Garlic Mustard (Alliaria petiolata)


The bane of woodlands!!! This non-native plant can quickly overrun a woodland or savanna with a “take no prisoners” approach. When we purchased our land in 2005, the remnant oak-hickory woodland was a garlic mustard monoculture. We began in earnest to remove it.

Working smarter rather than harder, I use knowledge when I need workarounds. Determining the best answer for my goals and my unique piece of land requires a hybrid system of academic studies, biological sciences, and a dash of anecdotal evidence. I’m sharing in hopes it helps you, too.

Helpful Garlic Mustard Facts

  • Can self pollinate (Anderson et al 1996, Chapman et al 2012)
  • Seedbank persistance can be 3 years (Nuzzo 1991)
  • Seeds dispersed via foot traffic, animal fur, and water movement and not by wind (Cavers et al 1978)

Management Requires a Combination of Tools

Garlic mustard greens up in spring early, before many of the native plants. This is convenient.  Management can be timed so no collateral damage to spring ephemerals occur.

Herbiciding

When we began controlling garlic mustard, we sprayed rosettes with 2% glyphosate in spring and again in the fall. Pulling those we missed was necessary follow up. In the first 6 years, we substantially decreased the infestation. But we began to notice deformed garlic mustard plants; they were growing, flowering, and appeared to be setting seed. I do not know if these seeds were viable. Were the plants becoming resistant to glyphosate? In 2011, we switched herbicides to Progeny® and are having better success. Whatever herbicide you choose, read and follow the label directions.

Hand pulling

There’s good news! “Uprooting plants at the flowering stage prevented production of any viable seed, while early- and late-fruiting plants were still able to produce viable seed (Chapman et al 2012).

The study further demonstrated height and seed production were correlated; 13” or shorter plants had low seed viability and 16” or taller plants had high seed viability (Chapman et al 2012). The plant’s phenological stage is also a significant “tell;” early fruiting plants (silenes visible but flowers still attached) had significantly more viable seed than late-fruiting plants (silenes only) (Chapman et al 2012).

Mowing or weed whacking

Mowing is effective for 2 reasons. Cutting at the ground level “resulted in 99% mortality and reduced seed production to virtually zero” (Nuzzo 1991). Cutting around 4” high had 74% mortality and 98% seed reduction (Nuzzo 1991, Chapman et al 2012). Mowed plants late in the season typically do not regrow after mowing (Cavers et al 1978). Some may appear to resprout, but they lack the stored resources after bolting and will not produce viable seed (Chapman et al 2012). Knowing the biology of this plant helps us to know mowing is effective.

We weed whack the larger patches as a triage method when we don’t have time to pull the plants before they set seed.

Fire

There are a couple ways to use fire – prescribed burns and flame weeding.

Prescribed burns can be effective at the proper intensity.  “Low-intensity fire did not affect the incidence of A. petiolata  but mid-intensity reduced rosettes” (Nuzzo 1991). In a woodland setting where the fuels are leaf litter, a general way to think of fire intensity is to think of humidity. A low-intensity fire would occur when there was high humidity, either in the air or in the leaf litter – perhaps morning or evening.

Flame weeding uses a backpack flame weeder works similar to herbiciding — a particular plant is targeted and zapped. Fire wandering away from the target is something to be prepared for but if done when humidity is high or when morning dew remains.

Grazing

Grazing isn’t an effective tool for garlic mustard control. The plant contains a chemical that deters herbivory (Chapman et al 2012) and can add an unpleasant flavor to milk from animals grazing this (Cavers et al 1978). Unfortunately, we can’t depend on deer to graze it either; they find it “completely inedible” (Kalisz et al 2014). And more unfortunate, where deer are abundant so is garlic mustard because they depress native plants with their grazing.

For more info on prescribed fire, in general.

Combine Management Tools

Using different management techniques and tools ensures biodiversity and can save resources! As much as we all want a single “magic bullet” there isn’t one. Mix and match these management tools and planning follow up ensures success.

The native plants returned once we controlled the garlic mustard. Plants that we now enjoy that were suppressed include shooting star, Indian pipe, bellwort, wild geranium, wood anemone, solomon’s seal, false Solomon seal, and yellow pimpernel to name a few. Diversity is the key to a good healthy environment.

Below is a picture of our “purple carpet” of wild geranium. When these bloom, the woods have a wonderful light perfumely aroma!

Wild geranium in woods

References

Anderson, Roger C., Dhillion, Shivcharn S. and Kelley, Timothy M. (1996), Aspects of the Ecology of an Invasive Plant, Garlic Mustard (Alliaria petiolata), in Central Illinois. Restoration Ecology, 4: 181-191.

Cavers, Paul B., Heagy, Muriel I., & Kokron, Robert F. (1979). The biology of canadian weeds.: 35. Alliaria petiolata (M. Bieb.) Cavara and Grande. Canadian Journal of Plant Science59(1), 217-229.

Chapman, Julia I, Philip D. Cantino, Brian C. McCarthy. 2012. Seed Production in Garlic Mustard (Alliaria petiolata) Prevented by Some Methods of Manual Removal.” Natural Areas Journal 32(3): 305-315.

Kalisz, Susan & Spigler, Rachel & Horvitz, Carol. (2014). In a long-term experimental demography study, excluding ungulates reversed invader’s explosive population growth rate and restored natives. Proceedings of the National Academy of Sciences of the United States of America. 111. 10.1073/pnas.1310121111.

Nuzzo V. 1991.  Experimental control of garlic mustard [Alliaria petiolata (Bieb.) Cavara & Grande] in northern Illinois using fire, herbicide, and cutting. Natural Areas Journal 11: 158-167.





Poison Ivy – Live and Let Live


I haven’t thought about poison ivy (Toxicodendron radicans) in a very long time. When a friend sent two photos of it for ID confirmation last week, it became a highlight of my week. As we discussed this plant, the initial response was to get rid of it. Yet it’s native and wildlife depend on native plants. How many depend on this “unpopular” plant? I had to know.

As humans, we immediately want to eradicate anything that might cause us harm. Rather than learn to live with it and understand its value, our reaction is to kill it and remove it.

What if…we left it?

Electing to live in harmony with poison ivy means my small piece of the earth could gain from the diversity and benefits of this native plant and I could keep myself safe. Solid identification skills, a grasp of what makes it hazardous, and a list of wildlife using the plant makes living with poison ivy safe and enjoyable.

Poison Ivy Has Leaves of Three, But…

Poison ivy can be tricky to identify. While the “leaves of three” mantra is what I grew up learning as a way to identify the plant, it was confusing as there are many plants with 3 leaves. Adding to the complexity of this plant is its color changes —  “reddish in the spring; green in the summer; and yellow, orange or red in the fall” (Wilson, nd). And compounding that, poison ivy can be found as a hairy-looking vine climbing a tree, a small shrub, or a mass collection of short plants. However you might encounter it, all parts (roots, stem, leaves) can cause a skin rash.

The oily substance in poison ivy is “…urushiol (oo-roo-shee-ohl). Its name comes from the Japanese word “urushi,” meaning lacquer”(Wilson, nd). When urushiol makes contact with the skin, the body sends the white blood cells to fight this foreign substance. As the body’s immune system neutralizes this foreign agent some normal tissue gets damaged in the process. This damage is what we see on our skin as a rash.

 

Wildlife Uses Poison Ivy

Studying the biota as we restore our land’s native ecosystems caused me look at these “plants that could hurt me” differently. Each native plant is a host to insects, meaning they require this plant to sustain the next generation. These insects, in turn, are the protein birds, reptiles, amphibians, and small mammals require to raise their young. Berries and seeds are adult food; the babies require protein and that means insects. Aha! I began to look at all native plants with new eyes.

A little research uncovered 153 invertebrates, 48 birds, and 7 mammals that depend on or use this plant in some way to sustain life. While not an exhaustive list, it is an impressive list.

Coleoptera (Beetles)

Altica chalybea (Habeck 1988)
Analeptura lineola (Senchina, 2005, Senchina and Summerville 2007)
Apsectus hispidus (Habeck 1988, Senchina 2005)
Astyleiopus variegatus  (Habeck 1988)
Astylidius parvus (Steyskal 1951, Habeck 1988, Senchina 2005)
Astylopus macula (Senchina 2005)
Bassareus brunnipes (Habeck 1988)
Calligrapha floridana (Habeck 1988)
Chalcodermus aeneus (Habeck 1988)
Chauliognathus marginatus (Senchina, 2005)
Chauliognathus pennsylvanicus (Senchina, 2005, Senchina and Summerville 2007)
Cryptorhynchus fuscatus (Habeck 1988, Senchina 2005)
Ctenicera hamatus (Habeck 1988, Senchina 2005)
Derocrepis erythropus (Habeck 1988)
Diplotaxis bidentata (Habeck 1988, Senchina 2005)
Enoclerus rosmarus (Senchina, 2005, Senchina and Summerville 2007)
Euderces picipes – Senchina and Summerville 2007
Eugnamptus collaris (Habeck 1988)
Eupogonius  vestitus (Senchina 2005)
Eusphyrus walshi (Steyskal 1951, Senchina 2005)
Hypothenemus toxicodendri  (Habeck 1988, Senchina 2005)
Leiopus variegatus (Senchina 2005)
Leptostylus albescens (Habeck 1988, Senchina 2005)
Lepturges querci (Habeck 1988, Senchina 2005)
Lepturges signatus (Steyskal 1951, Habeck 1988, Senchina 2005)
Madarellus undulatus  (Habeck 1988, Senchina 2005)
Molorchus sp. – Senchina and Summerville 2007
Oberea ocellata (Senchina 2005)
Orthaltica copalina  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Pachnaeus opalis  (Habeck 1988)
Pachybrachys tridens  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Phyllophaga uklei (Habeck 1988, Senchina 2005)
Pityophthorous consimilis (Senchina 2005)
Pityophthorous rhois (Senchina 2005)
Pityophthorus corruptus (Habeck 1988)
Pityophthorus crinalis (Habeck 1988)
Pityophthorus tutulus (Habeck 1988)
Saperda lateralis (Habeck 1988, Senchina 2005)
Saperda puncticollis (Steyskal 1951, Habeck 1988, Senchina 2005)
Serica vespertina (Habeck 1988, Senchina 2005)
Strangalia acuminata (Senchina, 2005, Senchina and Summerville 2007)
Synchroa punctata  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Thanasimus  dubius (Senchina 2005)
Trischidias atoma (Habeck 1988)
Xyleborus affinis (Habeck 1988, Senchina 2005)
Xyleborus ferrugineus (Habeck 1988)
Xyleborus pecanis (Senchina 2005)

Lepidoptera (Moths and butterflies)

Acronicta impleta (Habeck 1988)
Acronicta longa (Habeck 1988)
Amorbia humerosana (Habeck 1988)
Anavitrinelia pampinaria  (Habeck 1988)
Antepione thisoaria (Habeck 1988)
Archips argyrospila (Habeck 1988)
Caloptilia diversilobiella (Habeck 1988)
Caloptilia ovatiella (Habeck 1988)
Caloptilia rhoifoliella (Habeck 1988)
Cameraria guttifinitella (Habeck 1988)
Celastrina neglecta  (Senchina, 2008b, Senchina and Summerville 2007)
Choristoneura rosaceana (Habeck 1988)
Cingilia  cantenaria  (Habeck 1988)
Dichorda iridaria (Habeck 1988)
Ecpantheria scribonia (Habeck 1988)
Epipaschia superatalis (Habeck 1988)
Epipaschia zeleri (Habeck 1988)
Episimus argutanus (Habeck 1988)
Eutelia furcata (Habeck 1988)
Eutrapela clemataria (Habeck 1988)
Hyphantria cunea (Habeck 1988)
Lambdina fiscellaria somniaria (Habeck 1988)
Lophocampa maculata (Habeck 1988)
Lymantria dispar (Habeck 1988)
Marathyssa basalis (Habeck 1988)
Nystalea eutalanta (Habeck 1988)
Orgyia leucostigma (Habeck 1988)
Oxydia vesulia transponens (Habeck 1988)
Paectes oculatrix (Habeck 1988)
Platynota rostrana (Habeck 1988)
Prolimacodes badia (Habeck 1988)
Sibine stimulea (Habeck 1988)
Sparganothis reticulatana (Habeck 1988)
Stigmella rhoifoliella (Habeck 1988, Steyskal 1951)
Thyridopteryx ephemeraeformis (Habeck 1988)
Xanthotype sp.  (Habeck 1988)

Hymenoptera (Bees, wasps, sawflies)

Agapostemon viriscens (Senchina and Summerville 2007)
Andrena spp (Senchina and Summerville 2007)
Andrena crataegi (Illinois wildflowers website)
Apis mellifera (Senchina and Summerville 2007)
Arge humeralis (Habeck 1988)
Augochlora pura (Senchina and Summerville 2007)
Bombus fervidus (Senchina and Summerville 2007)
Cimbex  americana (Habeck 1988)
Eumenes fraternus (Senchina and Summerville 2007)
Lasioglossum spp. (Senchina and Summerville 2007)
Osmia lignaria (Senchina and Summerville 2007)
Sceliphron caementarium (Senchina and Summerville 2007)
Vespula sp. (Senchina and Summerville 2007)
Xylocopa sp.  (Senchina and Summerville 2007)

Diptera (Flies)

Anthrax analis  (Senchina and Summerville 2007)
Dasineura rhois (Habeck 1988)
Laphria sp. (Senchina and Summerville 2007)
Lasioptera sp. (Habeck 1988)

Hemiptera

Alconeura sp. (Habeck 1988)
Aulacorthum rhusifoliae (Habeck 1988)
Carolinaia caricis (Habeck 1988)
Carolinaia carolinensis (Habeck 1988)
Carolinaia rhois (Habeck 1988)
Clastoptera obtusa (Habeck 1988)
Coelidia sp (Habeck 1988)
Cyrpoptus belfragei (Habeck 1988)
Duplaspidiotus claviger (Habeck 1988)
Ferrisia virgata (Habeck 1988)
Glabromyzus schlingere (Habeck 1988)
Graphocephala versuta  (Habeck 1988)
Heterothrips vitis (Habeck 1988)
Lygaeus kalmii  (Senchina and Summerville 2007)
Metcalfa pruinosa (Habeck 1988)
Nezara viridula (Habeck 1988)
Orthezia insignis (Habeck 1988)
Osbornellus rotundus  (Habeck 1988)
Penthemiafloridensis (Habeck 1988)
Phenacoccus pettiti (Habeck 1988)
Pseudaonidia duplex (Habeck 1988)
Pseudococcus longisetosus (Habeck 1988)
Pulvinaria acericola (Habeck 1988)
Pulvinaria floccifera (Habeck 1988)
Pulvinaria rhois (Habeck 1988)
Pulvinaria urbicola (Habeck 1988)
Rugosana querci  (Habeck 1988)
Saissetia oleae (Habeck 1988)
Selenothrips rubrocinctus (Habeck 1988)

Acari (Mites)

Aculops rhois  (BugGuide website)
Aculops toxicophagus (Habeck 1988)
Eriophyes rhois (Habeck 1988)

Birds

Bluebird (Martin et al 1951)
Bobwhite (Martin et al 1951)
Bush-tit (Martin et al 1951)
Catbird (Martin et al 1951)
Cedar waxwing (Martin et al 1951)
Chickadee, Black-capped (Martin et al 1951)
Chickadee, Carolina (Martin et al 1951)
Chickadee, chesnut-backed (Martin et al 1951)
Chickadee, Mountain (Martin et al 1951)
Crow (Martin et al 1951)
Finch, Purple (Martin et al 1951)
Flicker, red-shafted (Martin et al 1951)
Flicker, Yellow-shafted (Habeck 1989, Martin et al 1951)
Grouse (Martin et al 1951)
Junco (Martin et al 1951)
Kinglet, Ruby-crowned (Martin et al 1951)
Magpie, American (Martin et al 1951)
Magpie, Yellow-billed (Martin et al 1951)
Mockingbird (Martin et al 1951)
Pheasant (Martin et al 1951)
Phoebe (Martin et al 1951)
Quail (Martin et al 1951)
Sapsucker, Red-breasted (Martin et al 1951)
Sapsucker, Yellow-bellied (Illinois wildflower website)
Sparrow, Fox (Martin et al 1951)
Sparrow, Golden-crowned (Martin et al 1951)
Sparrow, White-crowned (Martin et al 1951)
Sparrow, White-throated (Martin et al 1951)
Starling (Illinois wildflower website)
Thrasher, Brown (Martin et al 1951)
Thrasher, California (Martin et al 1951)
Thrush, Hermit (Martin et al 1951)
Thrush, Russet-backed (Martin et al 1951)
Thrush, Varied (Martin et al 1951)
Titmouse, Tufted (Martin et al 1951)
Towhee, Spotted (Martin et al 1951)
Turkey, Wild (Martin et al 1951)
Vireo, Warbling (Martin et al 1951)
Vireo, White-eyed (Martin et al 1951)
Warbler, Cape May (Martin et al 1951)
Warbler, Myrtle (Martin et al 1951)
Woodpecker, Downy (Martin et al 1951)
Woodpecker, Hairy (Martin et al 1951)
Woodpecker, pileated (Martin et al 1951)
Woodpecker, Red-bellied (Martin et al 1951)
Woodpecker, Red-cockaded (Martin et al 1951)
Wren, Cactus (Martin et al 1951)
Wren, Carolina (Martin et al 1951)
Wren-tits (Habeck 1989)

Mammals

Black bear (Martin et al 1951)
Cottontail rabbit (Illinois wildflower website)
Deer, mule (Martin et al 1951)
Deer, White-tailed (Illinois wildflower website)
Muskrat (Martin et al 1951)
Pocket mice (Habeck 1989, Martin et al 1951)
Wood rat (Martin et al 1951)

Resources:

BugGuide website, https://bugguide.net/node/view/15740, Accessed 10 May 2020

Ewing, H.E., 2015. “Mites affecting the poison ivy.” The Proceedings of the Iowa Academy of Science, Volume 24

Habeck, Dale H. 1988. Insects associated with poison ivy and their potential as biological control agents. Proceedings VII International Symposium, Rome Italy

Illinois Wildflower website. https://www.illinoiswildflowers.info/trees/plants/poison_ivy.htm. Accessed 13 May 2020.

Martin, Alexander C., Herbert S. Zim, and Arnold L. Nelson. 1951. American Wildlife and Plants: A Guide to Wildlife Food Habits. New York: Dover Publications, Inc.

Senchina, David S. 2005. Beetle interactions with poison ivy and poison oak. The Coleopterists Bulletin, 59(2): 328-334.

Senchina, David S. and Keith S. Summerville. 2007. Great diversity of insect floral associates may partially explain ecological success of poison ivy. The Great Lake Entomologist 40(3, 4)

Steyskal, George. 1951. Insects feeding on plants of the Toxicodendron section of the genus Rhus. The Coleopterists Society 5(5/6): 75-77.

Wilson, Stephanie. How Poison Ivy Works. https://science.howstuffworks.com/life/botany/poison-ivy.htm. Accessed 13 May 2020





Aquatic Insects as Indicators of Water Quality


Photo above: Cybister fimbriolatus: Dysticidae (predaceous diving beetle) would have a tolerance score of 5.

Author: Dr. Hope Q. Liu (Biology)

Aquatic insects, also called benthic macroinvertebrates, are ideal bioindicators of water quality. What the heck is a benthic macroinvertebrate? Benthic means “bottom of a body of water” and macroinvertebrate means you can see the insect with your eye and insect has no backbone. Benthic macroinvertebrates are used as bioindicators of water quality because they are sensitive to environmental changes and its presence or lack thereof determines clean water or polluted water. 

How can an aquatic insect like a dragonfly, which lives in the air, help us determine the quality of the water? Aquatic insect adults lay their eggs in the water. The eggs hatch and the immature form lives in the water, sometimes for years, before transforming into winged adults. The composition of the aquatic insects population (aka bioindicators) is used to ascertain water quality and reveal pollution impact. Much like plants are assigned conservation numbers, aquatic insects have a numeric designation, too. This designation is called a Tolerance score and ranges from 0-10 with zero being the least tolerant to pollution.

Peltodytes edentulus: Haliplidae, benthic macroinvertebrate, aquatic insects

Photo above: Peltodytes edetulus: Haliplidae (crawling water beetle) would have a tolerance score of 7.

Photo to the right: This Hydropsychidae (common net spinning caddisfly) nymph would have a tolerance score of 4.

Hydropsychidae , caddisfly

Aquatic insects are a great starting point to get a sense of the water quality.  To assess a body of water using water sampling would require repeated testing visits to the site. Aquatic insects are not highly mobile and reside in the body of water for long periods of time. This means monitoring and testing the water isn’t needed as often.

For example, you are monitoring the water quality of Stream A. You sample the water for aquatic insects in June 2015, June 2016 and June 2017 and find diverse insect populations – stoneflies, caddisflies, beetles, dragonflies – and then you sample 

again in June 2018 and only find beetles and dragonflies. Generally, stoneflies and caddisflies are less tolerant to pollution when compared to beetles and dragonflies, so you deduce that somehow the water was polluted over the past year and wiped out those populations. You determine, based on talking to people along the stream, that the paper mill accidentally polluted the water in November 2017.

Now, let’s imagine you are sampling Stream A using water samples and laboratory tests. You sample in January, March, June and September of 2015-2018. Based on the tests, you determine the water is clean. Because you didn’t sample in November or December of 2017, there were no indicators showing the stream was polluted.

Now that you know WHY aquatic insects are great indicators of water quality, you may be wondering what they look like and how you can identify them. Purdue Extension publishes a Bioindicators of Water Quality Guide that provides detailed instructions for using bioindicators to determine the water quality. Using this excellent guide, the insects and their conservation values (known as a Tolerance Value) can be identified and calculated to estimate the water quality. Remember, there are other factors that impact the ability of aquatic insects to live in water, such as temperature, sediment, etc. Generally, where possible, it’s always best to collect other water data such as pH, temperature, and dissolved oxygen.

Additionally, the University of Wisconsin Extension offers citizen science training for monitoring water quality using benthic macroinvertebrates. For more information on that, check out the Water Action Volunteers (WAV) site. These classes will teach you how to sample bodies of water using a combination of tests, including aquatic insects.

Entomology Today has an article about insects and mites and what they tell us about water quality





Confluence, our Water Ways in art


The Blanchardville Public Library’s summer theme is “Library’s Rock”  which makes the art exhibit depicting the hydrologic cycle perfect. Ten community artists came together (confluence) to create a beautiful and educational exhibit illustrating elements of the hydrologic cycle — our “water ways.”

Land use and water quality

All land uses have an effect on water flow and water quality; some are positive, some are negative. In healthy ecosystems receiving little human disturbance, most rainfall soaks into the soil rather than running off the ground, stream flows are fairly steady, and water quality is good. In built-up areas with pavement and buildings or agricultural areas where land is bare rainfall causes runoff and poorer water quality. In fact, land use practices are the most important water quality factor.

Runoff

Runoff is the water draining off the land; it is a natural and necessary part of the landscape. Water will follow the rules of gravity and move from a higher point to a lower point. If the water is filtered through native plants’ roots, it is important for recharging our groundwater. Negative runoff situations arise when the land becomes bare. When the water runs off hard surfaces and accumulates contaminants. In urban areas, these hard surfaces are pavement and concrete. In rural areas, solid surfaces are created by bare land. Other runoff occurs in cropped lands via drain tiles or land tilled too close to a stream. These negative situations are mitigated with good conservation farming practices, maintaining native wetlands, planting native plants along streams, and ensuring stormwater is filtered before it enters our waterways.

Photo to the right: As the streambanks build up with erosion, the water channels scoop out the sides causing the land to cave. Drone photo by Jim Hess

Livestock create a direct channel for water runoff and the resulting erosion, emptying topsoil and manure into the stream.

Erosion

Karst

Karst is a topography characterized by carbonate rock (limestone, dolomite, gypsum) that easily dissolves in rainwater forming cracks, sink holes and even large cave systems. Water quickly moves through the cracks in karst and enters the groundwater. These cracks act as direct conduits for pollutants to enter our groundwater, wells, springs, and streams. There are many regions in the world that have karst geology, southwestern Wisconsin is one of them so are areas of Mexico, Germany, and Florida to name a few.

Lafayette County is sensitive to water pollutants because of our karst landscape. Whenever material above the aquifer is permeable, pollutants can readily sink into groundwater supplies and our drinking water supplies. Good conservation practices can ease the statistic that croplands are responsible for 96% of nitrates leached into groundwater.

Karst landscape is particularly easy to see in the winter. Where the road cuts through the earth you can see the beautiful icicles! This is the water seeping through the rocks, then freezing.

Groundwater

Groundwater is the water found underground in the cracks and spaces in soil, sand, and rock. It is stored in and moves slowly through geologic formations called aquifers. Groundwater is a necessary resource; it supplies drinking water for 51% of the total U.S. population and 99% of the rural population.

Groundwater is also a limited resource. It’s difficult to think this is possible when we currently average 34.5” every year, but only about 25% of all rainfall in the U.S. becomes groundwater. In the past that average has fluctuated from 21-44”annually.

Agriculture is the largest consumer of freshwater resources. In the United States 64% of groundwater is drawn down to irrigate crops. 

Karst

Well Depth and Construction

The safety of the water in your home is dependent upon proper well location and construction.  The well casing needs to extend into a confined aquifer, which must be quite deep in our karst landscape. As you can see from these diagrams, if the casing doesn’t extend deep enough, your water could be receiving contaminants from one half to one mile away from your home. The well should be located so rainwater flows away from it. Rainwater can pick up harmful bacteria and chemicals on the land’s surface.

Surface Water

Surface water is freshwater you see on the top or surface of the landscape. It includes rivers, streams, creeks, lakes, and reservoirs; these are vitally important to our everyday life. The amount and location of surface water changes, varying in response to climate and human activities.

Surface water represents only about 3% of all water on Earth. Freshwater lakes account for a mere 0.29% of the Earth’s freshwater. Lake Baikal in Asia has 20% of all fresh surface water; another 20% is stored in the Great Lakes.  What a precious resource we have near us!!

Runoff and erosion have negative effects for surface water and eventually our groundwater. Excess nitrogen and phosphorus from runoff causes the algal blooms on our lakes, subsequent deaths of animals, and a loss of tourism dollars. Excess nitrogen in the streams where livestock drink can cause disease. Pesticides are dangerous too and are found in surface water 97% of the time near agricultural areas and 61% of the time in other landscapes.

Karst
Karst

This shows how surface water is filtered thru confined and unconfined aquifers.

In karst landscape, it’s imperative your well supplying your drinking water is deep enough to draw from a confine aquifer.

Hydrologic Cycle

The hydrologic cycle is the way water moves through our world. Water falls to the ground in the form of precipitation which either evaporates into the atmosphere, soaks into the ground, or runs off into surface waters like lakes, rivers and oceans. The water that infiltrates into the ground is either picked up by plants and organisms that transpire it into the air or it becomes groundwater. Groundwater is stored in an aquifer. Some water spends hundreds of years beneath the surface in deep aquifers; other groundwater is drawn back to the surface through manmade wells. Shallow aquifers feed into our surface water through seeps or springs in the ground. All the water that evaporates enters the atmosphere, becomes clouds and the cycle continues.

The main elements of the hydrologic cycle are:

  1. Evaporation
  2. Precipitation
  3. Transpiration
  4. Runoff
  5. Infiltration

 

Precipitation

Precipitation is water released from clouds. It is visible to us in the form of rain, freezing rain, sleet, snow, or hail and is the primary method for water in the air to be delivered to earth. Most precipitation falls as rain. In our area, we expect an average of 34.5” of rainfall each year. Clouds are small droplets of water too small to fall to the ground. They create a vapor that appears as white fluffy objects in the sky. How many types of clouds can you name?

Evaporation

Evaporation is the process by which water changes from a liquid to a gas or vapor. Studies have shown the oceans, seas, lakes, and rivers provide nearly 90% of the moisture in the atmosphere via evaporation, with the remaining 10 percent being contributed by plant transpiration. Once evaporated, a water molecule spends about 10 days in the air.

hydrologic cycle

Transpiration

Transpiration is how we describe plants’ breathing. Plants’ roots draw water and nutrients up into the stems and leaves; some of this water is returned to the air by transpiration. Transpiration rates vary widely depending on weather conditions. During dry periods, transpiration can contribute to the loss of moisture in the upper soil zone, which can have an effect on food-crop fields.

An acre of corn gives off about 3,000-4,000 gallons of water each day, and a large oak tree can transpire 40,000 gallons per year. Keeping the numerous oak savannas in Lafayette County healthy would be very good for us!!

Watershed

A watershed is the land where all the water drains off of it before entering into a particular water body. Watersheds can vary in size and are determined by topography (the peaks and valleys). In southwestern Wisconsin, we are located in the Upper Mississippi watershed. Everything we do on our land here travels to the Mississippi River and eventually reaches the Gulf of Mexico either from overland flow or through underground channels. Major watersheds like the Upper Mississippi are made up of many little watersheds. In fact each creek or pond has its own defined watershed.

What watershed do you live in?

Lafayette County, watersheds, conservation

A depiction of the watersheds in Lafayette County. Courtesy SWWRPC

Freshwater ecosystem

Freshwater ecosystems – such as wetlands, lakes and ponds, rivers, streams, and springs – are a critical part of the global water cycle. The water in these ecosystems is our surface waters; the ones our watershed catches and directs to our drinking water source.

Freshwater is also imperative to the survival of humans. We cannot stay alive without fresh water, yet we are facing a number of threats to our supply: 1) runoff from agricultural and urban areas, 2) draining of wetlands for agricultural uses and development, 3) overexploitation (i.e. high capacity wells) and pollution, and 4) invasion of exotic species.

All freshwater ultimately depends on the continued healthy functioning of organisms interacting in the aquatic environment. These organisms include fish, aquatic insects, amphibians, turtles, water fowl, and mammals such as otters and beavers. Freshwater is home to 40% of the world’s fish species. At present, more than 20% of these fish species are extinct or imperiled.

Fish living in our creeks and streams need clean, fresh water to survive. Lafayette County is home to one of the best smallmouth bass fishing places in the U.S. Yellowstone Lake is also a source of pride and brings in tourism. 

 

 

There are three basic types of freshwater ecosystems:

  • Lentic: slow moving water, including pools, ponds, and lakes.
  • Lotic: faster moving water, for example streams and rivers.
  • Wetlands: areas where the soil is saturated or inundated for at least part of the time.

What types of freshwater ecosystems do you have near where you live?

Insects are great indicators of safe, clean water because they are not highly mobile; they reside in the water for long periods of time. Insects offer a method of testing water less often and more accurately. Many of them are not tolerant of pollution and will die off when the waters become contaminated.

 

Freshwater ecosystem

Ducks and waterfowl are indicators of the environment. If they’re in trouble, we’ll soon be in trouble. They rely on wetland areas for food and nesting. The primary threat to waterfowl is the loss of wetland quality and function by agricultural activities that aren’t complying with conservation practices.

Freshwater ecosystem

Streambank Erosion

As topsoil erodes from higher elevation it collects along the streambanks which funnels water flow to continue cutting into and eroding the banks.

Where water is not slowed down it erodes the land, sending the topsoil to the streams where it builds up our stream bank sides or silts in our lakes. Our hilly Driftless Area landscape is conducive to erosion. Losing soil and nutrients to streams isn’t good for the farmers or the environment. Soil is precious and losing it hurts a farm’s productivity.

Streambanks historically were feathered out to allow water to ebb and flow. The steep-sided banks we often see in our streams are the topsoil from the ridge tops and hillsides that drained to the valley streams and built up along the edges. Once the streambanks are built up with this excess topsoil, water cannot gently flow but rather is blasted through the channels. This creates more and more erosion. With every turn of the stream the water grooves out more and more soil; eventually the hollowed out bank crumbles. This topsoil becomes nutrient-laden sediment, clogging our streams and lakes, and de-oxygenating the water. Insects and fish cannot thrive and the ecosystem begins to fail.

streambanks
streambanks

The stream in the photo on the left has been feathered to prevent the sides being “cut out” by the water flow. These steep banks of the right hand photo are caused by topsoil eroding down from higher ground and depositing along the streambanks. Then the water cuts into the banks.

Wetlands and Infiltration

The negative effects of runoff and erosion are prevented by the deep roots of native plants. Wetlands adjacent to streams are important and positive for healthy, safe, and clean water. The root systems of native plants reach deep into the soil, many of them stretching 12-20 feet downward. Nonnative plants do not have long roots. The root length allows more microbes to exist in the soil; these microbes are responsible for absorbing the additional nutrients from crops and livestock waste and pesticide runoff from urban areas.

Nonnative plants do not have the same nutrient-absorbing abilities as our natives. Their root structure is short; this means they are dependent on water supplied by precipitation. Native roots extend far into the soil where they can extract water in times of drought. This increases their importance as they can continue to filter surface water when other plants have died. This filtration service is the most significant method for purifying our drinking water.

wetlands
wetlands
wetlands
wetlands




Gypsy Moth Treatment

If you received a notice about gypsy moth spraying in your county, you can check to see the target sites with the Department of Agriculture (DATCP) interactive map.

What is the killing agent?

Bacillus thuringiensis serotype kurstaki (Btk) is a group of bacteria which makes it a biological control agent. This bio-control agent is different from those where a non-native insect is brought in to kill off a non-native plant. All bio-control measures need a healthy dose of skepticism applied to them — two non-natives don’t make a native. Since Btk is commonly found in our soils, it does not introduce a foreign entity into our ecosystems.

How does Btk work?

I went in search of how Btk does the “dirty deed.” Btk is not a contact insecticide; the insect must ingest it. It is a stomach poison and will only effect the larval feeding stage (i.e., when it is a caterpillar). Andrea Diss-Torrance, Invasive Forest Insects Program Coordinator for the Wisconsin DNR, tells me that “among moths and butterflies, the effect can vary: about a third of species tested are sensitive, about a third are not [a]ffected at all, and about a third have an intermediate level of sensitivity. Btk is degraded by sunlight and very sensitive caterpillars, such as the Eastern tent caterpillar, are no longer [a]ffected about 11 days after application to foliage”(Andrea Diss-Torrance, personal communication, May 3, 2018).

“When Btk is ingested by a susceptible caterpillar, the highly alkaline environment of the caterpillar’s gut triggers the Btk bacterium to release a crystalline protein called an “endotoxin” that poisons the insect’s digestive system. The endotoxin acts by killing cells and dissolving holes in the lining of the insect’s gut. When a mixture of food, Btk spores, and digestive juices leaks through these holes into the insect’s blood, it causes a general infection that kills the caterpillar. Humans and other mammals have highly acidic environments in their stomachs that destroy Btk before it causes infection” (Ellis 2018).

Two types of Btk mixtures

There are two commercial brands of bio-control mixtures being used against the Gypsy Moth: Foray48® and Gypchek®. The DNR determines which to use based on insects listed in the Natural Heritage Inventory. I have repeatedly expressed my concern with this methodology. Current lists for Lafayette County will be insufficient to ascertain if classified species exist because our county is incredibly undersurveyed for insects (and plants for that matter). I suspect few counties have insect surveys covering the county.

Christopher Foelker, Gypsy Moth Unit Supervisor for DATCP, tells me Gypchek® is used in habitats having known T&E species that are in a vulnerable life stage during the treatment times. (Christopher Foelker, personal communication, May 3, 2018). DATCP considers Gypchek® to be less effective than Btk because it deteriorates quickly and has a much shorter window of efficacy. It is a viral insecticide that is specific to the gypsy moth but it iscostly to produce and there are limited amounts. It is manufactured by raising and infecting gypsy moth caterpillars with a virus (NPV-gypsy moth). These infected caterpillars are ground up and suspended in a liquid solution. This solution is Gypchek® and it is applied to the tree canopy.

Since it is a limited resource, state and federal governments agree to use Gypchek® only where rare species are known and not on every area proposed for Btk treatment. Unless a T&E insect is known, Foray48® is used.

Foelker says all the DATCP treatment plans are reviewed by the US Fish and Wildlife and US Forest Service for any potential effects on T&E species. They present any concerns for areas these species might be impacted.

Who else is affected?

Since I seldom take info from just one source, I continued my sleuthing on this topic. Jay Watson, who works in the Bureau of Natural Heritage Conservation,confirmed my suspicions, “Really, the impacts from Btk on other insects is very poorly understood.  I don’t know of any research that has looked at what impact this might have on insects like bumble bees.” (Jay Watson, personal communication, May 3, 2018). He specifically mentioned bumble bees because of our recently discovered rusty-patched bumble bee on our property.

There are two sides to every issue; this one is no different. Diss-Torrance stated, “the effect, or in this case non-effect, of Btk on a wide range of other creatures is very well known as this bacterially based insecticide has been used extensively in agriculture and forestry since the ‘80’s.”

In general, sunlight and other microbes destroy Btk applied to foliage within three to five days, so Btk does not multiply or accumulate in the environment (Ellis 2018). Yet, in a 1998 study, Btk was added to different types of soil in order to determine how the type of soil affected the persistence and concentration of Btk. The results of the study showed insecticidal activity started to decline after a month in one soil, while in another, toxicity was high after six months. The authors of the study noted that even though Btk is considered non-toxic to non-target species, the accumulation and persistence of the Btk toxins could eventually lead to environmental hazards or the selection of Btk-resistant lepidopterans (Wikipedia 2018).

The EPA has studies demonstrating a small level of toxicity to certain fish, a slight toxicity to honey bees at high level doses, and “practically non toxic” at low level doses. It is slightly toxic to the convergent lady beetle (Hippodamia convergens) (EPA 1998). Caterpillars that become ill or die after ingesting Btk are not considered dangerous to birds or other animals that feed on them (Ellis 2018).

I wasn’t thinking there would be a moral to this story when I began researching it, but I believe that there is. The value of citizen science is priceless and saves lives. Wisconsin DNR’s decision-making about gypsy moth treatments relies solely on the information at the Natural Heritage Inventory. The information behind many decisions that mitigate impacts to our natural community and our T&E community originates from citizen scientists.

Sources:

Ellis, Jodie A. (04 May 2018). Exotic Insects Education Coordinator Department of Entomology, Purdue University. Retrieved from https://extension.entm.purdue.edu/GM/PDF/GMquestions.pdf

Entomological Society of America. (May 2018). Is Bt safe for humans to eat?

Environmental Protection Agency. (1998). EPA 6452 Fact Sheet. Retrieved fromhttps://www3.epa.gov/pesticides/chem_search/reg_actions/registration/fs_PC-006452_01-Aug-98.pdf

Tobin, Patrick C. and Andrew M. Leibhold. “Gypsy Moth” in Encyclopedia of Biological Invasions. (Los Angeles: University of California, 2011): 298-304.

Wikipedia. (04 May 2018). Retrieved from https://en.wikipedia.org/wiki/Bacillus_thuringiensis_kurstaki