A holiday for the trees


Thousands of years ago, rabbis created an annual holiday to honor trees: Tu B’Shevat, which was celebrated last month. The rabbis knew what we lose when we sacrifice trees, long before the we began to pay the price of industrialization. The cedars of Lebanon, the pines of Rome, the rich forests of Greece – all were brought down for purposes now forgotten, and the nations that fell them soon enough fell themselves. As documented in the book Collapse, by Jared Diamond, civilizations that have allowed their forests to be destroyed have gone on to perish. It’s fairly simple, a well-known cycle in history. When trees and forests are cut down, the land turns barren. Disastrous flash floods, erosion of top soil, desertification, drought and famine follow. The rabbis knew this.
    Tu B’Shevat celebrates the trees, the care and protection they offer, as well as what they can give in return for our care, the tangible and tasty fruits of our mutual efforts. They are our finest ecological producers, our planet’s life support system. They produce oxygen and take in carbon dioxide, but just as important, if less discussed, is the role they play in moderating climate, soaking up downpours, filtering pollution out of water and out of the air, cooling us and shading us and protecting us from the heat and radiation of the sun.      In Los Angeles, trees are even more vital than in many Eastern cities. Here, in our dry, often hot climate, trees soften our hardscapes, reducing the “urban heat island effect” by ten degrees Fahrenheit, or even more, with equivalent savings in air conditioning costs. The more vegetation we plant, the cooler our city. Trees are just as vital during rainstorms, to break up the destructive power of downpours, and, with mulching and care, can  retain tens of thousands of gallons of water in the porous soil around their enduring root systems.
    Once Los Angeles was a lovely natural ecosystem, and one that supported itself on its winter rainfall and its year-round stream flow. Now the city is two-third paved. Leading water supply experts agree that we in Los Angeles could still largely support ourselves on local water, save energy and money, bolster our resilience and protect ourselves against global warming. All we need do is treat our rainwater as an asset, and not a liability, and recognize that living trees, plants, and aquifers will save our water supplies as safely and effectively (and far more beautifully) if we understand their function as Green Infrastructure and “engineer” them back into our neighborhoods. The Elmer Avenue Project in Sun Valley, which we helped shepherd to completion last year, is a wonderful example of the effectiveness of this approach.
    But most of all trees, by their nature, build connections. From the tiny mitochondrial fungi that make it possible for the trees to pull nutrients from the soil, to the sanctuary their branches offer flocks of birds, to their ability to pull together people in blocks and schools and neighborhoods, their powers are unparalleled.
    Science tells us what Thoreau and many nature-lovers have long believed, that immersion in nature is profoundly beneficial not just for our souls, but for our minds. But here at TreePeople, after planting millions of trees, we are just as confident that it’s not just being in the presence of trees that heals us, it’s the act of planting, of caring, of protecting, of nurturing trees that heals best.
    People like trees, but it’s more than that – we need trees.