Title

Allometric and growth data of an evergreen oak, Quercus glauca, in a secondary broadleaved forest

Authors

Hiroki Itô ^1,* and Akihiro Sumida ²

• ¹ Hokkaido Research Center, Forestry and Forest Products Research Institute
• ² Institute of Low Temperature Science, Hokkaido University

^* Corresponding author: Hiroki Itô
Hokkaido Research Center, Forestry and Forest Products Research Institute
Toyohira, Sapporo 062-8516, Japan
E-mail: abies.firma@gmail.com
Tel: +81-11-590-5523
Fax: +81-11-851-4167

Abstract

The evergreen oak Quercus glauca often dominates secondary broadleaved forests in Western Japan. It is regarded as a mid-successional species, whose diameter and height growth fall between those of early- and late-successional species. Despite the ecological importance of this evergreen oak in the secondary succession of the evergreen broadleaved forest zone in Japan, tree-felling data that allow estimations of tree mass and leaf area from non-destructive measurements are lacking. This paper provides stem growth data, read from tree rings on disks sampled from 13 Q. glauca stems, and their allometric data. The samples were collected in 1994 from the Ginkakuji-san National Forest, Kyoto City, Japan. Allometric data comprised data on stem age, diameter at breast height, diameter at 10 % height, tree height, height of the lowest living branch, height of the lowest living leaf in the crown, volume of the main stem, squared stem diameter just below the lowest living branch, total leaf area of the stem, dry weight of the total leaves, dry weight of all branches, dry weight of the main stem, total aboveground dry weight, mean relative photosynthetic photon flux density (PPFD) above the crown, mean relative PPFD below the crown, crown projection area, and specific leaf area. These data can be helpful for estimating the biomass and leaf area index of a Q. glauca stand by enabling the derivation of allometric relationships between non-destructive measurements (such as stem diameter at breast height, and tree height) and tree mass or leaf area. Diameters (including bark thickness) at ground height and above (at 0.5- or 1-m intervals) for each stem are also provided. Stem growth data were based on tree-ring reads from disks taken from heights of 0.0 m and 0.3 m, and at 0.5-m (stem height < 7 m) or 1.0-m (stem height ≥ 7 m) intervals above that. Stem volume growth derived from these tree-ring data can be converted into stem mass growth if combined with an analysis of the allometric data, which may serve as a useful resource for the estimation of carbon fixation by evergreen oaks in relation to global climate change.

Keywords

• allometry
• diameter growth
• evergreen oak
• height growth
• leaf area
• leaf weight
• light conditions above the crown
• pipe model
• stem analysis
• tree ring

Introduction

The evergreen oak Quercus glauca Thunb. is distributed from Central Japan to the Himalayas, and it often dominates secondary broadleaved forests in Western Japan (Itô 2007a). Itô (2007b) showed that the basal area of Q. glauca in a stand in the Ginkakuji-san National Forest (Kyoto City) increased from 4.42 m²/ha in 1993 to 6.41 m²/ha in 2005, with annual increments of 3.1 %.

Early-successional tree species tend to grow vertically by allocating materials for height growth, whereas late-successional tree species tend to grow laterally by allocating materials for crown growth (Hara et al. 1991). Quercus glauca is regarded as a mid-successional tree species or an early-successional evergreen broadleaved tree species (Itô 2007a), with an intermediate trait in the height–diameter relationship. Sumida et al. (1997) demonstrated that it grows vertically in its seedling stage and then gradually allocates materials for lateral growth, especially in suppressed trees, whereas diameter growth is relatively unchanged. Itô et al. (1997) demonstrated that the crown expands laterally as the stem size increases, and the crown expansion increases the total leaf area (Itô et al. 1997). However, allocation for height growth resumes when light conditions improve (Sumida et al. 1997).

Despite the importance of Q. glauca as an evergreen oak in secondary succession in the evergreen broadleaved forest zone in Japan, quantitative open data that allow the estimation of tree mass and leaf area from non-destructive measurements are scarce. Matsubara and Hiroki (1989) reported allometric relationships of Q. glauca, but they were for 1- to 4-year old seedlings. The present data paper provides allometric and stem growth data from 13 Q. glauca stems growing in an uneven stand, which were also used by Sumida et al. (1997) and Itô et al. (1997). To the best of our knowledge, open data including adult Q. glauca trees, as in the present study, are not available elsewhere. The allometric data comprised stem age, diameter at breast height (excluding and including bark thickness), diameter at 10 % height (including bark thickness), height of the stem, height of the lowest living branch, height of the lowest living leaf in the crown, volume of the main stem (including bark thickness), squared stem diameter just below the lowest living branch, total leaf area, total leaf dry weight, dry weight of all branches, dry weight of the main stem, total aboveground dry weight, mean relative photosynthetic photon flux density (PPFD) above the crown, mean relative PPFD below the crown, crown projection area, and specific leaf area. In particular, the squared stem diameter just below the lowest living branch, leaf area, and leaf weight can be used to derive an allometric relationship of the pipe model theory (Shinozaki et al. 1964a, b), which is known to be insensitive to differences in stand age (Kira and Shidei 1967, Sumida et al. 2009).

Diameters (including bark thickness) at ground height and above (at 0.5- or 1-m intervals) were also provided for each stem. Growth data comprised annual tree-ring widths read from tree rings obtained from disks taken at ground height and above (at 0.5- or 1-m intervals). Stem volume growth, derived from these tree-ring data, can be converted into stem mass growth if an allometric relationship between stem volume and stem mass is prepared. The data in the present paper will also be useful for estimating carbon fixation by evergreen oak in studies of global climate change.

Metadata

Contributors

1. Data set owner

Forestry and Forest Products Research Institute
Address: Matsunosato 1, Tsukuba 305-8687, Japan

2. Contact person

Hiroki Itô
E-mail: abies.firma@gmail.com
Affiliation: Hokkaido Research Center, Forestry and Forest Products Research Institute
Address: Toyohira, Sapporo 062-8516, Japan

Akihiro Sumida
E-mail: asumida@lowtem.hokudai.ac.jp
Affiliation: Institute of Low Temperature Science, Hokkaido University
Address: Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan

3. Principal investigators

Hiroki Itô and Akihiro Sumida

Methods

1. Location

The sample stems were collected from a secondary broadleaved stand in the Ginkakuji-san National Forest (35.0283° N, 135.8014° E), which is located east of Kyoto, Japan. The mean temperature and mean annual precipitation from 1981 to 2010 at the Kyoto Local Meteorological Office, approximately 6 km west of the stand, were 15.9 ℃ and 1,491.3 mm, respectively (http://www.data.jma.go.jp/obd/stats/etrn/view/nml_sfc_ym.php?prec_no=61&block_no=47759&view=p1, accessed on July 4, 2016). The elevation of the stand was approximately 140–195 m above sea level, and the surface geology was granite.

In the 1880s, the forest was covered with the small Japanese red pine Pinus densiflora Siebold et Zucc. (Ogura 2002), although it changed to a mixed forest of pines and broadleaved species, such as the oak Quercus serrata Murray and the longstalk holly Ilex pedunculosa Miq., by the 1930s (Osaka Regional Forest Office 1936). In 1993, the stand was dominated by broadleaved trees such as Symplocos prunifolia Siebold et Zucc., Gamblea innovans (Siebold et Zucc.) C.B.Shang, Lowry et Frodin, Ilex macropoda Miq., Q. glauca, and Q. serrata (Itô 2007b).

2. Data collection

A. Allometric data

In November 1994, 13 Q. glauca stems in the stand were selected from representative height classes and felled.

Prior to felling, the height of the lowest living leaf in the crown and crown width (in two orthogonal directions) of each stem were measured using a height pole to the nearest 1 cm. The crown projection areas were calculated by an ellipse approximation using the crown widths, which were measured in two perpendicular directions under the crown using a measuring tape. Mean relative photosynthetic photon flux densities (PPFDs) above and below the crown were measured using two quantum censors (LI-190SA, LI-COR, Inc., Lincoln, NE, USA) and a data logger (LI-1000, LI-COR, Inc.). Details of the PPFD measurements are available in Sumida et al. (1997).

After felling, tree height (the length measured along the main stem) and height of the lowest living branch were measured using a measuring tape to the nearest 1 cm. Girths (including bark thickness) at 10 % of the stem height, at the height of the lowest living branch, at heights of 0.0 m and 0.3 m, and then at 0.5-m (stem height < 7 m) or 1.0-m (stem height ≥ 7 m) intervals above that were measured using a measuring tape to the nearest 1 mm, and the corresponding diameters were calculated by dividing by pi; diameters at breast height (1.3 m) were also measured. In cases where girth could not be measure because the stem was too small, the diameter was measured directly in one direction using a caliper to the nearest 1 mm. The main stem volume (including bark thickness) at the time of felling was estimated using a truncated cone approximation using the diameters measured at each height as mentioned above. After measuring the fresh weights of each stem segment (see below), disks were taken from heights of 0.0 m and 0.3 m, and at 0.5-m (stem height < 7 m) or 1.0-m (stem height ≥ 7 m) intervals above that. They were used for stem growth data, as described below. Stem age was estimated from the number of tree rings in the 0.0-m height disk.

All branches were cut off from the main stem, and all leaves were clipped from each tree. The fresh weights of total leaves, total branches, and stem segments were measured for each tree. Then, all leaves and all branches were mixed well, and a portion of each mixture was sampled for conversion to dry weights. The fresh weights were measured in the field, and then they were taken to the laboratory. Stem discs for fresh-to-dry weight conversion were also sampled in the same way as the disks used for the tree-ring analyses, as stated above. The samples were oven dried at > 90℃ to constant weights, and the dry weight was measured to obtain the dry-to-fresh weight ratio. The dry weights of leaves, branches, and stems were estimated using the dry-to-fresh weight ratios. Another portion of the fresh leaves was also sampled for leaf weight to leaf area conversion. The total leaf area was measured using an area meter (AAM-7, Hayashi Denko, Inc., Tokyo, Japan), and the dry weights were measured as described above, which allowed us to calculate the leaf area to leaf dry weight ratio (specific leaf area, SLA). The total leaf area of each tree was estimated using this ratio. Although the variation of the SLA within a crown could not be estimated using our data, the average SLA of a tree may reflect the mean relative PPFD levels above each crown to some extent (see Allometric_data.csv). Total aboveground dry weight was calculated as the sum of the dry weights of leaves, branches, and stems.

At least three significant digits were obtained when measuring weights, as there was a large variation in total stem weights among the trees, as well as in the amounts of the portions weighed.

B. Stem growth data

Disks taken from various heights were desiccated naturally, and stem analyses were conducted for each disk. Tree-ring widths were measured using a tree-ring reader (Type 1805, Auto Process, Inc., Tokyo, Japan) in four directions from the center of the rings; two on the longest width of the disk and the others on the line that intersected with the longest width at right angles. In cases where some directions were lacking because of cracks or other reasons, widths were measured in the other directions. The diameter in a given year and at a given height of a cross section was calculated as the doubled mean of the measurements. Disk measurements are shown in the data file. The mean diameter values calculated from the ring widths differed slightly from those calculated from the girths in the fresh state, as described above, because of the absence of bark and the use of different methods.

3. Content of data file

Accessibility

License

This dataset is provided under a Creative Commons Attribution 4.0 International license (CC-BY 4.0) (https://creativecommons.org/licenses/by/4.0/legalcode).

Acknowledgements

We thank Dr. K. Kamo, Dr. Y. Isagi, and Ms. A. Tosa for conducting the fieldwork, and Dr. Kunihiro Tanaka and Dr. Rempei Suwa for providing information. We also thank the Kyoto District National Forest Office (presently the Kyoto-Osaka District National Forest Office) for supporting the study. This study was partially supported by the Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (KAKENHI) program (grant no. JP26450215) and a Forestry and Forest Products Research Institute research grant (no. 201504).

Conflict of interest

The authors have no conflict of interest to declare.

References

Hara M, Kimura M, Kikuzawa K (1991). Growth patterns of tree height and stem diameter in populations of Abies veitchii, A. mariesii and Betula ermanii. J Ecol, 79:1085–1098

Itô H (2007a) Quercus glauca. in “Silvics of Japan Volume 1” (Japan botanical history editing committee ed.) (in Japanese)

Itô H (2007b) Twelve-years change of a broad-leaved secondary forest in Ginkakuji-san National Forest. Bull FFPRI 6: 93–100 (in Japanese with English summary)

Itô H, Sumida A, Isagi Y, Kamo K (1997) The crown shape of an evergreen oak, Quercus glauca, in a hardwood community. J For Res 2:85–88

Kira T, Shidei T (1967) Primary production and turnover of organic matter in different forest ecosystems of the Western Pacific. Jpn J Ecol 17: 70–87

Matsubara T, Hiroki S (1989) Ecological studies on the plants of Fagaceae V. Growth in the Sapling stage and minimal new shoots of the evergreen Quercus galuca Thunb. Ecol Res 4: 175–186.

Ogura J (2002) Satotyama vegetation landscape in the southern part of the Kyoto Prefecture in the Meiji Era. in “Red data book of the Kyoto Prefecture Volume 2” (Kyoto Prefecture ed.), 159–177 (in Japanese)

Osaka Regional Forest Office (1936) Landscape planning of the Higashiyama National Forest. Osaka Regional Forest Office, 154pp. (in Japanese)

Shinozaki K, Yoda K, Hozumi K, Kira T (1964a) A quantitative analysis of plant form–the pipe model theory I. Basic analysis. Jpn J Ecol 14: 97–105

Shinozaki K, Yoda K, Hozumi K, Kira T (1964b) A quantitative analysis of plant form–the pipe model theory II. Further evidence of the theory and its application in forest ecology. Jpn J Ecol 14: 133–139

Sumida A, Ito H, Isagi Y (1997) Trade-off between height growth and stem diameter growth for an evergreen oak, Quercus glauca, in a mixed hardwood forest. Func Ecol 11:300–309

Sumida A, Nakai T, Yamada M, Ono K, Uemura S, Hara T (2009) Ground-based estimation of leaf area index and vertical distribution of leaf area density in a Betula ermanii forest. Silva Fenn 43: 799–816