Invasive Alien Species: The Second Biggest Threat To Biodiversity


Invasive Alien Species (IAS) are the second biggest threat to biodiversity (after habitat destruction) and are a major cost to the economic wellbeing of the planet. They cause enormous and often irreversible harm to biodiversity around the world by displacing native and useful species and changing ecosystems. They are responsible for the extinction or decline of many species and continue to pose a huge threat to many more. They cost economies billions of dollars every year, in lost production, control and mitigation efforts, loss of ecosystem services and many other ways.

Invasive species can profoundly perturb environments, and communities or societies that value these in any way are negatively affected as a result. The species which invade from other part of the world to a new habitat are called alien species, are biggest threat to the biodiversity and also to the economic security .In the recent past Anthropogenic activities has facilitate the alien species to move across the globe and creating havoc in natural ecosystem.

Ecological Loss due to Invasive Species:

Invasive species affect the local biodiversity of the ecological system by altering the natural processes .They affect the native ecological biodiversity such as competition for resources, habitat alteration and spreading of pathogens; upsetting ecological interactions and contributing synergistic effect with other invasive species. The initial impact of invasive species towards ecological loss may be low but later the consequence shown by displacing native species, which causes changes in the ecosystem functioning • Causing extinctions, which may have “cascade” effects and cause further extinctions • Damage ecosystem services (such as nutrient cycling, energy flow ) • Shifting environmental conditions such as widespread soil erosion .

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Disturbing ecological processes and thereby facilitating invasion by other alien species • Altering of the food web and nutrient cycles which are the strength of ecosystem to support the evenness of the ecosystem.

Research Question:

To what extent the alien species Parthenium has affected the sustainable agriculture in Chandka area over a period of last five years, 2015 to 2018?

Study Area:

The study was carried out near Chandka Sanctuary (ANP), 8 km south-east of Bhubaneswar at 39o 48′ – 40o 10′ E and 8o 50′ – 9o 10′ N. ANP lies to the either side of the main NH-60 highway between Chandaka industrial estate and Barang. Its altitude ranges from 705 -2007 m a. s .l. Chandaka is one of the most geographically active regions of the India sub-continent (Birdlife International, 2008). Much of the grassland in the northern and western part of the Sanctuary overgrazed, resulting in up to 50% bare soil and rock and the domination of invasive, unpalatable species such as needle grass Aristida spp. Shrubby areas around the grassland are more mixed with some Acacia, Grewia spp., Psiadia incana and Vernonia sp (Birdlife International 2008). Chandaka Sanctuary has been experiencing the semi -arid agro-ecological condition.

The study was conducted in Sungai Petani of the state of Kedah, Malaysia (Fig. 5) during July 2016

Sampling Method:

A reconnaissance investigation was carried out to see the pattern of parthenium weed distribution and to design suitable sampling method. Based on the uniform distribution of the weed along the Highway run east-west a total length of 50 m x 13.5 km was considered in both sides of the road. A preferential sampling method was used.

The sampling plots were arranged on the transect line laid on both side of the road. A quadrat of 2mx2m was laid in an interval of 250. At each point two quadrats, one from infested (IN) and one from non-infested (NI) and a total of 216 quadrats were considered. Each species available in the quadrat was counted and recorded. Visual cover estimation of each specie was taken. For stand crop biomass determination, 1mx1m area in the center of the main quadrat was harvested at ground level. For the infested plots separation was made to parthenium and non-parthenium (INNP) and kept in separate paper bag. The harvested biomass was made to dry in an oven adjusted to 1050C for 24 hours for Dry Matter (DM) determination. Voucher specimens were collected, coded, pressed and taken to Addis Ababa University National Herbarium and identified to species level following Flora of Ethiopia and Eritrea volumes. Simpson’s diversity index in disturbed and undisturbed area by Invasive species: Soil quality of disturbed and undisturbed area by Invasive species: NPK Soil water holding capacity Soil respiration.


Due to the invasive capacity and allelopathic effects of Parthenium hysterophorus (Grice 2006), natural ecosystems are disrupted and thus become a big threat to biodiversity (Evans 1997).

According to Ayele (2007), more than 90% of the sample farmers in Jigiga (south-east Ethiopia) observed that Parthenium hysterophorus poses threat for the loss of biodiversity. Livestock grazing could also have a profound effect on vegetation change, in which grazing intensity increased the herbaceous composition change from high palatable to less palatable species (Amsalu 2000). A study in Kobo (Ethiopia) (Mulugeta 2006) also showed that soil samples taken from highly infested areas of Parthenium hysterophorus were negative for nematode count. Studies in Australia and India have also demonstrated that parthenium adversely affects the composition and diversity of species thereby resulting in displacement and imbalance in natural and agricultural system (McFadyen 1992, Chippendale and Panetta 1994, Grice 2006).


It is evident from primary data This weed is known to cause many health hazards which have now reached epidemic proportions. The pollen from P. hysterophorus not only affecting food and fodder crops, but also provoke allergic contact dermatitis in humans. Dermatitis disease manifests as itchy erythematous papules and papulovesicular lesions on exposed areas of the body . The older persons those who are exposed to this plant for prolonged period manifest the symptoms of skin inflammation, eczema, asthma, allergic rhinitis, hay fever, black spots, burning and blisters around eyes.

Parthenium hysterophorus also causes diarrhoea, severe papular erythematous eruptions, breathlessness and choking. Exposure to P. hysterophorus pollens causes allergic bronchitis also. Ramos et al. (2001) assessed the mutagenic potential of a crude extract of P. hysterophorus in the Salmonella/microsome (Ames) assay and the mouse bone marrow micronucleus test. However, it did not show genotoxic potential. Sharma et al. (2005) observed that the clinical pattern of Parthenium dermatitis progresses from airborne contact dermatitis to mixed pattern or chronic actinic dermatitis pattern. Eczema herpeticum is reported to complicate parthenium dermatitis. Srirama Rao et al. (1993) worked on the use of murine polyclonal anti-idiotypic antibodies as surrogate allergens in the diagnosis of P. hysterophorus hypersensitivity.

Parthenium-sensitive patients with rhinitis who had positive results on skin prick tests to P. hysterophorus pollen extracts responded with a positive skin reaction to mAb-2. Akhtar et al. (2010) studied the involvement of TH type cytokines in Parthenium dermatitis. Exposure to P. hysterophorus also causes systemic toxicity in livestock Alopecia, loss of skin pigmentation, dermatitis and diarrhoea has been reported in animals feeding on P. hysterophorus. Degenerative changes in both the liver and kidneys and inhibition of liver dehydrogenases have been reported in buffalo and sheep.


The analysis of primary and secondary data showed that the propagation and potential existence of Parthenium hysterophorus L. weed in diverse; from dry cropland to swampy area and also to different economically important ecosystem at associate appealing rate, which supplies the impression of issue to manage its distribution within the future.

Further area of studies:

The management strategies to counteract the invasive species perthenium till now are not productive due to high fecundity of regeneration, resistance to herbicide; conjointly high ability to adapt adverse environmental conditions and high germination ability throughout the year in wide range of ecosystem. This noxious weed can be managed by public awareness and participatory integrated approaches. There is a need to encourage the research on utilization of this weed for insecticidal properties and try to evaluate the potential on pests of different crops. So far only fewer efforts have been made to control P. hysterophorus by using bio herbicides .More intense research in this direction is vital in the development of bio herbicides. Also, more efforts need to be done by agriculturists, scientists and government to work together for managing this troublesome weed through integrated and eco-friendly approaches.

This baneful colonial weed could be managed by public awareness and democratic integrated approaches .Therefore, there is a necessity to encourage the analysis on utilization of this biomass for insecticidal properties and check out to judge the potential impact on pests of various crops. To date solely fewer efforts are taken to regulate P.hysterophorus by application of bio herbicides .Therefore, more intense analysis during this direction is important within the development of bio-herbicides. Also, additional efforts must be taken by horticulturist, scientists and government to figure along for management this alien weed through integrated and eco-friendly approaches.

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Invasive Alien Species: The Second Biggest Threat To Biodiversity. (2022, May 27). Retrieved from

Invasive Alien Species: The Second Biggest Threat To Biodiversity
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