Forests

66 quotes found

"In order to explore the effect of forest bathing on human immune function, we investigated natural killer (NK) activity; the number of NK cells, and perforin, granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields. Twelve healthy male subjects, age 37-55 years, were selected with informed consent from three large companies in Tokyo, Japan. The subjects experienced a three-day/two-night trip in three different forest fields. On the first day, subjects walked for two hours in the afternoon in a forest field; and on the second day, they walked for two hours in the morning and afternoon, respectively, in two different forest fields. Blood was sampled on the second and third days, and NK activity; proportions of NK, T cells, granulysin, perforin, and granzymes A/B-expressing cells in PBL were measured. Similar measurements were made before the trip on a normal working day as the control. Almost all of the subjects (11/12) showed higher NK activity after the trip (about 50 percent increased) compared with before. There are significant differences both before and after the trip and between days 1 and 2 in NK activity. The forest bathing trip also significantly increased the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells. Taken together, these findings indicate that a forest bathing trip can increase NK activity, and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins."

- Forests

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"We previously reported that forest bathing trips enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after the trip in male subjects. In the present study, we investigated the effect of forest bathing trip on human NK activity in female subjects. Thirteen healthy nurses, age 25-43 years, professional career 4-18 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields. On day 1, the subjects walked for two hours in the afternoon in a forest field; on day 2, they walked for two hours each in the morning and afternoon in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire. Blood and urine were sampled on the second and third days during the trip, and on days 7 and 30 after the trip. NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, the concentrations of estradiol and progesterone in serum, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the trip on a normal working day. The concentrations of phytoncides in the forests were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air. These findings indicate that a forest bathing trip also increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins in female subjects, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity."

- Forests

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"We previously reported that 2-night/3-day trips to forest parks enhanced human NK activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that this increased NK activity lasted for more than 7 days after the trip in both male and female subjects. In the present study, we investigated the effect of a day trip to a forest park on human NK activity in male subjects. Twelve healthy male subjects, aged 35-53 years, were selected after giving informed consent. The subjects experienced a day trip to a forest park in the suburbs of Tokyo. They walked for two hours in the morning and afternoon, respectively, in the forest park on Sunday. Blood and urine were sampled in the morning of the following day and 7 days after the trip, and the NK activity, numbers of NK and T cells, and granulysin, perforin, and granzyme A/B-expressing lymphocytes, the concentration of cortisol in blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trip on a weekend day as the control. Phytoncide concentrations in the forest were measured. The day trip to the forest park significantly increased NK activity and the numbers of CD16(+) and CD56(+) NK cells, perforin, granulysin, and granzyme A/B-expressing NK cells and significantly decreased CD4(+) T cells, the concentrations of cortisol in the blood and adrenaline in urine. The increased NK activity lasted for 7 days after the trip. Phytoncides, such as isoprene, alpha-pinene, and beta-pinene, were detected in the forest air. These findings indicate that the day trip to the forest park also increased the NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted for at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity."

- Forests

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"As the atmosphere's most abundant element, nitrogen plays a significant role in ecosystems, and one to which scientists and policymakers are paying greater attention. Growing evidence suggests that as humanity pumps more nitrogen into the environment, forests could become bigger carbon sinks and help mitigate climate change. But experts warn that it's a dangerous experiment that could have serious consequences. Nitrogen comes from a vast array of sources: farm fertilizer, car exhaust, factory and power plant emissions. Scientists expect nitrogen deposition this century to jump two to three times above current levels, dramatically influencing the planet's environment and thermostat. "It is pretty important to recognize that human effects on the nitrogen cycle have significant effects on climate," said Alan Townsend, North America director of the International Nitrogen Initiative. That's why Kurt Pregitzer of the University of Nevada, Reno and his fellow researchers essentially fertilized four experimental forests in northern Michigan. They applied nitrogen at two to three times current concentrations—about what society is expected to emit a century from now, thanks to increasing use of fertilizer and fuel. Tree growth, as expected, took off, with the newly formed wood absorbing and storing more carbon. The surprise was what happened on the forest floor. There scientists found that decomposition of twigs and other tree litter slowed. Lignin—the tough substance that gives vegetables their crunch and is quite good at storing carbon—proved more resistant to the forest floor's microbes. Those microbes, said Pregitzer, are "the gatekeepers of carbon transformation." "What we didn't anticipate was that storage of carbon in soil is directly altered by the addition of nitrogen," he said. "The really novel part, I think, is that the microbial community is actually altered." This is significant, said team member Donald Zak of the University of Michigan. With microbes dining lightly on lignin, more dead plant matter stays in the soil. Zak said this litter traps as much carbon as the robustly growing trees—a considerable boost to the forest's ability to sequester carbon emissions. Scientists don't yet understand the mechanisms that slow the decomposition, Zak cautioned. It's a crucial question they'll need to answer if they hope to understand the role that forests play in carbon sequestration."

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"In Japan, “Shinrin-yoku”, which can be defined as “taking in the forest atmosphere or forest bathing” is currently receiving increasing attention for its capacity to provide relaxation and reduce stress. Humans empirically recognize that getting in touch with nature provides a feeling of comfort. In carrying out their investigations on “Shinrin-yoku”, the authors of this article have assumed that the reason underlying this feeling of comfort with “nature” or “natural matters” is closely linked with the human evolutionary process. Frumkin supports this view and reports that a deep-seated connection between the natural world and humans is unsurprising from an evolutionary perspective; based on this description, we have also assumed that human physiological functions have had to adapt to the natural environment through the course of evolution. Consequently, living in our modern “artificial” society is inherently stressful. Given this background, it should be natural for humans to feel a sense of comfort or affinity with the natural environment. “Shinrin-yoku” is considered to be one of the most accessible ways to get in touch with the natural world and to lower excessive stress to levels that are commensurate with what our bodies are “expected” to cope with. In Western societies, this approach has been incorporated into the lives of individuals since the nineteenth century. The best known example of this may be Kneipp therapy in Germany. Kneipp therapy utilizes forests mainly as the fields for exercise therapy, which is one of the five pillars of the method. However, although Kneipp therapy somewhat realizes the concept of “Shinrin-yoku” in a practical context, its precedents in the Western countries are based mostly on empirical knowledge. The effects of “Shinrin-yoku” have yet to be verified by scientific evidence. The term “Shinrin-yoku” and its concept were introduced in Japan by the Forest Agency of the Japanese government in 1982. Over the 25 years that have passed since then, interest in stress control or relaxation among those living in our modern-day society has greatly increased. In addition, in the fields of medicine and nursing, there has been a trend toward evidence-based medicine or nursing, emphasizing the need for scientific evidence. Based on this social background, in 2005, the Forest Agency instituted the “Therapeutic Effects of Forests Plan,” which emphasizes the importance of scientific investigation."

- Forests

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