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INVASIVE ALIEN SPECIES: A THREAT TO THE BIODIVERSITY AND ENVIRONMENT

INVASIVE ALIEN SPECIES: A THREAT TO THE BIODIVERSITY AND ENVIRONMENT. BY ZAHIDULLAH KHAN PhD Scholar QAU Islamabad. Introduction.

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INVASIVE ALIEN SPECIES: A THREAT TO THE BIODIVERSITY AND ENVIRONMENT

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  1. INVASIVE ALIEN SPECIES: A THREAT TO THE BIODIVERSITY AND ENVIRONMENT BY ZAHIDULLAH KHAN PhD Scholar QAU Islamabad

  2. Introduction Plants originally originated in specific habitats, under particular set of edapho-climatic conditions and historically flourished their for thousands of years with out mixing with flora of another region. This was because natural biogeographic barriers isolated the continental biota for millions of the years. So that each biogeographic zone of the world was occupied by specific type of flora, different from that of another such region.

  3. Introduction However the increased travel, transport, trade and tourism associated with globalization have lead to the drastic breaching of biogeographic barriers resulting in mixing or homogenization of the earths biota at local, regional, continental and global levels. This intentional or unintentional human aided introductions of taxa from one part of the globe into another part of the globe is causing severe harm to the environment, economies, human health and biodiversity. Therefore invasion ecology is now a days the most rapidly developing field of biology and is the area of most intense research the world over. However in Pakistan even the scientific community is not aware of this global issue in the era of biodiversity.

  4. Concepts & Terminology Alien terminology: • Terms & concepts crucial to invasion Biology are often ambiguous, problematic & non-operational. Native or Indigenous: • Taxa in a given area that have originated & evolved their without human involvement & that have inhabited that area historically for thousands of years are called indigenous or native.

  5. Concepts & Terminology Endemic: Taxa that are confined, restricted, peculiar and specific to a particular locality, or geographic zone, or a country and that don’t occur elsewhere on the surface of the globe. Alien: (non-native, exotic, introduced, non-indigenous, anthropochores, neophytes, adventives, immigrants) • Plant taxa in a particular area that have been introduced by humans intentionally or unintentionally to areas outside their place of origin & natural range of distribution are called Alien.

  6. Concepts and terminology Invasive: According to the Global Invasive Species Program (GISP): “Invasive alien species (IAS) are non-native organisms that cause, or have the potential to cause, harm to the environment, economies, or human health. Invasive alien species (IAS) are one of the most significant drivers of environmental change worldwide.”

  7. Invasive alien species are globally recognized as the second greatest threat to the biodiversity after direct habitat destruction. • Invasive species have the potential to spread vigorously and quickly, out-compete native plant species and degrade natural ecosystem.

  8. What makes an invasive, invasive?Typical characteristics of (IAS) • Aliens that are successful invaders are species that have some advantage over native species.  • Introduced from other habitats • Rapid growth & maturity • Prolific seed production • Aggressive spreaders and prolific reproducers • Highly successful seed dispersal, germination and colonization • Rampant vegetative spread

  9. Typical characteristics of (IAS) • Ability to outcompete native species for space, water, food, and other essential resources • Adapt to a variety of conditions • No natural predators, parasites, etc • High cost of removal and control • Are difficult to control or eliminate once established

  10. Impacts of invasive species • Direct costs in lives (diseases), crop losses • reduced ecosystem function/services • biodiversity loss • Compete with & replace rare and endangered species • Encroach upon limited habitat of rare and endangered species  • Reduce or eliminate localized or specialized native plant communities, such as TDDF Margalla hills • Disrupt insect-plant associations necessary for seed dispersal of native plants

  11. Impacts • Disrupt native plant-pollinator relationships • Reduce eliminate host plants for native insects and other wildlife • Hybridize with native plant species, altering their genetic makeup & reduce gene pool. • Serve as host reservoirs for plant pathogens and other organisms that can infect and damage desirable native and ornamental plants and

  12. Impacts • Replace nutritious native plant foods with lower quality sources  • Kill trees and shrubs through girdling • Increase the incidence of plant disease and stress in forested areas • Prevent seedling establishment of native trees and shrubs • Reduce vigor of mature trees through shading

  13. Impacts • Reduce the amount of space, water, sunlight and nutrients that would be available to native species  • Increase erosion along stream banks, shorelines and roadsides • Change characteristics of the soil structure and chemistry • Alter hydrological flows and conditions

  14. Pathways of Introduction Pathways include: • movement of goods (species translocated in containers, planting media, untreated wood packaging, some food products) • movement of people (by air, road, rail and sea transport) • postal and courier services (including biological material purchased via the Internet) • agriculture and forestry (direct introductions of crops and livestock, unintentional introduction of pests and diseases)

  15. horticulture (dispersal of ornamentals from gardens, ponds etc.) • habitat restoration and landscaping (use of non-native genotypes of native plants, escapes • Plants (Grasses) as packing material

  16. Hypotheses that allow naturalization and invasion: • Enemy Release • Highly competitive • Extra resources • New niche with little overlap • Competitive release from generalist predators or herbivores • Disturbance for colonization

  17. Invasive Aliens in Pakistan • Total Flora about 6000 • Aliens +1000 • Invasive more than 70 species • Drastic Invasive 16 species Lantana camara, Brousonettia papyrifera, Eucalyptus camaldolensis, Parthenium hysterophorus, Leucanea leucosephala, Leptochloa chinensis, Eicchornia crassipes, Prosopis juliflora, Salvinia molesta, Ipomoea carnea, Lolium temulentum, Xanthium stromarium, Bromus unioloides, Phalaris minor

  18. Invasive Aliens of Islamabad • Broussonetia papyrifera • Lantana camara • Parthenium hysterophorus • Prosopis juliflora • Sylibum marianum • Bromus unioloides

  19. Broussonetia papyrifera • Paper Mulberry: • Origin: East Asia • Planted during the 1960s • Prime objective: greening the town • control soil erosion • Act as an aggressive tree • Replaced native flora in a few decades.

  20. Broussonetia papyrifera cont…. • pollen allergy during the months of March and April. • CDA had so far chopped 36, 000 mature trees, 14,000 in the last two years • Considerable measures are still required to ensure the control of paper mulberry from high infestatio area and the adjacent regions

  21. Lantana camara Lantana:native to the US and Mexico. • Among the ten worst weeds of the world • Form continuous thickets at the infected sites in Pakistan. • Due to its aggressive behavior it has replaced native flora • wooden barriers are visible in highly infested Margalla Hills, around Rawal Lake and in Potohar plateau and the Salt Range

  22. Lantana camara cont….. • Occupied a lot of natural grazing ground & is threatening wildlife. • hazardous to animals and humans • leaves and seeds are toxic to (livestock) • Plant acts as potential breeding place for Tsetse Fly • Studies show the allopathic impacts on soil micro flora & fauna

  23. Parthenium hysterophorus • Native to the subtropics of North and South America • Introduced from India • in to Pakistan in 1970s • Invading aggressively in: • wasteland, degraded areas, rocky crevices, along water channels, roadsides, and railway tracks, cultivated land

  24. Parthenium hysterophorus cont…. • This noxious weed affects • crop production • animal husbandry • human health • and biodiversity • Contains Parthenin lactones which are Lethal to humans, Animals and agriculture.

  25. Invasive Plant Control Methods • an amount of Rs. 102 m have been allocated for a project to deal with the IAS problem in the country. • Physical (Mechanical) • Chemical (Herbicide Application) • Biological

  26. Mechanical eradication • Mechanical: Hand pulling, Cutting, weed wrench and wood talon Brush hog or tractor • Mowing • Covering • Grazing root talon weed wrench

  27. Mechanical + Chemical • Cut plant followed by direct herbicide application to cut • cut stump painting • bark injection • Concerns with Mechanical Removal • Erosion caused by disturbed soil can be an avenue of entry for other invasive plant species • Disturbance of nesting areas Bark injection

  28. Chemical • Chemical • Foliar: wipe-on, backpack sprayer, spray bottle, boom applicator • for some plants cut and spray of regrowth will minimize the amount of chemical used. • Basal Bark • Pre emergent • (rarely used in natural areas)

  29. Concerns with Herbicide Use • Contamination of surface or ground water • Accidental application to desired species • Disturbance of nesting areas

  30. EXOTIC/INVASIVE Management Issues • 1. Invasive species will not stop their spread at county, state, or national borders • 2. New invasive species will arrive • 3. Rate of introductions will probably increase because of increasing worldwide trade + global climate change • 4. Coordinated efforts at all levels (county, state, national, international) are needed for effective education and prevention, early detection & rapid response, and control • 5. Adequate funding is essential to success

  31. Inventory(where are all the places that the exotic plants live) Monitoringfor population increase [Density] [Spread] Monitoringfor impact The Decision to Manage Outline (Research) • Biotic Invasions

  32. RESOURCES FOR MORE INFORMATION Global Context - IAS Databases Global Invasive Species Database (GISD) URL: http://www.issg.org/database and http://www.invasivespecies.net/database 100 of the World’s Worst Invasive Alien Species (in GISD) Global Compendium of Weeds (GCW) URL: http://www.hear.org/gcw/alpha_select_gcw.htm European Information System on Invasive Alien Species – Regional Biological Invasions Centre (RBIC) North European and Baltic Network on Invasive Alien Species (NOBANIS) Database URL: http://www.nobanis.org/Search.asp

  33. Thanks for your Attention QUESTIONS

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