TREES
"On the last day of the world, I would want to plant a tree...."
Tropical Forests
The three types of tropical forests are rainforests, dry forests, and coniferous forests.
The trees of the tropical rainforests retain their leaves and continue to grow throughout the year. These forests contain the greatest diversity of plant species because the plants can specialize due to the possibilities created by the tropical climate. The tropical warmth and humidity fuel this abundance: there is so much moisture that rainforests create their own weather and clouds. Because life cycles are so brief, there is little time for nutrients to build up in the soil. If the rainforest is lost, the soil will become infertile.
The tropical dry forests are more distant from the equator, their climate varying between abundant rainfall and drought. Monsoons provide moisture for only part of the year so, during the dry season, many plants drop their leaves while animals may migrate or become dormant.
The coniferous forests of the western hemisphere are often a mixture of conifers and oaks in the mountains. With their origins in the pine and redwood forests of Pacific North America, the tropical conifers have developed into many different species. Coniferous forests in Asia, however, often contain only one species of pine but have a wide variety of broadleaf trees.
Habitats was published by DK Publishing in 2023.
The trees of the tropical rainforests retain their leaves and continue to grow throughout the year. These forests contain the greatest diversity of plant species because the plants can specialize due to the possibilities created by the tropical climate. The tropical warmth and humidity fuel this abundance: there is so much moisture that rainforests create their own weather and clouds. Because life cycles are so brief, there is little time for nutrients to build up in the soil. If the rainforest is lost, the soil will become infertile.
The tropical dry forests are more distant from the equator, their climate varying between abundant rainfall and drought. Monsoons provide moisture for only part of the year so, during the dry season, many plants drop their leaves while animals may migrate or become dormant.
The coniferous forests of the western hemisphere are often a mixture of conifers and oaks in the mountains. With their origins in the pine and redwood forests of Pacific North America, the tropical conifers have developed into many different species. Coniferous forests in Asia, however, often contain only one species of pine but have a wide variety of broadleaf trees.
Habitats was published by DK Publishing in 2023.
Trees United
The 2018 article "Do Trees Talk to Each Other?" in the Smithsonian magazine by Richard Grant highlights Peter Wohlleben's book The Hidden Life of Trees: What They Feel, How They Communicate. Grant visits the author, a German forester and writer, and walks with him through a forest reserve.
One of the book's subjects is the mycorrhizal networks that link the root tips of the trees with underground fungi which provide benefits for both. The more vulnerable young trees also benefit from the network through the sugar transported from the older trees.
Wohlleben also provides an example of a tree communicating through the air by means of pheromones and other scent signals. When a giraffe begins eating the leaves of a white-crowned acacia, the tree releases an ethylene gas and nearby acacias react by pumping tannins into their leaves, which can sicken large herbivores. Trees are also able to send electrical signals when they are under attack by caterpillars or deer.
Some scientists disapprove of how Wohlleben frames the processes. Stephen Woodward of the University of Aberdeen in Scotland believes that trees under attack are merely "emitting distress signals" without the "intention to warn." To Wohlleben, to write about nature without emotion is " inhuman, because we are emotional beings, and for most people, scientific language is extremely boring to read. The wonderful research about giraffes and acacia trees, for example, was done many years ago, but it was written in such dry, technical language that most people never heard about it."
Grant also covers Suzanne Simard's work at the University of British Columbia on mycorrhizal networks.
The article can be found online at smithsonianmag.com/science-nature/the-whispering-trees-180968084/.
One of the book's subjects is the mycorrhizal networks that link the root tips of the trees with underground fungi which provide benefits for both. The more vulnerable young trees also benefit from the network through the sugar transported from the older trees.
Wohlleben also provides an example of a tree communicating through the air by means of pheromones and other scent signals. When a giraffe begins eating the leaves of a white-crowned acacia, the tree releases an ethylene gas and nearby acacias react by pumping tannins into their leaves, which can sicken large herbivores. Trees are also able to send electrical signals when they are under attack by caterpillars or deer.
Some scientists disapprove of how Wohlleben frames the processes. Stephen Woodward of the University of Aberdeen in Scotland believes that trees under attack are merely "emitting distress signals" without the "intention to warn." To Wohlleben, to write about nature without emotion is " inhuman, because we are emotional beings, and for most people, scientific language is extremely boring to read. The wonderful research about giraffes and acacia trees, for example, was done many years ago, but it was written in such dry, technical language that most people never heard about it."
Grant also covers Suzanne Simard's work at the University of British Columbia on mycorrhizal networks.
The article can be found online at smithsonianmag.com/science-nature/the-whispering-trees-180968084/.
The Merwin Conservancy
While living in rural Hawaii, W. S. Merwin and his wife created the Merwin Conservancy in 1977. He wanted to plant native Hawaiian rainforest trees, but it proved impossible because of the poor soil and windy conditions. He planted Cassuarinas which improved the soil; still, native koas would not grow in the disturbed soil, so instead he planted palms. He was able to purchase additional acreage and now the Conservancy has over seven hundred species, including many endangered varieties. Lacking an irrigation system, he planted during the rainy seasons and tried to plant a palm every day during these periods.
You can see pictures of the Merwin Conservancy and read essays about it in What Is a Garden? by W. S. Merwin and photographed by Larry Cameron. The book was published by the University of South Carolina in 2016.
Another artist who dedicated himself to planting trees and other plants was the Brazilian garden designer Roberto Burle Marx. He spent years collecting and propagating Amazonian flora to help preserve it. His garden Sitio Roberto Burle Marx was donated to the Brazilian government after his death.
An iconic sycamore by Hadrian's Wall in northern England was cut down recently during a storm and people were shocked to discover its loss the following morning. The three-hundred-year-old tree was a well-known landmark popular with visitors and photographers. The National Trust collected seeds and cuttings from the tree, and there is hope that the tree might regrow from the stump.
You can see pictures of the Merwin Conservancy and read essays about it in What Is a Garden? by W. S. Merwin and photographed by Larry Cameron. The book was published by the University of South Carolina in 2016.
Another artist who dedicated himself to planting trees and other plants was the Brazilian garden designer Roberto Burle Marx. He spent years collecting and propagating Amazonian flora to help preserve it. His garden Sitio Roberto Burle Marx was donated to the Brazilian government after his death.
An iconic sycamore by Hadrian's Wall in northern England was cut down recently during a storm and people were shocked to discover its loss the following morning. The three-hundred-year-old tree was a well-known landmark popular with visitors and photographers. The National Trust collected seeds and cuttings from the tree, and there is hope that the tree might regrow from the stump.