WHY LEAVES CHANGE COLOR

 
If you are lucky, you live in one of those parts of the world where Nature has one last fling before settling down into winter's sleep. In those lucky places, as days shorten and temperatures become crisp, the quiet green palette of summer foliage is transformed into the vivid autumn palette of reds, oranges, golds, and browns before the leaves fall off the trees. On special years, the colors are truly breathtaking.

How does autumn color happen?

For years, scientists have worked to understand the changes that happen to trees and shrubs in the autumn. Although we don't know all the details, we do know enough to explain the basics and help you to enjoy more fully Nature's multicolored autumn farewell. Three factors influence autumn leaf color-leaf pigments, length of night, and weather, but not quite in the way we think. The timing of color change and leaf fall are primarily regulated by the calendar, that is, the increasing length of night. None of the other environmental influences-temperature, rainfall, food supply, and so on-are as unvarying as the steadily increasing length of night during autumn. As days grow shorter, and nights grow longer and cooler, biochemical processes in the leaf begin to paint the landscape with Nature's autumn palette.

Where do autumn colors come from?   

A color palette needs pigments, and there are three types that are involved in autumn color.

Chlorophyll, which gives leaves their basic green color. It is necessary for photosynthesis, the chemical reaction that enables plants to use sunlight to manufacture sugars for their food. Trees in the temperate zones store these sugars for their winter dormant period.

Carotenoids, which produce yellow, orange, and brown colors in such things as corn, carrots, and daffodils, as well as rutabagas, buttercups, and bananas.

Anthocyanins, which give color to such familiar things as cranberries, red apples, concord grapes, blueberries, cherries, strawberries, and plums. They are water soluble and appear in the watery liquid of leaf cells. Both chlorophyll and carotenoids are present in the chloroplasts of leaf cells throughout the growing season. Most anthocyanins are produced in the autumn, in response to bright light and excess plant sugars within leaf cells.

During the growing season, chlorophyll is continually being produced and broken down and leaves appear green. As night length increases in the autumn, chlorophyll production slows down and then stops and eventually all the chlorophyll is destroyed. The carotenoids and anthocyanins that are present in the leaf are then unmasked and show their colors.

Certain colors are characteristic of particular species. Oaks turn red, brown, or russet; hickories, golden bronze; aspen and yellow-poplar, golden yellow; dogwood, purplish red; beech, light tan; and sourwood and black tupelo, crimson. Maples differ species by species-red maple turns brilliant scarlet; sugar maple, orange-red; and black maple, glowing yellow. Striped maple becomes almost colorless. Leaves of some species such as the elms simply shrivel up and fall, exhibiting little color other than drab brown.

The timing of the color change also varies by species. Sourwood in southern forests can become vividly colorful in late summer while all other species are still vigorously green. Oaks put on their colors long after other species have already shed their leaves. These differences in timing among species seem to be genetically inherited, for a particular species at the same latitude will show the same coloration in the cool temperatures of high mountain elevations at about the same time as it does in warmer lowlands.

How does weather affect autumn color?

The amount and brilliance of the colors that develop in any particular autumn season are related to weather conditions that occur before and during the time the chlorophyll in the leaves is dwindling. Temperature and moisture are the main influences.

A succession of warm, sunny days and cool, crisp but not freezing nights seems to bring about the most spectacular color displays. During these days, lots of sugars are produced in the leaf but the cool nights and the gradual closing of veins going into the leaf prevent these sugars from moving out. These conditions-lots of sugar and lots of light-spur production of the brilliant anthocyanin pigments, which tint reds, purples, and crimson. Because carotenoids are always present in leaves, the yellow and gold colors remain fairly constant from year to year.

The amount of moisture in the soil also affects autumn colors. Like the weather, soil moisture varies greatly from year to year. The countless combinations of these two highly variable factors assure that no two autumns can be exactly alike. A late spring, or a severe summer drought, can delay the onset of fall color by a few weeks. A warm period during fall will also lower the intensity of autumn colors. A warm wet spring, favorable summer weather, and warm sunny fall days with cool nights should produce the most brilliant autumn colors.

What triggers leaf fall?

In early autumn, in response to the shortening days and declining intensity of sunlight, leaves begin the processes leading up to their fall. The veins that carry fluids into and out of the leaf gradually close off as a layer of cells forms at the base of each leaf. These clogged veins trap sugars in the leaf and promote production of anthocyanins. Once this separation layer is complete and the connecting tissues are sealed off, the leaf is ready to fall.

What does all this do for the tree?

Winter is a certainty that all vegetation in the temperate zones must face each year. Perennial plants, including trees, must have some sort of protection to survive freezing temperatures and other harsh wintertime influences. Stems, twigs, and buds are equipped to survive extreme cold so that they can reawaken when spring heralds the start of another growing season. Tender leaf tissues, however, would freeze in winter, so plants must either toughen up and protect their leaves or dispose of them.

The evergreens-pines, spruces, cedars, firs, and so on-are able to survive winter because they have toughened up. Their needle-like or scale-like foliage is covered with a heavy wax coating and the fluid inside their cells contains substances that resist freezing. Thus the foliage of evergreens can safely withstand all but the severest winter conditions, such as those in the Arctic. Evergreen needles survive for some years but eventually fall because of old age.

The leaves of broadleaved plants, on the other hand, are tender and vulnerable to damage. These leaves are typically broad and thin and are not protected by any thick coverings. The fluid in cells of these leaves is usually a thin, watery sap that freezes readily. This means that the cells could not survive winter where temperatures fall below freezing. Tissues unable to overwinter must be sealed off and shed to ensure the plant's continued survival. Thus leaf fall precedes each winter in the temperate zones.

What happens to all those fallen leaves?

Needles and leaves that fall are not wasted. They decompose and restock the soil with nutrients and make up part of the spongy humus layer of the forest floor that absorbs and holds rainfall. Fallen leaves also become food for numerous soil organisms vital to the forest ecosystem. It is quite easy to see the benefit to the tree of its annual leaf fall, but the advantage to the entire forest is more subtle. It could well be that the forest could no more survive without its annual replenishment from leaves than the individual tree could survive without shedding these leaves. The many beautiful interrelationships in the forest community leave us with myriad fascinating puzzles still to solve.

Where can I see autumn color in the United States?

You can find autumn color in parks and woodlands, in the cities, countryside, and mountains - anywhere you find deciduous broadleaved trees, the ones that drop their leaves in the autumn. Nature's autumn palette is painted on oaks, maples, beeches, sweetgums, yellow-poplars, dogwoods, hickories, and others. Your own neighborhood may be planted with special trees that were selected for their autumn color.

New England is rightly famous for the spectacular autumn colors painted on the trees of its mountains and countryside, but the Adirondack, Appalachian, Smoky, and Rocky Mountains are also clad with colorful displays. In the East, we can see the reds, oranges, golds, and bronzes of the mixed deciduous woodlands; in the West, we see the bright yellows of aspen stands and larches contrasting with the dark greens of the evergreen conifers.

Many of the Forest Service's 100 plus scenic byways were planned with autumn color in mind. In 31 States you can drive on over 3,000 miles of scenic byways, and almost everyone of them offers a beautiful, colorful drive sometime in the autumn.

When is the best time to see autumn color?

Unfortunately, autumn color is not very predictable, especially in the long term. Half the fun is trying to outguess Nature! But it generally starts in late September in New England and moves southward, reaching the Smoky Mountains by early November. It also appears about this time in the high-elevation mountains of the West. Remember that cooler high elevations will color up before the valleys. The Forest Service's Fall Color Hotline (1-800-354-4595) can provide you with details as the autumn color display progresses.

Persons of any race, color, national origin, sex, age, or religion, or with any handicapping condition are welcome to use and enjoy all the facilities, programs, and services of the U.S. Department of Agriculture. Discrimination in any form is strictly against agency policy and should reported to the Secretary of Agriculture, Washington, DC 20250.

http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm

Blueberries Planted In A Container

For the best results, containerize your blueberry plants. We show you the proven way to do it.
Dave Wilson Nursery

Ed Laivo demonstrates planting a Southern Highbush Blueberry called a Revielle in a pot. The planting steps are detailed out.

The California Ballot Initiative: Standing Up to Monsanto

By Ronnie Cummins
Organic Consumers Association, Oct 7, 2011

"If you put a label on genetically engineered food you might as well put a skull and crossbones on it." - Norman Braksick, president of Asgrow Seed Co., a subsidiary of Monsanto, quoted in the Kansas City Star, March 7, 1994

Monsanto and Food Inc.'s stranglehold over the nation's food and farming system is about to be challenged in a food fight that will largely determine the future of American agriculture. A growing corps of organic food and health activists in California - supported by consumers and farmers across the nation - are boldly standing up to Monsanto and its minions, taking the first steps to expose the widespread contamination of non-organic grocery store foods with Genetically Modified Organisms (GMOs), and moving to implement mandatory GMO labeling through a grassroots-powered Citizens Ballot Initiative process.

This month, lawyers representing a broad and unprecedented health, environmental, and consumer coalition, including the Organic Consumers Association, Dr. Bronner's Magic Soap, Center for Food Safety, Mercola.com, Nature's Path, Natural News.com, LabelGMOs.org, Food Democracy Now, and the Institute for Responsible Technology, are filing papers with the California Attorney General's office to place a Citizens Initiative on the Ballot in November 2012 that would require mandatory labeling of genetically engineered foods and food ingredients. If California voters pass this ballot initiative in 2012, it will likely be the beginning of the end for Monsanto and genetically engineered food in the U.S.

According to Zuri Star, a Southern California field organizer for the Organic Consumers Association, "The California Ballot Initiative is perhaps our last chance to stop the Biotech Express, to overthrow Biotechnology's dictatorial regime and build a safe and sustainable food and farming system based upon the ethical principles of consumer choice and BioDemocracy."

Moving the Battleground

After twenty years of biotech bullying and force-feeding unlabeled and hazardous genetically engineered (GE) foods to animals and humans, a critical mass of food and health activists has decided it's time to move beyond small skirmishes and losing battles and go on the offensive. It's time to move the food fight over labeling GE food from the unfavorable terrain of Washington D.C. and Capital Hill, where Monsanto and Food Inc. exercise near-dictatorial control, to California, the heartland of organic food and farming and anti-GMO sentiment, where 80-85% of the body politic, according to recent polls, support mandatory labeling.

The trillion-dollar biotech, supermarket, and food industry are acutely conscious of the fact that North American consumers, like their European counterparts, are wary and suspicious of genetically engineered food. Consumers understand that you don't want your food safety or environmental sustainability decisions to be made by out-of-control chemical and biotech companies like Monsanto, Dow, or DuPont - the same people who brought us toxic pesticides and industrial chemicals, Agent Orange, carcinogenic food additives, PCBs, and now global warming. Biotech, food, and grocery corporations are alarmed by the fact that every poll over the last 20 years has shown that 85-95% of American consumers want mandatory labels on genetically engineered foods.

Europe Shows Labels Drive GMOs off the Market

Why are there basically no genetically engineered foods or crops anywhere in Europe, while 75% of U.S. supermarket foods - including many so-called "natural" foods - are GE-tainted? The answer is simple. In Europe genetically engineered foods and ingredients have to be labeled. In the U.S. they do not. Up until now, in North America, Monsanto and the Biotechnocrats have enjoyed free reign to secretly lace non-organic foods with gene-spliced viruses, bacteria, antibiotic-resistant marker genes, and foreign DNA-mutant "Frankenfoods" shown to severely damage the health of animals, plants, and other living organisms in numerous scientific studies.

Monsanto and their allies understand the threat that truth-in-labeling poses for GMOs. As soon as genetically engineered foods start to be labeled in the U.S., millions of consumers will start to read these labels and react. They'll complain to grocery store managers and companies, they'll talk to their family and friends. They'll start switching to foods that are organic or at least GMO-free. Once enough consumers start complaining about GE foods and food ingredients; stores will eventually stop selling them; and farmers will stop planting them.

Genetically engineered foods have absolutely no benefits for consumers or the environment, only hazards. This is why Monsanto and their friends in the Clinton, Bush, and Obama administrations have prevented consumer GMO truth-in-labeling laws from ever getting a public discussion, much less coming to a vote in Congress. And this is why activists are launching the California Ballot Initiative. By moving the battle from the federal level to the state level, by employing one of the last remaining tools of direct grassroots democracy in the USA, the ballot initiative, concerned consumers can bypass Washington and regain their fundamental right to know what they are eating.

Passing mandatory GMO labeling in just one large state, California, where there is tremendous opposition to GE foods as well as a multi-billion dollar organic food industry, will ultimately have the same impact as a national labeling law.

If California food and health activists succeed in putting a GMO labeling initiative on the ballot in 2012 and the voters pass it, the biotech and food industry will face an intractable dilemma. Will they dare put labels on their branded food products in just one state, California, admitting these products contain or may contain genetically engineered ingredients, while withholding this ingredient label information in the other states? Will they allow their organic and non-GMO competitors to drive down their GMO-tainted brand market share? The answer to both of these questions is likely no. What most of them will do is start to shift to organic and non-GMO ingredients, so as to avoid what the Monsanto executive 16 years ago aptly described as the "skull and crossbones" label.

California Label Laws Have National Impact:
Proposition 65

A clear indication of the impact of warning labels on consumer products was established in California in 1986 when voters passed, over the strenuous opposition of industry, a ballot initiative called Proposition 65, which required consumer products with potential cancer-causing ingredients to bear warning labels. Rather than label their products sold in California as likely carcinogenic, most companies reformulated their product ingredients so as to avoid warning labels altogether, and they did this on a national scale, not just in California.

This same scenario will likely unfold again in California in 2012. Can you imagine Kellogg's selling its Corn Flakes breakfast cereal in California with a label that admits it contains or may contain genetically engineered corn? This would be the kiss of death for their iconic brand. How about Kraft Boca Burgers admitting that their soybean ingredients are genetically modified? How about the entire non-organic food industry (including many so-called "natural" brands) admitting that a large proportion of their products are GE-tainted?

Once food manufacturers and supermarkets are forced to come clean and label genetically engineered products, they will likely remove all GE ingredients, to avoid the "skull and crossbones" effect, just like the food industry in the EU has done. In the wake of this development American farmers will convert millions of acres of GE crops to non-GMO or organic varieties.

Finally consumers will be able to tell the difference between organic food (labeled as "organic" and thereby GMO-free); natural food (which will not have a GMO label), and bogus "natural" food (which will be required to display the label "contains or may contain GMOs").

What Now? The Campaign Needs Volunteers and Money

Monsanto, the Farm Bureau, and the Grocery Manufacturers Association are already gearing up to fight against the California Ballot Initiative. They will literally spend millions to spread lies and disinformation that GMO foods and crops are perfectly safe; and that we need more, not less GMO food and biofuel crops in this era of climate change and growing population, etc. As the campaign progresses, they will lie and say that GMO labels will be costly to the food industry and raise food prices. We'll have to counter these lies of course, now and throughout the campaign, but first of all we must make sure that the 2012 GE Food Labeling Initiative actually gets on the ballot.

When corporations like Monsanto decide to launch a ballot initiative in California, or other states, one of the first things they do is hand over a couple of million dollars to a professional petition gathering business. Since, unlike Monsanto, we don't have a couple of million dollars to spare, we're going to have to rely on an army of volunteers to gather signatures. These volunteers can be trained and coordinated by our small, but highly dedicated and experienced, paid campaign staff and consultants, but for the most part we must drive this campaign forward with volunteer labor.

In order to hit the ground running in December, gathering 500-700,000 petition signatures of registered voters to put this measure on the ballot, we need your help now. We need an army of thousands of volunteer petition gatherers to step forward in California. And we need money. OCA and our allied lobbying organization, the Organic Consumers Fund, estimate that we need to raise at least $60,000 over the next month in order to effectively play our part in the California Ballot Initiative Campaign, to pay our staff, consultants, and other campaign expenses.

If you want more information, or if you are willing to volunteer to collect petition signatures, or donate money to this campaign click here: http://www.organicconsumersfund.org/label/

It's time to take back control over our food and farming system. It's time to stand up to Monsanto and the Biotech Bullies. Join us!

http://www.organicconsumers.org/articles/article_24074.cfm