Preserving our Natural World

The American Indians believed in leaving the land as they found it. It is a worthy endeavor to keep this tradition going. Whether we are hiking in native areas, horseback riding or any activity that would take us into native areas we need to take care not to bring non-native seeds on our clothing.

The following series of articles is taken from a study that was performed and printed in the Journal of Environmental Management "Testing the capacity of clothing to act as a vector for non-native seed in protected areas." by Ann Mount, Catherine Marina Pickering.

Although humans are a major mechanism for short and long distance seed dispersal, there is limited research testing clothing as a vector. The effect of different types of material (sports vs hiking socks), or different items of clothing (boots, socks, laces vs legs) or the same item (socks) worn in different places on seed composition were assessed in Kosciuszko National Park, Australia. Data was analyzed using Repeated Measures ANOVA, independent and paired t-tests, Multi-dimensional Scaling Ordinations and Analysis of Similarity. A total of 24,776 seeds from 70 taxa were collected from the 207 pieces of clothing sampled, with seed identified from 31 native and 19 non-native species. Socks worn off-track collected more native seeds while those worn on roadsides collected more non-native seeds. Sports socks collected a greater diversity of seeds and more native seeds than hiking socks. Boots, uncovered socks and laces collect more seeds than covered socks and laces, resulting in 17% fewer seeds collected when wearing trousers. With seeds from over 179 species (134 recognized weeds) collected on clothing in this,
and nine other studies, it is clear that clothing contributes to unintended human mediated seed
dispersal, including for many invasive species.

1. Introduction
Anthropogenic mass movement of species is one of the greatest environmental challenges faced by conservation organizations (WRI, 1992; IUCN, 2000). Human activities are an important mechanism for long distance dispersal of plants and animals including invasive species Human mediated dispersal of plants can be deliberate for agricultural and ornamental purposes (Groves et al., 2005; Benvenuti, 2007), or accidental such as through agricultural seed contamination in: soil (Rejmanek, 2000; Benvenuti, 2007), garden waste (Groves et al., 2005; Hulme, 2006), on equipment or even on clothing (Table 1). Both deliberate and accidental introductions have dramatically increased the scale and rate at which plants are dispersed, including many invasive species (Reichard and Hamilton, 1997; Groves et al., 2005; Wichmann
et al., 2009). Limiting human mediated dispersal of non-native plants is important, particularly when they are invasive. Invasive plants can adversely affect flora and fauna, prevent the recruitment of native plants, alter hydrology and nutrient content of soils, change fire regimes, and affect fauna that use the plants for food and habitat (Csurhes and Edwards,1998; Williams andWest, 2000; Mayers and Bazely, 2003). Although there is renewed interest in understanding
the invasive process, there is still limited research on the initial dispersal of species, particularly empirical studies (Puth and Post, 2005). For example out of 873 recent articles examining the process of invasion of exotic species, only 15 were empirical studies examining the initial dispersal of species in terrestrial systems. The initial step in unintended human mediated seed dispersal is seed attachment. Although seeds are commonly observed on socks, laces, boots and trousers there is limited empirical data on clothing as a seed vector (Table 1). The authors have only found nine published empirical studies, and only three involved statistical testing
of hypothesis. Seven studies examined seed attached to shoes and/or boots, four examined socks, two examined laces and four examined seed on trousers. Only two of the studies examined dispersal (Bullock and Primack, 1977; Wichmann et al., 2009). Based on the nine studies 139 species of plants have been identified that have seeds that can attach to clothing and hence have the potential to be dispersed by humans over long distances. Although these studies established that clothing can be an important mechanism for human mediated seed dispersal,
research is required to quantify the amount and composition of seeds that can collect on clothing, and determine if factors such as the location the clothing is worn, the type of material it is made of, and if different clothing items, affect the amount and type of seeds collected. For example, the surface area of the item, the location (such as height) of the item and the adhesive quality of the item are all likely to effect seed attachment to clothing (Bullock and Primack, 1977; Whinam et al., 2005). Different combinations of clothing may affect what seeds attach so that someone wearing shorts, socks, shoelaces and boots may collect different seed than if they were wearing trousers which covered the socks, shoelaces and the top of boots. There are also likely to be differences in the seeds collected when hiking through disturbed areas such as roadsides and car
parks where there are many non-native plant species, to the seeds collected when hiking in intact native vegetation away from roads and tracks. As hikes can commence from roadsides and car parks there is the risk that people may carry non-native seeds from these areas into the natural vegetation in protected areas. The objectives of this study were to experimentally test aspects of seed attachment to clothing as part of assessing the risk of human mediated seed dispersal including for non-native plants. Three field experiments were conducted in a popular national park with high conservation values, Kosciuszko National Park, to determine: (1) What seeds are collected on clothing (species and number, native vs non-native); (2) If there are differences in the seeds collected on socks depending on where someonewalks; (3) If there are differences in the seeds collected on different types of socks; (4) If there are differences in the seeds collected on different items of clothing (boots, socks, laces and trouser leg) and d (5) if
wearing trousers reduces the amount of seeds collected.

(WRI, 1992; IUCN, 2000;
Groves et al., 2005; Nathan, 2008; Wichmann et al., 2009).
* Corresponding author. Tel.: þ61 7 5552 8059; fax: þ61 7 5552 8067.
E-mail address: c.pickering@griffith.edu.au (C.M. Pickering).
Contents lists available at ScienceDirect
Journal of Environmental Management
journal homepage: www.elsevier.com/locate/jenvman
0301-4797/$ – see front matter 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.jenvman.2009.08.002

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Earthyman Harvests Big Blue Stem at Ion Exchange

As the fall draws to a close Ion Exchange our sister site is busy harvesting all the wildflower and grass seed. Enjoy Earthyman's video.

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What Everybody Should Know Abou Wild Parsnip!

Recently Gabby of Ion Exchange got burned by wild parsnip while mending some fence. She did some research to find out exactly what this plant was all about. We felt our friends might benefit from her research.
A 1999 issue of Wisconsin Natural Resources Magazine
Burned by wild parsnip
Sun-induced burns from a common weed stump medical professionals and outdoor enthusiasts alike.
DAVID J. EAGAN

As children, we are warned away from fires and stoves, though most of us learn the truth of that lesson the hard way. But what if wild plants could cause burns, too -- and nobody ever told you which ones? Well, such plants do exist, and if you spend time outdoors, chances are they have burned you or someone you know. And equally likely, neither you, nor your doctor or nurse recognized the burn for what it was.
Unexpected patches of redness and blisters following a romp in the woods or fields usually are blamed on poison ivy, stinging nettles, insects or spiders. But there's another potential culprit: Wild Parsnip (Pastinaca sativa), the hobo brother of cultivated parsnip. Wild parsnip contains chemicals in the juices of its green leaves, stems and fruits that can cause an intense, localized burn -- actually, a sunburn.
In my research for this article I found that very few people, including medical professionals, know this plant and can confidently recognize its burns. At a recent dermatology conference, I was told slides of wild parsnip burns were shown at a stump-the-experts quiz session. Only a few in the audience knew the answer.
One physician I spoke with referred to the plant as a "medical orphan" that might be mentioned in medical school, but is rarely covered in detail. And even doctors familiar with how wild parsnip looks on skin would have trouble identifying the plant in the field.
Parents, pharmacists, landowners, naturalists, teachers, park employees -- I asked a wide range of people what they knew. And it was rare indeed when someone understood the whole parsnip story. Many thought the burns arise from an immune response, like poison ivy. They do not. A manager at a state park always warns his employees to be careful around wild parsnip -- he was familiar with the burns -- but he didn't know that sunlight triggered the reaction. And the general public? The same park manager told of seeing a little girl one sunny summer day with a wreath of fresh parsnip flowers in her hair, which is a little like playing with fire.
Animals can be burned in a similar manner to people if the animals have lightly-pigmented skin covered with little hair so both plant juices and sunlight reach the skin.
How an old flame singes new admirers
Wild parsnip is an eye-catching, non-native weed that hails originally from Europe and Asia. There are varieties grown for their edible roots, but whether the wild type came to America as a garden vegetable or in the cuffs of some immigrant's pants, no one knows. Dried specimens at the University of Wisconsin-Madison herbarium date back to 1894 in southeast Wisconsin, and a specimen was collected on Madeline Island at the northern tip of the state in 1896.
Although not a native plant, wild parsnip has likely become "naturalized" in all of Wisconsin's 72 counties and is here to stay. Wild parsnip grows in large patches or as scattered plants along roadsides, in abandoned fields, on pastures, on restored prairies, and in disturbed open areas. And, according to observers around the state, its range has been expanding rapidly in recent decades.
The fact that wild parsnip is spreading is one more reason people are coming into more frequent contact with it. Another reason is it is one of the chief targets for weed removal in prairie restorations. Unlike benign weeds, wild parsnip can take over an area, outcompeting native plants. The ecological impact of this invader puts it high on the hit list of land managers.
There are chemicals in wild parsnip called psoralens (precisely, furocoumarins) that cause what dermatologists call "phyto-photo-dermatitis." That means an inflammation (itis) of the skin (derm) induced by a plant (phyto) with the help of sunlight (photo). When absorbed by skin, furocoumarins are energized by ultraviolet light (present during sunny and cloudy days) causing them to bind with nuclear DNA and cell membranes. This process destroys cells and skin tissue, though the reaction takes time to produce visible damage.
The chemical in wild parsnip may be a defense mechanism, just as healthy, green celery plants will produce higher levels of furocoumarins when they are under attack from pink-rot fungus.
In mild cases, affected skin reddens and feels sunburned. In more severe cases, the skin reddens first, then blisters rise -- some are impressively large -- and for a while the area feels like it has been scalded. Places where skin is most sensitive (arms, legs, torso, face, neck) are most vulnerable. Moisture from perspiration speeds the absorption of the psoralens.
Ouch! A run-in with wild parsnip can cause blisters and discoloration of the skin. © David J. Eagan
Blisters appear a day or two after sun exposure. Soon after blisters rupture and the skin begins to heal. One of wild parsnip's "signature" effects is a dark red or brownish discoloration of the skin in the area where the burn occurred. This hyper-pigmentation can persist in the skin for as long as two years.
Parsnip burns often appear as streaks and long spots. These reveal where a juicy leaf or stem drags across the skin, and is then exposed to the sun. Because of its surface resemblance to the effects of poison ivy, and because wild parsnip is so rarely accurately identified, it nearly always is diagnosed and treated as poison ivy. If you note the six clinical differences (see sidebar), however, you can readily tell them apart.
Treating a parsnip burn
If you get a parsnip burn, relieving the symptoms comes first. The affected area can be covered with a cool, wet cloth. If blisters are present, try to keep them from rupturing for as long as possible. The skin of a blister is "nature's bandage," as one doctor put it, and it keeps the skin below protected, moist and clean while healing occurs. When blisters pop, try to leave the skin "bandage" in place. To avoid infection, keep the area clean and apply an antibiotic cream.
Adding Domeboro powder to cool cloth compresses can help dry weeping blisters. Some doctors recommend a topical or systemic cortisone-steroid for extreme discomfort. For serious cases with extensive blistering, consult a physician.
Avoiding exposure, of course, is the wisest tactic. By learning to recognize the plant in different seasons and in different stages of growth, you can steer clear of it, or protect yourself by wearing gloves, long pants and long-sleeve shirts. Some people pull up the wild parnsips in the evening, when exposure to sunlight is minimal. If you do get the plant juice on your skin, the sooner you thoroughly wash the area, the less you will be affected.
Tales from the field
In case you're wondering, I've learned about wild parsnip burns firsthand. Over a decade ago, and newly arrived to Wisconsin where wild parsnip is common, I didn't believe my naturalist-friend who told me that it could cause blisters. Regarding myself as more of a botanist than she, and having never heard of such a danger, I scoffed. While she looked on dubiously, I picked a leaf, crushed it in my fingers and rubbed it on the underside of my forearm.
As I'd expected, nothing happened all that day and I remember feeling a bit smug. By afternoon the next day, however, I was not feeling so confident. The area on my arm turned red and quite sore. A few hours later, a three-inch long blister bubbled up and swelled like a miniature balloon.
I learned my lesson, but that didn't stop me from experimenting further. Borrowing a term from prairie managers, I now conduct "controlled burns" on my arms most summers; using the resulting small blisters and spots for show-and-tell to educate others about wild parsnip.
Many friends and acquaintances have shared their experiences with parsnip burns. One person told of a small burn that appeared unexpectedly on his leg. He had been pulling wild parsnip from a prairie on a sunny day while wearing protective clothing. It wasn't until the burn appeared that he noticed a small hole in his jeans, just large enough to admit plant juice and a bit of sunlight. One friend received a frighteningly bad case of parsnip burns. He had been clearing parsnip from a field with a scythe while wearing sandals and shorts. The resulting burns were so bad that his legs looked like they had been sprayed with acid.
In the literature about wild parsnip and other phototoxic plants, there is mention of a contemporary contributor to the problem: weed whackers or string trimmers. These machines can spray bits of pulverized leaf and stem over the exposed skin of their operators, resulting in bizarre speckled patterns of small blisters and redness. One dermatologist in Madison saw such a case last summer. And another family practitioner in southwest Wisconsin regularly treats high school students who are hired to cut weeds along roadsides, typically while shirtless, for parsnip burns.
Have you been burned?
Keep these three points in mind when you encounter wild parsnip:
1. Everyone can get it. Unlike poison ivy, you don't need to be sensitized by a prior exposure. Wild parsnip causes a non-allergic dermatitis that can occur with the right combination of plant juice and sunlight.
2. You can touch and brush against the plant -- carefully -- without harm. Parsnip is only dangerous when the juice gets on skin from broken leaves or stems. Fair-skinned people, however, may be extra-sensitive to tiny amounts of juice.
3. Wild parsnip's "burn" is usually less irritating than poison ivy's "itch." Generally, wild parsnip causes a modest burning pain for a day or two, and then the worst is over. The itch and discomfort from poison ivy, in contrast, can drive people crazy for a long time.
Some unanswered questions remain. I did not test, nor did I find in the medical literature, how long skin remains sensitive to sunlight after being exposed to parsnip juice. And there are also other plants in Wisconsin -- such as Queen Anne's lace or wild carrot (Daucus carota) and cow parsnip or hogweed (Heracleum maximum and Heracleum mantegazzianum) -- that are reported to contain psoralens that cause phytophotodermatitis.

DAVID J. EAGAN is a field botanist, naturalist and native plants gardener who works for the Institute for Environmental Studies at the University of Wisconsin-Madison.
Botanical basics
Life history: Wild parsnip typically lives for two years. The first year, as a spindly rosette of leaves, it keeps fairly low to the ground while the plant's carrot-like taproot develops. It may live two or more years this way until conditions are right for flowering. The second year, a hollow, grooved flower stalk rises 2-5 feet high, first holding clusters of yellow flowers and later dozens of flat, oval seeds.Leaves: Pinnately compound, with a main stem and 5 to 15 leaflets.Flowers: Yellow, in flat-topped umbrella-like clusters at the top of the plant.Season: Wild parsnip rosettes are among the first plants to become green in spring, and its flowers turn a prominent yellow in midsummer. After flowering and going to seed, plants die and turn brown in fall, but first year rosettes remain green until frost.Habitat: Roadsides, abandoned fields, unmowed pastures, edges of woods, prairie restorations.