Invasion Nation: Anthropogenic dispersal of pioneering species and their perception as invasive rather than successive or beneficial in the industrial era.
Abstract:
Organisms are inherently migratory and seeds, fungi, bacteria and insects have dispersed across continents. Human dispersal and natural dispersal are inherently equal in our ability to distribute other species, however, we degrade ecosystems and have co-evolved with numerous other survivors of our civilization, in places that have been disturbed, some organisms thrived in the face of this adversity and reproduce in higher numbers, more frequently and produce enough stored energy to survive long migrations and extreme conditions. Investigations into the true nature of invasive species reveal political ambitions to maintain chemical industrial infrastructure in farming at all costs and make carcinogenic chemicals somehow seem more benign than organisms that have crosses a political boundary. The study of invasion biology has lost sight of succession, acclimation and other fundamental beliefs in the fluid nature of life on earth, and ecological facts. Invasion Biologists' view a static world where very little contact and migration occurs and ignore many relationships that are beneficial or unaffected by each other's presence. To determine the extent that a local forest had been subdued by non native species, samples along 4 transects were counted and identified. There were no observable effects on native species from grasses or dandelions identified close to paved or dirt roads.
Introduction:
Humans and countless other migratory species have traveled long distances, and often transported other organisms within their migratory movements as they expand and contract their territory. In evolutionary biology, species recede and advance in pulsing patterns as climatic changes occur. Sometimes this takes place more rapidly than their ability to evolve and adapt to changing circumstances, other times it makes areas that had been hostile and makes them ideal. Birds have migrated thousands of miles annually for millions of years often dispersing organisms. Storm events such as hurricanes and floods have been known to redistribute species thousands of miles, often as seeds and spores, a surviving in both salt and fresh water. Natural dispersal of organisms is found to be frequent and long distance, and receiving biota are resilient and accustomed to such events. Man aided dispersal can in no way be distinguished from natural dispersal (Theodoropolous 2001). As we approach the sixth mass extinction of planet earth, attributed primarily to anthropogenic disturbances, is it logical to label certain highly adaptable species as “invasive”,“noxious or“alien when they may be the best suited for small scale wild harvesting, bioremediation and wildlife habitat in some areas? In a theory that aims to suggest a consistent reason for invasions asserts that a plant community becomes more susceptible to invasion when there is an increase in the amount of an unused resource (Davis et. Al 2000).
The use of the term invasive species was first coined by Charles Elton in 1953. Elton was highly influenced by a fellow Oxford student, Alexander Carr Saunders, secretary of the Eugenics Education Society, which promoted the study and practice of selective breeding in humans. Eugenics also suggested pseudo-scientific notions of racial and ethnic superiority and was crucial to Nazi scientists who justified genocide and human experimentation through this scientific discipline. The prejudiced mentality towards living organisms deemed “out of place” migrated into the sub discipline of invasion biology. Terms such as genetic pollution, which are still used today, have the heritage of a hate-based philosophy, and often trigger reactionary emotional responses to romanticized ideals of nature rather than logic or sound scientific reasoning.“the field of invasion ecology has largely dissociated itself from other sub-disciplines of ecology, particularly succession ecology”(Davis et al 2001).
The sub disciplines of invasion biology or invasion ecology are controversial within ecology and have far reaching ecological and economic consequences. (Grime, J.P. 2001) Chemical corporations stand to lose billions of dollars if a more relaxed stance is taken towards invasive species, or integrated pest management begins to take favor, governmental and private eradication programs could loose funding and many researchers and field workers could loose their jobs. Monsanto, the maker of Round-up, the most common of all herbicides containing the compound glyphosate, falsified data on at least 2 occasions in scientific laboratories. Monsanto has also been convicted of false advertising in French court, and has created more than 30 superfund sites.
In terms of habitat destruction, threats to global biodiversity, soil erosion and water contamination, the three plants that have consumed the largest areas of land are wheat, corn and soya. Although these plants do not often colonize undisturbed habitat, their use as an agricultural commodity, especially when grown in large monocultures that often contain genetically modified organisms (GMO) may pose the greatest threat of any species, displacing more native species than any other organisms. The use of “round-up ready”GMO plants has spurred what scientists call “superweeds”. These are crops that are round up ready (resistant to glyphosate) that have spread from one field to another, and also common weeds like Palmer Amaranth (Amaranthus palmeri), which has selected a glyphosate resistant gene after constant exposure to the substance.
While some see invasive species as“the second greatest threat to biodiversity”(Vitousek 1996) others view invasive species as a solemn symbol of succession, resilience and abundance. They symbolize a reminder that nature always finds a way to rebuild it self, literally from the ground up. Seeds, like most organisms, have evolved to survive in the most hash conditions, but are much less likely to succeed outside of their optimal range of preferred soil and climate. After countless generations of breeding and selection, both with and without human intervention, some terrestrial plants have evolved to favor soil and microclimates that has been modified by human use. Feral waste areas are often mistaken for being crowded out by invasive alien species, when in fact, they are the only thing that can survive there at that time, filling the niche of an extinct or ecologically extinct organism. Ecologists coined the term “subsidized species” to describe organisms that respond well to human activity (Klemens 2000).
There is research coming out demonstrating the possible benefits of of some introduced species. Although it receives much less funding from herbicide companies than studies that include massive eradication efforts. Beneficial relationships between introduced species and native have often been overlooked and understated. They often provide forage for both native and domesticated animals, including cows, goats, chickens, turkey, ducks, bees, deer, butterflies, birds, and countless others. Invasive species have often been introduced as a ground-cover, to hold in exposed soils and preventing erosion. Many aquatic species such as water hyacinth can remove toxins from human sources of water pollution, and can then be used to make bio fuels and other non-food products.
Almost every introduced species in the United States prior to World War II had some kind of use in medical professions or as a food or fodder crop for livestock. When post-war suburbia became an institution, people began to look down upon growing a food garden as backwards and a sign of poverty, and suddenly there was a much larger yards and lawns than people had owned before, so landscape companies and nurseries began importing“exotic”plants as show pieces in their yard to add color, textures and sophistication to their yard. Most of these plants cannot survive in the wild, but there are exceptions that adapt to, and thrive in some local or wide ranging conditions. We can see similar trends in flora that followed the destruction of habitat for rail travel in the United States and how plants adapted to the newly disturbed train track areas. Some species such as Eucalyptus, where planted along the railroads to serve as future railroad ties were later found to be inadequate. Although Eucalyptus serves many functions in native habitats, it may also alter other aspects of nearby native plants, animals and aquifers.
Methods:
To determine if terrestrial plants labeled invasive truly reduce biodiversity in undisturbed natural habitats, waste areas or ecotones of two such areas. By making an evaluation of what species and how many are present in each samples of 4 zones establishes an idea of what plants are tolerant of non native species and if areas that contain non natives there is a reduced diversity of native species. If there are invasive species present, they should lower the diversity of the area and occur in an unrivaled abundance, limiting or prohibiting the growth of native species.
Using a tape measurer to determine a transect and recording the different species present in 4 locations along 10ft. x 1ft. strip of vegetation progressively distant from a paved road. If a plant is truly invasive and a threat to native species it will have migrated out of disturbed, shoulder areas into areas that contain primarily native species. After identifying the species present, and determining which, if any were labeled invasive species it could determine wether any of the invasive species might prohibit any natives from completing their natural cycles of reproduction. To determine the proper identification of terrestrial plants I employ a typical guide to the the most common and invasive plants of North America.
Results:
After identifying and counting all the observable species along transects in 4 zones, there was no evidence indicating that any non-native species had either colonized outside of disturbed areas, crowded out native vegetation or reduced biodiversity on this site. The biodiversity was higher in some areas that contained non native species than areas where only natives were present. The most abundant species in the area were native wild flowers, and all 4 transects were within 100 feet of a paved or dirt road. Although this study is small and produces inconclusive evidence scientifically, it does not fit any theories about invasive species and how they interact with natives in terrestrial habitats. While grasses and dandelions might be a big problem for agriculture and industry, it does not seem to be much of a problem for forests, deer or bees.
The other possible invasive species that was present was grass. It is unknown to me at this time if this species of grass is native or introduced, but I find it safe to assume that it has been in contact, and hybridized with at least one non native grass, so I will give the benefit of the doubt that it is potentially an invasive species. It occurred in limited numbers in the 2 samples closest to the paved road.
In most situations except the most fragile ecologies such as deserts oases and small tropical islands where there is a small population of endemic and rare species, it is much more likely that both native and non-native species will learn to cope with each others company, and while species are constantly going extinct for many reasons, invaders will also continue to adapt, evolve and continue to migrate as conditions continue their cycles of fluctuation and succession.
When Zebra Mussels (Dreissena polymorpha) invaded Lake Erie it lowered eutrophication levels, which lead to more invertebrate growth, resulting in a 5 time increase in yellow perch catch between 1990 and 1996 (Sagoff 1999). Water Hyacinth (Eichhornia crassipes) and Waterlettuce (Pistia stratiotes) have increased dragonfly species richness in South America by providing perching and refuge sites for them (Steward and Samways, 1998)
Discussion:
Although it does not surprise me that an ecosystem by the road side could be resilient from outside invaders, there are always threats lurking from not so far away places. The only a few non native plants were noted, and they were closest to the road, occupying waste soil, and relatively few of them; the dandelion (taxacarum officinale), a plant that has been cultivated and documented by humans as a green and medicinal root for centuries in Asia, the Middle East and Europe, as well as a consistent food source for domesticated animals and dozens of species of wildlife in North America. It is rumored that sailors used dandelions on sea voyages to prevent scurvy, with abundant Vitamin C present in their leaves, and there is evidence they were brought to the New World both accidentally and intentionally on early voyages of explorers and settlers. It has been used in phenology studies to track changing temperatures and their relationships to the flowering time of plants. While many domesticated crops failed to show any difference, wild plants have responded to changing temperatures by flowering earlier in the spring. Dandelion is an excellent candidate for further studies of wider scope in phenology because it is so common.
While many rare species such as keystones species continue to be killed intentionally by humans or by our development and consumption habits, a wide range of species have also adapted to tolerate our presence and in some cases, thrive from our impact on the planet, some in captivity, some free to roam and procreate in the wild. While reductions in biodiversity may be taking place, it is unfounded and naive to assume that“invasive species”bear much responsibility towards our loss of diversity when global warming and climate change, over development and consumption. The threat of “invasive species”is more often used as a selling point of chemical pesticides, fungicides and herbicides than by real ecologists. The Chemical Industry thrives on the psychological view of invasive species and many pests in general as scapegoats that creates a culture of fear towards the natural world and promotes the constant expansion of large scale agriculture, mining and development into natural habitats which poses a far greater risk to biodiversity than exotic plants can ever impact any ecosystem.
Literature:
Theodoropoulos, D.I., (2003), Invasion Biology: Critique of a Pseudoscience, Blythe, Ca: Avvar
McNeely, J., (2001), Land Use and Water Resources Research, Invasive species: a costly catastrophe for native biodiversity, Director, IUCN Biodiversity Programme, Gland, Switzerland
Inoue, M.N., Goka, K. (2009), The invasion of alien ants across continents with special reference
to Argentine Ants and Red Imported Fire Ants. Biodiversity, 10(2) 67-71.
Grime, J.P. (2001), Plant Strategies, Vegetation Processes, and Ecosystem Properties.Chichester:John Wiley & Sons, LTD
Johnson, E.A., & Klemens, M.W. (Eds.). (2005), Nature in Fragments: The Legacy of Sprawl, New York: Columbia University Press
Colautti, Robert I., MacIsaac, Hugh J. (2004), A neutral terminology to define 'invasive' species" (PDF), Diversity and Distributions 10: 135–141,
Hails, Rosie; Timms-Wilson, Tracey, (2007) Genetically modified organisms as invasive species? In: Nentwig, Wolfgang, (ed.) Biological Invasions. Springer, 293-310. (Ecological Studies, 193).
Charles S. Elton and the Dissociation of Invasion Ecology from the Rest of Ecology, by Mark A. Davis, Ken Thompson and J. Philip Grime, (2001) Diversity and Distributions, Blackwell Publishing
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