The largest land animal remaining on the earth, the African elephant is of much importance to African ecosystem. Unlike other animals, the African elephant is to a great extent the builder of its environment. As a giant plant-eater, it significantly shapes the forest-and-savanna (大草原) surroundings in which it lives, therefore deciding the conditions of existence for millions of other animals that live in its habitat.

It is the elephant’s great desire for food that makes it both a disturber of the environment and an important builder of its habitat. In its continuous search for the 300 pounds of plants it must have every day, it kills small trees and underbush, as well as pulls branches off big trees. This results in numerous open spaces in not only deep tropical forests but also the woodlands that cover part of the African savannas. In these open spaces are numerous plants in various stages of growth, which attract a variety of other plant-eaters.

Take the rain forests for example. In their natural state, the spreading branches overhead shut out sunlight and prevent the growth of plants on the forest floor. By pulling down trees and eating plants, elephants create open spaces, allowing new plants to grow on the forest floor. In such situations,the forest becomes suitable for large-hoofed plant-eaters to move around and for small-sized plant-eaters to obtain their food as well.

Scientists are worried now that the African elephant has become an endangered species. If the elephant dies out, scientists say, many other animals will also disappear from vast areas of forest and savanna, greatly changing and worsening the whole ecosystem.

US psychotherapist(精神治疗师) Virginia Satir (1916-1988) once said: “We need four hugs a day survival. We need eight hugs a day maintenance. We need 12 hugs a day for growth.” She believed that hugging was necessary and important. Researchers have found scientific evidence that backs up her beliefs. According to a recent study published in the journal Psychological Science, receiving a hug can reduce stress and help protect us from illness.

In the study, researchers from Carnegie Mellon University (CMU) in the US invited 404 healthy adults to participate in interviews about how often the experienced conflicts in their daily lives, as well as how many hugs they received within a period of two weeks. These participants were intentionally exposed to cold viruses during the interview.

According to the research, people who received hugs on the same days when they experienced conflicts tended to report fewer negative feelings during the following days. They have also found that people who received hugs were less stressed out. The physical contact that we get through hugging especially loved ones, is a “marker of intimacy(亲密) and helps generate the feeling that others are there to help in the face of adversity(困境)”, according to Scientific American People feel more comfortable and relaxed after hugging.

The researchers have also found that the more hugs people get, the less likely they are to catch colds, Science Daily noted. When people receive hugs, they release more oxytocin(后叶催产素), which is also known as the “love hormone”. According to the researchers, this hormone can decrease one’s heart rate and lower blood pressure. This can put people into a state of emotional well-being. When people are in this state, their immune systems become stronger.

Of course, hugging is not the only way to comfort others. But physical contact like hugging can comfort people without “making any judgments (about right or wrong)”, Michael Murphy from CMU told Time.