The state of Kerala has recently witnessed the emergence of alien invasive plant species in its water bodies, fueled by the occurrence of floods and landslides. The swift overflow of rivers and the creation of physical routes due to landslides have facilitated the formation of primary colonies of non-native plants. These include species such as Nila grass (Mimosa diplotricha), Mikania (Mikania micrantha), Lantana (Lantana camara) and Siam weed (Chromolaena odorata).
The Dangers of Invasive Species
An invasive species can be any organism – a fish, insect, plant, fungi, or even seeds – that is not endemic to an ecosystem but poses significant harm. Whether they’re affecting the economy, environment or public health, invasive species are notorious for their damage. They are especially challenging to control after colonizing a landscape due to their natural phenotypic plasticity, an adaptation mechanism to environmental stress.
Invasive plant species change the soil structure and microenvironment to favor their growth, often resulting in the degradation of local biodiversity. They produce allelochemicals which are detrimental to native species. For instance, the invasive species Anthemis cotula excretes allelochemicals that inhibit the germination of native competitor’s seeds and retard seedling growth. Similarly, Black Walnut produces an allelochemical called Juglone, which negatively impacts plants like tomatoes, peppers, and potatoes.
Impact on Kerala’s Native Ecosystem
These invasive species jeopardize both farmland and wildlife habitats. Specifically, in the Kuttanad region, the invasive water hyacinth (Eichhornia crassipes) and giant salvinia (Salvinia molesta) have begun colonizing paddy fields, cultivated lands, and other isolated water bodies. The Kole wetland in Thrissur is another victim of the invasive onslaught, with species such as matamat (Rhynchospora corymbosa), desho grass (Pennisetum pedicellatum), giant salvinia, and water hyacinth leading to potential marsh to dry land conversion.
| Region | Invasive Species | Impact |
|---|---|---|
| Kuttanad | Water Hyacinth and Giant Salvinia | Colonization of paddy fields and cultivated lands. |
| Thrissur | Matamat, Desho Grass, Giant Salvinia, and Water Hyacinth | Potential conversion of marshy wetlands into dry land. |
Addressing the Invasive Threat
The issue of invasive species must be managed during post-flood rebuilding efforts. The involvement of communities in identifying and reporting these plants to the Forest Department is crucial. The department should conduct a thorough survey to gauge the area and density of invasive plant spread in wildlife sanctuaries, national parks, and protected areas. Sufficient time and budgetary allocation are required to manage this substantial task.
The Role of the Cartagena Protocol on Biosafety
The Cartagena Protocol on Biosafety is an international agreement fostering the secure handling, transport, and application of living modified organisms (LMOs) originating from modern biotechnology that could negatively affect biological diversity or pose risks to human health. The Convention on Biological Diversity recognizes the urgency to address the effects of invasive species and mandates each member state to prevent, control or eradicate such alien species that pose a threat to ecosystems, habitats or other species.
Protecting Globally Important Agricultural Heritage Systems (GIAHS)
The Kuttanad Wetland Agriculture System, an area significantly impacted by the invasive plants, is India’s unique system for sub-sea level rice cultivation formed by draining delta swamps in brackish waters. This agricultural system is recognized as a Globally Important Agricultural Heritage systems (GIAHS) site by the Food and Agriculture Organization, an initiative aimed at protecting sustainable agricultural models around the world. Besides Kuttanad, India has two more GIAHS sites – Koraput Traditional Agriculture in Odisha and Pampore Saffron Heritage in Kashmir. It’s pivotal to protect these sites from the adverse effects of the invasive species.