Changes in growth trends and die-off of forest trees due to the climate variability/change have been frequently reported, and under such situation, this review introduces the status quo and its causes, summarizing recent papers. As results, temperature and precipitation have been main factors controlling forest trees, and therefore growth of trees increased because of the temperature increase in some cases, while growth reductions were observed in other cases because of the relative increase of drought stress. Tree growth is also considered to be interactively affected by radiation as another climatic factor, and by non-climatic factors such as increases in atmospheric carbon dioxide, emission of atmospheric pollutants, biotic/abiotic disturbances and stresses. Tree growth should widely and continuously be measured hereafter because it is closely correlated both with responses to climate and with longevity in trees. Impacts of climate variability/change on Japanese forests might be unremarkable at present, but future researches could clarify the situation.

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Traditional dwellings remain well even at present in the San-in region, and there are various examples of environmental design with adaptation to climate, especially to seasonal wind in winter. “Tsuijimatsu” in the Izumo Plain is widely known for the windscreen of pine tree trimmed perpendicularly. In the Oki-Dogo Island, the windbreaks which utilized effectively plants and natural materials, such as “Kakiyane”, “Itakabe”, “Takekabe”, and “Sasakabe”, exist in the Kumi Village. The pine tree woods for protection against winds and sand is utilized as the place of residents’ relaxation and recreation in the Nakamura Village. The windbreaks which utilized natural materials called “Itagakoi” and “Takegakoi” exist in other villages at western part of the island. There are many persimmon trees and persimmon huts called “Kakigoya” for production of a dried persimmon in the Hata Village, Higashi-Izumo Town, and the residents cooperate and produce the specialty which was adapted for the climate in the beautiful landscape. Around the Shimane Peninsula, there are many vernacular houses which put the ridges made of the Kimachi Stone called “Munaishi” or “Muneishi” on the roof.

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The sap flow and circumferential variations of 12 evergreen hardwood trees, —six from a primary forest and six from a secondary forest—, were investigated in Brazilian Amazon from 2009 to 2011. In the morning on sunny days, tree stems contracted because the transpiration was larger than sap flow, while in the afternoon, the stems changed to expand because the transpiration became smaller than sap flow; consequently, the sap flow showed a contrary phase to the circumferential variation. When it rained in the daytime, the stem slightly expanded because the transpiration suspended but the sap flow continued; then, the stem contracted again as the transpiration restarted after the shower. Trees continued to recharge water for a while after the sunset even though the transpiration stopped, and the stems gradually expanded. When it rained at this time, the recharge and expansion increased speeds, which shared about 16% of all the reactions of trees to showers during the two years. The circumferential variation was indistinct in rainy seasons because showers occurred at any time in a day, and it expanded due to increases in sap in the xylem and cell division at the cambium. On the other hand, in dry seasons, contractions and expansions repeated, and the circumferential variations tended to contract because water consumption surpassed water recharge.

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