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The Regents of the University of Colorado, a body corporate, contracting on behalf of the University of Colorado at Boulder for the benefit of INSTAAR Effects of Climatic Conditions on Shoot Elongation of Alpine Dwarf Pine (Pinus pumila) at Its Upper and Lower Altitudinal Limits in Central Japan Author(s): Koichi Takahashi Source: Arctic, Antarctic, and Alpine Research, Vol. 35, No. 1 (Feb., 2003), pp. 1-7 Published by: INSTAAR, University of Colorado Stable URL: http://www.jstor.org/stable/1552323 . Accessed: 12/06/2014 15:28 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. . INSTAAR, University of Colorado and The Regents of the University of Colorado, a body corporate, contracting on behalf of the University of Colorado at Boulder for the benefit of INSTAAR are collaborating with JSTOR to digitize, preserve and extend access to Arctic, Antarctic, and Alpine Research. http://www.jstor.org This content downloaded from 185.44.78.113 on Thu, 12 Jun 2014 15:28:18 PM All use subject to JSTOR Terms and Conditions

Effects of Climatic Conditions on Shoot Elongation of Alpine Dwarf Pine (Pinus pumila) at Its Upper and Lower Altitudinal Limits in Central Japan

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The Regents of the University of Colorado, a body corporate, contracting on behalfof the University of Colorado at Boulder for the benefit of INSTAAR

Effects of Climatic Conditions on Shoot Elongation of Alpine Dwarf Pine (Pinus pumila) at ItsUpper and Lower Altitudinal Limits in Central JapanAuthor(s): Koichi TakahashiSource: Arctic, Antarctic, and Alpine Research, Vol. 35, No. 1 (Feb., 2003), pp. 1-7Published by: INSTAAR, University of ColoradoStable URL: http://www.jstor.org/stable/1552323 .

Accessed: 12/06/2014 15:28

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

INSTAAR, University of Colorado and The Regents of the University of Colorado, a body corporate,contracting on behalf of the University of Colorado at Boulder for the benefit of INSTAAR are collaboratingwith JSTOR to digitize, preserve and extend access to Arctic, Antarctic, and Alpine Research.

http://www.jstor.org

This content downloaded from 185.44.78.113 on Thu, 12 Jun 2014 15:28:18 PMAll use subject to JSTOR Terms and Conditions

Arctic, Antarctic, and Alpine Research, Vol. 35, No. 1, 2003, pp. 1-7

Effects of Climatic Conditions on Shoot Elongation of Alpine Dwarf Pine (Pinus pumila) at Its Upper and Lower Altitudinal Limits in Central Japan

Koichi Takahashi

Department of Biology, Faculty of Science, Shinshu University, Matsumoto 390-8621, Japan. [email protected]

Abstract The effects of climatic conditions on the shoot elongation of alpine dwarf pine (Pinus pumila) were examined at its lower and upper altitudinal limits on Mt. Norikura (2500 and 2840 m a.s.l.) and Mt. Shogigashira (2640 and 2675 m a.s.l.) in central Japan. Altitudinal forest-structural changes were also described. Shoot

elongation and stem height of P. pumila increased with decreasing altitude, but its abundance was markedly decreased at the altitudinal ecotone between the

upper P. pumila zone and the lower Betula ermanii zone because of the suppres- sion by tall B. ermanii. Thus, the lower altitudinal limit of P. pumila was probably determined by the competition with B. ermanii. The interannual variation in the shoot elongation of P. pumila was related to climatic conditions; long shoot length was associated with high summer temperatures of the previous year at both the

upper and lower altitudinal limits on the two mountains. In addition, rates of the increase of shoot elongation in response to the increase of air temperature were not different between the upper and lower altitudinal limits. Thus, the increase of summer temperatures would enhance the growth of P. pumila from its upper to lower altitudinal limits. However, it is harder to predict the altitudinal distribution shift of P. pumila due to environmental change because its lower altitudinal limit is largely affected by competition with B. ermanii. Therefore, this study concluded that long-term monitoring of the population dynamics at the P. pumila-B. ermanii ecotone is necessary to predict the distribution shift of P. pumila.

Introduction

Global warming may affect the distribution shift of altitu- dinal vegetation zonation. The upper limits of plant distributions are thought to be due to physiological stresses such as cold and insufficient temperature for plant growth and survival, while the lower limits of plant distributions are probably due to competi- tion with species in the lower adjacent vegetation zone (Wood- ward, 1988; Ohsawa, 1990). In terms of the effects of climatic conditions on the growth of trees, recent studies suggested that limiting effects of low precipitation and/or high temperature on the growth of trees are more significant near the lower altitudinal limits, while the importance of low temperature increases near the upper altitudinal limits (Ettl and Peterson, 1995; Gostev et al., 1996; Buckley et al., 1997; Solomina et al., 1999; Peterson and Peterson, 2001; Takahashi et al., 2001). However, there are few reports from Japan concerning the altitudinal difference in the growth responses to climatic conditions. Increased knowl-

edge of responses to climatic conditions at both the upper and lower altitudinal limits is of great importance for understanding the effects of global warming on the altitudinal distribution shift of plant species, especially in Japan, where there are many high mountains.

In central Japan, dwarf pine scrub (Pinus pumila Regel) is distributed in the alpine zone above the timberlines formed mainly by a deciduous broad-leaved tree species (Betula ermanii Cham.) (Yoshino, 1978). The scrub height and shoot elongation of P. pumila decrease with increasing altitude or near wind- exposed ridges (Okitsu and Ito, 1983; Kajimoto, 1993), appar- ently as a result of unfavorable environments for the growth of

P. pumila. Sano et al. (1977) intensively studied the interannual fluctuation of shoot elongation of P. pumila in relation to cli- matic conditions and showed that shoot elongation was posi- tively correlated with summer temperatures of the previous year. Okitsu (1988) also reported that the interannual fluctuation of shoot elongation of P. pumila synchronized with one another within the same mountains, irrespective of altitude. Although there is concern about the distribution shift of P. pumila due to global warming (cf. Kajimoto et al., 1996), little information is available to demonstrate how shoot elongation of P. pumila re- sponds to climatic conditions at its upper and lower altitudinal limits. In addition, few attempts have been made to describe the stand structure throughout the altitudinal distribution range of P. pumila, including the ecotone between the upper P. pumila zone and the lower B. ermanii zone. Examination of forest structure at the ecotone is necessary for understanding the formation of the lower altitudinal limit of P. pumila in relation to the com- petition with B. ermanii.

Thus, the purpose of this study was (1) to describe altitu- dinal changes in stem height and stem density of P. pumila and B. ermanii from the P. pumila-B. ermanii ecotone to the upper altitudinal limit of P. pumila, and (2) to examine what climatic conditions affect the shoot elongation of P. pumila at its upper and lower altitudinal limits.

Materials and Methods STUDY SITE

This study was carried out on Mt. Shogigashira and Mt. Norikura in central Japan. The study site on Mt. Shogigashira

? 2003 Regents of the University of Colorado 1523-0430/03 $7.00

K. TAKAHASHI / 1

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was located on the north-facing slope near the summit (2699 m a.s.l., 35?48'N, 137?50'E) in the Nishikoma Experimental Forest of Shinshu University. P. pumila was dominant only near the summit. One deciduous broad-leaved tree species (B. ermanii) and three conifers (Abies mariesii Mast., A. veitchii Lindl., and

Tsuga diversifolia Mast.) were distributed from ca. 1400 to 2640 m a.s.l. in the subalpine zone, but the upper altitudinal limits of the three conifers were ca. 100 m below the upper altitudinal limit of B. ermanii. The mean monthly air temperature at Sen-

jojiki (2650 m a.s.l., ca. 3.5 km from the study area) ranged between -12.1?C (January) and 11.9?C (August), with the mean annual temperature at 0.8?C during 1990-1992 (Fukuyo et al., 1998). On the east-facing slope of Mt. Norikura (3026 m a.s.l., 36?06'N, 137?33'E), P. pumila was distributed from ca. 2500 m a.s.l. to near the summit. B. ermanii and four conifers (A. veit- chii, A. mariesii, T. diversifolia, and Picea jezoensis var. hon- doensis Rehder) were dominant between ca. 1600 and 2500 m a.s.l. in the subalpine zone, but B. ermanii dominated over the four conifers near the timberline on Mt. Norikura. The mean annual temperature at 2500 m a.s.l., the lower altitudinal limit of P. pumila, was estimated as -0.5?C from temperatures re- corded at Nagawa Weather Station (1068 m a.s.l., ca. 11 km from the study area) using the lapse rate of -0.6?C per each + 100 m altitude (cf. Hasegawa, 1970). The mean monthly tem-

peratures in the coldest month of January and the warmest month of August were estimated as -12.1 and 11.7?C, respectively.

FIELD METHODS

Interannual fluctuation of shoot elongation of P. pumila was examined at the lower and upper altitudinal limits on Mt. Sho-

gigashira (2640 and 2675 m a.s.l.) and Mt. Norikura (2500 and 2840 m a.s.l.) in September 2001. Although small saplings of P. pumila were distributed in the B. ermanii zone, the density of P. pumila was low. Therefore, the lower altitudinal limit of the P. pumila zone was defined as the upper altitudinal limit of the B. ermanii zone in this study (i.e., the lower altitudinal limit of P. pumila does not mean the position of the lowest individual P. pumila tree). Annual shoot elongation rate was measured from bud scars for at least 20 yr for each P. pumila tree. Forty and 30 trees of P. pumila were examined at the upper and lower altitudinal limits on Mt. Norikura, respectively; 35 and 30 trees were examined at the upper and lower altitudinal limits on Mt.

Shogigashira, respectively. Altitudinal changes in the stem height and stem density of

P. pumila and B. ermanii were investigated from the upper to lower altitudinal limits of P. pumila on Mt. Shogigashira, in-

cluding the P. pumila-B. ermanii ecotone. This survey was not conducted on Mt. Norikura because of the long distance between the upper and lower altitudinal limits of P. pumila. A 10 X 35 m plot (horizontal width X vertical length) was established at the P. pumila-B. ermanii ecotone on Mt. Shogigashira. The up- per and lower sides of this plot were located in the P. pumila zone and the B. ermanii zone, respectively, because this ecotone was a narrow transitional zone (Fig. 1). There were no canopy gaps in this plot. An additional 13 quadrats (1 X 2 m, 1 X 3 m, or 1 x 5 m) were established at 5-m intervals between the upper side of the plot and the upper altitudinal limit of P. pumila. The inclination of the slope was also measured at 5-m intervals from the lower side of the plot to the upper altitudinal limit of P. pumila. The vertical stem height and stem diameter at 30-cm distance from the stem base were measured for all trees within the plot and additional 13 quadrats. Annual shoot elongation of P. pumila was measured.

DATA ANALYSIS

The 10 x 35 m plot was divided into seven 10 X 5 m quadrats. Mean stem height, stem density, and mean shoot elon-

gation rate of P. pumila were calculated for each 10 x 5 m

quadrat to reveal the altitudinal forest-structural changes. How- ever, this quadrat size of 10 x 5 m was not large enough for B. ermanii because of the low density (a few trees per this quadrat size). Thus, the stem density of B. ermanii was calculated for each 10 x 10 m quadrat, instead of the 10 x 5 m quadrat. Although the size of the uppermost quadrat was 10 x 5 m, there were no trees of B. ermanii in this quadrat because this quadrat was located in the P. pumila zone. Most of B. ermanii reached to canopy layer and its saplings were rare in this ecotone (i.e., the variation in stem height was rather small). Therefore, the mean stem height of B. ermanii was calculated for each 10 x 5 m quadrat.

The shoot length chronology of P. pumila at each site (i.e., the upper or lower altitudinal limit on Mt. Norikura or Mt. Sho-

gigashira) was calculated by averaging the shoot length among the examined P. pumila trees in each year, according to Sano et al. (1977). The shoot length chronology at each site was deter- mined from 1975 to 2001 (n = 27). A simple correlation test was used to show what climatic conditions affect shoot elon-

gation of P. pumila at each of the upper and lower altitudinal limits on each mountain. The nearest weather stations to Mt. Norikura and Mt. Shogigashira were Nagawa (36?05'N, 137?41'E, 1068 m a.s.l., ca. 11 km from the study area) and Ina (35?48'N, 137?59'E, 674 m a.s.l., ca. 13 km from the study area), respectively. However, the available meteorological data at Na-

gawa and Ina began in 1979 and 1993, respectively (i.e., the

recording periods at the two weather stations were shorter than the shoot length chronology of P. pumila). A long-term record was available at Matsumoto Weather Station (36?15'N, 137?58'E, 610 m a.s.l., ca. 35 to 50 km from the two study sites). Therefore, I used the monthly mean temperature and monthly sum of precipitation recorded at Matsumoto for the correlation test in this study. The shoot elongation of P. pumila at each site was compared with the meteorological data from the beginning of the previous growth period to the end of the current growth period. The growing season of P. pumila at each site on the two mountains was determined as June to September because the mean monthly temperature exceeded 5?C, an effective heat for

plant growth (Kira, 1948), during this period.

Results

Saplings of the two conifers (Abies veitchii and A. mariesii) were found in the P. pumila-B. ermanii ecotone on Mt. Shogi-

gashira, but their abundance was negligible. B. ermanii and P.

pumila were distributed exclusively from each other (Figs. 1, 2a). The stem height of B. ermanii gradually decreased with

increasing altitude, and its density was markedly lower at 35 m from the lower side of the plot (ca. 2645 m a.s.l.) (Figs. 2a, 2b). More than half of B. ermanii showed the multistemmed form with apparent scars of past breakage on the main trunk, probably because of snow pressure. P. pumila dominated over B. ermanii above the distance 35 m (Fig. 2a). The stem height of P. pumila was highest between 35 and 55 m (i.e., above the upper altitu- dinal limit of B. ermanii) and gradually decreased with increas-

ing altitude (Fig. 2b). The stem height of P. pumila increased again at about the distance 90 m because this site was relatively leeward compared with the site between the distances 70 and 90

2 / ARCTIC, ANTARCTIC, AND ALPINE RESEARCH

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FIGURE 1. The Pinus pumi- la-Betula ermanii ecotone on Mt. Shogigashira in central Ja-

pan on 5 October 2002. Pinus

pumila (dark gray) and Betula ermanii (light gray) dominate the upper and lower parts of the

slope, respectively. The leaves

of B. ermanii have turned com- pletely yellow.

m. The altitudinal change in the shoot elongation of P. pumila corresponded well to that in stem height (Fig. 2c).

The annual shoot elongation of P. pumila fluctuated at both the upper and lower altitudinal limits on Mt. Norikura and Mt.

Shogigashira (Fig. 3). Although the shoot elongation was always higher at the lower altitudinal limits than at the upper altitudinal limits on the two mountains, the interannual fluctuation in the shoot elongation showed a similar trend between the upper and lower altitudinal limits on each mountain (r = 0.591, P = 0.001 for Mt. Norikura, and r = 0.666, P < 0.001 for Mt. Shogiga- shira).

The monthly mean temperatures (July to September or July to October) of the previous year were positively correlated with the shoot elongation rates at both the upper and lower altitudinal limits on the two mountains (Fig. 4). The January and March

temperatures of the current year were also positively correlated with the shoot elongation rates of P. pumila at the upper and lower altitudinal limits, respectively, on Mt. Norikura (Fig. 4). In addition, the shoot elongation rates were negatively correlated with precipitation (monthly sum) in summer of the previous year (July or August, or both), except for the upper altitudinal limit on Mt. Norikura (Fig. 4).

To compare shoot elongation rates of P. pumila in response to air temperature between the upper and lower altitudinal limits, mean temperature between July and September was used as an

independent variable because the shoot elongation rates were

positively correlated with monthly mean temperatures during this period at each site. The shoot elongation rate of P. pumila at its lower altitudinal limit was higher than that at its upper altitudinal limit at any mean temperature between July and Sep- tember (F 5,, = 123.4, P < 0.001 for Mt. Norikura, and F, , =

84.3, P < 0.001 for Mt. Shogigashira). Furthermore, the slopes of the regressions were not different between the upper and low- er altitudinal limits of P. pumila on each mountain (P > 0.05, Fig. 5). This indicates that the rates of increase in shoot elon-

gation of P. pumila in response to the increase of summer tem-

peratures were not different between its upper and lower altitu- dinal limits on the two mountains.

Discussion

The stem height and the shoot elongation of P. pumila de- creased with increasing altitude, and long shoot length of P.

pumila was associated with high summer temperatures of the

previous year, irrespective of the upper or lower altitudinal limit. Shorter shoot length at the upper altitudinal limit than at the lower altitudinal limit was probably attributable to its wind-ex-

posed environments near the summit because the altitudinal dif- ference between the upper and lower altitudinal limits of P. pum- ila on Mt. Shogigashira was only 35 m. It is known that shoot

growth of alpine plants is reduced by wind (Kajimoto, 1993; Fukuyo et al., 1998), probably due to the decrease of leaf tem-

perature by wind (Jones, 1992). Wind also possibly affects plant growth by winter desiccation at timberlines (Hadley and Smith, 1983, 1986; Wardle, 1968, 1985). However, the needles of P.

pumila are hardly damaged by winter desiccation (Maruta et al., 1996), because P. pumila is completely covered with snow in winter (Okitsu and Ito, 1983) and because P. pumila has a high freezing tolerance up to -70?C (Sakai and Kurahashi, 1975). Thus, winter desiccation does not strongly affect the shoot

growth of P. pumila even in wind-exposed environments. Al-

though Sano et al. (1977) showed that summer temperatures reg- ulated shoot elongation of P. pumila, the present study revealed that this relationship is applicable to the whole of its altitudinal distribution range.

The growth responses of several tree species to climatic conditions have been examined in the subalpine zone on Mt. Norikura. Fujiwara et al. (1999) found a positive correlation be- tween August temperature and the tree-ring width in Abies mar- iesii, but not in Picea jezoensis var. hondoensis at 2000-2200 m a.s.l. (the upper zone of their distribution). In contrast, Takahashi et al. (unpublished data) showed negative correlations between the August temperature and the tree-ring widths of A. veitchii and B. ermanii at 1600 m a.s.l. (the lower limit of their distri- bution), while positive correlations of August precipitation were found in the two species. It seems that importance of summer

temperatures to the tree growth decreases with decreasing alti- tude at least on the scale between 1600 and 2840 m a.s.l. on Mt.

K. TAKAHASHI / 3

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FIGURE 2. (a) Stem density and (b) mean stem height of Bet- ula ermanii (circle) and Pinus pumila (dot), and (c) mean annual shoot elongation rate of Pinus pumila from its lower to upper altitudinal limits on Mt. Shogigashira in central Japan. The dis- tances 0, 50, and 100 m from the lower side of the plot corre-

spond to 2627, 2653, and 2675 m a.s.l., respectively. Note that ordinate scales in the top figure are different between Betula ermanii and Pinus pumila.

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Norikura. Therefore, the similar responses in the shoot elonga- tion to climatic conditions between P. pumila growing at its upper and lower altitudinal limits are ascribed to its narrow al- titudinal distribution range in the alpine zone.

The abundance of P. pumila was markedly decreased at the P. pumila-B. ermanii ecotone on Mt. Shogigashira, although the stem height and shoot elongation of P. pumila were highest at its lower altitudinal limit. In addition, no negative correlations between summer temperatures and the shoot elongation of P. pumila were detected even at its lower altitudinal limits. These suggest that P. pumila physiologically can grow at lower altitude than the current lower altitudinal limit, but tall B. ermanii sup- presses the growth and invasion of P. pumila at lower altitude. Therefore, the lower altitudinal limit of P. pumila seems to be determined by the competition with B. ermanii. Although in- crease of summer temperatures enhances the growth of P. pumila throughout much of its altitudinal distribution, the growth of B. ermanii at its upper altitudinal limit also may be enhanced by the increase of the summer temperatures. The increase of crown area of the present B. ermanii trees may suppress the growth of more trees of P. pumila in the P. pumila-B. ermanii ecotone, which in turn brings about the upward distribution shift of P. pumila to some extent.

However, the possible effects of future global warming on the altitudinal distribution of P. pumila are harder to predict; i.e., the upward shift of P. pumila scrub due to competition with B. ermanii is uncertain for the following two reasons. Firstt Betula ermanii is a typical light-demanding species with very small seeds and cannot establish unless mineral soil is exposed in sun- lit conditions such as canopy gaps (Seiwa and Kikuzawa, 1996). Pinus pumila densely covers the forest floor and regenerates by vegetative growth such as layering (Kajimoto, 1992). The re-

petitive vegetative growth allows long-term persistence of P. pumila, which prevents the seedling establishment of B. ermanii. Kajimoto et al. (1996) also pointed out the importance of habitat competition between P. pumila and other subalpine conifers on the distribution shift of P. pumila. Second, Okitsu and Ito (1989) suggested that the altitudinal distribution range of P. pumila is associated with strong wind, heavy snow accumulation, and rocky substrate rather than with air temperature because the P. pumila zone is formed near mountain summits, irrespective of the height of the mountains (ranging between ca. 1050 and 2150 m a.s.l. in northern Japan). This indicates that the altitudinal position of the P. pumila-B. ermanii ecotone is not determined by air temperature alone. Therefore, the effects of global warm- ing on the distribution shift of P. pumila will be complex.

6

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FIGURE 3. Fluctuation of an- nual shoot elongation of Pinus pumila at the upper (solid line) and lower altitudinal limits (dot-

' ' ' ' ' ' ed line) on Mt. Norikura (left) 1995 2000 and Mt. Shogigashira (right),

central Japan.

4 / ARCTIC, ANTARCTIC, AND ALPINE RESEARCH

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Month FIGURE 4. Correlation coefficients between the annual shoot elongation of Pinus pumila and the monthly climatic conditions (monthly sum of precipitation and monthly mean temperature) at the upper and lower altitudinal limits on Mt. Norikura (2840 and 2500 m a.s.l.) and Mt. Shogigashira (2675 and 2640 m a.s.l.), central Japan. Shaded bars indicate significant correlation (P < 0.05 by Pearson correlation test).

K. TAKAHASHI / 5

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FIGURE 5. Relationship be-

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This study concluded that the increase of the summer tem-

peratures enhances the growth of P. pumila throughout its alti- tudinal distribution range, and the formation of the lower alti- tudinal limit of P. pumila largely depends on competition with B. ermanii, which forms the lower adjacent vegetation zone. Therefore, long-term monitoring of the population dynamics at the P. pumila-B. ermanii ecotone is necessary to predict the distribution shift of P. pumila scrub due to environmental

change.

Acknowledgments This study was partially supported by a grant from the Min-

istry of Education, Science, Sports, and Culture of Japan (No. 13780418).

References Cited

Buckley, B. M., Cook, E. R., Peterson, M. J., and Barbetti, M., 1997: A changing temperature response with elevation for La- garostrobos franklinii in Tasmania, Australia. Climatic

Change, 36: 477-498. Ettl, G. J., and Peterson, D. L., 1995: Growth response of sub-

alpine fir (Abies lasiocarpa) to climate in the Olympic Moun- tains, Washington, USA. Global Change Biology, 1: 213-230.

Fujiwara, T, Okada, N., and Yamashita, K., 1999: Comparison of growth response of Abies and Betula species to climate in Mt. Norikura, central Japan. Journal of Wood Science, 45: 92- 97.

Fukuyo, S., Kurihara, M., Nakashinden, I., Kimura, K., Iijima, Y., Kobayashi, Y., Masuzawa, T, Yamamoto, S., Morimoto, M., Kouyama, T, Kobayashi, S., Yamamoto, T, Mizuno, K., and Machida, H., 1998: Short-term effects of wind shield on phenology and growth of alpine plants in Mount Kiso-Ko- magatake, central Japan. Proceedings of the NIPR symposium on Polar Biology, 11: 147-158.

Gostev, M., Wiles, G., D'Arrigo, R., Jacoby, G., and Khomen- tovsky, P., 1996: Early summer temperatures since 1670 A.D. for Central Kamchatka reconstructed based on a Siberian larch tree-ring width chronology. Canadian Journal of Forest Re- search, 26: 2048-2052.

Hadley, J. L., and Smith, W. K., 1983: Influence of wind ex- posure on needle desiccation and mortality for timberline co- nifers in Wyoming, U.S.A. Arctic and Alpine Research, 15: 127-135.

Hadley, J. L., and Smith, W. K., 1986: Wind effects on needles

tween the mean temperature be-

Shogigashira tween July and September at Matsumoto and the annual shoot

0 elongation rate of Pinus pumila O at the upper (dots) and lower al-

0 -. titudinal limits (circles) on Mt. o0 Norikura (left) and Mt. Shogi-

CG~D39O D ~ ~ gashira (right), central Japan. Correlation coefficients of re-

)r u ) , ^6 gressions for the upper and low-

0 ^ fO ? O er altitudinal limits were r = 0 0.626 and r = 0.663, respective-

ly, on Mt. Norikura, and those

for the upper and lower altitu- dinal limits were r = 0.665 and

l I~ , l l l l lr = 0.611, respectively, on Mt.

Shogigashira. All regressions were statistically significant (P <

ember at Matsumoto (?C) 0.001).

of timberline conifers: seasonal influence on mortality. Ecol- ogy, 67: 12-19.

Hasegawa, C., 1970: On the lapse-rate of the air temperature in Japan. Earth Science, 24: 35-39. (In Japanese.)

Jones, H. G., 1992: Plants and Microclimate. 2nd ed. Cam-

bridge: Cambridge University Press. 428 pp. Kajimoto, T, 1992: Dynamics and dry matter production of be-

lowgrand woody organs of Pinus pumila trees growing on the Kiso mountain range in central Japan. Ecological Research, 7: 333-339.

Kajimoto, T, 1993: Shoot dynamics of Pinus pumila in relation to altitudinal and wind exposure gradients on the Kiso moun- tain range, central Japan. Tree Physiology, 13: 41-53.

Kajimoto, T, Kurachi, N., Chiba, Y., Utsugi, H., and Ishizuka, M., 1996: Effects of external factors on growth and structure of Pinus pumila scrub in Mt. Kinpu, central Japan. In Omasa, K., Kai, K., Taoda, H., Uchijima, Z., and Yoshino, M. (eds.), Climate Change and Plants in East Asia. Tokyo: Springer, 149-156.

Kira, T, 1948: On the altitudinal arrangement of climatic zones in Japan. Kanti-Nogaku, 2: 143-173. (In Japanese.)

Maruta, E., Nakano, T., Ishida, A., Iida, H., and Masuzawa, T, 1996: Water relations of Pinus pumila in the snow melting season at the alpine region of Mt. Tateyama. Proceedings of the NIPR symposium on Polar Biology, 9: 335-342.

Ohsawa, M., 1990: An interpretation of latitudinal patterns of forest limits in south and east Asian mountains. Journal of Ecology, 78: 326-339.

Okitsu, S., 1988: Geographical variations of annual fluctuations in stem elongation of Pinus pumila Regel on high mountains of Japan. Japanese Journal of Ecology, 38: 177-183. (In Jap- anese with English summary.)

Okitsu, S., and Ito, K., 1983: Dynamic ecology of the Pinus pumila community of Mt. Taisetsu, Hokkaido, Japan. Envi- ronmental Science, Hokkaido University, 6: 151-184. (In Jap- anese with English summary.)

Okitsu, S., and Ito, K., 1989: Conditions for the development of the Pinus pumila zone of Hokkaido, northern Japan. Vegetatio, 84: 127-132.

Peterson, D. W., and Peterson, D. L., 2001: Mountain hemlock growth responds to climatic variability at annual and decadal time scales. Ecology, 82: 3330-3345.

Sakai, A., and Kurahashi, A., 1975: Freezing resistance of co- nifers in Japan with special reference to their distributions. Japanese Journal of Ecology, 25: 192-200. (In Japanese with

English summary.) Sano, Y., Matano, T, and Ujihara, A., 1977: Growth of Pinus

6 / ARCTIC, ANTARCTIC, AND ALPINE RESEARCH

This content downloaded from 185.44.78.113 on Thu, 12 Jun 2014 15:28:18 PMAll use subject to JSTOR Terms and Conditions

pumila and climate fluctuation in Japan. Nature, 266: 159- 161.

Seiwa, K., and Kikuzawa, K., 1996: Importance of seed size for the establishment of seedlings of five deciduous broad-leaved tree species. Vegetatio, 123: 51-64.

Solomina, O. N., Muravyev, Y. D., Braeuning, A., and Krav- chenko, G. N., 1999: Two new ring width chronologies of larch and birch from the Kamchatka Peninsula (Russia) and their relationship to climate and volcanic activities. In Naruse, R. (ed.), Cryospheric Studies in Kamchatka II. Sapporo: In- stitute of Low Temperature Science, Hokkaido University, 111-124.

Takahashi, K., Homma, K., Shiraiwa, T, Vetrova, V. P., and Hara, T., 2001: Climatic factors affecting the growth of Larix cajanderi in the Kamchatka Peninsula, Russia. Eurasian Jour- nal of Forest Research, 3: 1-9.

Wardle, P., 1968: Engelmann spruce (Picea engelmannii Engel.) at its upper limits on the Front Range, Colorado. Ecology, 49: 483-495.

Wardle, P., 1985: New Zealand timberlines. 1. Growth and sur- vival of native and introduced tree species in the Craigiebur Range, Canterbury. New Zealand Journal of Botany, 23: 219- 234.

Woodward, F I., 1988: Temperature and the distribution of plant species. In Long, S. P., and Woodward, F I. (eds.), Plants and Temperature. Cambridge: Society for Experimental Biology Symposia, 59-75.

Yoshino, M. M., 1978: Altitudinal vegetation belts of Japan with special reference to climatic conditions. Arctic and Alpine Re- search, 10: 449-456.

Ms submitted March 2002

K. TAKAHASHI / 7

This content downloaded from 185.44.78.113 on Thu, 12 Jun 2014 15:28:18 PMAll use subject to JSTOR Terms and Conditions