A thing or two about trees

Trees can be male, female, or both

Some trees have a single “gender” but many do not. The way to tell is to see if the male (pollen) parts are present on separate flowers on different trees from the “female” (ovary – ie, infant fruit) parts. Also, you should be aware that issues with pollination may not always be related to needing both “male” and “female” trees around – sometimes a tree has what is called a “perfect” flower (with both male and female parts) but because the pollen from the male portion does not ripen at the same time or is in some other way incompatible with the female portion, it may require others of its kind around with different pollination times in order to set fruit.

Trees help you breathe

Trees absorb carbon dioxide through their leaves and break it down, releasing oxygen into the air. One mature tree can produce enough oxygen for up to 18 people, depending on the size and type of tree. Together with other plants, trees have created enough oxygen to fill up one-fifth of the Earth’s atmosphere. That makes our planet the only member of the solar system with so much oxygen for living organisms.

Trees can act as a compass

First, find a nearby tree with a large diameter and observe the thickness and direction of the branches. In the northern hemisphere, the branches on the south-facing side of the tree will be fuller, while branches on the north-facing side will be thinner and grow upwards. Depending on the tree, this is usually easiest to see if you look up along the trunk. Also, the north-facing side of the tree would be more humid than the south-facing side, which is something most species of moss likes, and consequently, there will be more of it on the north face.

Some trees can produce chemicals to ward off predators

Plants have defences in their very tissues; chemicals that can prevent or reduce the amount that herbivores feed upon them. There some chemicals, called tannins, that protect plants in two ways; one way involves simply making leaves bitter and unpalatable, this means that animals will find the plant unpleasant tasting and they will avoid feeding upon it. Another way, perhaps even more cunning, is that the tannins decrease the efficiency of herbivores’ digestive systems, making it hard for animals to gain the required nutrients and so it is in their best interest to avoid eating plants with the bitter tastes because it will not do them good.

Trees are among the world’s oldest living things

Trees can live anywhere from less than 100 years up to more than a few thousand years. It all depends on what type of tree it is. In the United States, the tree with the longest lifespan is the bristle cone pine,which grows in the mountains of Nevada and southern California. A single tree can live up to 5,000 years! Aspens can individually live for 40–150 years above ground, but the root system of the colony is much longer-lived. In some cases, this is for thousands of years, sending up new trunks as the older trunks die off above ground.

Stress makes trees stronger

A forest that has been subjected to storms is much sturdier than woodlands in protected areas. The weaker trees have been removed, allowing more room for the stronger trees to thrive. A forest protected from adverse weather becomes overcrowded with thin, weak trees all competing for nutrients and sunlight. When this area is eventually exposed to a storm, virtually all of the vegetation will be leveled.

Fungus helps trees grow

Actually, most species of tree and plant are routinely infected by what’s known as “mycorrhizal fungi,” but this is no cause for alarm. Surprisingly, trees can actually benefit from their fungal friends. Many trees and plants not only host mycorrhizal fungi–they have actually come to depend on them. As the fungi grow, they send fine tentacles streaming into the soil. These tentacles help channel large amounts of water and nutrients back to the host tree, far more water than the tree would be able to trap with its roots alone. One study found that conifers with the fungus are twice as likely to survive a drought as those without.