Monday, April 15, 2013


     This blog is an exploration of what forests mean to the lives we want to be living-- what threats forests face, what changes they are undergoing, and what the outcome of those changes seems likely to be.  My hope is that it will be a place where news about forests in this region, your ideas and articles on forest topics, and resources for learning about trees and forests in this area can all come together in one place.  Your thoughts, contributions, comments, and photos are not only welcome but strongly encouraged!

     The blog contains sections from a book I've been working on of the same name.  Feel free to ignore it, if you wish.  Drafts of several chapters are listed on the right hand side of the blog, under "Pages," and can be accessed by clicking on the title of the section you want to read.   You can skip clicking on the "Necessary Forests" page, since that is the Home page that you're reading right now.

     I've posted the chapters with the hope that you will offer your suggestions, criticisms, and corrections.  My hide is reasonably thick, and I'm interested in anything that might help me make improvements.  Nitpick my grammar, challenge my assertions, ask for more evidence, suggest new lines of thought, critique structure--fire away!  You can either post in the comment section or e-mail me directly at

      Also on the right is a set of links to various tree- and forest-related websites.  I'll be adding to that as time permits.  The two links at the bottom are totally unrelated blogs of mine, for anyone interested.  The Live Poets Society is a Charlottesville group that has been around since the 1980s, and each week I try to add a new poem by one of our local poets.  The other blog, Of Principalities and Powers, is a semi-regular series of weekly columns on social-political topics--written with a light touch, I hope, but my left-handedness is readily apparent. 

     Unless noted otherwise in a caption, photos in the blog are my own work.
Many thanks,

Tony Russell 

Secluded Farm; October 31, 2011

Brown Bag Lunch talk by Virginia Department of Forestry official

People concerned about deforestation in Virginia and elsewhere might be interested in a presentation at the Rivanna Conservation Society’s monthly Brown Bag Lunch Discussion Forum this Thursday.   Brown Bag Lunches are held at the downtown library in Charlottesville, 201 E. Market St., on the third Thursday of each month.  They begin at noon, and last an hour.  They also count as Advanced Training for Master Naturalists.

Robbi Savage, RCS’s director, sent the following information about the topic and speaker:

TOPIC:  VA Department of Forestry’s new initiative to Mitigate Forest Loss

Virginia has been losing 16,000 acres of forestland to conversion annually and the U.S. Forest Service estimates that suburban encroachment alone will lead to 12 million acres of southern forests being converted to development between 1992 and 2020.  The economic and ecosystem services impact of this loss is significant and the Virginia Department of Forestry, joined by South Carolina and Georgia, is leading an initiative to mitigate forest loss and reduce the rate of forest conversion in the Commonwealth. 

ABOUT OUR SPEAKER: Greg Evans recently joined the Department of Forestry as the Voluntary Mitigation Program manager responsible for developing the program which will also serve as a model for other southern states to follow.  Greg came to the Department of Forestry following a diverse career in the federal government (including the White House) and the private consulting industry where he focused on complex environmental policy and management challenges.  He has also been very active in Virginia serving in various elected and appointed natural resource and conservation related capacities at the local, regional and state.  Greg also served on the grants decision board for the Chesapeake Bay Restoration Fund.

Monday, March 18, 2013

Trees Around Us ~ Tree of Heaven (Ailanthus altissima)

Tree of Heaven is the dandelion of the tree world.  It arrives unbidden and unwanted; it thrives with zero care; and it’s the devil to get rid it of once it gets its foot in the door.  It thrives in the face of pollution, poor soil, drought, salt, heat, neglect, or hand-to-hand combat.  And it looses hordes of seeds to be scattered by the wind.

“Tree of Heaven” is its common name, but it’s often referred to simply by the genus part of its scientific name, Ailanthus, and they’re used interchangeably.  Turned off by the tree’s odors (the male flowers are often compared to cat urine, and the leaves and twigs to rancid peanut butter); the litter from its numerous seeds and easily-broken twigs; the hazards of its often-hollow trunk; the tendency of its shallow but wide-ranging roots to damage sewers, sidewalks, and foundations; and the difficulty of ridding it from their yard, frustrated homeowners turn the common name around: they call it “the tree from hell.”  The  picture below catches some of that whiff of brimstone.

Tree of Heaven in Winter
February, 2009

The photo, unretouched, shows the top of a large Ailanthus, bathed in the lurid light of a winter dawn, and seemingly writhing in flames.  This tree is a typical “volunteer” that sprouted in a fencerow behind Burnley-Moran School, at the top of Grace Street hill.  Tree of Heaven is an opportunist that appears in any neglected or disturbed area--vacant lots, alley edges, property lines.  Or just follow a bulldozer; you’ll find Ailanthus springing up along new roads, railroad embankments, right of ways, interstate highways, housing developments, and areas that have been logged.

Ailanthus sprouts
April 1, 2008

This second photo is of a group of Ailanthus sprouts.  You can glimpse them across the guardrail at the base of Free Bridge, on the right as you are preparing to exit the city, and they illustrate why Ailanthus is so tough to get rid of.  All of the sprouts in the group (the photo shows only a handful of a large number) have shot up from the roots of a single tree, after someone cut it down.  Ailanthus fights back with a vengeance; simply hacking away at it is a lost cause.  It will sprout from its stump, and any roots or fragments left behind will almost certainly regrow and create a clonal clump.

A friend looked at the photo of these sprouts and gave a small shudder.  “They’re spooky,” she said.  And maybe she was feeling something of its menace.  Tree of Heaven is allelopathic, meaning it produces a toxin that poisons the ground around it to eliminate its rivals.  Seedlings are baby assassins.  They develop a taproot within three months after they germinate, and the young trees grow so rapidly they shade out native trees that try to compete.  Ailanthus may be the fastest growing tree in the United States. Live fast, die young; its average lifespan is only 30 to 70 years.

Tree of Heaven could be considered the prototypical invasive.  It took the classic, well-traveled invasive’s route from east Asia to America; was introduced in 1784; and was sold by nurseries from about 1840 on.  (As a side note, I was interested to learn that the first Tree of Heaven in North America,  the 1784 planting, was in Bartram Botanical Garden in Philadelphia, a quiet, somewhat neglected place that I liked to retreat to when I was in graduate school in that city, many years ago.)  Like many other troublesome invasives, such as Oriental bittersweet, Autumn Olive, Siberian Elm, and multiflora rose, it didn’t sneak into the county.  It was invited and promoted for its virtues.  

In fact, early on, from the standpoint of a developer or urban tree planter, the species must have seemed like the fulfillment of a wish list--a veritable dream tree.  It has few insect enemies or diseases; is tolerant of smoke, salt, and dust; establishes easily; and grows fast. It makes itself at home almost anywhere, up to and including a crack in the sidewalk.  So it was widely planted in U.S. cities in the 19th century.  Yet nowadays it’s hard to imagine someone deliberately planting it.  I say that, but a few minutes on the Internet show nurseries still offering Ailanthus for sale, with the claim that it "will add that special touch to make your lawn look great"!

That shift in our perception of the species--from adaptive and attractive to repugnant and invasive--should cause us to meditate deeply on our normal "good tree/bad tree" categories.  And when we consider that not only the import, but the disturbances and harsh urban environments that favor Tree of Heaven are the work of human hands, we might hold the tree less responsible for its behavior, and introduce our own responsibility into the equation.

In early April, when Ailanthus begins to sprout out, its new foliage can be as colorful and eye-catching as a flower, as you can see in the first photo below.  The second shows the same sprouts that looked so spooky above, this time clothed in the fresh, hopeful green of new growth.  It's worth having many impressions of a tree.

Ailanthus is dioecious, meaning that male and female flowers grow on separate trees.  When a friend commented last year that the Ailanthus were in flower, I realized that he had mistaken the colorful seed clusters on the female trees for flowers.  In our area, the winged seeds--which are called samaras, just as maples' winged seeds are--become a cheerful red as the seeds are maturing.  This is actually a trait that varies with varieties and geography.  The more common version stays a greenish yellow.  Both bleach out as the seeds fully ripen and dry.  

Tree of Heaven's invasive potential is magnified because a single female produces an astounding 350,000 seeds, with a high germination rate, and fruit production begins at an early age.  Stories abound of even one- and two-year-old Ailanthus producing seeds.   The twisted seeds are centered in a papery sheath, and are about the size of an ash seed.  They hang on the tree in large clumps that persist all winter, releasing slowly over a long time and spiraling off into the distance with each breeze.

A cluster of Ailanthus seeds

Ailanthus’s huge compound leaves--up to 41 individual leaflets--are the largest of any tree in Virginia, and act as disposable branches.  The long, pinnately compound leaves can be confused with those of Black Walnut (and like Black Walnut, it is one of the last trees to emerge from dormancy in the spring) as well as sumac.  If people are having trouble distinguishing between Ailanthus and Black Walnut, it is likely because we focus so much on using leaf collections to identify trees in school.  The reality is that, leaves aside, the two species could hardly be more different.  Their bark, their twigs and buds and leaf scars, their scents, their flowers, their fruits, their forms--nearly everything about them is distinctly different.

Newer-growth Ailanthus twigs are thick but lightweight and flimsy, with a smooth light chestnut-brown bark, and look nothing like Black Walnut twigs.  If you’re in doubt, breaking off a twig and taking a sniff will erase it; the smell of Ailanthus is unmistakable.  You could also check out the bark; that of Ailanthus resembles the skin of a cantaloupe.  Or look for the one to five rounded lobes at the base of Ailanthus leaves.  Each lobe has a small, dark rounded gland protruding on the underside of the leaf.

Ailanthus bark

Black Walnut bark
Currently Ailanthus ranks as the 42nd most abundant tree in Virginia, already surpassing many natives and moving steadily up the list.  I remember hiking through the woods at Ivy Creek and coming across an oak that had come down in a storm.  Perched in the earth atop its rootball was an Ailanthus seedling, already making its way toward the sun.  That’s important to keep in mind, because Ailanthus needs sunlight for its seeds to germinate and its seedings to thrive; thus it prospers on disturbed sites and in canopy gaps, but can’t get a toehold under a closed canopy.  It often establishes within forests along roads or after logging.  One obvious strategy for fighting the spread of Ailanthus, then, would be to minimize human disturbance of natural woodlands.  

The Virginia Department of Forestry has investigated ways of marketing products made from Ailanthus’s wood as one means of Ailanthus control.  These include things like furniture (some pieces of which can be seen at the Forestry Building on Ray Hunt Drive), charcoal, pulp, and biomass.  It’s a tricky business, trying to create an incentive for people to cut and work with the wood while not creating an incentive to grow more of the trees.  

With its increasing abundance and its many flowers per tree, Ailanthus inevitably ends up being visited by honeybees.  I don't have any firsthand experience with this, but several resources claim that the honey from the foul-smelling male flowers is itself foul-tasting--but that the nasty taste disappears as the honey ages, leaving behind an especially nice-tasting honey.  I'd welcome some input from beekeepers on their experience with Ailanthus!

Contemplating a future in which native forests are further decimated by disease, insects, and climate change, and Ailanthus makes ever greater inroads, another friend--Tim Tigner, a woodworker and retired forest health specialist--tried to make the best of it.  “You know,” he said, “the wood isn’t really that bad to work with, if you don’t mind the color.”

          © Tony Russell, 2013


Peter Dutnell wrote: A note on the Ailanthus altissima.  It seems to me, quite a few have died and are dying as a result of the last two or three dry and hot summers; this also predisposes to a fungal affliction.  Now whether this means they die from the top down or bottom up remains to be seem.  I only know of one insect which affects or uses the tree, the Ailanthus webworm, and as the tree has a male and female plant, then pollination has to take place. The question is, with such a large female seed count and few male mature trees, could this effect an invasive control? The web worm Atteva punctella is the pollinator and is common in the Fall and appears to pollinate quite a few plants so that control would be ineffective. 

Tony's response:  Spoken like a true naturalist, Peter.  You have some interesting thoughts in your e-mail, and I wonder if you'd be willing to have our correspondence here posted to the blog, as I'm sure a number of folks would be interested in your follow-up.

I've been following the Verticillium fungal issue with Ailanthus for several years now.  As you probably know, a significant number of dead Ailanthus were spotted by Donald Davis of Penn State University back in 2002 in south-central Pennsylvania, and he subsequently identified Verticillium albo-atrum fungus as the killer.  He immediately recognized its potential as a biological control to help check Ailanthus's progress.  In his experiments, he used a special hatchet to drive the fungus into the tree's sapwood, where it grew into the tree's vascular system and clogged it up.  Since the vascular system runs both up and down, I don't think the direction of the disease's progress is one-way.  However, wilting leaves seem to be the first tell-tale symptom of the tree's distress.  The holdup in using V. albo-atrum as a biological control is the need to be very sure that it doesn't attack other species in the forest, such as oaks, maples, and ashes, if the fungus is introduced to kill Ailanthus.  Studies I've read to date are encouraging in that the killing fungus seems to be highly host-specific to Ailanthus.

Ailanthus webworm (now known as Atteva aurea, formerly known as Atteva punctella) is an ermine moth and an interesting story, since it has jumped species from its original larval host plant, the Paradise Tree, to make wide use of Ailanthus.  I haven't seen anything to indicate that this webworm is a potential check on the spread of Ailanthus, but I'd be glad to hear of anything you've come across that suggests that is a possibility.

Like tent catepillars, Ailanthus webworms create nests of loose webbing around their larvae in the crowns of trees and feeds on the trees' leaves.  It can't survive cold winters, but migrates north from Florida and points south each year.  As I said, I haven't seen anything that indicates Atteva aurea does enough damage to act as an invasive control.  It does serve as a pollinator for Ailanthus, but in most areas probably not the primary one.

Ailanthus webworm moth
Photo by JJ Wilson et al, from Wikimedia Commons

A 2008 master's thesis by Jessica Thompson at Virginia Tech focused on the pollination biology of Ailanthus,  She found that its flowers were easily accessible to a variety of insects and required no specialization on a pollinator's part to access pollen and nectar.  She identified a variety of pollinating visitors, with beetles most numerous and flies next.  The most frequent visitor was a beetle called Chauliognathus marginatus, commonly known as Margined Leatherwing or Soldier Beetle.

One line of thinking in attacking Ailanthus is that the very factor that makes it such an aggressive colonizer--its ability to create clonal colonies from root sprouts--also makes it highly vulnerable.  That is, if you can introduce a fungus or other disease to one of the stems in the colony, it may be spread throughout the entire colony and wipe the whole thing out.

Peter responded:    Further on the Ailanthus.  I had read of the hatchet fungal introduction  somewhere, but the info from Jessica Simpson at VT I found very interesting. The inhibiting chemical that Ailanthus puts out, does it have a name?  And how pervasive is it?

Tony wrote:  Thanks for your willingness to share our conversation, Peter.  The allelopathic chemical is called ailanthone.  The chemistry is over my head, but it's a quassinoid and highly phytotoxic (which simply means poisonous to plants).  Two interesting things about it.  One is that while it's killing plants around the tree, it doesn't have any impact on Ailanthus seedlings, which means the plant has some way of preventing being poisoned by its own kind.  And two, it loses its phytotoxicity within five days in natural soils because of microbial activity.  That makes me think the most phytotoxic period might be when leaves are falling and the ailanthone is gradually leaching out of the leaves into the soil over an extended time.

The USFS Silvics Manual says that in experiments over 35 species of hardwoods and 34 species of conifers were vulnerable to allelopathic action by Ailanthus.

Friday, February 22, 2013

Conservation of Tree Species by Botanic Gardens

Thanks to Ruth Douglas for forwarding the following article.  It seems especially timely, given recent discussions on the importance of trees and forests.  I've taken the liberty of breaking the text into more paragraphs to make it more reader-friendly.


Protected remnant native dryland forest between Mauna Kea and Mauna Loa, Hawai'i.

The Overstory #252
Conservation of tree species by botanic gardens
by Sara Oldfield and Adrian C. Newton
February 19, 2013

Importance of tree species

Trees are of exceptionally high ecological, socioeconomic and cultural importance. As the principal biomass component of forest ecosystems, they provide habitat for at least half of Earth’s terrestrial biodiversity (Millennium Ecosystem Assessment, 2005), supporting 80% of amphibian, 75% of bird and 68% of mammal species (Vié et al., 2009). Forest ecosystems play a major role in the Earth’s biogeochemical processes, and contain about 50% of the world’s terrestrial carbon stocks (FAO, 2010; Millennium Ecosystem Assessment, 2005), highlighting their importance for moderating human induced climate change.

Trees and forest ecosystems provide a wide range of benefits to people including production of timber, fuelwood and fibre, and ecosystem services such as clean water, flood protection and prevention of soil erosion from watersheds, as well as being of high cultural and spiritual value (Millennium Ecosystem Assessment, 2005; UNEP, 2009). The total value of such services has been estimated at US$4.7 trillion per year (Costanza et al., 1997). Some 1.6 billion people depend directly on trees for their livelihoods (World Bank, 2004), and forest industries contribute around $468 billion annually to the global economy (FAO, 2011). Recent research has confirmed that high plant diversity is needed to maintain provision of many ecosystem services (Isbell et al., 2011).

In situ conservation

It is generally recognized that the most effective way to ensure the long-term survival and evolution of tree species, and the ecological communities of which they are a part, is to maintain viable populations in their native environment (Kramer et al., 2011). This is referred to as in situ conservation. Typically this is achieved through the designation and management of some form of protected area, such as national parks, wilderness areas and nature reserves (Newton, 2007). The extent of the global network of protected areas continues to increase, with nearly 133,000 areas now designated, representing 12% of the Earth’s terrestrial surface (Butchart et al., 2010). Parties to the CBD recently committed themselves to raise this figure to 17% by 2020.

Despite the substantial efforts being made to support the development and management of protected areas, many are currently under threat from human activities such as urban encroachment, infrastructural development, habitat conversion, illegal harvesting and fire (Chape et al., 2005). Additional problems include policy-related issues such as weak government institutions, conflicting policies and resource tenure (Brandon et al., 1998). Because of such problems, and the fact the coverage of protected area networks is not complete, additional conservation approaches are also required.

Ecological restoration and reintroduction

The widespread environmental degradation that has occurred as a result of human activities has led to a growing interest in ecological restoration. This may be defined as the process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed (Bullock et al., 2011). Ecological restoration has grown rapidly over the past few decades, both in terms of a scientific discipline and in terms of environmental management practice (Nellemann and Corcoran, 2010). Billions of dollars are now being invested in restoration actions throughout the world (Goldstein et al., 2008), supported by international policy commitments such as the CBD. Many environmental organisations and community groups are actively engaged in ecological restoration projects, but increasingly restoration actions are also being undertaken by other organisations, including governments and large companies.

A number of related terms are widely used. Rehabilitation emphasizes ecosystem recovery, without including the re-establishment of some pre-existing state as a management goal. Reclamation generally refers to the environmental improvement of mined lands, and may incorporate soil stabilization and aesthetic improvement (Newton, 2007). In this case there may be less emphasis on restoring the original biodiversity present at a degraded site, and greater emphasis on restoring productivity. Afforestation and reforestation refer to the establishment of trees on a site, in the former case where no trees existed before, and in the latter case following deforestation (Mansourian, 2005).

It is also helpful to differentiate approaches involving the restoration of entire ecosystems or ecological communities, from those that focus on individual species. For example, conservation actions might focus on restoring populations of an individual tree species that had been depleted by timber harvesting. This could be achieved by artificial establishment of individuals of the tree species concerned, for example by enrichment planting, using planting stock derived from an ex situ population. If a species has been extirpated from its original habitat, it may be a candidate for reintroduction, which aims to re-establish new, self-sustaining populations of a species in the locations where it occurred previously.

In recent years, reintroduction has increasingly been used as a plant conservation tool (Falk et al., 1996). For example, one-fourth of the plant species listed by the U.S. Endangered Species Act include reintroduction as a component of their recovery plan (Kramer et al., 2011). To be successful, reintroductions are dependent on the availability of appropriate material either from other nearby adapted populations or from suitable ex situ populations. Integrated conservation approaches will therefore generally involve an element of reintroduction of an individual species, as described in this manual. However, such reintroduction might form part of a broader effort to restore an entire ecosystem, as also explored further below.

Ex situ conservation

Ex situ conservation can be defined as the conservation and maintenance of samples of living organisms outside their natural habitat, in the form of whole plants, seed, pollen, vegetative propagules, tissue or cell cultures. As many plant species are declining in abundance as a result of human activities, and increasing numbers are becoming threatened with extinction, there is an increasing need for ex situ conservation approaches. Botanic gardens play a major role in the ex situ conservation of plants, but a number of other organisations also maintain ex situ plant collections including academic institutions, non-profit organizations, forest services and other government agencies. Such collections can have value for research, horticulture and education, but here the focus is on their potential value for conservation.
The value of ex situ collections for conservation depends on three main factors (from Kramer et al., 2011):

1) The type of plant material collected (including seeds, explants, and living plants), which varies according to each species’ reproductive biology, seed characteristics, and/or adaptability to ex situ conditions. For species with orthodox seeds (i.e. able to be dried and stored at low temperatures for many years and still remain viable), ex situ collections maintained as seed banks provide the greatest direct conservation value at the lowest cost. For species with recalcitrant seeds (i.e. not able to be dried and stored), tissue culture or cryopreservation collections can also provide high direct conservation value but at a higher cost. Living plant collections can also be of conservation value, depending on how they are collected and maintained.

2) The protocols used for collecting; in general, welldocumented, wild-collected ex situ collections that capture as much genetic variation of the species as possible will have the greatest conservation value. Botanic gardens often maintain collections of living plants represented by one or more specimens per species, and from sources that are of wild or non-wild (cultivated or unknown) origin. As only genetically diverse and representative collections are appropriate to directly support in situ conservation (e.g. through reintroduction), living collections represented by only a few individuals will often be of limited value. However they can nevertheless be of indirect conservation value, for example through research, horticulture and education. It is also important to note that ex situ collection efforts must be conducted carefully to ensure wild populations are not placed at additional risk.

3) The subsequent maintenance of viable germplasm, which plays a critical role in determining the ultimate conservation value of an ex situ collection. Without proper curatorial management, the conservation value of a collection, or the collection itself, can be entirely lost. Collections with the most direct conservation application are genetically diverse and representative of the species, and must be managed to ensure the material is genetically sound and available for conservation activities over the long-term.

Many living collections today do not meet these standards, owing primarily to genetic issues such as having too little genetic diversity, being of unknown provenance, or losing genetic diversity via drift or adaptation to cultivation and hybridization. Management of ex situ collections should also minimize the risk of loss due to random events or natural disasters (such as staff changeover, theft, fire, disease, or other catastrophic loss) by ensuring that collections are maintained at more than one site. Additionally, curatorial oversight of living collections through time is crucial to maintaining associations between collection data (e.g. provenance) and specimens.

Integrated conservation approaches

In recent years, increasing emphasis has been placed on integrated conservation approaches, in which in- and ex situ approaches are combined, often together with reintroduction and ecological restoration. The traditional idea that the role of botanic gardens was to hold cultivated stocks of threatened species during a period of habitat degradation, in what has been described as the “ark paradigm,” is no longer believed to be sufficient (Havens et al., 2006). Rather, for botanic gardens to be effective with respect to conservation, the species banking approach must be integrated with other conservation approaches focusing on habitats and ecosystems (Havens et al., 2006).

The concept of integrated conservation of plant species is described by Falk (1987), who notes the need for multiple conservation approaches to be employed. Given the variety and complexity of threats to biodiversity, a single approach, such as legal protection for a species or the acquisition of land, is unlikely to be successful. According to Falk (1987), integrated conservation is based on the assessment and synthesis of three sets of information:

(i) determination of the biological entity of concern, including definition of the target level of biological organization (such as species, sub-species, variety or race);
(ii) identification of the threats to this entity; and
(iii) consideration of the full range of conservation resources that may be brought to bear on the problem.

Integrated conservation approaches deliberately seek a broad base of information about a conservation problem and employ a wide range of complementary tools to accomplish a given objective (Falk, 1987). Such approaches are typically highly site-specific and based strongly on local context, in contrast to traditional approaches that are more general in scope. Individual approaches can be of value at different scales; for example, seed banks are well suited to conserve genetic diversity within a population, but are incapable of conserving communities or ecosystems. However, they may play a role as part of an overall integrated strategy to address diversity at multiple levels of organization.

Rather than being viewed as separate and distinct, in and ex situ conservation approaches can therefore be viewed as part of a spectrum of compatible, mutually reinforcing methods (Falk, 1987). For example, Falk (1987) provides the example of the successional management of a fire-adapted ecosystem, such as a prairie or savanna, which may involve fencing, site preparation, controlled burns, and reseeding with native species.

Such a management regime may differ from a reintroduction program only in terms of the number of years during which a particular species is absent from the site, or from ecological restoration only in terms of the number of species that are the focus of conservation efforts.

Integrated conservation of tree species therefore includes both in situ and ex situ action, linked by restoration, reintroduction and collection, to support species survival. This process can be supported by research, horticulture and education that can ultimately increase the success of conservation efforts (Figure 1). Botanic gardens and related organizations can play a major role in integrated plant conservation throughout the world, and are uniquely positioned to be able to support such efforts (Havens et al., 2006).

Figure 1. Integrated plant conservation combines in situ (on-site) and ex situ (off-site) conservation approaches to support species survival. In situ conservation protects species in their native habitat, while ex situ conservation ensures plant material is available for research, horticulture, and education activities that ultimately support reintroduction efforts, to prevent species from going extinct. (Adapted from Kramer et al., 2011)


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This article was excerpted from the original with the kind permission of the publisher and authors from:
Oldfield, S. and Newton, A.C. 2012. Integrated conservation of tree species by botanic gardens: a reference manual. Botanic Gardens Conservation International, Richmond, United Kingdom.

Botanic Gardens Conservation International (BGCI) is an international organisation that exists to ensure the world-wide conservation of threatened plants, the continued existence of which are intrinsically linked to global issues including poverty, human well-being and climate change. BGCI represents over 700 members - mostly botanic gardens - in 118 countries. We aim to support and empower our members and the wider conservation community so that their knowledge and expertise can be applied to reversing the threat of extinction crisis facing one third of all plants.
Descanso House
199 Kew Road
Surrey, UK TW9 3BW
Telephone: +44 (0)20 8332 5953
Fax: +44 (0)20 8332 5956

Help Build Tree Cages in Shenandoah National Park

Help Build Tree Cages in Shenandoah National Park 

Shenandoah National Park Trust is funding a multi-year initiative to help our park control invasive, non-native plants and re-establish native species in high-priority areas, including Loft Mountain. You are invited to help build cages to protect native saplings that our park is planting in areas where invasive species have been cleared.

DATE:    Saturday, March 23, 2013
TIME:    11:00 am – 1:00 pm
PLACE:  Loft Mountain in Shenandoah National Park – mile post 79.5  (meet in the parking area)

The park will provide supplies and equipment. You can bring a lunch or snack to eat while we work. Dress in layers and wear sturdy shoes. Children who are able to help are welcome.

Rain or snow/ice will cancel the event. In case of “iffy” weather, we will make a decision on Friday, March 22. If we decide to cancel, we will notify you via email.

RSVP by March 3 to or (434) 293-2728. Please indicate the number of people coming with you.

Thank you for your help!
Our mailing address is:
414 E. Market Street, Suite D
Charlottesville, VA 22902
Copyright (C) 2010 Shenandoah National Park Trust. All rights reserved.
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Thursday, February 14, 2013

Tree Identification in Winter

I’ve created a video of a portion of my Keynote presentation “Tree Identification in Winter.”   This is the part I normally use in teaching sessions, with a focus on working with twigs, and their buds and scars.  There are other parts dealing with using site, bark, and branching patterns, but those bring the total to somewhere around 350 slides--far too many for a typical class, and things better taught in the field anyway.

As a guide to a number of specific trees, the presentation will probably work well in much of the eastern United States.  As a guide to terminology, techniques, and identification tools, it should have  value in a much wider area.  To reach the presentation, click on the “Tree Identification in Winter” link on the right hand side of the Home page.

The presentation isn’t limited to native forest species, although they dominate. I’ve also included commonly-planted lawn and street trees, as well as invasive species.  It’s likely you will encounter all of these, and I imagine you will want to know them when you meet them.  Once you begin to practice the kinds of observations depicted in the video, you may find that identifying trees is actually easier when their leaves are off, and the absence of leaves enables you to focus on other aspects of the tree, things that can be a unique signature. 

American Beech
It takes about 40 minutes to run through the video, which has no audio accompaniment.  That saves band width, so people should have less trouble viewing it.  Most of the material is already explained on slides in the presentation.

I tried to pace the video at a slow enough speed that people who are trying to read carefully can take in all the text, and will have a chance to actually look at the photos.  (I think now that I slowed it down too much, and will try to edit it down when I get a chance.)  If people are wanting to reread something or take notes, they can pause the presentation, and then resume playing it when they're ready to move on.

There's a band running along the bottom of the video panel that disappears, but will reappear if you put your cursor anywhere on the slide.  On the left side of the band you'll see a Play/Pause button.  Immediately to the right of that it tells you how much time has elapsed so far in the presentation, and at the very far right it tells you how much time remains.  If you plan to go back to something, you can jot down the time for the slide you want to revisit.  There is a small diamond that moves along the band, showing where you are in the presentation.  You can move that diamond backward or forward, and that will take you backward or forward in the presentation.

My hope, as always, is that the video adds to your love and appreciation of trees. 

                           © Tony Russell, 2013


Tuesday, February 12, 2013

Tree and Forest Websites: An Annotated Guide

Introduction to 2012 edition

The following list of websites was created in 2008 and revised and expanded in February, 2012.   My hope is to update it each year, since the Internet is constantly evolving.   New websites are created, while old ones are constantly updated, revised, or abandoned.  I went through all the websites to check that links still worked in 2012, and deleted non-working sites, as well as changed addresses for sites that had been moved or restructured.  In addition, several new sections were added--one on identification of trees in especially difficult genera; one on Virginia forests, and one on forest education and advocacy organizations.   Hopefully this annotated list provides a handy guide for users, deepening their understanding and appreciation of forests and trees.  If you enjoy trees and have some spare moments to explore the sites listed,  I believe you’ll find many of them intriguing and rewarding.

The list represents a culling from hundreds of sites that might have been selected.  The three most important criteria for inclusion were: 1) usefulness for a variety of potential users, including naturalists, teachers and students at many levels; people seeking information on organizations active in forest protection; and members of the general public; 2) relevance to Virginia residents in particular, although I’ve felt comfortable going farther afield, since most species of trees and shrubs have a fairly wide range of distribution; and 3) coverage of a variety of topics, starting with identification and “branching out” to the other topics listed below under “Contents.”

Note that some sites appear under more than one heading; for example, the “Key to Leaves of Virginia Trees” entry appears in both the Tree ID section and in the Virginia Forests section.  Rather than send people back and forth, I have usually simply repeated the same information each time a site is listed.

The descriptions and judgments of the sites are my own.   I have tried to be as fair as possible in my descriptions and evaluations, but doubtless I have many blind spots.  Your comments on the accuracy and usefulness of different entries are welcome; as I mentioned earlier, sites undergo changes that may make what I had to say inaccurate or irrelevant.  As of February, 2012, all sites listed were up and running; if you find a site is no longer available, I would appreciate your letting me know.  I would also welcome suggestions for additional sites that might be worthwhile inclusions in the next edition of the list.  

Tony Russell ~

Skyline Drive
October 25, 2011


  1. Tree Identification
  2. Tree Identification: Various Genera
  3. Winter Tree Identification
  4. Tree Photo Sites
  5. Invasive Trees
  6. Riparian Forestry
  7. Urban Forestry
  8. Tree Health
  9. American Chestnut Recovery
  10. Comprehensive Forestry
  11. Virginia Forests
  12. Forest Education and Advocacy Organizations
  13. Miscellaneous

Tree Sites

A. Tree Identification

1.  Dendrology at Virginia Tech ( )
This is THE site for tree identification in Virginia, built around keys to tree identification and then fact sheets for a large number of species.  Each tree species has a page, with text and photos devoted to leaf, flower, fruit, twig, bark, and form.  The consistency and detail with which these six factors are applied throughout the entire site are the great strength of the VT project, and the descriptions are among the most useful and accurate I've seen.  The photos are also well done.  Though they are fairly small, you can click on each one to bring up a larger version.

 The http address takes you to the homepage.  To access keys, click “Tools” at the top and then “ID Keys” in the drop-down menu.  This takes you to both dichotomous keys (a leaf key and a twig key) and a multichotomous key.  Then, to access information on the tree, once you have identified it, click on “Fact Sheets” at the top of the homepage.  That will take you to a starting point where you can search the database for all or some part of a name (common or scientific).  

One minor quibble: the dichotomous key only narrows the possibilities to a group of species; it doesn’t normally lead you to a single species as an answer.

Created at Penn State, this is a fine tool intended to teach the key elements in leaf terminology.  It makes an excellent preliminary unit before moving on to tree and shrub identification using leaves.  The language and illustrations are simple and easy to understand; in addition, to check on understanding, each section ends by going to a Test Pilot for practice.  Sections provided include leaf structure, leaf blade shape, leaf grouping, leaf arrangement and venation, and leaf margins.  Highly recommended.

3.  Key to Leaves of Virginia Trees (
Eye-catching visual design highlights this key, created by Dr. Jeff Kirwan and James Ward for use with a 4-H tree identification project.  Click on “I’ve got my leaf, let’s get started!” and you’re propelled into the most usable dichotomous key imaginable.  Each choice features photos, with key features pointed out, to help you make your choice, all on a stylish black background with luminous red and blue lettering.  If you can’t learn with this site....  Highest recommendation.

4.  Bioimages: Key to common trees of middle Tennessee (
A superb dichotomous key with both gymnosperms and angiosperms.  The neat thing is that each step has both very brief written choices as well as photos of the choices; you can click on any of the photos to enlarge them.  Highly recommended.

5.  LEAF: Learning Experiences and Activities in Forestry (
A site offered by the Wisconsin K-12 Forestry Education Program, this too offers practice in using a dichotomous key.  The choices are framed as simply as possible, and like the Virginia site above, this one has photos to illustrate the choices.  The site explains what a dichotomous key is, contains simple instructions on its use, has twenty-seven mystery trees to match and identify, and offers a list of the twenty-seven tree species.  Click on a name, and you arrive at a fact sheet, replete with photos, about that species.  A nice site.  Not as stylish and technically sophisticated as the Virginia site, but simple and clear, with some interesting add-on features.

A very useful guide to tree identification put out by the Ohio State University Extension Service.  Contains a key to deciduous and evergreen trees of Ohio, with clear, simple drawings to illustrate different forms of leaves, leaf margins, leaf tips and bases, and leaf arrangements.  Also contains instructions on using the key to identify trees, with the instructions geared toward a novice.  One of the handiest features is that trees are grouped by genus, with every genus having its own page.  Then the text, photos, and illustrations show how to differentiate between the various species in the genus.  The site is laid out well and is user-friendly.

7.  UConn Plant Database of Trees, Shrubs, and Vines (
An attractive, well-designed site (created by Mark Brand), highly recommended.  Plants can be searched for by Latin name, common name, or attributes. An  outstanding feature of this site is the quality and abundance of photos--there might be four or five photos of different trees to show the habit and form of the species, for example, or several photos to show variations in bark patterns.  Another is the range of information for each tree--habitat, habit and form, summer foliage, autumn foliage, flowers, fruit, bark, culture, landscape uses, liabilities, ID features, propagation, and cultivars/varieties.  Information under each of these headings is presented in a simple, user-friendly, bullet-point style.

 As a sidebar, another positive feature of this site is the photo gallery of “virtual plant walks” at five different universities in the area.

This is a tree identification tool from the UConn site.  Can be used with both wild specimens and cultivars.  A three-page dichotomous key with a very attractive layout---large type, with pairs of features in alternating pale salmon and pale olive color bands, so it is easy to move from one level to the next with a minimum of visual strain.  The steps are also presented in clear, simple language. Link to a glossary if needed.  Highly recommended!  

9.  What Tree Is That?   (
Very nice online key to identifying tree species once leaves are on.  Offered by The National Arbor Day Foundation, and used by special permission to TreeLink.  Very user-friendly, with simple directions, and clear, well-written choices as one works through the process of making an identification. The site describes itself as “a guide to the more common trees found in the Eastern and Central U.S.,” but it enables the user to key out a much larger number of species than that description implies.  The site also contains an alphabetized index to the trees, merging common and scientific names, as well as a brief glossary, with terms explained in very short, straightforward language.  An excellent key for beginners, as well as those further along in learning trees.
10.  Trees, Shrubs, and Woody Vines of North Carolina (
This site, compiled by Will Cook, attempts “a full list of the woody plants of north Carolina.”  It tells where each plant is found (mountains, piedmont, or coastal plain), and indicates whether the plant is common, uncommon, occasional, rare, or very rare. The site has separate sections for trees, shrubs, and woody vines, with over two hundred and twenty species of trees listed.  Click on the name of a species, and you arrive at a page devoted to that tree.  The pages are uncluttered, with good-quality photos of leaves, flowers, fruit, and bark.  The photo contents are inconsistent, however; pages for some species have photos for all the plant parts just mentioned, while other pages only have two or three photos.
The site also contains a summer key to common tree species (more than sixty species included), based on leaf characteristics.

 Since North Carolina contains topographical and climatic similarities to Virginia, this site is a significant resource for Virginians as well. 

An excellent site, copyrighted by Tim Rhodus, with separate sections devoted to trees, shrubs, grasses, vines, perennials, etc.  The tree section covers a variety of ornamentals and cultivars, as well as many native species in their natural form, so it provides a good supplement to those sites focused strictly on native species or invasives.  

 Material on the page for each species is presented in clear, non-technical prose, within a well-laid-out bulleted format.  The pages contain an abundance of information, including form, culture, foliage, flowers, fruits, twigs, trunk, ID summary, function, texture, assets, liabilities, habitat, alternative selections, and variants.

Another state’s university extension tree ID website.  This one features an interactive dichotomous key for summer identification, and is dependent on sketches and photos as well as description of tree characteristics.  Easy to use.

A nice site intended primarily for people working in urban and community forests; colorful, easy to navigate. Click “Resources” on the home page and a drop-down menu gives you choices such as Tree Facts, Tree Guides, Tree Quotes, etc.  Clicking on “Tree Guides takes you to the updated Arbor Day What Tree Is That” tree identification field guide.  There is also a link to get the app for iphone, or to access a mobile site for free id anywhere in the U.S.

14.  Tree & Shrub Field Guide (Harris County Flood Control District, Houston, Texas)  (
A bit far afield for Virginia naturalists, but take a good look at it; you’ll like it.  Not comprehensive by any means, but concise and good at what it covers.  A downloadable 34-page guide in pdf format, with almost three-quarters of the species being ones you’ll encounter in our area.  To access it, go to “Manuals & Guides” in the box on the left side of the pace, and click on “HCFD Tree & Shrub Field Guide.”  

 Compact one-page entries for each species, with photos of leaves and fruit, a brief description, a brief note on preferred locations, short descriptions of the leaves and fruit, useful remarks, and the typical lifespan.  (A ruler is included in the photos to give a good sense of scale.)  For easier viewing, click on the percentage box above the slide and blow up the slide by increasing the percentage.

Backyard Plants” is a subsection of Jim Conrad’s “Backyard Nature” website.  It’s a commercial website, but not annoyingly so.  Extremely colorful and stylish, designed to attract a general audience and appeal to students.  There is a “special focus” section on trees, and numerous links to items such as stem types, plant defenses, tree bark, plant galls, and on and on, all copiously illustrated and full of interesting information.  Highly recommended.

The five sites below are much less authoritative, much less technical, and much less comprehensive than the sites above.  Nonetheless, I’ve included them because they have value for a person just learning trees, walking through the woods and trying to identify the more common species he or she sees.

Taken from “Fifty Trees of Indiana” by T. E. Shaw, this is a brief but handy guide to tree identification, approaching the task as a process of elimination.  It places tree identification for this limited number of species within the context of tree communities and tree “relatives,” and provides a simple chart for identifying them, based primarily on characteristics of their leaves.  Contains links to a glossary for tree terms, as well as to a variety of tree-related topics.

Just what the name says.  Nothing comprehensive, but some useful tips for identifying trees based on distinctive leaves, bark, buds, fruit, etc.  A nice complement to other sites for those beginning to learn their trees.  Not especially long--probably the equivalent of three or four typed pages.  Non-technical and helpful for a novice; well worth reading and remembering.

Something fun to try your hand at--identifying trees by examining a cross section of wood.  Common species only, not meant to be exhaustive.  This is another section of the Iowa State website listed earlier.

19. Field Guide to Trees (
This large commercial site provides online field guides to birds, butterflies, insects and spiders, mammals, reptiles and amphibians, seashells, seashore creatures, and wildflowers, in addition to the guide to trees.  The tree section divides trees by their leaf type into seven separate simple categories (needle-leaf conifers, scale-leaf conifers, untoothed simple leaves, toothed simple leaves, lobed simple leaves, compound leaves, and palms).  Beyond that, however, the categories become problematic.  It’s unclear how pages for species are organized, although stretches seem alphabetized, and members of a genus are grouped together.

 Advertisements take up at least half of each page, and the thumbnail photos and text for each species are discouragingly small.  Clicking on the name of the species does, however, take the viewer to a page for that particular species, with a good-sized photo and text as well as a fair amount of solid information.

20.  West Virginia Trees: Basic Tree Identification for FFA Forestry Contest (
A simple site for learning over thirty basic trees quickly, developed for high school FFA students.  All of the trees shown are common Virginia species as well.  The material is stripped down to the most helpful and most essential information, presented in non-technical language.  Obviously amateur writing and photography, but each tree is presented via clear photos of a leaf and the trunk/bark, and a short paragraph giving key identification tips.  Useful for someone just getting started.

B. Tree Identification: Various Genera

21.  Native Pines of Eastern North America (
An online guide to the pines, developed by Karen Hall and Richard Braham of the Dept. of Forestry at North Carolina State.  Designed as a tutorial for students studying the eastern pines.  Simple, uncluttered layout with audio accompaniment to give correct pronunciations.  Links to numerous sub-features, such as bark, leaves and buds, range and habitat, and reproductive structures, each with very good images.  Additional links to a glossary, references, and an interactive comparison tool.

A very handy key for a difficult genus.  Dichotomous, has photos of leaves and acorns, is easy to follow and use.  Based on trees in leaf; not a winter key.  Highly recommended. 

C. Winter Tree Identification

23.  Winter Twig Keys to Common, Native, Fully Deciduous Trees and Phanerophyte Shrubs of the North Carolina Eastern Piedmont {,%20Woody%20twigs.pdf)
As the title well indicates, this is an academic publication, heavy with passive voice and a bloodless style, but it provides a useful online tool for keying out winter twigs.  No illustrations or photos.

24.  A Beginning Guide to Winter Tree Identification (
This guide by Steve Nix is on the Forestry portion of the “” website.  Contains some very helpful basic information along with identification tips.  Also links to additional pages such as “Tree Leaf Identifier and Key,” “Tree Identification Guidebook,” “100 Most Common Trees,” “20 Common Tree Diseases,” “Tree Anatomy and Identification,” “Tree ID Glossary,” etc.   This is a commercial site, and the ads can be distracting, but it is useful and informative.

A brief one-page article by Violet Snow on using bark, buds, growth patterns, and lingering seed pods to identify trees.  This article references only deciduous trees, but there is a link to another article on “Pines, Conifers, and Evergreens.”  A more focused--but still brief--article by the same author on “Identifying Trees by Their Bark” may be found at

D. Tree Photo Sites

26.  Forestry Images    (
A fabulous site for the visual learner, created as a joint project of The Bugwood Network and USDA Forest Service, and the University of Georgia - Warnell School of Forestry and Natural Resources - College of Agricultural and and Environmental Science - Dept. of Entomology.  Contains sections on trees and plants, silviculture, invasive species, forest pests, wildlife, and more, with thousands of photos in each image category.

 Each section mentioned has a home page with a drop-down menu.  The section on forest pests, for example, has sub-sections on insects, diseases, and other damage agents.  The sub-sections are themselves subdivided, so that under “Insects” you find bark beetles, foliage feeding, wood boring, and invasive.  Clicking on any item in the menu leads you to a treasure-trove of photographs on every element of the item, most taken by Forest Service personnel.  An enormous resource, with over 75,000 photos in the collection.

As the name implies, this site is an extensive set of photos. One section of the site is devoted to trees, shrubs, and woody vines. (Another section is devoted to forbs, and a third to grasses and grasslike plants.) Photos can be accessed via a common name index, a scientific name index, or by family.

E. Invasive Trees

28.  National Invasive Species Information Center (
A USDA site with legal definitions and guidance for responses to invasive species, as well as profiles for a variety of invasive plants.  It has a “Plants Custom Search Engine” to search for invasive species information.  Links to economic impacts, educational resources, image galleries, and management, as well as numerous government publications, many excellent.

29.  Plant Invaders of Mid-Atlantic Natural Areas~4th edition, 2010 (
Created by the National Park Service and U.S. Fish and Wildlife Service, this is a well-designed site with explanations of the history of each plant’s introduction, its distribution, the ecological threat it poses, and a description of the plant and its biology.  Text accompanied by clear and colorful photographs. 

Click on the photo of the book title on the left of the home page to get to the Table of Contents, and then click on the name of the desired plant to go to a page devoted to that species.  Plants are grouped under “Aquatic Plants,” “Herbaceous Plants,” “Shrubs,” “Trees,” and “Vines.”

30.  Invasive Plants of the Eastern United States: Identification and Control (
This website does an excellent job of describing itself, so the simplest approach is simply to quote it:  “Drawing on recent publications by the USDA Forest Service, National Park Service, U.S. Fish and Wildlife Service, USDA APHIS PPQ and the Southeast Exotic Pest Plant Council, this web site covers identification characteristics, distribution, and control options for 97 tree, shrub, vine, grass, fern, forb, and aquatic plant species that are invading the eastern United States. For each species, a menu of control options is presented, including mechanical treatments, specific herbicide prescriptions, and, for selected species, recent advances in biological control.

 Following the introduction is a list of invaders, with both their common and their scientific names, divided into categories--aquatic forbs, ferns, forbs, grass/grasslike, shrubs, and trees.  Clicking on the name of a plant takes you to a number of photos of the plant, as well as a link to the USDA NRCS Plant Guide page for the species, and a distribution map.

31.  Invasive Alien Plant Species of Virginia (
Part of the Virginia Department of Conservation and Recreation website, this site explains what invasive alien plant species are and why they are a problem.  It provides species fact sheets by clicking on “Factsheets” on the right side of the page.  Factsheets are available for thirty of the species, but only a handful of those are trees or large shrubs (Autumn Olive, Russian Olive, Tree-of-Heaven, Winged Burning Bush).  An invasive plants list and a ranking of the threats they pose can be accessed by clicking on “Invasive Plants List.”

32.  Forestry Images       (
See the description for this site listed in the “Tree Identification” section above.

F. Riparian Forestry

This one-page article from the University of Idaho Extension can be accessed by going under the “Riparian Management” heading and clicking “Riparian Zone Tree Plantings” in the “Articles” subsection.  Defines riparian zones, explains why they are ecologically important, and provides lists of flood tolerant and very flood tolerant species.  (Note that other articles and resources are available on aquatic and invasive plants, silvicultural decisions relevant to riparian management, and other topics.)

Excellent discussion of the role of forest management in improving environmental quality for stream organisms, thus sustaining and promoting aquatic biodiversity.  Somewhat academic style, but readable.

The final report of a statewide task force in South Carolina, with 94 pages of discussion of the value of forest buffers, as well as techniques for creating and managing them.  While the report is specific to South Carolina, the definitions and methodology have broad applicability.  An excellent resource. 

G. Urban Forestry

Developed by D. Andrew White, “Urban Trees” examines the suitability of over fifty species for urban planting.  The section for each tree discusses its relationship to other trees, its natural range, its uses, and its pluses and minuses for city planting.  Each entry ends with a link to the tree’s ISA Species Rating.  Links to some photos as well.  An interesting site with a different perspective. 

37.  TreeLink        (
The motto emblazoned across the top of the webpage is “Knowledge empowering people, and technology enabling cities to support urban and community forests.”  Their “welcome” says, “This site was created to provide information, research, and networking for people working in urban and community forestry.”  Their mission statement reads:  “To raise awareness and raise support for healthy urban forests.”

Key sections of the site index include a range of communications information (including “who’s who in your state”), as well as a long list of resources, sponsors, a volunteer match, listservs, and a job link.  
An excellent starting point for a community group interested in promoting local forestry; less useful for students unless they are especially interested in the organizational aspects of urban forestry.

38.  Canopy         (
“Canopy is a Palo Alto Based non-profit advocate for the urban forest and works to educate, inspire, and engage the community as stewards of young and mature trees,” says their website.  Although the organization is on the opposite coast, its award-winning program is a model for encouraging interest in urban forestry.

39.  Forestry Images    (
See the description for this site listed in the “Tree Identification” section above.  One of the site’s categories, under “Trees, Plants, and Stand Types,” is “Urban Forestry.”

40.  University of Alabama at Huntsville Grounds Management Home Page (
A site with a different slant, this one is offered by the Grounds Management staff of the University of Alabama at Huntsville.  The campus currently has over three hundred different kinds of trees, many of which are seldom seen, with a long term goal of featuring five hundred or more different trees that might be useful to an urban forester, landscaper, or homeowner.  The grounds staff have a clear goal “to acquaint the public and professional with different trees that are successful in the landscape, but not well known, and thus offer a varied palette beyond the twenty to thirty trees that are commonly used in the landscape today.”

Double click on “The Campus Trees” (in the menu line directly under the page heading) and you travel to a page where you can decide between “The Deciduous Trees” and “The Conifers.”  If you then click on “The Deciduous Trees,” you arrive at a listing of all the deciduous trees found on the campus.  Clicking on the name of a species takes you to a page where the campus specimen’s progress is assessed in terms of growth rate, likely ultimate size, hardiness zone, pest and disease problems, and so forth.  (No photos.)

H. Tree Health

41.  Forest Health Web Sites  (
A section of Jim Worall’s “” website, this page lists sites which he describes as of “general interest related to forest pathology and entomology,” and as such, the page could serve as an entry point for anyone interested in tree health.  Each listing also serves as a link to the external site.  Categories covered include: government agencies; scientific societies and North American regional groups; universities and extension services; mycology; and web sites on specific disease types.  

 While on this page, which is essentially a referral service, you can click on “” and find the extensive material available on the home site, which itself covers a host of topics, ranging from fungi, root diseases, cankers, etc., through invasive species, disease profiles, and disease notes.
The site is relatively up-to-date, having been updated as of February, 2010.  Highly recommended.

42.  Plant Problem Image Gallery (
Developed by the Dept. of Plant Pathology, Physiology, and Weed Science at Virginia Tech, this webpage has a huge gallery of photos depicting plant problems, accompanied by each plant’s common name, scientific name, the disease name, the pathogen’s scientific name, and the pathogen type.  The list can be sorted and searched using any of those factors except the disease name.  Clicking on the image of a plant takes you to a page devoted to that plant and disease, with multiple images, symptoms, a detailed description, and identification of all of the other factors.  A wonderful resource, which includes not just trees but all kinds of plants.

43.  Texas Plant Disease Handbook  (
Offered by the Texas A & M Dept. of Plant Pathology and Microbiology.    The link connects you with the home page for their handbook.  Once there, click on “Main Menu,” and then on “Trees.”  That is followed by a page for each species or group of related species (nineteen pages in all), with a list of the diseases most likely to attack it.  Each disease entry includes a discussion of such things as how the disease is contracted, what the symptoms are, and how it should be treated. 

44.  Shigo on Tree Systems (
This site features articles written by Dr. Alex Shigo, a tree biologist who worked as chief scientist for the US Forest Service.  Articles on tree autopsies, tree survival, the science behind tree treatments, “What Arborists Need to Know About Lichens,” etc.  There is a very extensive dictionary for terms related to trees; tree pests; tree diseases and treatment; and related topics.  It can be accessed by clicking on “Dictionary MAIN PAGE” at the bottom of the webpage.  The dictionary alone is well worth a look.

This is an online version of a University of Missouri Extension publication.  Although it is aimed toward the homeowner, the discussion of the causes of tree decline is useful, as is the review of symptoms of decline. 

46.  The Tree Bark Pages      (
A good self-description:  “This site was designed to provide a place to learn about the anatomy and physiology of tree bark, fungal canker diseases that affect tree bark, the wound responses of injured tree bark, and the role of wound responses in the resistance of living tree bark to wound pathogens.”  One caution: Although this site is a top-of-the-line source on anything related to tree bark, it is intended for the professional more than a general audience.  The description of anatomy and physiology is highly technical; the sections on wound responses and fungal canker diseases, at the time of this writing, are still under construction.

Although this site is, in general, a disappointment, the “Tree Health Guide” portion is a strong section, with links to information on a variety of current plant and pest issues.  Aside from that, the site has a distinct commercial orientation toward selling trees, books, etc.  The “Tree Guide” portion lists promising topics in addition to the “Tree Health Guide”--topics such as “Layers of the Forest,” “Tree Classification,” “Types of Swamps,” and “Anatomy of a Tree,” but most are brief and superficial.  

I.   American Chestnut Recovery  (Note: A special section is devoted to American Chestnuts because of their immense historic, economic, and environmental importance, and because Virginia plays a central role in restoration efforts.  As the American Chestnut Cooperators’ Foundation says on its website, “In the first 40 years of the 20th century, blight destroyed 3.5 billion American chestnuts. [Chestnut trees made up a fourth of the entire forest in their range.] What had been the most important tree in our Eastern forest was reduced to insignificance. No comparable devastation of a species exists in recorded history.”)

48.  The American Chestnut Foundation (
The TACF site has its mission statement, a detailed history of the blight and the organization’s response, descriptions of their research farms, and profiles of the staff at the farms.  They also describe their educational programs and their partnerships in the restoration effort.  The organization’s four farms in Meadowview, Virginia, have almost 34,000 chestnut trees planted on more than 150 acres.

 Of special interest is the site’s field guide for locating, pollinating, and harvesting nuts from flowering American chestnut tree sprouts, which still exist in large numbers in the woods of Appalachia.  TACF hopes to enlist volunteers in this effort in order to incorporate as much genetic diversity as possible into their breeding program.

A full page is devoted to resources and links for people wishing more information on chestnuts.

49.  Virginia Chapter of The American Chestnut Foundation (
This site adopts a practical approach to efforts to restore the American Chestnut, and stresses the importance of education in its effort.  Tabs on the left of the home page take the user to such topics as the chestnut story, chestnut science, student programs, news and events, and a “How Can I Help?” section.  Click on “Student Program [sic]” and then on “Robert Strasser Slide Presentation” to see an excellent educational tool on chestnuts.

 The site also features links to the major organizations and some of the sites involved in chestnut recovery efforts.

50.  American Chestnut Cooperators’ Foundation (
Sponsored by the Virginia Tech Dept. of Plant Pathology, Physiology, and Weed Science, this site contains click-on links to such topics as “Impact of American Chestnut Blight on Forest Communities,” “When Money Grew on Trees,” “Integrated Management for Chestnut Blight Control,” and a “Webrary” of links to numerous other sites dedicated to chestnut growing, breeding, management, history, etc. The American Chestnut Cooperators’ Foundation works to restore American chestnuts from an entirely American chestnut plant base, whereas The American Chestnut Foundation uses backcrosses to Chinese chestnuts, which are blight resistant.

J. Comprehensive Forestry
51.  Silvics of North America (Agriculture Handbook 271) (
Oriented not toward identification but toward timber production and management, written for the professional.  Nonetheless, the most comprehensive information available on the web, with maps of species range; detailed discussions of the influence of climate, soil, and topography on the tree’s distribution; lists of species in associated forest cover; thorough examinations of the species’ life history; tables of timber yields; assessments of reaction to competition; discussion of damaging agents; etc.  Each page ends with a long list of professional books and articles that can serve as additional resources.

52.  Forest Inventory and Analysis National Program  (
The Forest Service’s “Forest Inventory and Analysis Program (FIA) is the starting point for a great deal of the nation’s management, planning, and research pertaining to forests.  The site contains numerous reports, data banks, reporting tools, maps, etc., based on a nationwide network of scientifically selected and monitored sample sites.  A sprawling enterprise with material for anyone looking for research-based information on the state of our forests.

53.  World-Wide Web Virtual Library: Botany / Plant Biology (Biosciences) (
This page is essentially a long, alphabetized, directory of listings for a host of sites in the areas of botany, plant biology, agriculture, and biosciences.  Each listing also functions as a link to the site.  The listings may have a few words of description (e.g., “full text,” or “for Scientists and Projects,” or “database with several thousand plant images,” or no notes at all.  A great site to go to if you simply want to roam the Internet, exploring the field, or if you want to find some subject related to trees/forestry that isn’t covered in the annotated list you are using.

54.  Forest Biology Textbook, Virginia Tech
This online dendrology textbook contains nine chapters of college-level material dealing with tree structure and physiology, dormancy and coldhardiness, forest soils and productivity, etc.  Not light reading, but a solid online resource.

K.  Virginia Forests

55.  2009 State of the Forest:  Annual Report of Virginia’s Forests  (
A 28 pp. pdf file of the Virginia Department of Forestry’s annual report, which summarizes trends in the state’s forests, tracks the extent and types of forests, examines who owns forests, evaluates sustainability efforts and forest benefits, looks at forest health and forest research, and also reviews urban and community forest efforts--plus much more.  The best starting point for an overview of Virginia forest issues.

56.  Natural Heritage Program, Virginia Department of Conservation and Recreation   (http://www.dof.virg
The Natural Heritage Program, while not focused on trees and forests, contains valuable information on them as elements of ecosystems and plant communities.  This is the site to go to for information on Virginia’s efforts to inventory and preserve rare plants and natural communities.  Clicking on “Native Plants” in the menu will take you to, among other things, a summary of Virginia’s physiographic provinces; clicking on “Natural Community Overview” will lead you to an excellent overview of the different landscapes in Virginia and their varied plant communities.

57.  Key to Leaves of Virginia Trees (
Eye-catching visual design highlights this key, created by Dr. Jeff Kirwan and James Ward for use with a 4-H tree identification project.  Click on “I’ve got my leaf, let’s get started!” and you’re propelled into the most usable dichotomous key imaginable.  Each choice features photos, with key features pointed out, to help you make your choice, all on a stylish black background with luminous red and blue lettering.  If you can’t learn with this site....  Highest recommendation.

58.  Virginia Chapter of The American Chestnut Foundation (
This site adopts a practical approach to efforts to restore the American Chestnut, and stresses the importance of education in its effort.  Tabs on the left of the home page take the user to such topics as the chestnut story, chestnut science, student programs, news and events, and a “How Can I Help?” section.  Click on “Student Program [sic]” and then on “Robert Strasser Slide Presentation” to see an excellent educational tool on chestnuts.

The site also features links to the major organizations and some of the sites involved in chestnut recovery efforts.

59.  Invasive Alien Plant Species of Virginia (
Part of the Virginia Department of Conservation and Recreation website, this site explains what invasive alien plant species are and why they are a problem.  It provides species fact sheets for thirty of the species, but only a handful of those are trees or large shrubs (Autumn Olive, Russian Olive, Tree-of-Heaven, Winged Burning Bush).

60.  History of the Montpelier Landmark Forest  (
A report on the work of a team of foresters and other volunteers, led by Tom Dierauf, who managed to recapture much of the history of Montpelier’s Landmark Forest.  This is a thorough, readable, and highly professional account of the various means by which someone can begin to understand a forest’s history--an exemplary case study on how to read a forested landscape.  Highly recommended.

61.  Wildlife Neighbors of the Williamsburg Area (
Text and photos of a book put out by the Williamsburg Publishing Co. (Text by Bill Snyder and illustrations by wildlife artist Jerry Ellis.)  Contains brief but interesting sections on Virginia trees, birds, animals, and wildflowers, with an emphasis on their regional use and history.  Interesting resource that provides a different slant from the usual guide.

62.  Virginia’s Forest Resources (Chapter 4 of Virginia Naturally)  (
Part of an assessment of environmental elements prepared by the state’s Department of Environmental Quality, this webpage is a good brief summary of information on the status of Virginia forests, our forest types, their history, and the challenges they face.

63.  Virginia Cooperative Extension: Trees, Shrubs, & Groundcovers
This page is a lengthy and varied list of all the Extension Service’s publications relating to trees, shrubs, and groundcovers.  The list can be sorted by title, author, date of publication, etc.  The publications are available in PDF format; click on the title to download a publication and print your own copy, or order from the ID number given.

L.  Forest Education and Advocacy Organizations

64.  Global Forest Watch: United States’ Forests   (
Global Forest Watch is dedicated to preserving forest--especially larger tracts of relatively-unspoiled “low-access” forest.  This webpage surveys the fragmentation and degradation of natural forests, documenting trends with data, identifies areas where such tracts can be found, and makes recommendations for their preservation. 

65.  Virginia Forest Watch  (
Virginia Forest Watch is an environmental advocacy group committed to “maintaining and restoring the natural ecology and biodiversity of Virginia’s forests” through education and citizen participation.  They encourage investment in sustainable forestry and oppose all commercial logging of public lands.

 66.  Wild Virginia  (
Wild Virginia, an organization devoted to protecting forests on public lands, is headquartered in Charlottesville.  Its mission statement says, “Wild Virginia is a grassroots non-profit organization dedicated to preserving wild forest ecosystems in Virginia’s National Forests.”  The organization has been very active in organizing citizen input into the management plan for the George Washington National Forest, and prioritizes the protection of wilderness areas, roadless areas, and watersheds.  The group holds monthly hikes into the GWNF to familiarize people with key areas.

67.  Heartwood    ( 
Heartwood describes itself as “a regional network that protects forests and supports community activism in the eastern United States through education, advocacy, and citizen empowerment.”  The organization operates in an 18-state area, with special attention to what it has designated as “at-risk” forests in six states--among them Virginia and West Virginia.

68.  World Rainforest Movement   (
This is an environmental movement with a strong social justice tie-in.  WRM’s general orientation is “against the greening of capitalism and mercantilitzation of life and in defence of common goods.”  Specific focuses include deforestation, plantations, and indigenous lands and communities.  

M.  Miscellaneous

69.  Botanary, the Botanical Dictionary   (
An alphabetized list of over twenty-one thousand botanical words, along with each word’s meaning and etymology (usually), as well as a guide to its pronunciation.  They issue a helpful warning via a quote from W.T. Stearn:  “"Botanical Latin is essentially a written language .... How they are pronounced really matters little provided they sound pleasant and are understood by all concerned..."  Having struggled with the pronunciation of numerous botanical names over the years, I heartily appreciate that news.  It also explains why my different learned botany teachers so often pronounced the names of species differently.

70. Latin Plant Name Dictionary
I’ve found this dictionary useful.  It’s intended, they say, to help people “understand the [Latin] roots of botanical plant names.”  (I don’t know if the ‘roots’ pun was intentional or not.)  The listing and search mechanism is a tad unusual in that they supply an alphabetized list of two-letter combinations, and you go through it until you find the first two letters in the spelling of the word you’re searching for.  That brings up an alphabetized list of words beginning with those two letters; scroll down through that list to see if the word you’re seeking has been included.

71.  Ultimate Tree-Ring Web Pages (
This site was created by Henri Grissino-Mayer, he explains, because he felt there was “an overwhelming need” for an online site that would act as “a permanent repository of information [on tree-ring dating] that was free to the public, easily understandable, and as comprehensive as humanly possible.”  He also designed the pages, he says, “to be easily understood by people at all levels of education.”  That said, many portions of the site are actually aimed toward the university community.  Pages on the site include “New in Dendro,” which is basically a list of academic announcements, internships, conferences, etc.; an elaborate A-Z index; resources; links; software; hardware; principles; references; photo gallery; and more.

72.  Tree Trail         (
Tree Trail appears to be a labor of love.  It is a non-commercial site--allows no advertising and offers nothing for sale--created by Billy Bruce Winkles and devoted to the preservation of rare native trees.  I’ll let him speak for himself:  “The purpose of this website is to assist people who want to help preserve these rare species by growing them on their own properties or other suitable locations in their communities. The site provides information on how to select and obtain the needed plants, and how to grow them."

On the left side of the home page is a list of sixteen smaller native trees which he feels are adaptable and attractive enough to be good candidates for homeowners.  Clicking on the name of a species takes you to a page loaded with information and photographs, all of excellent quality.  In addition to the normal descriptive information, each page also includes the species’ normal range, its conservation status, tips on cultivation, and sources where it may be obtained.

An unusual site, created by the Illinois State Museum, chronicling the role of forests in Illinois history.  Sections on forest types, people in forests, ancient forests, conservation, forests in art, a tree guide, a glossary, and activities and resources.  A nice model for the role of forests in history, with insights and information transferable to other locations as well.  Intended to be used by students and teachers, as well as the general public.  In the tree guide, you can click on the name of a tree and get a very nice write-up of the species, with shape and distribution, interesting facts, identifying features, and uses.  Recommended.

74.  Science Daily: Forest News  (
Science Daily presents brief digests of articles appearing in research journals, sorted by topic.  The topics themselves cover the whole gamut of science, and can be as broad or as narrow as you wish--from Environmental Issues on one end, say, to Hazardous Waste on the other.  You can select a topic and have the newest articles e-mailed to you each day.  The brief synopses are readable and hit the key findings of each study, and end with information enabling you to move on to the complete original, if you wish.  Forest News is one of the topics they cover.  This is an indispensable site for someone wanting to stay abreast of current forest research.

75.  Some Southeastern U.S. Trees and Woody Plants by Blooming Date (
A Vanderbilt University site, in table form, that lists trees and other woody plants in the order of their blooming, with both scientific and common names, the families each species belongs to, starting and ending blooming dates, and a thumbnail-sized photo of the bloom of each species. Note that in the column for starting and ending dates, numbers appear in a decimal form.  They represent the blooming time in the Nashville, Tennessee area in a single year, with the first number representing the month (i.e., 1 is January, 2 is February, etc.) and the second number the week of the month.  The important information is the sequence of blooming; actual dates will vary from year to year and location to location.  

 Clicking on the scientific name takes you to a series of photos of different parts of the species--form, leaf, bark, etc.  Excellent resource!

76.  USGS: Digital Representations of Tree Species Range Maps (
These are versions of the range of tree species in North America, compiled by the US Forest service and digitalized by the USGS.  Files for individual species; can be downloaded.  They warn that some of the scientific names may have changed, but they have kept the names used in the original text.

                 © Tony Russell, 2013