Menace of Cuscuta in Vedanthangal Bird Sanctuary UPSC

CUSCUTA DODDER

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Picture Courtesy: https://blog.invasive-species.org/2021/02/09/cuscuta-reflexa-identified-as-problematic-dodder-devastating-farmers-in-western-kenya/

Context: An invasive parasitic vine called Cuscuta dodder is rapidly spreading in the Chengalpet forests and Vedanthangal Bird Sanctuary, threatening the local vegetation and habitat of migratory birds.

About Cuscuta Dodder

It is an invasive plant species native to North America. It is a holoparasitic plant that lacks roots and depends on host plants for nutrients. The vine wraps around the host plant, forming a dense canopy of tendrils that can eventually lead to the strangulation and death of the host.
It has already infested acres of trees in the Chengalpet forests and has entered Vedanthangal Bird Sanctuary. The plant has been observed covering the canopy of Barringtonia trees, which are preferred nesting sites for migratory water birds.
It poses a serious threat to the local vegetation, ecology, and the habitat of migratory birds. The dense growth of Cuscuta dodder can impact the health of host plants and may lead to the decline or death of native trees.
The seeds of Cuscuta are noted for their durability, surviving up to 50 years in dry storage and at least 10 years in the field. Unlike root parasites, Cuscuta seeds do not require a specific stimulant to induce germination.
It is recognized as a serious problem in various states in India, affecting oilseeds, pulses, and fodder crop Globally, legislation in 25 countries lists it as a 'declared noxious weed,' with restrictions on the movement of seeds and plant material.

Forest officials and staff are reportedly manually removing the Cuscuta dodder during the summer months when water levels in the lake recede, and migratory birds are not present. However, the invasive nature of the plant and its rapid spread require immediate attention and effective control measures.

Vedanthangal Bird Sanctuary

It is the oldest bird sanctuary in India, located in Kanchipuram district, Tamil Nadu. It was established in 1798 by the Nawab of Carnatic and officially declared a bird sanctuary in 1930.
It is located in a low-lying area, surrounded by agricultural lands and ponds.
Some of the common birds include painted storks, spot-billed pelicans, cormorants, darters, egrets, herons, ibises, spoonbills, ducks, geese, teals, shorebirds, raptors, owls, kingfishers, swallows, and warblers.
The Palar River passes near the sanctuary and provides a source of water for the lake.

PRACTICE QUESTION

Q. What is Cuscuta Dodder, which is frequently seen in the news?

A) A type of carnivorous plant

B) A parasitic vine without roots

C) A medicinal herb

D) An ornamental flower

Answer: B

Explanation:

Cuscuta Dodder is a parasitic plant that belongs to the genus Cuscuta. Unlike typical plants, Cuscuta Dodder lacks chlorophyll and true roots, rendering it unable to photosynthesize and absorb nutrients from the soil. Instead, it relies entirely on host plants for sustenance. The vine wraps itself around the host plant, forming a dense network of tendrils that penetrate the host's vascular system to extract water and nutrients.

The absence of roots makes Cuscuta Dodder entirely dependent on its host for survival, earning it the classification of a holoparasitic plant. Its parasitic nature can be detrimental to the host plant, as the Cuscuta Dodder can weaken, strangle, and eventually kill its host. This invasive behaviour can have significant ecological implications, leading to concerns when it is observed in natural habitats, as reported in the news.