Trees and People

The date palms of Judea are praised in the Bible and the Koran for their beauty, shade, food and medicinal qualities. Now we may get a chance to taste the famed fruit. A date seed found during archeological excavations of Masada, where Jewish Zealots killed themselves rather than fall to the Romans, has germinated and appears likely to survive.

Radiocarbon dating confirms the archeological evidence: the seed is about 2,000 years old. This is the oldest seed ever germinated. Lotus seeds of about 1200 years' age have been germinated in China, but none as old as this.

The seed was obtained by Dr. Sarah Sallon, a physician and scholar of medicinal plants of the Middle East. It was germinated by Dr. Elaine Soloway of the Arava Institute for Environmental Studies.

At the time of the fall of Masada, when Israel ceased to exist for 1900 years, vast plantations of date palms were found throughout the region. Dates were an important food and medicine. The biblical land of "milk and honey" refers to date honey. The Koran describes the date as a symbol of goodness, and the date palm is associated with heaven. By the time of the Crusades, all the date palms had been destroyed. Modern Israel, for which dates are important symbolically and economically, grows date trees imported from California and originating elsewhere in the Middle East. So, the growth of this seedling could potentially resurrect a highly important plant, both economically and culturally.

There is an important unknown, that will not be revealed for at least 20 years: is the tree a male or female?  Dates are dioecious, bearing male flowers on one tree and female on another. If this tree is a male, it will only be a historical curiosity. If it is a female, there should be adequate pollen from males of other date palms to allow the tree to bear fruit.

If all goes well, we could once again taste the fruits of the land of milk and honey, thanks to the Zealots of Masada and the curiosity of a group of scientists.

Festivals to celebrate the blooming of trees are held all over the world, and can be a major tourist draw. Most famous among blooming festivals are the various celebrations of cherry blossoms in Japan, Washington DC and other places. The vagaries of weather means that blossoms often fail to appear at the scheduled time for festivities. Since festivals have to be scheduled well in advance, it is easy to miss the actual bloom date. As cities become warmer, both because of climate change and the urban heat island effect, blossoms are occurring much earlier, often well before tourists arrive to celebrate the event.

Authorities in Hirosaki, in northern Japan, are funding research by tree biologists to try to control blossoming so that it occurs when the festivals are scheduled. Since hundreds of thosands of tourists may descend on a properly timed festival, the city stands to lose a lot of money if it is unable to predict the timing of blossoming. Hirosaki is in a cooler area than most Japanese cities and the blossom time of cherries often coincided with Golden Week, a national week of holidays. Up to two million visitors go to Hirosaki when the blossoms coincide with Golden Week.

Scientists at Hirosaki University are experimenting with hormone sprays and injections and piling snow around cherry trees. To date, none of the treatments have been effective. This is not surprising. Once a tree's dormancy requirement has been met, the timing of flowering in temperate trees is tightly tied to degree days (heat accumulation above a threshold temperature). It seems very unlikely that hormonal control of flower timing is significant. Packing snow may cool the roots, but flower development is more likely dependent on air temperature. I suspect that the scientists will spend a lot of money without any significant outcome. Maybe it is time to reschedule Golden Week.

The article describing this issue doesn't address some important questions: how often is Golden Week missed, and has there been a trend toward earlier blooming over time? The article says that there has but does not describe the trend in sufficient detail. Also, the urban heat island effect, which is often much larger in cities than other sources of climate change, is not addressed. While little can be done over the short term regarding climate change, the urban heat island effect can be mitigated.

Horticulturists have selected and bred fantastic ornamental plants with showy, often dramatic flowers. Along the way to today's modern flowers, something has been lost. In the last 50 years, as breeders have selected for better or new colors, larger flowers, longer stems and longer shelf life, they seem to have inadvertently selected against smell. Many modern flowers lack odor or have minor smells compared to their wild ancestors or older cultivars. Now breeders are beginning to pay more attention to smell and to select modern cultivars for odor as well as appearance. Nursery catalogs are beginning to list smell along with color and other descriptors. The desire for strong fragrance is also behind the resurgence in traditional and heirloom varieties.

In Palo Alto, CA, an innovative volunteer program is improving the health of city trees. Volunteers working with the citizen organization Canopy are taking care of 1200 street trees planted in the last five years. The volunteers are examining the trees for water needs, support stake removal and problems. Problem trees are reported to the city arborist. They are also leaving leaflets with homeowners to remind them to care for the young trees and providing tips on their care. Water needs of young trees are particularly critical in the summer-dry mediterranean climate of coastal California.

While many cities have active tree planting programs, few have the budgets to properly care for the trees. Citizen organizations like Canopy are a great way to mobilize concerned residents to help care for street trees.

New Scientist has an article (subscription required) about the largest ecological restoration/management project ever. Dust storms from Inner Mongolia and Northwestern China have always swept across northern China, but centuries of deforestation and overgrazing have made matters much worse. Chinese families are forced to stay indoors during the spring wind storms, and the dust destroys machinery and crops. The problem is worldwide: dust from China causes problems, including airport closures, in Korea and Japan. The dust darkens the sky as far away as Colorado.

The Chinese government initially tried building a wall of trees to block the dust. Now, China, along with Korea, Japan and Mongolia, are implementing the largest ecological management project to try multiple approaches to reducing the dust problem. Plans include grasslands restoration in dry areas, reforestation of uplands and a switch from wood as an energy source to wind and solar. There is no shortage of either of these energy sources in the region. One part of the forest restoration scheme involves the use of waste water to irrigate young pine plantations.

Although the project is huge, multinational and well funded, it may not work. Centuries of neglect of western China have made a natural phenomenon into a serious problem, and centuries of effort may be required to resolve it.

Thanks to Dave Roberts at Gristmill. He has a good account of the article here.

The Springwatch project in Britain, sponsored by the Woodland Trust and the BBC, is a large-scale effort to record the timing of spring events in nature. The project has been enormously successful, with over 114,000 observations turned in to date. Initial results suggest that many events normally associated with spring have been occurring throughout the mild British winters of recent years. What is most important is that this kind of large-scale citizen participation in phenology records, if kept up over a long time, will provide scientists with enormously useful information on the impacts of climate change on the natural world.

This is also a great educational tool, one that could easily be implemented in the US. It not only serves an important role in climate change research, but it is an educational tool as well. Any community process that enhances the ability of the citizenry to observe nature is a benefit.

The Woodland Trust found that 94% of British children are unable to identify common native trees. Even oaks were only recognized by 20% of kids in the survey. The survey of 7 to 14 year olds found that the most recognizable tree was holly, known for its indoor use as a holiday decoration.

See earlier Growing up without nature post

An interesting article in the New York Times today about the disconnection of children and nature. Kids are so involved in computer games, television, game boys etc. that they seem to spend less and less time out of doors. Neighborhoods are increasingly unfriendly to outdoor play - closing school yards after hours, prohibiting treehouses - and parents are having a hard time getting kids out of the house. A new book due out this summer by Richard Louv calls this "nature deficit disorder." 

All of this is based on anecdotal evidence, but I think it is true. Kids know every Pokemon or Power Rangers character but can't name the birds in their back yard - indeed have never even seen the birds in their back yard. My kids are very interested in nature, and spend a lot of time outdoors, but mostly in the back yard. We don't seem to get out in the woods as much as I'd like, though it is certainly very accessible from here. Many of their classmates seem to never have been in the woods. 

There is a danger here - it is hard to care about something that is distant and unknown. The more kids are removed from nature, the less likely they are to care about its conservation. Oh, sure, kids are passionate about protecting rainforests, but rainforests are a distant abstraction.

Some years ago, I started asking my Natural Resources students how many were bird watchers.  To my astonishment, over 10 years of asking this question, not one student ever admitted to being a birder. That may not be surprising in the general student population, but presumably natural resources students have some larger connection to nature. Not only were they not birders, but they generally could not identify anything in nature - trees, wildflowers, birds - until they took a course in it.

Somehow, we need desparately to reenergize the connection between kids and nature. Environmental education in the schools is important but not sufficient. We need nature education.  We need to make knowing your neighborhood trees as important as knowing Pokemon. How do we do that? I'm not sure except by immersion. Kids like mine have an advantage - their parents are biologists. Maybe I should start taking their friends on weekend walks in the woods.

As a forester, I understand that clearcuts can be a useful management tool. In the Appalachians, where I live, small patch clearcuts are an excellent method to regenerate forests, return of vegetation is rapid (from stump sprouts especially), and impacts on water quality are minimal. As my silviculture professor, Doc Johnson, used to say, all silviculture is clearcutting - we're only arguing over the size of the cut. In other words, there is a continuum from cutting a single tree to cutting an entire watershed. Both ends of this continuum are probably worse than somewhere in the middle. Nevertheless, clearcutting has to be used with care and responsibility. So it is really disturbing to see the satellite photos of clearcuts in British Columbia using Google Maps. It is difficult for me to believe that this represents responsible, sustainable forestry. Google Maps lets us look at vast areas of North America with detailed maps and satellite photos. They give ordinary citizens a chance, not just to see what our continent looks like, but what we are doing to it. Read more at Organic Matter and Mezzoblue. Then go to Google Maps to see the actual maps. You can pan and zoom the maps to get an impression of the vast scale of the clearcuts.

Satellite image courtesy of Organic Matter, derived from Google Maps

Oak flowering in central Kentucky is almost done for the year. This is good news for allergy sufferers, here in the pollen capital of the US. Oak catkins (male flowers, pictured on the right is scarlet oak) are dropping from the trees, and pollen counts are declining. This has been a good year for oak flowers, with no late-season frosts. Most of the wind-pollinated trees flower early (oak, elm, hackberry, hickory) before or at the time of first leaf flush. For the remainder of the season, insect-pollinated trees will continue flowering. These do not pose problems for people with allergies, since they do not release large amounts of pollen. However, grass pollens will begin to pick up shortly.

Rebuilding Aceh, the Indonesian province most devastated by the December tsunami, will require huge amounts of wood. The World Wildlife Fund estimates that reconstruction in Aceh will require over 1 million cubic meters of wood. Illegal logging is rampant throughout Indonesia, and there are fears that the demand for wood in Aceh will accelerate the ongoing destruction of Indonesia's rainforests. Ralph Ashton, WWF spokesman, says that donor countries should supply wood from sustainably managed forests to assist in reconstruction efforts without denuding Indonesian forests.

WWF-Indonesia has launched a set of green reconstruction guidelines to provide a policy framework for rebuilding Aceh. The guidelines are avalable here (.pdf).

Dari WWF-Indonesia: "Kawasan Aceh yang luluh lantak akan semakin buruk keadaannya bila negara-negara donor tidak segera menyediakan kayu dari sumber yang dikelola secara lestari untuk propinsi yang dilanda tsunami ini."

Lexington, KY, my home town, is this year's official Pollen Capital according to the Asthma and Allergy Foundation of America. It is ranked first among US cities in tree pollen measures this spring. Rankings are based on pollen counts, rates of allergy medicine use, and per capita numbers of allergists. But it is pollen that accounts for year-to-year changes in the rankings, and our tree pollen is very high this year. Elm, hackberry, oak and hickory are the major spring offenders.

Here is an article in the Herald Leader, and this year's rankings.

A Florida couple has lost their latest effort to save the grapefruit trees in their back yard. Florida is struggling with citrus canker, caused by the bacterium Xanthomonas axonopodis pv. citri. Quarantine rules require all trees within 1900 ft. of an infected tree to be destroyed. The Boca Raton couple, Edmund and Laura Gerstein, sued to stop their two grapefruit trees from the ax. They claimed that the Geneva Convention prohibited government destruction of civilian food sources in time of war. Claiming that the war on terrorism and the Iraq war could cause a food shortage, the Gersteins posted the Geneva Convention on their front door and tried to stop agriculture officials from cutting the trees. The court didn't buy it and the trees have been cut down.