GardenDesignOnline

Brooklyn Botanic - Saving Plants in Georgia

BBG President Scot Medbury recently attended an international conference in Tbilisi, Georgia aimed at helping the Tbilisi Botanical Garden develop a conservation strategy to save some of the country's most threatened plants.  One of the conference sponsors was the London-based Botanic Gardens Conservation International (BGCI), an alliance of 500 gardens around the world that works to establish conservation measures in countries where native plant life is disappearing. BGCI secretary general Sara Oldfield noted that "The flora of the Caucasus is phenomenally diverse and incredibly beautiful, but is increasingly endangered for a variety of reasons." 

In an interview with Garden Design Online, BBG's Medbury said some threats to plant diversity in Georgia include the following:

• Timber harvesting below the timber-line zones in the Caucasus.  "A lot of trees are being cut legally or otherwise and being exported to Turkey," he said, "and as with timber harvesting in other parts of the temperate world ... there are severe impacts on not widely distributed rare herbacious plants."
• Road building in timber regions is threatening meadow environments and plant species like peonies and orchids.  He said scientists at the conference reported that "in one region of the Caucasus, 40 percent of the ecosystems above timber line have been vulnerable to degradation and 40 percent have been lost with a consequent loss of species diversity."
• Over-grazing due to timing.  Mebury explained that if sheep are grazed in early spring, some of the earliest spring ephemeral plants are lost due to root compaction, or the animals eat the tiny seedlings, and over time, it means a severe loss of plant population.
• The spread of invasive plants (like the North American Black Locust) that choke out native species.

Medbury said the Caucasus is "one of the bio-diversity hot spots in the world" that has an amazing number of species that are worth preserving, both in the mountains and also in western Georgia, which he said is a refuge of plants from earlier geological periods.

Medbury hopes to establish a permanent partnership between the Brooklyn Botanic Garden and the Tbilisi Botantical Garden, which was a royal garden as early as 1630, known for its plant introductions, and which was established officially as a botanical garden in 1845.  It has a herbarium with one million plant specimens, an enormous library, and a sizeable staff.  He said the garden needs help with things like information technology, sharing plant databases, and field work, and he hopes that's where BBG, BGCI, and perhaps even the US government can be of help.

Invasives & Global Warming

Leafy spurge, shown left, is a troublesome invasive plants in many states, and global warming is likely to exacerbate its spread, according to a new study by ecologist Dana Blumenthal of the USDA's Agricultural Research Service.

Euphorbia esula, also called green spurge, is native to Eurasia, and was first reported in Massachusetts in 1827.  From there, it rapidly spread across the United States and now infests over two million hectares in 35 states and more in Canada.  It is a particular problem in northern plains states, where it chokes out native plants in prairie habitats. 

Blumenthal, of the ARS research unit in Fort Collins, Colorado, along with scientists at the University of North Carolina and in the Czech Republic, have found that fast-growing, weedy invasives are likely to spread in new environments for two main reasons: first, they've escaped from their natural enemies like insects and diseases that keep them under control in their homelands.  Second, greenhouse gases released in global warming increase the levels of carbon dioxide and nitrogen in soil, both of which promote the spread of weedy plants.

The study concluded that as long as climate change continues unabated, so will the spread of invasive plants. 

(photo: ARS)

Trees & the Carbon Footprint

Not exactly a big surprise to those in the know ... but yes, trees can play an important role in reducing carbon dioxide emissions, one of the major culprits in global warming.

The University of California San Diego reports that its 200 thousand trees are reducing CO2 emissions by 10 thousand tons a year, five percent of the university's total annual CO2 output.  A forest study conducted by Urban Ecos in San Francisco says UC - SD is saving more than $ 2 million a year because of its trees (a 112-acre eucalyptus grove is shown above).

The forest study is the latest part of the university's effort to promote sustainable practices and research on climate change.  UC San Diego was named a "Tree Campus USA" last year by the Arbor Day Foundation, and the university accepted the honor by planting 100 more trees, including sugar gums, magnolias, and Torrey pines.  It was just one of nine schools around the country cited for healthy urban forest management.

The university's campus forester Samuel Oludunfe said that trees not only provide spatial definition, but also "enhance the quality of life by removing air pollutants, reducing energy consumption, facilitating erosion control ... and increasing property values."  He also said the university's urban forest serves an important educational role as a living laboratory.

In addition to reducing carbon emissions, the forest study said the trees also trap and filter 140 million gallons of storm water runoff every year; they support a diverse ecosystem home to more than 100 species of birds, small mammals and plants -- and they serve as a winter site for the monarch butterfly.

Other large universities could take a cue from UC - San Diego.

And PS ... Today is Arbor Day -- so buy a tree and plant it!

Project BudBurst Reminder

If you haven't already joined Project Budburst -- or if you forgot that this year's info is just as important as last year's -- take a trip into your yard or local park or wherever -- to track the appearance of buds, leaves, and flowers.  Report back to Project Budburst, which is tracking climate change and global warming.

And yes, let's all be glad there's money in the new US budget proposal for more work on these issues, which are affecting all of us.

If you're not familiar with the project, read my previous post on Budburst here.

(image of wild Cinquefoil © UCAR, Photo by Carlye Calvin)

US Tree Deaths Linked to Global Warming

A new study by the US Geological Survey says tree deaths have doubled in old-growth forests in the western part of the country in recent decades.  The scientists attribute the high death rate to global warming. 

Phil van Mantgem, a USGS scientist and co-leader of the research team, explained that average temperatures in the West rose by more than one degree over the last few decades. "While this may not sound like much," he said, "it has been enough to reduce winter snowpack, cause earlier snowmelt, and lengthen the summer drought."

The study noted that tree death rates are pervasive, affecting trees of all sizes at all elevations.  Pines, firs, hemlocks, and many others are dying so fast that forests are losing more trees than they are gaining.

The scientists also believe the unfolding situation in western forests is likely affecting wildlife and may also speed up climate change because the forests are releasing more carbon dioxide into the atmosphere.

The study ruled out air pollution, fire suppression and normal forest dynamics as possible causes of the tree deaths.  In fact, they said longer droughts in summer could be causing more tree stress and higher temperatures are promoting insects and diseases that are harmful to trees.  USGS scientist Nate Stephenson said the high rate of tree death may lead to sudden forest die-back, which has been noted recently in the southwest, Colorado and British Columbia. "That may be our biggest concern," he said. 

(image: Nate Stephenson, US Geological Survey)

DNA Tests to Combat Florida's Invasive Pines

Australian pines were first brought to the United States in the early 1900's as lovely ornamental shade trees, thought to be a perfect solution for many yards in hot, sunny sites.  The "pine" is now a troublesome invasive plant that has escaped into the wild in south Florida, the Virgin Islands, Puerto Rico and Hawaii.  The plant, which is not related to our north American pines, has become a highly invasive problem weed that is choking out native species in southern US coastal areas, and it is a particular problem in Florida's Everglades National Park.  It is commonly referred to as ironwood, horsetail tree, or Australian pine.

There are actually three different species of Casuarina -- C. equisetifolia, C. glauca, and C. cunninghamiana,  but the three look so much alike that it is very difficult to tell them apart.  Scientists at USDA's Agricultural Research Service are now conducting research to positively identify each species by its specific DNA and then finding insects for each one that might be used as biological control agents.

ARS scientists have traveled in recent years to Australia, where they collaborated with Australian colleagues to collect DNA samples from native Australian trees and to identify insects that might be used to stop the spread of the plant in the United States and its territories. ARS entomologist Greg Wheeler says that although Casuarina has some "fine qualities ... its negatives far outweigh its positives."  Wheeler and Australian scientists collected over 300 insects that might be used to control the weed, and narrowed the field of potential control agents to just 12, including a wasp that eats the plant's seeds and a moth that attacks the foliage.

By the end of this year, the researchers expect to complete their DNA studies, which will allow them to positively identify which species is which -- and then match them with an insect that will help stop the spread of a now-deadly plant that inhibits the growth of native American species.

(image: ARS, courtesy Amy Ferriter, S. Florida Water Management District, Bugwood.org)

Skyscraper Gardening

More and more people around the world are moving off the farm and into cities ... and if the world's population keeps growing, will there be enough land to grow the crops needed to sustain all the people?

Columbia University Public Health Professor Dickson Despommier, a microbiologist and ecologist, has been asking those questions and coming up with some interesting answers.  For the past several years, Dr. Despommier has been advocating vertical farming -- on skyscrapers -- and has lined up some architects to design "living towers" where urban residents could raise food crops.

An article in today's New York Times, which you can read here, says the idea has caught on with Manhattan borough president Scott Stringer, and his office plans to urge the mayor's office to think about a vertical farming pilot project.

According to Dr. Despommier's website, The Vertical Farm Project, 80 percent of the world's cropland is now in use, and by 2050, there will be an additional three billion people on earth.  One solution for farming could well be vertical farming, with new cutting-edge technologies to make the "farms" economical and sustainable. "The time is at hand," he says, "for us to learn how to safely grow our food inside in environmentally controlled multistory buildings within urban centers.  If we do not, then in just another 50 years, the next 3 billion people will surely go hungry."

Food for thought.  And check out some of the stunning architectural designs on the Vertical Farm Project website.

(images: Vertical Farm Project)

The White House Grows

Roosevelt Redux?

Presidents like to rip up the records of their predecessors, and that includes changes on the grounds of the White House.  Reagan ripped off the solar panels that Jimmy Carter installed on the mansion, and there's no trace today of the Victory Garden planted by the Roosevelts. 

So in this time of climate change and high fuel prices, Roger Doiron thinks it's time to "Eat the View" at the White House.  In an interview with Garden Design Online, Doiron, founder of Kitchen Gardeners International, said he's urging the next president to re-plant "an edible landscape" at the White House as an example to all Americans to conserve energy.

Doiron points out that it takes 10 calories of fossil fuel to produce every one calorie of food consumed.  Put another way, the average food item in the United States travels 1500 miles to get to your plate -- and costs 400 gallons of fuel.

Greening the Dog

For all green roof fans afraid to try one on your own home:  experiment with your dog.

The June 3rd Home & Garden section of the Los Angles Times has an article about dog houses with green roofs designed by landscape designer Stephanie Rubin and her partner, sculptor Chris Isner. They go for around one to four thousand dollars, but the article says you can make one yourself for much less.  They keep the dog cool, and the roofs are planted with natives that are animal-friendly.  Read more about it here.  Or try the company's web site, www.sustainablepet.com.

Edible Front Yards at Descanco

Architect Fritz Haeg has recently installed one of his edible front yards at Descanso Gardens in La Cañada Flintridge, CA. You can read an article about it in the Pasadena Star News (scroll down for article), or see pictures of the installation here from Descanso itself,  and decide for yourself whether you should try it out on your own landscape.

FYI, I reviewed Haeg's book in a post earlier this year.