Biological Invasions

Biological Invasions
Name	Biological Invasions
Discipline	Ecology, Conservation Biology, Invasion Biology
Related	Charles Darwin, Alfred Russel Wallace, Joseph Dalton Hooker

Biological Invasions

Biological invasions are the establishment, spread, and impact of non-native species in regions outside their historical ranges; they interact with concepts such as Island biogeography, Ecological niche, Species distribution models, Conservation biology, and Global change biology influencing biodiversity, ecosystem services, and human well-being. Research draws on methods and institutions including Linnean Society of London, Smithsonian Institution, Royal Society, and networks such as the Global Invasive Species Programme while intersecting with policies like the Convention on Biological Diversity, Cartagena Protocol on Biosafety, and national regulations exemplified by the Endangered Species Act and Lacey Act.

Definition and Concepts

Invasion science frames introduced taxa through stages—introduction, establishment, naturalization, and spread—concepts that relate to Niche conservatism, Propagule pressure, Allee effect, Founder effect, and Metapopulation theory; key analytical frameworks include Neutral theory, Adaptive radiation, and Island biogeography while drawing on historic syntheses by figures linked to Charles Darwin, Alfred Russel Wallace, and Joseph Dalton Hooker. Terminology distinguishes invasive taxa from Introduced species, Naturalized species, Pest species, and Cryptogenic species using criteria developed by organizations such as the IUCN and the Global Invasive Species Specialist Group. Quantitative metrics—incidence, abundance, range expansion—use methods from Species distribution models, Phylogeography, Population genetics, and Landscape ecology.

Causes and Pathways

Pathways of introduction include deliberate releases (for Hunting, Agriculture, Aquaculture, Horticulture), accidental transport via Global shipping vectors like Ballast water and biofouling, and secondary human-mediated dispersal through Road networks, Rail transport, Air travel, and Pet trade channels highlighted in regulatory responses by the International Maritime Organization and trade instruments such as the World Trade Organization. Historical drivers include colonial-era exchanges associated with Age of Discovery, Columbian Exchange, Great Eastern Railway expansion, and large-scale projects like the construction of the Suez Canal and the Panama Canal which altered biotic corridors; recent drivers involve Urbanization, Climate change, Land-use change, and global supply chains linked to multinational corporations and policy arenas such as the United Nations Framework Convention on Climate Change.

Ecological and Evolutionary Impacts

Invasive taxa can cause trophic disruptions (examples include predatory impacts like Cane toad predation, Brown tree snake depredation), compete with native taxa as seen with Rock pigeon introductions, facilitate hybridization (e.g., Mallard hybrid swarms), spread disease vectors and pathogens (such as West Nile virus, Phytophthora ramorum, or Batrachochytrium dendrobatidis), and trigger regime shifts in ecosystems impacted by events comparable to outcomes studied in Lake Victoria and Aral Sea transformations. Evolutionary consequences include rapid adaptation, genetic swamping, and novel selection pressures investigated using techniques from Genomics, Molecular ecology, Phylogenetics, and case studies involving taxa linked to Charles Darwin's finches, Guppy adaptation experiments, and island endemic responses documented in the Galápagos Islands and by researchers affiliated with institutions like the University of Oxford and Harvard University.

Economic and Social Consequences

Economic impacts encompass losses in agriculture, forestry, fisheries, and human health costs quantified in analyses by entities such as the World Bank, FAO, and national agencies like the USDA and DEFRA; notable economic case studies involve costs associated with Emerald ash borer, Asian carp, and invasive plant species affecting commodities traded under World Trade Organization rules. Social dimensions include effects on indigenous rights and cultural practices observed in regions governed by instruments like the United Nations Declaration on the Rights of Indigenous Peoples, public health outbreaks linked to invasive vectors addressed by World Health Organization guidelines, and livelihood disruptions documented in reports by the International Union for Conservation of Nature and Conservation International.

Management, Prevention, and Policy

Response strategies combine prevention, early detection and rapid response, eradication, containment, and long-term control using integrated approaches informed by agencies such as the US Fish and Wildlife Service, Environment Agency (England), Australian Biosecurity frameworks, and international agreements including the Convention on Biological Diversity and Santiago Declaration-style commitments. Tools include regulatory restrictions exemplified by the Lacey Act, mechanical removal programs exemplified in eradication of rodents on South Georgia and the South Sandwich Islands, biological control projects employing agents assessed through protocols developed by the Food and Agriculture Organization and risk analyses like those used by European Food Safety Authority. Adaptive management leverages monitoring networks coordinated by organizations such as the Global Invasive Species Database, research consortia at institutions like the Royal Botanic Gardens, Kew and CSIRO, and citizen science platforms modeled on projects linked to the National Audubon Society and iNaturalist.

Monitoring, Detection, and Risk Assessment

Effective monitoring uses remote sensing technologies from agencies like NASA and European Space Agency, molecular detection methods (eDNA, qPCR) developed in laboratories at institutions such as Scripps Institution of Oceanography and Woods Hole Oceanographic Institution, and statistical risk frameworks, including pest risk analysis used by the International Plant Protection Convention and probabilistic invasion models employed by researchers at Cornell University and University of California, Davis. Risk assessment integrates climate projections from the Intergovernmental Panel on Climate Change, habitat connectivity analyses informed by The Nature Conservancy, and decision-support tools used by managers in contexts framed by case law and policy from entities like the Supreme Court of the United States and national legislatures.

Category:Invasion biology