Effects of climatic conditions on annual shoot length and tree-ring width of alpine dwarf pine Pinus pumila in central Japan

Abstract

This study compared the effects of climatic conditions on annual shoot length (ASL) and tree-ring width (TRW) of alpine dwarf pine Pinus pumila in central Japan, by using dendrochronological techniques. Chronologies of ASL (1951-2009) and TRW (1972-2009) were standardized to remove non-climatic signals, and correlation tests were done for non-standardized observed values and standardized indices with monthly temperatures and precipitation. Monthly mean temperatures from March to October, except for July, increased during 1951‒2009; observed values and a standardized index of ASL increased during this period. For the rate of increase in ASL, the standardized index was lower than the observed values. However, these values of TRW showed no trends. The observed values and standardized index of TRW positively correlated with temperatures of the beginning of the growing season of the current year. The observed values of ASL positively correlated with temperatures during the growing season of the previous and current years. However, the standardized index of ASL positively correlated with only June temperatures of the previous and current years. The different results of ASL between observed values and standardized indices indicate that many significant correlations of observed values were attributable to increasing trends of temperature and ASL. This study suggests that standardized ASL of P. pumila tended to increase greater than TRW, that high temperatures at the beginning of the growing season increases ASL and TRW, and that analyzing observed values of ASL may overestimate the effects of temperature on ASL of P. pumila.

Root Foraging Precision of Pinus pumila (Pall.) Regel Subjected to Contrasting Light Spectra

“…Previous studies also revealed similar promotions on light-adapted species, such as Bletilla striata [ 10 ], Pinus koraiensis [ 16 , 20 ], and Larix principis-rupprechtii [ 15 ]. As was mentioned above, P. pumila is also a sunlight-adapted species and its shade tolerance is disputed [ 34 , 38 , 39 ]. In contrast, the spectrum enriched with red light did not clearly promote growth in deep-shade-tolerant species.…”

“…As a result, their populations concentrate in large forest gaps or better illuminated slopes while individuals shaded by tree crowns appear suppressed, such as in the mountains in the Russian Far East [ 38 ]. However, P. pumila populations in central Kamchatka of Russia and northern parts of Japan are also regarded as a shade-tolerant species [ 34 , 39 ]. Understory light quality was found to vary in different forests of temperate montane ecosystems [ 7 , 8 ].…”

Virtual issue: Alpine and subalpine plant communities: importance of plant growth, reproduction and community assemblage processes for changing environments

“…Climate and growth of alpine plants: Yoshie 2010examined the vegetative phenology of 29 alpine species in Japan, and showed the importance of early growth initiation for the increase of growth of alpine plants as the growth period of leaves and stems correlated with the time of growth initiation stronger than with the time of growth cessation. Takahashi and Aoki (2015) also showed that high temperatures at the beginning of the growth period increase the annual shoot length and treering width of alpine dwarf pine Pinus pumila in central Japan. 4.…”