Category Archives: food chain

Botany, food chain, Invasive Species, Wildlife Habitat

Pink Ribbon or Blue?

Why we should proactively control Ailanthus altissima.

Ailanthus bud scar
Ailanthus bud scar is very large with numerous bundle scars – quite unusual.

Early spring, before thicket vegetation in in full leaf, is a good time to locate sprouts and trees of “Tree of Heaven” (Ailanthus altissima) – if we know what they look like.   Today, at a restoration site, I was tying blue ribbons on staghorn sumac (Rhus typhina), with exceptional wildlife habitat value. Pink ribbons were tied on young, invasive Ailanthus, which is remarkably like sumac, though unrelated. Ailanthus is not yet an abundant invasive in Connecticut, but it is a serious threat. Basal treatments of Ailanthus with triclopyr ester in oil are planned for mid-July. Blue stands for “save”, pink stands for “treat”. We do not want to treat the staghorn sumac accidentally!

Staghorn sumac has a narrow bud scar encircling the bud
Staghorn sumac can be distinguished by its narrow bud scar encircling the bud.

To tell them apart before leaf-out, use an obvious Ailanthus field mark: the huge leaf scars with numerous bundle scars. Staghorn sumac has a narrow U-shaped bud scar that wraps around a furry bud. Viewed from a distance, both have similar thick branches, but Ailanthus bark is smooth, whereas staghorn sumac has “velvet” on the thick, blunt, antler-like twigs, obvious in all seasons.

In summer young Ailanthus looks like a sumac on steroids, and when mature it resembles black walnut.  It grows 80 to 100 feet tall, and its compound leaves have up to 40 leaflets.

Ailanthus foliage
Ailanthus foliage

Each Ailanthus leaflet has smooth edges except for one or two snaggle teeth at the base, whereas sumac and walnut leaflets are serrated from tip to base. For more information on lookalikes, see:

                                            https://extension.psu.edu/tree-of-heaven     and

https://mortonarb.org/plant-and-protect/trees-and-plants/staghorn-sumac/.

Cluster of spotted lanternfly nymphs
Cluster of spotted lanternfly nymphs

Why is proactive control of Ailanthus a priority? Foremost, Ailanthus fosters spotted lanternfly (Lycorma delicatula), a serious, polyphagous pest of vineyards, orchards, street trees, and many other woody plants.  Both come from  China. The lanternfly reaches high population densities, killing woody vines and saplings and damaging full-size trees. This opens up the landscape for colonization by Ailanthus, which requires high light levels to grow. Lanternfly nymphs can feed on a wide range of plants, but a 2020 study showed that nymphs that develop on Ailanthus grow more quickly and produce more offspring than those on other trees species, like maple and walnut.  Fall lanternfly nymphs on Ailanthus were much more likely to lay their eggs before frost.

 

Ailanthus leaf tissue is also the source of the cytotoxins (quassinoids) that confer a repugnant taste that protects spotted lantern flies from birds and other predators. Birds that have experienced the foul-tasting nymphs will also avoid palatable nymphs that have fed on other plants. (It is unclear to what extent the quassinoids are also toxic.) Through social learning, this avoidance behavior hinders expansion of avian biological control, as explained in a 2024 article by Daniel Stroembon et al.

 

Ailanthus emits volatile attractants that attract spotted lanternflies like a magnet, sometimes by the thousands.  Where lanternfly is well-established, in the mid-Atlantic states, Ailanthus trees are used by pest control firms to trap these pests, before killing them en masse. Spotted lanternfly is just beginning to reach Connecticut.  Scattered early colonizers are likely to bypass an Ailanthus-free community. More aggressive control of Ailanthus altissima will slow down the spotted lanternfly invasion.

 

Without a doubt Ailanthus altissima meets Les Mehrhoff’s widely accepted definition of an invasive species:  It has very high reproductive potential and is able to expand into natural areas and outcompete native plant species.

  • It is a fast-growing, clonal tree, and an expanding patch can take over more than half-acre of habitat, outcompeting native tree and shrubs, in part by means of allelopathy. Ailanthus roots secrete chemicals that inhibit growth of other competing plants, some species more than others.
  • It produces vast numbers of seeds. According to a 2007 dispersal study published in Plant Ecology, Ailanthus altissima “is able to disperse long distances [by wind] into fields and into mature forests and can reach canopy gaps and other suitable habitats at least 100 m from the forest edge. It is an effective disperser and can spread rapidly in fragmented landscapes where edges and other high light environments occur.”
  • Water-borne seed dispersal is also important. Even in a truly urban setting, where wind-dispersed seeds would not reach farmland or natural forests, Ailanthus seeds wash into catch basins, and then into rivers, and floodwaters deposit the seeds on river levees. Throughout the US, its distribution follows river networks.
  • This tree also excels at seedling establishment. Betty Smith got the science right in A Tree Grows in Brooklyn. Ailanthus can colonize cracks in pavements – or crevices in cliffs. I was dismayed to find an Ailanthus clone on the steep mountainside just west of Castle Craig, in Meriden. I also saw many on rip-rap Amtrak railroad embankments in Old Saybrook. It needs ample light, but not deep, fertile soil.

Ailanthus altissima is relatively easy to control but often overlooked, except for the mature female trees, which bear conspicuous masses of dark red flowers in late summer and early fall. Females are sold, bare-root, on-line.  If money or volunteer resources are short, the priority should be removal of the female seed-producing trees. Trycera, Pathfinder and Garlon 4 are safe, systemic herbicides that can be purchased on-line and applied to the lower stem of Ailanthus suckers.  They are all triclopyr esters, with an oil carrier, but only Trycera may be applied by volunteers and property owners without a pesticide applicator’s license in Connecticut, though not for pay.  Mid-summer is the optimal time to apply, to minimize resprouting.

Per a 2023 article in Forestry and Wildlife by Nancy Loewenstein et al, basal oil application of trichlopyr ester is most useful “where the target tree or shrub density is moderate to low, manual labor is available, and dead standing trees and shrubs can be tolerated.”  The method should be used only in low to moderate density invasive stands, to prevent changes to the soil microbe community, and impacts to non-target plants via root systems. Note that treatment of trees over five inches in diameter requires a modified “hack and squirt” method. (See Aces link to the Forestry and Wildlife article below for more information).

This invasive tree is an indirect economic threat as well as an ecological one. EDRR (Early Detection and Rapid Response) should be a high priority for Tree of Heaven. It would be helpful if land trust stewardship directors and town tree wardens could be alerted about Tree of Heaven (Ailanthus altissima) occurrences, so infestations can be nipped in the bud and further spread minimized.   Spotted lanternfly sightings should be reported to  CAES (The Connecticut Agricultural Station) using this link:  Spotted Lanternfly – SLF (ct.gov).

Should male Ailanthus trees (which produce no seeds) be spared in urban areas or school yards?  The answer is no, despite the fact that a mature Tree of Heaven blesses its neighborhood with shade, cooling, beauty, and air pollution filtration, like any large urban tree. Their scent, unpleasant to humans, is a magnet for stray lantern flies, and will attract stray dispersing spotted lanternflies. Other urban trees will soon be infested as well. These male trees will bear no seeds, but they can be productive lanternfly nurseries, yielding thousands of vile-tasting nymphs. As discussed in the 2024 Stroembon article, local birds will learn to avoid spotted lanternflies altogether, and such aversion does spread through social learning. This will reduce the potential for effective avian biological control of palatable – and nutritious – lanternfly populations in orchards, preserves, and treed residential neighborhoods.

Landenberger, Rick E. Nathan L. Kota , and James B. McGraw. 2007. Seed dispersal of the non-native invasive tree Ailanthus altissima into contrasting environments.  Plant Ecology (192):5–70.

Loewenstein, Nancy Stephen Enloe, Ken Kelley, and Beau Brodbe.  July 21, 2023. Basal Bark Herbicide Treatment for Invasive Plants in Pastures, Natural Areas & Forests. https://www.aces.edu/blog/topics/forestry-wildlife/basal-bark-herbicide-treatment-for-invasive-plants-in-pastures-natural-areas-forests.

Stroembon, Daniel, A. Crocker, A. Gray, A. Sands, G. Tulevich, K Ward, Swati Pandey.  February 2024. Modelling the emergence of social-bird biological controls to mitigate invasions of the spotted lanternfly and similar invasive pests. Royal Society Open Science. 11(2) https://royalsocietypublishing.org/doi/10.1098/rsos.231671

Uyi, Osariyekemwen, J. Keller, A. Johnson, B. Walsch, D. Long, and K. Hoover. 2021. Spotted Lanternfly can complete development and reproduce without access to the preferred host, Ailanthus altissima. Environmental Entomology nvaa 083.

http://doi-org/10.1093/ee/nvaa083.

By Sigrun Gadwa, Carya Ecological Services, LLC    www.caryaecological.com     3-16-24

Botany, food chain, Invasive Species

ALERT: MOW DOWN MUGWORT BEFORE SEEDS RIPEN

ALERT: MOW DOWN MUGWORT BEFORE FROST,

WHEN ITS SEEDS START TO FLY

Connecticut plant scientists and volunteers who work on invasive issues are gravely concerned that mugwort (Artemisia vulgaris) is spreading rapidly throughout our road network. Minute seeds are blown across the winter landscape and carried in road dirt, in tire treads, on undercarriages, and by snow plows.  The seeds germinate well in bare spots,  and new mugwort patches spread from roadsides into adjacent meadow and forested habitats. A two- meter-tall plant yields up to 200,000 seeds!

We urge a time-sensitive measure: please mow the mugwort on your own land and encourage roadside mugwort mowing on municipal, DOT, utility,  & commercial land preferably before a hard frost, when the tiny seeds start to fly. Weed-whack mugwort plumes behind guard rails.   If the mugwort is past bloom but still not brown and crisp from frost,  the cuttings can be moved and piled up, then covered with  mugwort-free hay mulch or brush,  or bagged for disposal, without risk of dispersing the seeds during the initial moving process. However,  a new patch is likely to form at  the disposal pile.   In a large existing patch, it is best to leave the cuttings in place.

Mugwort was repeatedly transported from Europe to New England several centuries ago  in ship ballast. Ignored for centuries. as a tough, clonal weed of vacant land, it has begun to spread by seed, as well as by rhizome bits – found even in screened commercial topsoil. Each established patch has a large network of vigorous rhizomes (underground stems), like Japanese knotweed, also shown in bloom in the background of photo at left, which depicts a stand of mugwort in bloom, relatively low because it was mowed in early summer. Note that  most  Japanese knotwood clones have non-viable seeds, but seed germination has been detected in a few studies, an urgent research need, as Japanese Knotweed is, like mugwort, a “supercompetitor”.

Mugwort grows in sun or shade, and in droughty or soggy soil. Dense mugwort colonies crowd out even the hardiest native goldenrods, grasses, and asters, but mugwort has far less ecological value. The seeds are too small for birds to eat. In September, mugwort plants form plumes with tiny, dull white flowers  which yield no nectar, though the abundant wind- dispersed pollen causes hay fever. The finely dissected, gray-green leaves have a strong medicinal smell, and are eaten by few herbivores;  because it repels fleas and vermin, mugwort has been  used as bedding for  livestock. Mugwort often reaches over 4.5  feet in height, though early summer mowing, shade,  or very infertile soil may reduce its mature height to 1-2  feet.  Artemisia vulgaris threatens Connecticut’s biodiversity, agriculture, public health, and natural scenery.  Simple mowing can much slow down its advance. Other control measures include double layers of landscape fabric or other mulch.  Treatment with herbicides is very challenging, due to the deep, dense rhizomes.

Unfortunately, mugwort has begun to colonize some of Connecticut’s most special, beautiful places where uncommon and rare plants can still be found, such as rocky summits, sand plains, and river floodplains, termed “Critical Habitats” by the Wildlife Division of the Connecticut Department of Environmental Protection (CTDEEP).  On a CBS botany field trip in North Haven, last summer, we noticed that mugwort is now abundant in the beautiful pin oak forest east of the Quinnipiac Marsh and in a silver maple floodplain forest along the Still River, in a Weantinoge Land Trust preserve in New Milford.

In a botanically diverse state park or preserve, careful pulling of young plants may prevent establishment of new colonies, but only if done before  formation of rhizomes (underground stems). Research is needed to find out at what stage  this takes place, and also how long rhizome fragments remain viable. Snow plows & street sweepers likely disperse seed & rhizome bits. Would additional mowing during the summer be helpful?

This photo of a mugwort seeedling  (or rhizome sprout) was taken in about 2015 at the edge of a gravel tracking pad in Meriden, at the Platt High School  construction site (where I was an erosion & sediment control monitor). Nearby, I noticed that along the Sodom Brook  linear trail the city practice of  trailside mowing in early summer was allowing mugwort to coexist with native goldenrods and small white asters, over a two-year period – but for how long?   Frequent mowing will help control a mugwort colony, but will result in a mugwort-dominated lawn, NOT a scenic meadow, with perennial grasses & flowers like chickory, goldenrods, Joe Pye, ox-eye daisies, asters, and Vernonia.

Members of the Right-of-Way Sub-committee of the CBS Ecology & Conservation Committee are concerned that Eversource’s new wide gravel roads and gravel pads along powerlines, will in all likelihood become new mega-seed sources, and spread into remaining ROW habitats, which are especially rich in biodiversity, including rare Lespedeza bush clovers, shrubland birds, Eastern box turtles, and the New England cottontail, our only rare rabbit species.

Although mugwort seeds are known to remain viable for several years, protracted sprouting from the seed bank may not be an issue, after a nearby seed source is controlled, according to Kathleen Nelson.  She is the tireless CIPWG volunteer scientist, who has been leading successful efforts to slow down the advance of  Mile-a-Minute vine in Connecticut. She made a welcome discovery: mugwort seedlings entirely  stopped sprouting on her land,  the first year after a large, neighboring mugwort stand was mowed  in early October of 2015 & 2016.

The Connecticut Botanical Society suggests you call an official you know at your town hall, and explain why it is wise to control mugwort colonies; mention that prompt stabilization of  bare soil will help eliminate seed beds for mugwort patches, as well as protect water quality.  You could e-mail the link to this on-line article. The photo below shows mugwort and Japanese knotweed colonies on a  former soil pile.  Eversource officials and/or the CT Siting Council also need to understand that even thick gravel pads are readily colonized by mugwort, and become a significant seed source, statewide.  

food chain, Soils, Uncategorized, Wildlife Habitat

Trace Minerals & Toxins: GMO Concerns

Why does food grown organically seem to taste better than conventionally grown food. Is this my imagination or due to some real difference? I read that levels of trace minerals (micro-nutrients) were usually lower in non-organic food. This makes sense for hydroponic foods, but why should conventional agribusiness crops have lover levels of trace minerals?

Truthfully, I’ve been somewhat sceptical about health and safety risks from GMO (genetically modified organism) crops? Inserting genes for disease resistance does seem sensible. The Environment Committee of the Connecticut Legislature happens to be reviewing a bill (HB 5117) that would require labeling all such food, so I read Hearing testimony and did some research.

A recognized concern, from a health and environmental standpoint, is the gene that has been spliced into crop plants, for a persistent bacterial toxin (from BT or Bacillus thuringensis). This toxin is now found in the blood of the majority of American women. It is a natural pesticide that attacks cell membranes – not just in the target pest caterpillars, but also membranes in rats and potentially in humans, especially fetuses. However, I did not see any data on toxin concentrations, and information on threshold concentrations for harmful effects is sorely lacking.

Analysis of potential impacts on adjacent ecosystem biodiversity from BT GMO crops has also been wholly inadequate. How will populations of economically insignificant species of caterpillars, moths and butterflies -and their predators- be affected by feeding on leaves and pollen from GMO plants along field edges? Ill effects on migrating monarch butterflies were in the news last year.

I see even less less public concern with the largest category of GMO crops: those with an inserted gene that makes them “Roundup Ready”, able to tolerate its active herbicide ingredient, glyphosate, although application rates must be cranked up several fold. Interference with uptake of micro-nutrients by glyphosate was studied in Stuttgart, Germany, at the University of Hohenheim, over ten years ago. German researchers warned us that mineral-deficient plants would be more susceptible to soil fungal diseases; this is now well documented for many fungal diseases – most recently widespread Fusarium wilt in GMO Roundup Ready soybeans in the southern US. The Stuttgart scientists found two causes of the problem: 1) glyphosate firmly latches (chelates) onto soil trace minerals, making them unavailable and 2) it eliminates or suppresses soil microbes and invertebrates. These include beneficial mycorhizal fungi) which help the plant extract soil nutrients (trace minerals included), and earthworms, springtails, isopods and man other soil organisms that recycle nutrients from plant debris into soil (trace minerals included). [As glyphosate is only one of many agrichemicals that suppress populations of soil organisms, my first question was answered; I can now see a scientific basis for lower levels of trace minerals in non-organically raised foods!

Because Roundup application rates increase sharply when GMO Roundup Ready crops are planted, this micro-nutrient problem has become more severe. Scientists at several US midwestern universities followed the lead of the Stuttgart researchers, including Don Huber at Purdue in Illinois, Barney Gordon in Kansas, and Kurt Thelan in Michigan. They have continued to investigate the trace mineral deficiencies, particularly manganese, but also zinc and others, that are an unwelcome side-effect of Roundup use (glyphosate). [The URL of a review article is http://www.environment.co.za/gm-foods-crops-biofuels-pesticides/missing-micronutrients-glyphosate.html. It was posted out of Western Illinois University by Enviroadmin on Sunday, 23 May 2010.}

It is now also known that the inserted gene in GMO Roundup Ready soybeans interferes with production of a root secretion that solubilizes minor mineral nutrients. (This is in addition to glyphosate directly chelating micro-nutrients, and suppressing or killing beneficial soil microbes and invertebrates.) Attempts to cope with the problem by fertilizing GMO Roundup Ready crops with heavy dosages of micro-nutrients have been challenged by the chelating (tight-attaching) properties of glyphosate. Similarly, human assimilation of mineral supplements in pill form is usually poor, unless the dietary supplements are bulky and food-derived! I, for one, balk at swallowing horse pills three times a day.

Nor has there been adequate analysis of the impacts on surrounding ecosystems of expanded Roundup use on Roundup Ready GMO crops. How much has it reduced the extent of field edge buffers with grass and forb (“weed”) seeds that used to be available for songbirds? Such buffer strips between and around fields are still available in a sustainably managed organic farm. More and more weeds are evolving resistance to to glyphosate; the response is accelerated efforts to develop GMO crops resistant to other herbicides, that have their own suites of risks and side-effects – which will also not be adequately tested as this is not yet required by EPA.

I can envision genetic modification for the purpose of inserting blight resistant genes from related plant species or perhaps to improve crop quality, but only after far more rigorous testing than is the current practice – directed by a third party entity (not Monsanto Corporation testing its own GMO crops!). But inserting genes for herbicide tolerance – or insecticidal proteins – seems fundamentally unwise. Expansion of organic agriculture is important for the human diet as well as for the surrounding natural environment; not just to avoid possible pesticide residues, but perhaps more importantly, for the sake of nutritional quality.

A version of this post was sent to several Connecticut members of the Environment Committee, and published by CT NOFA (Northeast Organic Farming Association)

Link: http://environmentalheadlines.com/ct/2012/03/18/a-letter-to-ct-nofa-folks-from-a-farmer/

 

Energy efficiency, food chain, Native Landscaping, Soils, Water Quality, Wildlife Habitat

Water Woes on Drumlins

What is a drumlin anyway?  A gremlin with an aptitude for percussion?   Seriously, a rounded, elongated hill in the Connecticut landscape is probably a “drumlin”. The best known is Horsebarn Hill on the eastern side of the UConn campus at Storrs. Landing Hill in East Haddam was  in the local limelight several years ago. Lately I’ve been working on Meetinghouse Hill and Misery Hill in Franklin.  The Goshen Wildlife Management Area is another. The word “drumlin” comes from Ireland, where this land form also occurs.

The core of a drumlin hill is fine-textured, compact glacial debris, though bedrock may be underneath, poking through in a few places.   The compact “hardpan” layer (in common parlance)  may be over 100 feet thick, and dates from the prior Illinoisan glaciation (over 128,000 thousand years ago). Only the top layer, usually just a few feet deep, is sandier, looser soil, formed from the melting ice masses of the more recent Wisconsin glaciation, underlain by the compact till (scientists’ terminology).

These soils are seasonally wet.  Though the level summits seem, at first glance, to be well-suited to community development, they are challenging to develop, whether on drumlins or elsewhere, such as plastered onto the sides of traprock ridges. Most gently sloping drumlin hilltops in New England used to be productive hayfields, growing lushly in spring when soil moisture was available, going dormant in mid summer.  Pockets of wet meadow were rich in flowers, like New England Aster. Drumlin fields make fine hunting territories for raptors like barred owl.

Colorful wet meadow perched on top of drumlin.

Multiple seasonal seepage wetlands and headwaters streams flow down drumlin hillsides. They are a valuable source of clean water for the drainage basin if the drumlin is undeveloped, they but may become conduits for construction runoff.

There is more groundwater discharge on the nearly level sections of drumlin hillsides than on the steep sections. These are also prone to septic breakout.

Only a small percentage of Connecticut’s soils are compact tills but a disproportionate share of construction site fiascos and problem-plagued new subdivisions occur on hardpan soils. Wet, silty, sticky  hardpan  soils, on drumlins and also in other landscape settings,  can become a mire for heavy construction equipment because the snowmelt and spring rains “perch” on top of the hardpan. Saturated silty soils are highly erosive,  often an erosion control nightmare. Flooding problems are more severe than on absorbent soils, and water pollution from lawns and septic systems becomes a problem at lower home densities.  Break-out from home septic systems happens more often.

Typical complaints of drumlin residents: wet and moldy basements, icy sidewalks;  soggy, fungus-infested grass, burned-out grass, and dying shade trees; extended sump pump operation (not energy efficient), mosquitoes, and septic odors; and polluted down-gradient ponds.  These all become more of an issue for seasonally wet, drumlin soils, because more water stays at the surface, as it cannot soak into dense hardpan soil. (Runoff coefficients are higher, in engineering jargon.)

With careful home and septic system placement, curtain drains, and appropriate landscaping, one can avoid some of these problems – but only if home densities are relatively low.

Ironically, the loose upper soil layer of a drumlin is usually so shallow that it holds little reserve water during dry spells, so drumlin lawns need much irrigation in summer, though excess water is the problem in other seasons.   Solutions: small lawns, partially wooded yards, and/or a meadow landscape with drought-tolerant grasses like Little Blue Stem, a.k.a. Poverty Grass.

A Plea for Guidance

Could  CTDEEP and our Conservation Districts provide land use boards, planners, and developers  with more guidance on drumlins’  multiple constraints?  On-line mapping (Web Soil Survey or WSS) available from the Natural Resource Conservation Service (NRCS) does show the approximate locations of seasonally wet, hardpan soil units, like the Paxton, Woodbridge, and Wethersfield soil series.

More guidance is needed to make sure fertilizers and pesticides are not applied before or after heavy rains.  This happens all the time in Connecticut suburbs!  Turf chemicals tend to run off drumlin soils, more than off more absorbent soil types, especially when the soils are already soggy.

Few understand that watercourse setbacks often need to be wider and  septic system densities need to be lower on compact till soils, to protect down gradient wells, headwaters streams, pools, and lakes from excessive nitrogen,  in nitrogen enriched groundwater and runoff. Because they reduce lot yields, these constraints need  explanation in an official DEEP guidance document, preferably also in a  CT Health Department memorandum!

Clear-cutting may seem to be  more economical for the developer, who should be warned that this is not wise on a drumlin!  To minimize future “water woes”,   maximize  remaining tree cover when subdivisions are built. The reason is two-fold: 1) to slow the velocity of the falling rain, and 2) because trees spew thousands of gallons of water into the air as water vapor (transpiration), helping dry out those surface soils.  After clear-cutting, a drumlin hillside that used to be wet only in March and April may stay wet to the surface though June – and before long, one will see the tell-tale mottles and grayish matrix color of a jurisdictional Connecticut wetland soil.

Some, but not all engineers use underdrains and clay stops  to prevent frost heave damage to roads and utility pipes, and to allow shallow groundwater to continue to seep down slope to wetlands that depend on this water source – instead of being shunted along  roadbeds and sewer lines.  Guidance is also needed in this area.

Once aware of drumlins’ constraints and resources, town  zoning boards  will be able to  guide development more appropriately,  protecting valuable vernal pools and hillside streams, and at least a portion of the productive forests. For expansive overgrown fields on flat-topped drumlins, if the alternatives of farmland or grassland wildlife habitat are not possible, at least the damage to down-gradient headwaters resources,  from a  low density, large-lot residential community, with small lawns,  will be  much less than from a large, dense subdivision.

(First version of blog posted on 9-6-08)

food chain, Invasive Species, Wildlife Habitat

The Red Menace

Euonymus alata, also known as burning bush, is at least a clear-cut villain, unlike  some of the other invasives.    I recall spending a long June day collecting vegetation data in an an immense Euonymus thicket, a former estate  in Wilton. I did not even  observe a catbird, the most common thicket songbird in Connecticut! And beneath the dense bushes, the ONLY plants growing were Euonymus  seedlings.

This species must have high-powered chemical defenses. The glossy leaves look almost artificial (and might as well be), no holes where caterpillars or leaf beetles have nibbled.  Pickings are slim for foliage-gleaning parent songbirds.  No “chain migration”  for this species with a suite of nearly pre-adapted species waiting in the new world, to make use of the new immigrant – and keep it in check, as has happened with the cherries.  Gray’s Manual of Botany (Fernald) shows only two  native  cousins  in this genus, and neither has a range that overlaps southern New England or Long Island.

Euonymus alata, from Asia,  is an effective invader of forests, because it grows well in shade, unlike bittersweet, multiflora rose, everlasting pea, and Phragmites. It spreads well by runners as well as seed. Unfortunately, it thrives especially in the mineral-rich, sub-acidic  soil of traprock (basalt)  ridges.

Euonymus has overrun much of Peck Mountain, in north Cheshire,   because suburban yards on the flanks of the traprock ridge provide abundant seed sources.  As recently as the mid 1980’s the ridge crest and its steep talus slopes were botanically  diverse and special. At that time they were clear-cut  CTDEEP Critical Habitats, per the CTECO website (sub-acidic forest,sub-acidic talus slope, and sub-acidic summit  catgories.) Since then, these habitats  have become near monocultures of burning bush. The Euonymus even thrives in shallow soil pockets on ledges!  Some rare Staphylea trifolia  (bladdernut)  and marginal wood fern remains on the steep west slope  of Peck Mountain, and I last year I noticed a single non-blooming columbine patch.  The oak fern, dwarf saxifrage, and anemonella appear to be gone.

After that Wilton experience and a recent  eye-opening hike on Peck Mountain,   I knew we had to get rid of the burning bushes in our own yard. Emotionally, it was not so easy.  This is a beautiful shrub, especially when crimson in the fall, and it makes a dense, tidy hedge.  The wings or flanges on the stems also look interesting in winter.  Our bushes had special meaning because they been given to us by relatives who were dear to us.

Control  was very quick and simple, from a practical standpoint. We snipped them with a lopper, and painted the freshly cut stems  with Brush-B-Gon (8% triclopyr). For those who simply cannot kill their prize burning bush, thoroughly shearing off the seeds each September, with hedge clippers,  will at least prevent further spread by birds.

Connecticut nurseries are still battling the environmental regulators, to prevent an outright ban of Euonymus alata, because this is such a popular, lucrative species for  the landscaping business, especially for commercial sites.

For illustrations and discussion of other invasive plants, see the accompanying facebook album “Invasives- A Devil’s Advocate Perspective” (Sigrun Gadwa)

http://www.facebook.com/media/set/?set=a.496792513908.273505.588968908&l=ac65ae4d58

food chain, oil spill, PAH, Water Quality, Wildlife Habitat

Far-Travelling Toxins

 

Sperm and bottlenose whales

Very High Toxin Concentrations found in Arctic Whales

The link  below is  an article sent by a colleague on the surprisingly high levels of toxins, found in arctic whales.   Concentrations of toxic heavy metals like cadmium and chromium, were orders of magnitude higher than the danger levels for human fish consumption.  At every step in the food chain,  a persistent metal toxin (slowly- or non- biodegradable) bio-magnifies (tissue concentration becomes higher).  Metals in road runoff that reach the ocean biomagnify in seafood.  Abroad in many countries, DDT, which persists indefinitely, like metals, is also still used.  Persistent toxins are also transported thousands of miles though the oceans, in currents- potentially the gulf stream-   and by wind-driven surface flows, and  also by migrating fish and whales.  (This is similar to the insecticide bio-accumulation problem  mentioned in my recent zigzag dogwalking post.)

Oil Toxins will not be contained in the Gulf

The take home message: not just the Gulf of Mexico and its  coastal marshes  are threatened by the Gulf Oil Spill, and that threat is not just in the distant future.

http://news.yahoo.com/s/ap/20100624/ap_on_sc/whaling