Saturday, December 26, 2009

The Speed of Climate Change & Invasive Species Impacts

Nothing is ever simple when it comes to invasive species. Invasive species are a wicked inconvenience and as such are directly connected to the inconvenient truth of climate change. Invasive species are those species that are causing or have the potential to cause harm to a local environment or to human health and well being. [1] Gardeners are long familiar with invasive plant species known as weeds and the disease and insect pests that plant species can carry from garden to garden and to landscapes and ecosystems beyond the garden wall. Climate change and biological invasion are dynamically interconnected and interdependent phenomena, each influencing the other. The two wicked problems are infinite problems infinitely connected.

Climate which is the long-term weather pattern of an area, including temperature, precipitation, and wind[2], affects the range of individual species habitat and suitability. Too cold, too dry, too wet, too windy and a species will not survive. The speed at which physical properties of climate systems change affects the biology of an ecosystem. The change in climate patterns and the speed of these changes permits invasive species to become established and thrive when introduced into new ecosystem. In turn, the speed of ecosystem change, both physically and biologically, can be dramatically increased by the introduction of invasive species. These complex relationships between ecosystems and invasive species result in problems that resist simplified absolute solutions. It is important to understand that climates can exist without biological systems, but useful biological systems are defined by climate; consequently, ecosystem resources and services to humanity are dependent on and supported by a specific narrow range of climate types. [3]

The long march of kudzu and the fire ant demonstrate both the effects of climate change and the cost to human health and well being, as well as the negative impact on other ecosystem services and resources of invasive species. Changes in long term temperature are allowing both species to move northward . As an example, according to a University of Florida website, damage in excess of 150 million dollars a year from fire ants “…can cause significant damage not only to soybean crops, but citrus, corn, okra, bean, cabbage, cucumber, eggplant, potato, sweet potato, peanut, sorghum, and sunflower (Stimac and Alves 1994).” Noting the harm to ecosystem services, the University of Florida observes that the “[r]ed imported fire ants … reduce ground-nesting populations of rodents and birds. In certain instances, the RIFA may completely eliminate ground-nesting species from a given area (Vinson and Sorenson 1986). Because there is a 10 to 20 year lapse before reductions in bird populations are observed, it has been suggested that actual effects of the RIFA on animal populations may be underestimated (Mount 1981).” On the otherhand only this year, kudzu has been reported in Ontario Canada where once it wasthought too cold to harbor this species.

The migration of species because of climate change will radically confuse the definition of native, and will definitely create novel ecosystem questions. Conversations about assisted migration will move into the forefront of policy debates about resource allocation. And, the expected services and resources of a given ecosystem will be altered, requiring a dramatic reshuffling of agricultural services and resources such as food, fuel, feed, fiber, flower and forests along with quickly changing land use decision pressures. We will not be setting the clock back in our life time; we will be learning how to manage the resources of the planet through adaptation and technology, through alterration of consumer expectations and life styles (though not necessarily a lowering thereof). We shall have to confront the particulars of ecosystem services and resource externalities in both our private and public decisions. The idea that one can use the air or water or soil and leave them in altered states without cost is now part of the past. We shall be held accountable one way or another. For 6 billion people to survive and become 9 billion, we all will be adapting to the speed of ecological change.

[1] Beck, K. George and Kenneth Zimmerman, Jeffrey D. Schardt, Jeffrey Stone, Ronald R. Lukens, Sarah Reichard, John Randall, Allegra A. Cangelosi, Diane Cooper, and John Peter Thompson. ISAC 2006. Invasive Species Definition Clarification and Guidance White Paper. [Online] ISAC 2006. .

“Executive Order 13112 – defines an invasive species as “an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”

[2] A. P. M. Baede: [ed.]. Intergovernmental Panel on Climate Change. Working Group I: The Scientific Basis. Appendix I - Glossary. [Online] [Cited: December 17, 2009.]

“Climate in a narrow sense is usually defined as the average weather, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical climate system.”

[3] Menzel, Annette, et al. . The Atmosphere And The Spatial And Temporal Variability Of. [Online] , . [Cited: December 19, 2009.] .

“… react to variations of its atmospheric environment in a sensitive way and it is astounding as to which precision subjective observations of plants are able to reflect the spatial and temporal variability of atmospheric processes across various temporal and spatial scales.”

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