Andrew Kenney

 

Pbio 209

 

Web Assignment

 

February 11, 2008

 

 

Eastern Poison Ivy

 

 

      Eastern Poison Ivy, Toxicodendron radicans (L.) Kuntze, is a common plant that grows in North America, predominantly in the eastern half of the United States and Canada, stretching as far west as Arizona and Ontario (Toxicodendron radicans (L.) Kuntze, USDA, 2008.) According to the World Wildlife Foundation, Eastern Poison Ivy is located in several different habitats, including Temperate Broadleaf and mixed forests, Temperate coniferous forests, Boreal forests and taiga, Temperate grasslands, savannahs and shrub land and Deserts and Xeric Shrubland.  (Chris Hall, 2006.)

 

I chose Poison Ivy because I wanted to learn more about the plant that has been the bane of my existence every summer since I was a little boy, for I am extremely allergic to it. Eastern Poison Ivy is a perennial dicot that can grow in several different forms. It can grow as a shrub, sub-shrub or woody vine. Eastern Poison Ivy also has several different growth forms, such as dwarf, erect, decumbent and high climbing. It can grow from one to over six feet tall, with a trunk almost six inches in diameter. Eastern Poison Ivy’s very advantageous roots allow vines to stretch for up to 150 feet. The rhizomes of Poison Ivy can occur anywhere between deep underground to above the surface. Eastern Poison Ivy’s leaves are sets of three that can have smooth or jagged edges. Eastern Poison Ivy is deciduous, dropping its leaves for the winter. Eastern Poison Ivy also has a dry round fruit that is known as a drupe, which is a fleshy fruit with a seed inside it. 

 

 

                                                                                                     

(The above image is the habitats of Eastern Poison Ivy outlined in red, combining the sources of USDA and WWF) 

 

 

 

 

 

(A Poison Ivy plant during the summer-www.Poison-ivy.org)

 

 

 

            Eastern Poison Ivy has the ability to reproduce vegetatively and sexually. This means that it can either expand by producing more cells and increasing in size and biomass or by fertilizing its seeds and dropping them to produce a new colony. Eastern Poison Ivy takes three years to develop from a seed to a flowering plant. The plants’ seeds are usually dispersed by animals eating the seeds and distributing them, but they can also be dispersed by water because they float. In certain places in the United States Eastern Poison Ivy is very important to grazing wildlife like white tailed dear. It is their first choice of food and supplies them with much of their nutrients.  

 

 

 

(A creeping Poison Ivy plant- www.Poison-Ivy.org)

 

 

 

            Eastern Poison Ivy flowers when its leaves are half open, blooming between May and July. Its fruit matures from August to November and may stay with the plant until the next flowering season.

 

            Eastern Poison Ivy is a ruderal species, that is, a species that will grow in recently disturbed areas. It is a first and second succession species, which means that it can grow first in an area or it can come along after other plants have already been established (SPECIES: Toxicodendron radicans, USDA Fire Effects Information System, 2008.)

 

 

            Eastern Poison Ivy also produces a skin irritant on its leaves called urushiol. This causes a rash on most people who encounter it with bare skin. The technical term for this rash is urushiol-induced contact dermatitis. The severity of this rash can range from minor skin irritation to blistering and sores, depending on the person. This oil can be contracted by directly touching the leaves, touching something that has contacted the leaves or contacting smoke from the burning of the leaves (Toxicodendron radicans,Wikipedia, 2008.)

 

 

As mentioned in the first part of this essay, Eastern Poison Ivy lives in several different biomes as defined by the World Wildlife Federation. Here is a list of those biomes again:

 

1. Temperate Broadleaf and Mixed forests.

 

2. Temperate Coniferous Forests.

 

3. Boreal Forests/Taiga.

 

4. Temperate Grasslands, Savannahs and Shrubland. .

 

5. Deserts and Xeric Shrubland. (Chris Hall, 2006)

 

            In today’s modern world each individual biome where Eastern Poison Ivy lives is being threatened in some way. So to better understand each biomes hazards they will be broken down one by one in this essay and discussed to some extent. It would be impossible to discuss every possible threat to each biome in such a brief format so the main threats will be the focus.

 

            First will be the Temperate Broadleaf and Mixed forest. Almost all of these forests located in the eastern half of the United States spanning from Florida to Southern Canada have been disturbed in one way or another since the arrival of Europeans to the Americas. What is left of these forests still has looming threats such as logging, clear cutting for introduction of agriculture, human development as well as air pollution and acid rain.  (Temperate Broadleaf and Mixed Forest Ecoregions, 2006 )  

 

            Temperate Coniferous Forests located in the southeast United States also has its fair share of threats and disturbances. Over time this area has been heavily logged and cleared which has destroyed much of the native stands. The suppression of fire has also affected this region, allowing hardwoods to become the dominant species in many areas. As with many places in the United States urban sprawl and general development are encroaching on this ecoregion. (Temperate Coniferous Forest Ecoregions, 2006)

 

            Boreal Forests/Taiga located in the eastern half of Canada are in some danger as well, like the previously discussed forests Canada’s Boreal is being logged heavily, especially in the southwestern regions. Farther north very extensive mining activities are destroying large parts of the forest (Canadian Boreal Forests - A Global Ecoregion, 2006.)

 

            Temperate Grasslands, Savannahs and Shrublands of North America are located in the central and northern United States stretching into Canada.  Grazing and farming are taking their tolls on this ecoregion and the threat of oil and gas development is becoming more and more apparent as well as the construction of transportation corridors (Northern Prairie - A Global Ecoregion, 2006.)

 

Deserts and Xeric Shrubland is the last on the list of biomes where Eastern Poison Ivy lives. This ecoregion is located in the Southwest United States. Some problems this region is encountering are the introduction of irrigation, ranching, the introduction of non-native species and intensive recreational use. (Sonoran-Baja Deserts - A Global 200 Ecoregion, 2005 )

 

All of the threats to each of these biomes are man caused, whether it be logging, pollution or destruction of habitat for development.  Therefore they are all preventable or at the least we can monitor these threats. We as humans need to be mindful of the entire biome every time we begin a new project. If we are careful of where we expand to and try to leave the area as close to its natural state as possible, or maybe pass laws to prohibit certain things like over-logging or development in undisturbed areas then the future will be bright for our children.

 

            However, since Eastern Poison Ivy is a ruderal species the events that threaten and destroy local parts of the forest and other biomes in which it resides may actually be beneficial to individual plants.  Things like development and clear cutting in forests create more edges and fragmentation which is where Eastern Poison Ivy thrives (SPECIES: Toxicodendron radicans, USDA Fire Effects Information System, 2008)

 

 

 

 

 

 

Bibliography   

 

Canadian Boreal Forests - A Global Ecoregion. [Internet] [Updated 18 July 2006] World Wildlife Foundation. http://www.panda.org/about_wwf/where_we_work/ecoregions/canadian_boreal_forests.cfm

 

 

 

Chris Hallis. 2006. Living Planet Report. WWF International

 

Avenue du Mont-Blanc CH-1196 Gland, Switzerland.  

 

 

 

Northern Prairie - A Global Ecoregion. [Internet] [Updated 18 July 2006] World Wildlife Foundation. http://www.panda.org/about_wwf/where_we_work/ecoregions/northern_prairie.cfm

 

 

 

Poison Ivy Pictures [Internet]. [Updated 10 February 2008.] Poison-Ivy.org. http://www.poison-ivy.org/html/summer1.htm 

 

 

 

Sonoran-Baja Deserts - A Global 200 Ecoregion. [Internet] [Updated 13 November 2005] World Wildlife Foundation. http://www.panda.org/about_wwf/where_we_work/ecoregions/sonoran_baja_deserts.cfm

 

 

 

SPECIES: Toxicodendron radicans.[Internet]. [Updated 9 February 2008] USDA Fire Effects Information System. http://www.fs.fed.us/database/feis/plants/vine/toxrad/all.html#MANAGEMENT%20CONSIDERATIONS)

 

 

 

Temperate Broadleaf and Mixed Forest Ecoregions. [Internet] [Updated 11 July 2006] World Wildlife Foundation. http://www.panda.org/about_wwf/where_we_work/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat04.cfm

 

 

 

Temperate Coniferous Forest Ecoregions [Internet] [Updated 11 July 2006] World Wildlife Foundation. http://www.panda.org/about_wwf/where_we_work/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat05.cfm

 

 

 

Toxicodendron radicans. [Internet]. [Updated 10 February 2008] Wikipedia web encyclopedia. http://en.wikipedia.org/wiki/Poison_Ivy

 

 

 

Toxicodendron radicans (L.) Kuntze. [Internet]. [Updated 10 February 2008]. Natural Resources Conservation Service United States Dept. of Agriculture. http://plants.usda.gov/java/profile?symbol=TORA2.