In Amazonia, about 8% of the rainforests disappeared from the mid-1960s to the mid-1980s. During that time, military governments cut down large areas of the rainforest to facilitate the construction of roads and settlements, and the opening of farms and pastures. Since the 1990s, research has investigated the effects of such deforestation on the environment, with assistance from conservation projects such as the Pilot Program for the Protection of the Tropical Forests of Brazil. The seminal work in this area was the Large-Scale Biosphere-Atmosphere Experiment in Amazonia. For more than 20 years, specialists in a wide range of scientific disciplines have conducted fieldwork, measurements, laboratory experiments, and numerical simulations to examine vegetation and land-use monitoring, socio-economic change, forest fires, aerosol emissions, evapotranspiration, trace gas emissions, soil nutrition, soil carbon storage, carbon cycles, and terrestrial water budgets. Some issues and results related to these research efforts are briefly introduced in this paper.
It has been reported that nature experiences are effective at promoting healthy growth, especially in young people. Although nature experiences have been linked to better mental health, little research has examined the effects of tree-planting activities across all age group. Therefore, in this study, the effects of nature experiences and the educational benefits of tree-planting activities were investigated by using a questionnaire survey with respondents ranging from preschool age to their seventies. The principal findings of this research are as follows:
1) Of the respondents, 68.7% said that this was their first planting festival. In addition, 18.9-27.5% of elementary school children, teenagers, and respondents in their twenties did not regularly engage in outdoor activities.
2) Respondents who regularly engaged in outdoor activities tended to have experience planting and growing trees.
3) When asked to describe their impression of forests, respondents with nature experiences such as planting activities reported not only having a large number of different tree species growing in their community, but also having actual forests in mind.
4) The planting activity provided 33.0% of the older elementary school children with their first experience growing trees, and the planting festival offered a number of participants a sense of accomplishment and allowed them to engage all five senses through direct experience.
5) It can be presumed that there is a positive correlation between the number of planting experiences and consideration of one’s own behavior in relation to environmental issues.
Based on the concept of potential natural vegetation, indigenous tree species were planted to reforest a mining site in Kosaka, Akita Prefecture, Japan. The best growing plot among the planting areas was under the black locust forest, the soil of which was acidic and nutrients-rich. In contrast, the pH of the other planting sites was neutral. It is considered that the soil nutrient content is improving at all the planting plots. Both total nitrogen and total carbon have a positive correlation with the average volume index. The survival rate of trees planted in slag areas is higher than that in debris area, and does not depend on differences in moisture content between the debris and slag areas. The slag planting area had a more luxuriant appearance compared with the debris areas. The drying cold conditions due to the location and wind flow might be considered reasons for this appearance. Trees growing in the slag area have relatively longer shape. The relationship between total carbon and total nitrogen was linear for all plots. Fraxinus lanuginosa f. serrata showed better growth in soil with higher moisture and nutrient contents. Quercus crispula, showed greater sensitivity to soil moisture compared with Q. serrata.