Category Archives: Invasive Species

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.  

Botany, Invasive Species, Native Landscaping, Uncategorized, Water Quality

Lesser Celandine – a Temptress

Lesser Celandine

When lesser celandine (Ranunculus ficaria) came up in a shady moist part of my yard, I admit, I did not promptly rip it out, though I do know it is a confirmed Invasive Plant Species, on the official Connecticut List.  I realized that this patch  probably originated  from a bulblet that I had tracked back from the floodplain after field work, likely stuck in a boot tread.

Its glossy, yellow petals were  like those of a buttercup or marsh marigold, only there were more of them (eight versus five).   The  dark-green,  scalloped  leaves were shiny and heart-shaped, and formed a full,  weed-free ground-cover, though spreading far less  than the patches I had seen on the Quinnipiac River and Wharton Brook floodplains.  I rationalized that this species  was invasive in wetlands, not upland yards, so… I might as well let it grow and study it. When seed set  failed altogether, I was reassured that seeds could not disperse to the Ten Mile River floodplain, only half a mile away.  As a spring ephemeral, the lesser celandine  dwindled as the tree canopy expanded, and by August I saw only a few yellowed leaves- and many bulblets. I erected a barrier of logs and brush  so no one would walk there and pick up bulblets in their shoes.

Ranunculus ficaria  spreads aggressively by bulblets in river floodplains, where floodwaters move the buoyant bulbs around, but   I had rationalized that my patch  was innocuous as a small sterile clone in an inland, upland setting.  Two years later, my friend Jeanne Chesanow showed me a similar, small sterile patch of lesser celandine in her yard, also  in shaded, mesic upland soil. She lives about  a mile south of my house. I started to wonder, just how far do bees fly?

Lesser Celandine is reported to produce fertile seed erratically. Seeds may not have not formed in my and Jeanne’s  clones because the female flowers must receive pollen from a genetically different mating type, and none grow nearby.  However, with cross pollination between lesser celandine patches in multiple gardens, how soon will a threshold of abundance be reached, such that lesser celandine starts setting more viable seed? If that happens, will this plant “take off”  in mesic, upland habitats, as well as river floodplains?  Purple loosestrife spent many decades in the twentieth century, as a well behaved  garden plant,  producing few fertile seeds…. until that abundance threshold was reached and self incompatibility was no longer limiting. Only then did it start proliferating in a wide range of wetland and moist habitats.

This is a particularly tempting invasive, the more so because it forms a natural, attractive ground cover, and  is hardy and carefree. It is widely sold!  Most gardeners are probably unaware they are harboring an invasive species, may think it is Marsh Marigold (Caltha palustris).  I  wondered, just how many other yards in Cheshire also have celandine patches.  It was time to stop playing around. I dumped a thick layer of mulch over my patch, and Jeanne got rid of hers as well.  Digging it is risky, as bulblets are dispersed.

A year has passed, and it is early spring, mud season. My garden has no yellow celandine flowers. As a weekly erosion inspector at a school construction site,  I am trying to persuade the contractor to spread hay over the idle bare soil, to reduce the export of fine sediment and phosphorus to the Quinnipiac River.  I wonder, could the yellow-dotted carpets of Celandine over bare, floodplain soils actually benefit the river and Long Island Sound, by reducing phosphorus  loading to during the early spring season?   DSC09978ClaytoniaHowever, especially in moist floodplain habitats, large mats of lesser celandine obliterate other  delicate spring ephemeral  wild- flowers like trout lily, wild ginger,  and spring beauty, and  also compete with perennial sedges and spring-germinating annuals.

However, lesser celandine  is reported to be much less less invasive in uplands than floodplains. Could this plant  be useful as a spring ground cover for landscaping, in well-drained soils, until other garden perennials  have reached summer biomass?    Could it help reduce lawn areas and turf chemical use, to protect downstream water quality?  More funding is needed for applied research,  to more precisely understand which habitats are most vulnerable to a given invasive species, and also to study breeding systems.  Is increased production of fertile Lesser Celandine seed really a threat?

Ranunculus ficaria Long Island

 

Botany, Invasive Species, Soils, Uncategorized, Water Quality, Wildlife Habitat

Critical Habitats in Connecticut

Introduction

Ebony spleenwort, characteristic of rocky ridgetop critical habitats, regardless of the type of bedrock.

I am often asked, just what is a critical habitat, and is it protected or not?   My answer is drawn from  a hybrid  DEEP document  (map plus explanations and keys)  called “Critical Habitats” last revised in 2011.  Recently retired DEEP plant ecologist,  Kenneth Metzler wrote: “these habitat types have a long history of conservation interest and have been documented and studied as being among the most rare, unique, and threatened, habitats in the state.”    Critical habitats support uncommon ecological communities, because their geology, soils, and/or hydrology are distinctive, which also confers scientific, educational and heritage value.  They each  support a characteristic and unique suite of plant and animal species.   25  upland critical habitats were  identified in the Connecticut Comprehensive Wildlife Conservation Strategy (CWCS).  The intent of the DEEP document is to help towns with their conservation planning –  not to ban development  of all critical habitats,  but  as a planning tool, to prioritize open space protection initiatives, in conjunction with other conservation planning principles:  minimize habitat fragmentation, and maximize the size and ecological integrity of protected tracts. www.cteco.uconn.edu is the URL.

State statute does include protections for endangered and threatened species. Critical habitats are a good deal  more likely than the average field or woodlot to include state-listed species (Endangered, Threatened, and Species of Special Concern.)   Each critical habitat also has many other unusual plants and animals that don’t quite “make the cut” for  Connecticut’s List – pitcher plant in a Black Spruce Bog, for example.

Also expected in a critical habitat are rare species among the understudied life forms like lichens, mosses, and soil microbes.  These life forms are simply missing from the Connecticut Natural Diversity Database (NDDB) lists.

 Potential rare species are likely to be missed by a targeted search for one or two species, especially because they are readily detected during a  short window. Plant seeds may lie dormant in the seed bank, sprouting only in certain years.   Many small plants are usually overlooked, even by botanists, except during a brief window when they are in bloom. Most insects, including butterflies and moths, are detectable only for a brief portion of the year. Rather than doing exhaustive, specialized  searches, it is less expensive and simpler, to determine whether the expected suite of diverse, characteristic plant species is present, and if it is, to protect the critical habitat.

For example, we  assessed a pristine black spruce/white cedar/ sphagnum bog recently, with hundreds of pitcher plants.  The targeted listed species are insects that feed on pitcher plant; we are recommending conservation of the whole bog with a wide buffer, with no need for a search for the tiny rare insects.

A bog in Canterbury has 100’s of of pitcher plants, and land use boards fully understand that this critical habitat, and must be fully protected.; the biodiversity value of rocky outcrops is less widely understood.

 

Bedrock outcrop in Essex. A full inventory of the hilltop plant community is not possible outside the growing season. We recommended including  the entire hilltop  in the  open space portion of the subdivision.

 

Planning Considerations

The “critical habitat” label is a flag for land use planners  to commission  a thorough inventory and to search for rare, state-listed  species in multiple seasons, before the area  is developed, and if possible over a several year period.  Critical habitat status alerts planning boards  that a property  is likely to be a desirable, interesting  destination for recreation,  and a potential site for nature study and/or scientific investigations.   Trails, towers, boardwalks, maps, and informative web sites can enhance these human values.  Excessive human use may degrade them, but more often they are protected by human intervention,  such as invasive plant  control or occasional tree-trimming to maintain an open critical habitat.  Public education on a critical habitat helps with its long term protection.

Some critical habitats, like black spruce bogs and white cedar swamps,  are so  unusual that their  status is widely understood and accepted, and they also have the  protection of being wetlands. The special status of other critical habitats is much less widely understood.  As a botanist, I am most familiar with three largely overlooked critical habitats:

1)  The group of plant communities on soils derived from traprock or  limestone (subacidic/neutral and  mineral-rich),   including  glades, dry forests, and summit shrublands;  and

2) Outcroppings, ledges, cliffs, and rocky, open  summits, with pockets of mineral-rich soil.  These are defined as critical habitats in the ECO key, regardless of bedrock type.

3) The rich floodplains of larger rivers;

The status of these less well known critical habitats is not widely understood by regulators, natural resource professionals, and the general public; as explained above,  official DEEP Critical Habitat status does not confer protection from development or quarrying, unless the areas are demonstrated  to support Endangered or Threatened species.  However, CTDEEP typically requires a survey for rare species by an expert, if a development site includes a known critical habitat.  Floodplains are protected, but the main reason is avoidance of flood damage.  Protection for privately owned rocky knolls and summits is still lacking in most town zoning regulations, despite official DEEP Critical Habitat status.

For the volcanic traprock ridges and certain ridges with amphibolite minerals, there exists already a model ridgeline protection ordinance, based on a CT Statute (Sections 8-1aa and  8-2 c), incorporated into the zoning regulations of some towns.  This ordinance applies only to the more  dramatic, high ridges, though low ridges, if reasonably undegraded by man, also include critical habitats with characteristic and unusual traprock  geology, botany, and fauna.

Zoning regulations can also be amended  to protect better natural features meeting certain criteria with value for the community as a whole:  heritage value, outstanding aesthetics,  or  historic, scientific, and/or educational interest.  Protection of these natural features  can also be a goal guiding open space acquisition activities by municipalities, the state, and private land trusts.  However, consistent with the Connecticut Comprehensive Wildlife Strategy, the long term welfare of the fauna and flora will better served by one sizable (e.g. over 100 acres) preserve with a few critical habitat pockets, than by multiple critical habitat pockets (rock outcrops) in a matrix of small woodlots and development.

History of the “Critical Habitat:  Concept

DEEP has been refining its list of “Critical Habitats,” for many years, building off those identified by Joseph Dowhan and Bob Craig in Rare and Endangered Species of Connecticut and their Habitats (1976), with descriptions of all of the State’s Ecoregions (DEEP Natural Resources Center  Report of Investigations No. 6.)  My associate, George, and I have referred to this red book so much in our ecological consulting work, that both our copies are tattered.

For over a decade, natural resource professionals cited the List of 13 Imperiled Habitats developed by Ken Metzler of CTDEEP and David Wagner of the University of Connecticut at Storrs.  It includes one difficult-to-map habitat:  “headwaters springs and seeps”   that is not on the current DEEP critical habitat map key, although it is a fragile habitat for multiple rare and uncommon species, and crucial for the health of larger streams and rivers.  Better consistency is needed between the Imperiled Habitats List and the new CT ECO document.

The current CT ECO  (Connecticut Environmental Conditions On-line) classification system  includes a map showing the larger critical habitat units, and also a key with detailed  definitions of each critical habitat. Since the scale of the map is such that most occurrences are omitted and since much of the state has not yet been surveyed, the introduction and the key are  actually the most important parts of the document.  

A fine introduction  is Dr. Robert Craig’s  book Great Day Trips to Connecticut Critical Habitats (2004),  which is available, used, on line.  This readable book is a guide to actual examples of fascinating critical habitats, accessible to the general pubic, with much thoughtful, scientific explanation.    Foremost a bird expert, Bob Craig  now runs  Bird Conservation Research, Inc., a non-profit in Eastern Connecticut.  I knew him twenty years ago  in grad school at the University of Connecticut at Storrs.

Scale Considerations

The group of critical habitats  associated with The Metacomet  traprock ridges occupies a tiny fraction of the state of Connecticut, but is nevertheless  extensive enough to support large metapopulations of both common and uncommon plants and animals.   The river floodplain habitats are  include  unusually large critical habitats, ecologically and genetically linked by flowing water.

I keep encountering morphologically distinctive plant varieties in these critical habitats, and realize that genetic variability also encompasses unseen metabolic characteristics, that will help plants adapt to ecological change. A  gene pool with hundreds or preferably thousands of individuals is needed for a good prognosis for long term survival in the face of climate change and other disturbances.

Horticultural and landscaping potential and even potential for medicinal use are other reasons to preserve the botanical biodiversity in critical habitats.  For example, the  smooth aster variety shown below (Symphiotrichum laevis)  is  bushy & colorful, and tolerates a dry, rocky site on West Peak of Meriden’s Hanging Hills. It is a lovely and ornamental perennial wildflower, and would be well suited to xeriscaping.

Impressive data for many traprock taxa has been collected as part of development applications,  such as  the gas plant application on Cathole Mountain  in 1999. The Connecticut Botanical Society and the local bird clubs have  long term data from many field trips to subacidic and rocky  critical habitats.

Glade habitat on West Peak of the Hanging Hills, in Meriden, June 2011. The grassy “lawn” is Pennsylvania sedge, and the flower is smooth rock cress, the food for the caterpillar of the endangered orange falcate butterfly. Hop hornbean, a typical glade tree, of subacidic, mineral-rich soils, at left. A talus slope is in the background.

The complex of critical habitats on the Metacomet traprock ridges has large populations of characteristic species like ebony spleenwort, bottlebrush grass, dwarf saxifrage, and hop hornbeam.  They are not Endangered or Threatened species, protected by state statute,  but are still species that are scarce  in the surrounding, fragmented suburban landscape.  Other species like Eastern box turtle and Ribbon snake,  are listed as Species of Special Concern,  such that CTDEEP can require searches and management plans, but  cannot prohibit habitat development.  Similarly clusters of crystalline bedrock outcrops in several sizable forested tracts along the Connecticut coast (including “The Preserve”  in Essex and Old Saybrook) also support robust populations of Special Concern reptiles,   and metapopulations of  uncommon, rocky-site  plant species like smooth foxglove and orange-fruited horse gentian.  Along river floodplains, flowing water and waterfowl  disperse seeds and link small stands of rare and uncommon plants, like  Davis’ sedge,  into larger genetic metapopulations.

For some taxa, a critical habitat need not be large and continuous so long as other examples are within dispersal distances for  seeds, pollen, moths,   etc.  Such a parcel of critical habitat is still part of the overall unit, from a genetic standpoint. The on-line CT ECO map includes the large, contiguous well-known examples of critical habitats.  Many other smaller examples are also worthy of study and protection, if they have not been severely degraded by invasive species or past farming.

Critical Habitats  that lie within a much larger matrix of natural habitat are especially valuable from an overall  wildlife conservation standpoint, especially for forest birds, large mammals,  and for vernal pool amphibians. Example are the summits of Connecticut’s  northwest hills;  the extensive rugged forests with many bedrock outcrops in the undeveloped parts of Essex and Old Saybrook; and Cathole Mountain; and the Silvio Conte wildlife Refuge along the Connecticut River.   The lower forested slopes of traprock and limestone ridges are not critical habitats,  but they greatly increase the width and size of the habitat blocks.  They also help protect the critical habitats along the ridge lines from colonization by invasive plant species.  For example, the large, latent Summerlin Trails residential project on Cathole Mountain, as initially conceived, would avoid the upper ridge crests and critical habitat areas, but would much reduce the size of the overall habitat block,  with potential to harm  vernal pool species and area-sensitive  forest bird populations.

Potential Outreach

Ample interesting material is available for outreach on critical habitats.  A newspaper article or radio program could use examples  of success stories,  like Hubbard Park in Meriden and Quinnipiac State Park along  the floo0dplain of the Quinnipiac River;  of dramatic battles, like that over development of a  pristine section of Cathole Ridge off Kensington Road in Berlin and of Cedar Ridge in Newington with outcome still unclear;  and of destruction  like the  mined section of Corporate Ridge in Rocky Hill.  Media outreach could revisit the volcanic geologic history, and past dramas, like the story of the now-defunct gas powered plant on Cathole Mountain in Meriden.  It could remind the public and the land use boards of the successful campaign, led by Norm Zimmer in the 1990’s,  for a Ridge Protection Compact.

 

Botany, Invasive Species, Soils, Wildlife Habitat

Rich and Poor in the Plant World – Part 1

Red columbine grows in mineral -rich soil on rocky outcroppings. This thriving population was identified in Rocky Hill, at a site to become a shopping center. The plan was adjusted to preserve most of the knoll, not grade it away.

My much-loved,  old, heavy botanical manuals (e.g. Fernald and Britton and Brown)  always include a sentence or two about the habitat where a plant is found, as well as exceedingly detailed morphological descriptions.  “Found in rich soil” is a frequent description that can apply to fallow farmland, alluvial  floodplains, a bouldery forest at the base of a hillside,  or  a rocky summit with two inches of mineral-rich soil , covered with red columbines.  I used to think rich soil was rich soil, no matter where it was, with other ecological factors making the plant communities so different from each other. But I’ve learned that is only partly true.

Fallow Farm

A fallow, fertile crop field supports a rank stand of annual weeds like pigweed, ragweed, and giant foxtail, that have the genetic capacity to grow tall in response to high levels of  the three basic nutrients (especially nitrogen, but also phosphorus, and potassium).  The field produces abundant birdfood, but  weed competition excludes all the wildflowers and ferns than are genetically programmed to stay short for their whole lives. Frequent plowing  also excludes native perennials.  Soils may or may not be “rich” in ninerals like magnesium and calcium.  The probability of finding rare species is very low.

Floodplain

The dominant understory vegetation in a “rich” floodplain of a large river is also thick and lush, mostly annuals like jewelweed and false nettle, though flooding and ice, not plowing excludes perennials.  Frequent deposits of fresh silt and organic matter provide an abundant supply of the three, basic common  nutrients. Especially if the watershed has traprock ridges, alluvial soil is also rich in other minerals like calcium, magnesium, and manganese, and subacidic.

Such  soil is well-suited to late-season farming.   It also can support uncommon, minerotrophic (mineral-loving)  plants, where growing space and light is available. Floodplain annuals start growing only after floodwaters  recede, and tree falls and thick deposits of sediment often  open up new bare soil patches.

Jewelweed is dominant in alluvial soil with shale gravel, along Stocking Brook , in southwestern Berlin, Connecticut.

I have found delicate wildflowers only in early spring, before they are shaded by the rank annuals.  Dutchman’s Breeches (Dicentra cucullaria)  and spring beauty (Claytonia virginica) do grow on the banks of the Farmington River in Simsbury, with much traprock in its watershed. I also know a few rare floodplain sedges, like Davis sedge (Carex davisii),  with a vigorous,  tall growth form,  that can compete with the dense floodplain annuals – though not invasive shrubs like Euonymus alata.  Do  these uncommon floodplain plants need soil with high concentrations of minerals, with or without high availability of nitrogen, phosphorus and potassium?  Has any  research on this been published?

Base of a hillside

Another  place to find  “rich site” wildflowers, ferns  and sedges  in Connecticut is  the base of  a  hillside, among the boulders. Soil water at the base of a hill has been seeping slowly  downhill for hundreds of feet,and for many centuries,  dissolving minerals from the surfaces of soil particles and rocks. Topsoil has  also slowly washed downhill over the centuries. Slope-base soil  typically  has ample minerals and enough of the three basic nutrients, and is moist as well.  Stately bottomland trees grow in this rich, rocky soil:  sugar maple, red oak,  tulip poplar,  ironwood, and occasional basswood.   Spring ephemerals like red trillium (Trillium erectum) , bloodroot,  and trout lily  (Erythronium americanum) do most of their growing  before the trees leaf out.  However, some shade-tolerant minerotrophic plants  can keep growing  through the summer, like red elderberry and  broad beech fern – and other much rarer ones, like Goldie’s fern (which I have yet to find.)   The  understory is  less dense than in the floodplain, with less competition, and greater diversity. It still rankles me that a Target big box store was built  in this habitat at the base of a Meriden traprock cliff, without any ecological survey beforehand. It was over ten years ago, but I still boycott the store!

At the base of very long  seepage hillsides, soil water has the highest mineral concentrations,  and the slope-base plant community is potentially most diverse. The reason is simple, as I was taught by my major professor Ton Damman: the further the groundwater travels, the more minerals are dissolved.  I  recall an amazingly diverse  swamp at the base of a great hill in Winsted, Connecticut, west of Route 8.  We measured the nitrogen  levels, and they were quite low. Vegetation was low in density and stature, however, not a rank, impenetrable  thicket.  This allowed diverse, minerotrophic plants to coexist, including  melicgrass (Glyceria melicaria), chestnut sedge (Carex brunnensis), and a dwarf raspberry called Rubus pubescens.

Rocky Outcroppings

This year I  found these same plant species – and also Dutchman’s breeches  – on several  shale outcrops  in the  East Berlin geologic formation.  The laminated  shale rock structure increases surface area available for mineral dissolution. Positively charged cations (e.g. calcium and magnesium)  enter the soil water and increase the pH.  Subacidic soils derived from traprock, limestone, or shale  have the highest mineral levels, and  support diverse and interesting  plant communities.  Minerotrophic   plants are most likely in areas with subacidic soils, in large part because higher pH makes minerals more available to plants.  (This is the reason that farmers apply lime.)

Brittle fern, an uncommon minerotrophic species of rocky habitats is growing out of a shale rock face along an incised stream , Stocking Brook in Berlin, Connecticut.

Characteristic plant species, uncommon  in other habitats, as well as truly rare, state-listed species,   are also often associated with  ledges, outcroppings, and  crevices of  rock formations, regardless of bedrock type. Botanizing is always rewarding in such habitats! I often find red columbine (Aquilegia canadensis) on traprock summits,  but sometimes also in areas with  a metamorphic  outcrop of gneiss or schist.     Dwarf saxifrage, Dutchman’s Breeches, Canada moonseed (Menispermum canadense), and red elderberry (Sambucus racemosa), and brittle fern  grow at the base of a low traprock cliff  near Kensington Road in Berlin.  The first four species I  often see in  undisturbed trap habitats, but rarely elsewhere.  The brittlefern (Cystopteris  fragilis) is rarer, but less tied to traprock.  The only orange-fruited horse gentian (Triosteum aurantiacum)   I have ever seen was at the base  of  a sandstone shale rock face, but they have also been found on coastal bedrock outcrops in Branford.  Rare prickly pears  (Opuntia humifusa) have been found in Old Saybrook on bedrock outcrops on “The Preserve” property; this is  probably because the open, southern exposure mimics the warmer growing conditions at the center of its range., and may – or may not – be also related to mineral-rich soil.

Seedling of a Canada moonseed vine, in moist, rich soil at the base of a basalt rock face; north end of Cathole Mountain, Kensington Road, Berlin.

 

Questions

The term minerotrophic is widely used, but solid data is lacking as to exactly which minerals are needed by which plant species, and at what levels.  What are the relative roles of microclimate and soil mineral needs, as they affect plant  distributions on rocky summits and outcrops?    How often is the distribution of a “rich site”  species limited, not by soil composition, but rather  by competition with other plants?   Many  uncommon plants are known to be characteristic of rocky habitats.  How often is this  due to the role of rocks and boulders in reducing competition, rather than mineral availability?  To what extent are “rich site” plants found along slope bases or on “rocky site” plants on summits because  the areas were historically too bouldery for farming, so that the plants remain there, but were long since eliminated elsewhere by  agriculture?   A telling comparison is the nearly pristine, and botanically diverse, forested  north slope of the traprock ridge at Dinosaur State Park, versus the depauperate east slope, which has been farmed for over a century.  Parts of this this field  are  infested by invasive Japanese barberry and burning bush, and the dominant ground cover is the prickly dewberry, a very common dry-site plant.  But even this field, also supports populations of uncommon plants  like Carolina rose and panicled bush clover, growing in sweet (subacidic), mineral-rich soil with traprock near the surface.

These are opportunities  for interesting ecological research!  We really have not advanced very much past the “rich site”  or “rocky site”  habitat  characterizations in the old botany manuals.

 

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

Invasive Species, Wildlife Habitat

Rose Maze

Yesterday at dusk I was near downtown Wilton, at the site of a future apartment building.  I was trying to get out of  an approximately  2-acre thicket of invasive shrubs and vines, after characterizing them. It was raining hard, so I was clutching my glasses, trying to protect my notebook. (Had not put on the uncomfortable rain jacket, as it wasn’t raining yet when I started my field work.)

Five times I painfully pushed towards the outside, only to reach either a chain link fence, a truly impenetrable mound of multiflora rose, or a pile of logging debris – so I retraced my steps. I prayed on and off, felt like Tom Sawyer trying passage after passage in the cave. Or Sleeping Beauty, having woken up on her own, trying to escape through the thicket of roses that had grown up around her palace.  I remembered another consulting job site:  a tall, impenetrable multiflora thicket surrounding  a small  farmhouse occupied by an elderly  widow. Mowing had ceased when her husband had died.

Eventually, a patch of stately, thorn-free Japanese knotweed (like bamboo) was my gateway to the road and safety, my “prince”. I am so grateful to this grove of invasives, although Jap. knotweed is one of the most villified.

Growing up, I always thought of this plant as a privacy hedge, because the womens’ outdoor shower at the Nissequogue Point Beach Club was shielded from the prying eyes of outsiders by a knotweed thicket. Half a century later, I returned to find the same cold shower and the same dense thicket with large heart-shaped leaves. What a persistent monoculture! Overtime the knotweed at the Wilton site might well replace the multiflora rose (that is if the apartments weren’t built). At least it’s handsome, with bountiful nectar, welcomed by insects in late summer, when pickings are slim elsewhere (before all the goldenrods are in bloom.)

This is the king of the clonal perennial species, and the hardest of all the invasives to eradicate. Even after aggressive herbicide application, sprouts will come up the next year … and the next.  The latest control technique is to drill a hole into  every  tough, hollow stem in the knotweed patch and then inject herbicide into the hole; repeat for three successive years.

Energy efficiency, Invasive Species, Native Landscaping, Soils, Uncategorized, Wildlife Habitat

Ailing from Indoor Air Pollution? Go Outside!

This afternoon I heard on public radio (Faith Middleton Show) that  health problems from indoor air pollution are worst in the most energy efficient, air-tight homes (LEED- certified).  I also heard that on average Americans spend less than 95% of their waking day indoors. The Yale PHD interviewed praised his own leaky windows, for the healthy outdoor air they let into his house. (Research was done by Environment and Human Health, Inc. )

This is a very real problem, a major contributor to childhood asthma.  I have heard that it can be addressed without squandering energy by systems of ventilation that include heat exchangers – and by choosing building and decorating materials for minimal off-gassing- like wool rugs – or straw mats, rather than synthetic carpet with backings and  adhesives that generate unhealthy gasses.  It would be great for sustainable farmers to have a stronger market for sheep wool! Faith Middleton pointed out that better labeling of materials is needed, so that homeowners and contractors can make informed choices.

If structural changes are not possible in the short term, it helps to periodically open multiple windows to air the house, on warmer days in winter, and to spend more time outdoors.  My mother did not give me and my siblings a choice; we were sent outside to play and did indeed find interesting things to do.   A diverse natural environment with some wildlife, insect life, and wildflowers will hold your childrens’ interest longer!  Obviously we  breath fresh air while hiking and walking the dog.

Consider also that time spent working in the yard, is time breathing healthier air- typically also with less dust and mold spores than indoor air.  Pulling out lawn weeds, trimming bushes and raking weeds by hand is more time consuming than using power -tools.  It seems to me that the yard would be more inviting to many adults, with greater variety of plantings – and self-seeded plants –  native and non-native,  to keep track of and tend. My husband is not a trained horticulturalist or ecologist, but enjoys spending time outside with me, following my lead, and listening and learning as I point things out.  He now is able to recognize and mow around attractive native perennials – like buttercups and daisies – that crop up in the lawn, even before they bloom!

The outdoors is also more welcoming in summer,  if indoor and outdoor temperatures are similar. At our house in Cheshire, Connecticut, in lieu of air conditioning,  we use airflow drafts though open windows and screened doors, and  shade from an “umbrella” catalpa tree (pruned each fall) on the south side of the house.  Our extended family’s vacation house on Long Island is shaded to the south by two large hemlocks.  It has a long, narrow shape with many windows on both sides, allowing  for excellent cross ventilition. A screened second floor sleeping porch sleeps up to five (on cots) and is a pleasant place to spend time (read, sleep, or just rest and listen to the birds outside)  even in very hot, humid summer weather,  typical of Long Island.

Tomorrow, June 12th,  is the birthday of my brother, who believes lots of  work and play outdoors is the key to good health. We’ll be touring three demonstration alternative “organic” lawns in Newton, Massachusetts (Ecological Landscaping Assoc. http://www.ecolandscaping.org/), one with a solar house.   I expect to learn more ways to spend time outside on my piece of land, and have a fine-looking, dog-safe and wildlife-friendly, “organically ”  landscaped property – fodder for a future blog post. One way I know from childhood is to welcome black locust trees* and clover, which take nitrogen out of the air, by means of symbiotic rhizobium bacteria – free fertilizer! See photo below.

Sleeping porch: comfortable on hot LI nights- and days- in a pre-airconditioning house

*Black locust is on the invasive species lists of some states. It can spread aggressively, fertilize, and change,  sandy infertile natural habitats, as on the Cape in Massachusetts, but in a home landscape , in a pasture, or as a street tree, it is just fine, in my opinion (and that of other Long Island “natural resource professionals” and farmers).  Its abundant nectar is valuable for bees. Black locust  is in fact native to the US –  is from further south and west than Long Island and southern New England.

Invasive Species, Native Landscaping, Uncategorized, Water Quality, Wildlife Habitat

Zig-zag Dog Walks

When walking my dog Mackie in our tidy, suburban neighborhood, I zigzag back and forth across the street,  trying to avoid lawns that are aggressively chemical-treated, as Mackie is always “nose to the ground” unless he hears something of interest in the distance.

Mackie and I zig zag between sidewalks that border  apparently safe lawns.   I look for  clover leaves, variably green color (not evenly dark  green) ,  and small, low-growing patches of lawn wildflowers.  This odd behavior is  based on convincing anecdotes I have heard of repeated cases of the same cancer occurring among different dogs with similar exposures to pesticides.  It is also based on my reading of the results of epidemiological studies, summarized in the informative publications of Nancy Alderman’s non-profit, Environment and Human Health, Inc. based in North Haven.  Dogs are even more vulnerable to cancer than children, and we have already lost two family dogs to cancer: Tejana and Poka.   Poka died at Age 11 of jaw cancer, and would have died at 10, without expensive surgery.  Tejana lived to 15, but then during her first five years she was walked in urban vacant lots and on beaches, not in suburbia.

I began zig zag dogwalking after I heard several stories from the most dynamic trainer of organic landscapers in southern New England, Chip Osborne, out of Marlborough, Mass.   He was the keynote speaker at an Ecological Landscaping conference in Springfield, a few years back.  He told the class that he used to work in a greenhouse. His dog would lie under the potting table, with occasional drippings falling on them (with dissolved fertilizer, fungicide, etc.)  The dog, and then its successor, died of the same cancer.

He told a second anecdote: a  lady in a new residential community/cum golf course walked her dog on the lovely course every day. Her dog died of a nose cancer. She got a new dog, and walked the dog along the same route. Her new dog also got cancer, the same type – and she moved out. Of course dozens of fungicides, herbicides, and insecticides are applied to golf courses, so it is very hard to know, without a real epidemiological study. The story teller quit his propagation occupation and went on to start a successful organic lawn care business, and also teaches many training workshops for other landscapers, transitioning to this approach.  He testifies for citizens groups as well.

The man believes in what he teaches; he knows that the organic approach to landscaping is not only better for the bees and other insects and wildife; it is safer for people and dogs.
As John Stuart Mill (1806 to 1873)  said:

“One person with a belief is equal to a force of 99 who have only interests”

I heard Chip give an articulate presentation to a Westport land use board,  explaining how one achieves sustainable  affordable lawn care without chemical applications, refuting advocates of tire crumb athletic fields for children.

Besides the  health of children and pets, lawn care practices can affect our water resources.  My  subdivision was built before the days of stormwater management.  Whatever folks apply to their lawns    (e.g., excess fertilizer and pesticides) may also wash over the curb along the pavement into the catchbasins, and thence into the River.

When walking the dog, we use a pooper-scooper or plastic bag, not just to avoid being  verbally attacked by my neighbors, but also to keep the feces from being washed by the rain into the extensive system of catch basins, which dump directly into the streams in our neighborhood.

Not only does our neighborhood have fewer  wildflowers, wild bees and beetles than it used to;  the  tributary streams fed by runoff  (2 mg/l of nitrate last time I tested our stream ) are nearly devoid of life.  The Ten Mile River, dowonstream  also has  fewer aquatic insects to feed  trout , dace,  suckers, and wood turtles.

Friends say: why don’t you just walk your dog  in a park?   Here in north Cheshire, we do have lovely open space behind us, The Ten Mile lowlands are great for hiking and free runs  but only in the non-growing season, unless one is a bird watcher coated with bug spray. We can manage driving Mackie to a park maybe once a week, but not three times a day!  Fortunately traffic levels are low in our neighborhood, except in late afternoon and early morning, so zig-zagging across the much-too-wide road is pretty safe.

It is a relief to visit Ships Hole Farm in Long Island, with no dog-walking constraints related to pesticide anxiety.

Violets and a dandelion- early spring lawn wildflowers at Ships Hole Farm.

As a scientist I do  understand, that we are dealing with possible health risks,  and that the majority of applied chemicals are likely not hazardous to humans.  However, the other matter is that a sustainably managed lawn is a diverse and  interesting mini-ecosystem, and can be lovely as well.  It  dos not harm fauna, like Northern Flickers , song sparrows, flower beetles, honeybees, and moles.  …. more fun to walk past and look at-  and probably safer- than a lawn that receives an intensive turf chemical regimen.

Bluet is a lovely lawn wildflower, with grasslike leaves
Naturalized white violets, an attractive, even low groundcover

Flowering bushes buzzing with bumblebees may also indicate a safe lawn. Sadly,  it is years since I have seen a honeybee in my Cheshire neighborhood and the miniature solitary bees have also become very scarce.  However, I still do find honeybees on vacant lots (just yesterday on Broad Street in downtown Manchester) and in poorer neighborhoods.  On those properties  there is probably little use of expensive, beetle grub insecticides (imidocloprid is a neurotoxin that also harms a great many other insects, including bees.)

Invasive Species

Bittersweet Medusa

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A fat, single bittersweet vine is twining high into the crown of a tree, and there are no nearby sprouts to be seen. However, should you sever that vine and neglect to promptly paint the cut stump with an herbicide, the plant will become aggressively clonal. A plethora of bittersweet sprouts will soon be springing up, no longer inhibited by apical dominance (hormones from the top of the vine.)

Please don’t get the wrong idea:  that I condone routine herbicide use! However, cutting alone  means repeating the exercise on Medusa’s new “snakes” the following year and ad infinitum.

Even control by means of hand-pulling or with a weed wrench  will need follow-up, because the brittle roots break off, and remaining roots will sprout.  Because alternatives are absurdly difficult or time-consuming, one of the few herbicide uses that I reluctantly condone is to carefully apply  herbicide (with a window paintbrush, not a sprayer) . Several Nature Conservancy chapters recommend  triclopyr, the active ingredient in Brush-B-Gon and Garlon.

Seedlings can be identified by veiny, alternate, sharp-tipped leaves and orange roots

Apply to the cut surface and adjacent bark of a vine cut  less than ten minutes ago. This is possible when one works with a partner, one person cutting the vines, the other painting them (the “snip and paint” technique.)  In dense vegetation, it also may help to scout ahead of time and tie colored flagging  to the vines to be controlled.

Use a substantial container that will not tip over easily, and wear gloves, long sleeves, and goggles.   Based on my research, the only human health risk is eye-damage, if it splashes in your eyes.  As for the rest of the environment, available  data is too scanty to be confident of lack of harm;  therefore careful application is important.  However, we know an  invasive woody plant infestation will shade out native plants, and reduce the food supply for wildlife.  Therefore control by means of cut stump painting (within minutes after cutting) seems like the lesser of two evils.

A better solution would be to keep sheep, for whom the Medusa sprouts of bittersweet are a delicacy, but zoning forbids this on most smaller properties.

Note: I recommend that you check the product label and the active ingredient of any herbicide, insecticide, or fungicide you are considering using.  Google the name of the ingredient, and databases like Extoxnet will come up.   Look for the skull and crossbones symbol, the term “potential carcinogen”, and the list of types of organisms to which it is toxic, as a basis for your decision to use a product or not.

Additional photos of bittersweet have been posted on a blog dated 5-23-2010.