicates that a 20% increase of alien species in ecosystems can result in a dramatic loss of biodiversity, causing permanent damage to ecosystems as they push past the tipping points of biology.
However, this issue of invasive species remains a low profile in some regions of the world because of other priority socio-economic and political concerns.
Many people are also unaware of this growing global concern and its aftermath. If this sounds like you, let’s take a look at what invasive species are and how they threaten biodiversity in ecosystems!
What are Alien Invasive Species?
By definition, alien species are species that leave their habitats for another to reside. There are several causes behind alien species invading new ecosystems: from ballast water, firewood to accidental release, and people for exotic pet keeping or globalization.
If these alien specimens prosper and negatively affect the habitat on a large scale, they become invasive species. Invasive species invade the new region and negatively impact its ecosystem, causing economic, environmental, or health implications.
These species increase in number very quickly if their food chain includes the wildlife of their new environment. They then dominate that area by topping the food chain. It leads to biodiversity loss and disrupts the balance of the ecosystem. Sometimes some species are also presented to the new region intentionally for introducing wildlife or protecting endangered species. If they have no negative impacts, they are not deemed as invasive species.
Invasive species are not harmful because of what they are but because of where they are.
Effects of Invasive Species
Different kinds of species come together to create a balanced ecosystem. A slight modification can blunder up the whole ecosystem. These invasive species become very aggressive towards native species. They do so to dominate the food chains and change the habitat according to their likings. They can cause economic, environmental, or health implications.
Below are some examples from history for each!
The invasion of alien species may result in an economic loss as they attack. An example of this can be invasive pest attacks on the crops that ruin the harvest., resulting in loss of profit.
These kinds of species are destructive to the ecosystem because of their rapid speed of overtaking the environment. The reason for their rapid growth is that they have a great level of competence, knowing that there are not any active predators to overtake them in their new landscape. Because of their characteristics like speed, size, and strength, they can escape or win over potential predators. They cause native species extinction by going head to head for resources, making resources limited. When they make the resources limited, the food chain changes, triggering a change in the habitat for the essential wildlife. Another example can be the north-eastern emerald ash borer invading America and Canada. It attacked and destroyed a massive number of ash trees, causing economic loss.
There are many examples of invasive plants resulting in environmental loss throughout history. In the mid-1800s, north-eastern America witnessed the introduction of two non-native plants from the milkweed family. These were the black swallow-wort and pale swallow-worts. Due to their dense patches of the vine, these were famous for decorative purposes. Both the plants overtook their new environment and grew immensely, not letting others strive. Hence, earning the name dog strangling vine. Buckthorn is also one of the aggressive invaders. It invades the wetlands destroying the food sources and habitat of the wildlife. Buckthorn also kills off important plants for us and our ecosystem. Another instance is the accidental release of Zebra mussels residing in south Russian and Ukrainian waters globally. They block water pipes, steal food sources like plankton from the native fishes and hurt them with their razor-sharp shells.
Threat to us Humans
Invasive species not only make it hard for the natives to coexist but us humans too. Some non-invasive species may introduce diseases or virals unbeknownst to us millennials. Furthermore, there’s another perspective to it as well. We are where the problem stems from as we are also invasive. We chop down trees to make space for our civilizations, ruining the habits of many important species. Many species run away and invade other areas because we invaded theirs, or they die off. People hunt down animals for pleasure. It has wiped out the population of different animals, causing their extinction and disrupting the ecosystem.
Are Invasive Species a Threat to Biodiversity?
Biodiversity refers to the diverse range of life forms on Earth. It accounts for all ecosystem types, species, and genetic alleles. We need different organisms to produce, consume and decompose. The preservation of biodiversity is essential for sustaining all life forms. Invasive exotic species are causing permanent damage to ecosystems. The consistent increase in the number of invasive species is causing a decrease in biodiversity.
Invasive alien species are known for endangering biodiversity. However, not all alien species are harmful. Some non-native species bring benefits to their new area of habitation. Invasion of the alien species is known to destroy the habitat, but it can restore one with a dying habitat or an area whose ecosystem can’t be restored. Invasive species can take over that environment and create a new functioning habitat. Hence, we introduce some intentionally. They may provide a source of food for the birds and the herbivores. They also provide pollen, nectarines for bees and many other insects. For instance, the Biggest World’s toad, the Cane toad, is originally from Southern and Central America. They were introduced to the Caribbean and northern Australia to end destructive beetles that attacked the sugarcane in Queensland. These poisonous toads invaded their new area by killing their potential predators and competing with the native toads.
But it’s better to get rid of the invaders and replace them with the native plants, which will not overtake the environment and produce a source of food for the animals.