Increase in invasive species

An increase in invasive species refers to the proliferation and spread of non-native species that have been introduced to an ecosystem and subsequently dominate and disrupt the native plant and animal communities. These invasive species often have competitive advantages over native species, allowing them to outcompete and displace them.

The increase in invasive species is considered a form of land degradation due to the following reasons:

• Disruption of native ecosystems: Invasive species can disrupt the natural balance and functioning of ecosystems. They often have no natural predators or controls in their new environment, allowing them to multiply rapidly and outcompete native species for resources such as nutrients, water, sunlight, and habitat. This displacement of native species can lead to a loss of biodiversity and alter the ecological structure and dynamics of the affected ecosystem.

•  Reduction of native species diversity: Invasive species can outcompete native species for resources and directly or indirectly harm them. As a result, the presence of invasive species can lead to a decline in the diversity of native plant and animal species. Native species are often adapted to local conditions and play important roles in ecosystem functioning, such as providing food and shelter for other organisms. The loss or decline of native species can have cascading effects throughout the ecosystem.

• Altered nutrient cycles: Invasive species can alter nutrient cycling processes in an ecosystem. They may have different nutrient requirements or engage in different nutrient uptake and release mechanisms compared to native species. This can lead to imbalances in nutrient availability and affect the overall nutrient cycling dynamics, potentially impacting the growth and survival of native plants and disrupting the nutrient flow within the ecosystem.

• Habitat degradation: Invasive species can degrade and alter native habitats. They can change the physical structure of the landscape, alter the composition of plant communities, and modify the availability of food and shelter for native wildlife. Invasive plants, for example, can form dense monocultures that exclude native vegetation, reducing habitat complexity and biodiversity.

• Increased vulnerability to disturbances: Invasive species can increase the vulnerability of ecosystems to other forms of disturbance. They can create fuel loads that increase the risk and intensity of wildfires, alter hydrological patterns, and decrease the resilience of native communities. Invasive species can also facilitate the spread of diseases or pests that can harm native species, further exacerbating the degradation of the land.

• Economic and human health impacts: Invasive species can have significant economic and health implications. They can damage crops, reduce agricultural yields, clog waterways, impact infrastructure, and increase the costs of eradication and control efforts. Invasive species can also pose risks to human health by carrying diseases or causing allergic reactions.

Managing and controlling invasive species is essential to prevent further land degradation and protect the ecological integrity of ecosystems. Early detection, rapid response, and the implementation of appropriate management strategies are key to minimizing the negative impacts of invasive species on land.

There has been a significant increase in the number of invasive species worldwide in recent decades. According to a study published in the journal Nature in 2017, the number of invasive alien species has increased globally by about 70% since 1970, and continues to rise.

Another study published in the journal Global Change Biology in 2020 analyzed data on 16,019 alien species across 28 taxonomic groups and found that the rate of new introductions of invasive species has accelerated in recent decades, with more than 1,300 new introductions per year since 2000.

The consequences of invasive species can be severe, as they often outcompete native species for resources, alter ecosystems, and disrupt ecological processes. Invasive species can also cause economic damage, such as reducing crop yields or damaging infrastructure.