Larix Kaempferi Research Articles

The Three-year Effect of Thinning Intensity on Biomass in Larix kaempferi and Pinus koraiensis Plantation

The Three-year Effect of Thinning Intensity on Biomass in Larix kaempferi and Pinus koraiensis Plantation

Peculiarities of cambial growth of some woody plants introduced in Kakheti region

The paper deals with the study of cambial growth of 32 species of woody plants, carried out in Kakheti region during six years. We have studied several plants and found out that they begin their cambial growth (with the exception of some oak species) after bud opening. According to calendar time, two groups of plants were distinguished: the first group of the plants began cambial growth in late March and at the beginning of April. These plants are as follows: Larix decidua Mill and Larix leptolepis Gord., Acer negundo L., Aesculus carnea Haine., Aesculus hippocastanum L. and 20 other species. The second group of the plants began cambium activity in May. These are plant species like Picea orientalis (L.) Link., Pinus griffithii Mc Cleland, Quercus occidentalis J. Gay., Magnolia grandiflora L. and others. The earliest completion of cambial growth was observed in the lateral branches of spruce, fir and other trees. The latest accomplishment (the first half of October) of cambial growth occurred in case of Cedrus atlantica Mannetti. and Cedrus deodara Loud., Pinus griffithii Mc Clel., Magnolia grandiflora L., Firmiana platanifolia Schott., etc. The endogenous rhythm of the investigated plants (with few exceptions) is in synchronous connection with the climate of Kakheti region, so we consider these plants to be interesting species for the decorative gardening and forestry of Telavi district, and deserve widespread distribution.

Calibration for transpiration estimates of Japanese Larch (Larix kaempferi)

Calibration for transpiration estimates of Japanese Larch (Larix kaempferi)

Influence of layer arrangement on bonding and bending performances of cross-laminated timber using two different species

Cross-laminated timber (CLT) is a wood panel product that can be arranged in different ways. The advantage of utilizing CLT is the ability to use lamination even with low density materials or those that have defects, like knots. This study evaluated the bonding and bending performances of CLT utilizing domestic species in a shear wall or floor via a face bonding test of layers and a three-point bending test. The tests were carried out with three-layered CLT made up of Japanese larch and/or Korean red pine in various configurations. The layer arrangement for lamination was divided according to the species and grade of the wood. The out-of-plane and in-plane bending tests were conducted on the CLT according to the applicable direction in a wooden structure. The results of the bonding test showed that the block shear strength and delamination of all types of CLT met the BS EN 16351 (2015) standard requirements. The results of the bending test based on two wood species showed that the bending strength of the larch CLT was higher than that of the pine CLT in single species combinations. For mixed species combinations, the bending properties of CLT using larch as the major layer was higher than those using pine as the major layer. This demonstrated that the major layer had more influence on the bending properties of CLT and that Korean red pine was more suited for the minor layer of CLT.

Mixing litter from Larix kaempferi (lamb.) Carr. and broad-leaved trees enhances decomposition by different mechanisms in temperate and subtropical alpine regions of China

Larix kaempferi planting with broad-leaved trees can increase production and alleviate soil degradation; however, the mechanism is unclear, especially on large scales and in different climate regions. This paper attempts to explain the underlying mechanism in a temperate region and northern subtropical alpine region of China. Litter decomposition rates, nutrient release, enzyme activity and microbial community composition were determined in conifer litter, broad-leaved litter and mixed litter by the litterbag method during about 500 days in the two regions. Decomposition rate was increased by 4.00% in temperate region and 3.38% in the subtropical region after litter mixing and the synergistic effect increased with decomposition progress. However, nutrients release was not always enhanced, and enzyme activities were enhanced at the most of decomposition time and higher in the subtropical region. After litter mixing, a few new dominant taxa emerged, and the microbial gene quantities were increased in the temperate region, but not in the subtropical region. The dominant bacterial taxa were similar, while most of the dominant fungal taxa shifted with decomposition. In addition, the dominant fungi completely differed between the two regions. The environmental variables with greater influence on microbial community were similar in the two regions, including C:N, C:P and pH. After mixing with broad-leaved litter, the decomposition of Larix kaempferi was enhanced by increasing enzyme activities and microbial quantities in the temperate region, but the mechanisms were not clear in the subtropical region.

Arable land windbreak forests to reduce the impacts of fallen branches and branchlets from larch

In the Tokachi plain of eastern Hokkaido, Japanese larch, Larix kaempferi, is often planted in arable land windbreaks to prevent wind damage to sugar beets,potatoes, and beans during the spring cultivation season. Japanese larch is fast-growing and very effective in reducing wind damage in the early spring cultivation season, even if its buds are not open or its leaves are not fully extended. However, many farmers dislike Japanese larch arable land windbreaks because they shed a lot of branches and branchlets to cultivation fields every year, which may cause damage to agricultural tractors. Therefore, it is necessary to suggest a model of arable land windbreaks with less amount of fallen branches and branchlets of larches entering the cultivation field. It is recommended to plant three rows of trees: Japanese larch in the most windward and middle rows, and Japanese white birch, Betula platyphyllavar. japonica, in the most leeward row. Japanese larch in the most windward and middle rows reduces wind speed, whereas Japanese white birch in the most leeward row reduces branches and branchlets of Japanese larch entering cultivation fields.

If Sakhalin spruce or Sakhalin fir die in windbreaks on seasonally frozen soils, what species can be recommended?

Soil of the Tokachi plain of eastern Hokkaido freezes during the winter due to low temperatures and light snowfall. Deciduous and fast-growing Japanese larch, Larix kaempferi, is often planted in arable land windbreaks to prevent wind damage to cultivation plants. Japanese larch is more resistant to winter desiccation than evergreen trees. However,windbreaks made of Japanese larch are disliked by many farmers because they shed a lot of branches and branchlets every year; if not completely removed from cultivation fields, branches and branchlets may damage agricultural tractors. Therefore, some farmers favor planting evergreen trees like Sakhalin spruce, Picea glehnii, or Sakhalin fir, Abies sachalinensis, both indigenous to Hokkaido. However, the disadvantage of these evergreen trees is that they are susceptible to winter desiccation. In settings where spruce and fir do not survive winter desiccation,planting of the evergreen Korean nut pine, Pinus koraiensis, is recommended. Although not native to Hokkaido, this species is less likely to suffer damage from winter desiccation than the other two evergreen species.

Effect of top soil removal on transition of initial growth of Japanese larch

Effect of top soil removal on transition of initial growth of Japanese larch

Influence of planting density and thinning on timber productivity and resistance to wind damage in Japanese larch (Larix kaempferi) forests

In recent years, forest damage caused by typhoons has occurred frequently in Hokkaido, northern Japan. According to predictive reports, a typhoon's intensity increases and it then maintains its intensity as it moves north. The relationship between this prediction and forest damage is not clear, but the importance of dealing with forest damage is increasing. Therefore, to consider the countermeasures in forest management, we evaluated the influence of planting density and thinning on timber yield and resistance to wind damage in Japanese larch (Larix kaempferi), which is one of the main tree species used for afforestation in northern Japan. In this study, the following three management types were investigated: sparse (ST: relative yield index < 0.8), middle (MT: relative yield index < 0.9), and dense (DT: unthinned). To assess resistance to wind damage, the critical wind speed required to overturn and break the trunks of trees was calculated using a mechanistic model. Furthermore, timber volumes were estimated from a stand age of 10–50 years using the Yield Prediction System. The management type and planting density (1500–2500 trees ha−1) affected resistance to wind damage. Scenarios with ST and low planting density (1500 trees ha−1) showed a high resistance. In contrast, total timber volumes for scenarios varied from approximately 440 to 630 m3 depending on the site index (SI = 22, 25, and 28) at a stand age of 50 years. The merchantable log volume of the final cutting varied from approximately 210 to 470 m3 depending on the management type, planting density, and SI. There was a negative linear correlation between the log volume and resistance to wind damage. Therefore, it is important to balance both the decreased wind damage risk and higher timber yield or to prioritize them.

Developing Ozone Risk Assessment for Larch Species

Ozone (O3) risk assessment for the protection of forests requires species-specific critical levels (CLs), based on either O3 concentrations (AOT40) or stomatal uptake (PODY) accumulation over the growing season. Larch (Larix sp.) is a genus with O3-susceptible species, widely distributed in the northern hemisphere and with global economic importance. We analyzed published and unpublished data of Japanese larch (L. kaempferi) and its hybrid F1 (L. gmelinii var. japonica × L. kaempferi) responses to O3 exposure for developing a parameterization of stomatal conductance model and estimating PODY-based CLs with two Y thresholds, i.e. 0 and 1 nmol m-2 s-1 PLA. In parallel, we estimated AOT40-based CLs. The results show that the AOT40-based CLs for a 2% and 4% biomass loss in Japanese larch were 5.79 and 11.59 ppm h, i.e. higher than in hybrid larch F1 (2.18 and 4.36 ppm h AOT40), suggesting a higher O3-susceptibility of the hybrid. However, the use of PODY reconciled the species-specific differences, because the CLs were similar; i.e. 9.40 and 12.00 mmol m-2 POD0 and 2.21 and 4.31 mmol m-2 POD1 in Japanese larch, vs. 10.44 and 12.38 mmol m-2 POD0 and 2.45 and 4.19 mmol m-2 POD1 in the hybrid, for 2% and 4% biomass loss, respectively. Overall, the CLs were lower than in other forest species, which suggests a relatively high susceptibility of these larches. These results will inform environmental policy-makers and modelers about larch susceptibility to O3.

New Factors for Protoplast-Callose-Fiber Formation in Salt-Tolerant Mangrove Plants, Avicennia alba and Bruguiera sexangula and Analysis of Fiber Substructures

Elongated and spiral &amp;beta;-1,3-glucan (callose) fibers were obtained by new factors from protoplasts cultured in liquid medium from suspension cultured cells of two salt-tolerant mangrove species; Avicennia alba and Bruguiera sexangula. Differences in salt factor for protoplast-fiber formation were compared with those of the callose fibers developed from protoplasts of non-mangrove tree plants, Larix leptolepis and Betula platyphylla, which high concentrations of divalent cations, Mg2+ (50 mM) or Ca2+ (100 mM), were stimulatory. In the halophilic A. alba protoplasts, whose cell division was stimulated by up to 400 mM NaCl, addition of Mg2+, Ca2+, K+ ions inhibited protoplast-fiber formation. In B. sexangula, protoplast-fibers were rapidly and efficiently formed only by another new factor, electric cell fusion treatment of protoplasts. Spiral fibers developed from mangrove protoplasts were detected under an inverted microscope, and their specific blue-green color for callose after staining with Aniline Blue dye was detected under a fluorescence microscope. Enzymatic certification of callose was further performed with laminarinase, specific for callose, in comparison with cellulase CBH1, specific for cellulose. Differences in sub-structures, fibrils and sub-fibrils of two mangrove protoplast-fibers were analyzed using laser confocal scanning microscopy, atomic force microscopy and image J analysis. Tube-like fine structure was observed using transmission electron microscopy in single protoplast-fiber of B. sexangula selected with a micromanipulator.

Changes in Community Structure of Understory Vegetation by Silvicultural Treatments in a &lt;i&gt;Larix kaempferi&lt;/i&gt; Plantation Forest

Changes in Community Structure of Understory Vegetation by Silvicultural Treatments in a &lt;i&gt;Larix kaempferi&lt;/i&gt; Plantation Forest

The Effects of Veneer Selection by Radial Location in Logs on Strength Properties of LVL in Japanese Larch (&lt;i&gt;Larix kaempferi&lt;/i&gt;) Planted in Hokkaido

The Effects of Veneer Selection by Radial Location in Logs on Strength Properties of LVL in Japanese Larch (&lt;i&gt;Larix kaempferi&lt;/i&gt;) Planted in Hokkaido

Post-thinning Responses of Microbial Substrate Utilization in Temperate Japanese Larch Forests

ABSTRACT The present study examined microbial substrate utilization by community level physiological profiling and carbon-cycling enzyme assays (cellobiohydrolase, β-xylosidase, and oxidases) in three Japanese larch forests. The forests differed in their locations, topographies, and soil microclimates, and each covered three treatments, namely 20 (IT) and 35% basal area thinning (HT) without intensive residue harvests and an un-thinned control (UTC). Microbial substrate utilization and soil properties (temperature, moisture, total carbon and nitrogen, inorganic nitrogen, and pH) were analyzed at 0–10 cm depth, six years after thinning. Microbial utilization of carbohydrate group under IT was 27 and 62% higher than that under UTC and HT, respectively, in only one of the forests. This might occur because this forest featured a steeper slope, rockier soil texture, and cooler and drier soil surface than the other two forests, where no thinning effect was observed. However, neither microbial utilization of any other substrate groups nor enzyme activity changed by thinning across all forests. It could result from the exclusion of intensive residue harvests or the lack of changes in soil inorganic nitrogen and pH. These results indicate that the thinning effects on microbial substrate utilization might be inconsistent across multiple sites, and at least, not decline the associated forest ecosystem functions and sustainability.

A decrease in temperature during the late Middle Pleistocene interglacial stage (MIS 7.3) altered montane zone floral diversity: Plant macrofossil evidence from central Japan

Plant fossils from the Early and Middle Pleistocene have mainly been obtained from lowland sediments, and consequently, there is currently limited information on changes in montane zone vegetation prior to the last glacial stage. However, fossil plant assemblages occurring at high altitudes can be used to assess the influence of climate change on the vertical distribution of plants and vegetation. In this study, we analysed plant macrofossil assemblages from fluvial deposits in the upper Middle Pleistocene strata outcropping in a riverbed at 1160–1180 m a.s.l. in the southeastern foothills of Mt. Yatsugatake, central Japan. Ages of the assemblages were constrained by two widespread tephras that were detected above the interglacial peak of marine isotope stage (MIS) 7.3 (~212 ka). The annual mean temperature in the lower and middle sections of the profile was estimated to be warmer than that at present, based on the coldest temperatures limiting the distribution of Phytolacca japonica and Selaginella remotifolia, and the temperature decreased in the upper section. Since MIS 7.4, the fluctuation in plant altitudinal distribution has been exemplified by changes in the limits of S. remotifolia and Larix kaempferi distribution, and their coexistence at the same altitude varied depending on climate settings. Species diversity, estimated by rarefaction analysis of plant macrofossil assemblage composition, declined as temperatures decreased after the peak of MIS 7.3. Decreasing floral diversity during the subsequent cooling phase possibly coincided with a downward migration of the vegetation zone and extirpation of plants from the inland basin in central Japan.

Cascade effects of slope gradient on ground vegetation and small-rodent populations in a forest ecosystem

Abstract In this study, we set out to determine the cascade effects of slope gradient on ground vegetation and small-rodent populations in a forest ecosystem. We focused on two forest-dwelling small rodents with different habitat requirements, the striped field mouse Apodemus agrarius (preferring dense ground vegetation) and the Korean field mouse A. peninsulae (dense forest and woodland). The study area comprised natural deciduous forests and Japanese larch Larix kaempferi plantations in South Korea. The abundance of A. agrarius but not that of A. peninsulae was related to slope gradient. There was a negative effect of slope gradient on ground vegetation coverage and a positive effect of ground vegetation on A. agrarius populations. Our results highlight that the population of A. agrarius was indirectly influenced by the negative effects of slope gradient on ground vegetation. Slope gradient can, therefore, be a limiting factor in the microhabitats occupied by small rodents. This study reveals a critical role for slope gradient since it can modify not only microhabitat conditions, but also small-rodent populations, and this finding can contribute to improved microhabitat management.

Responses to drought stress in Prunus sargentii and Larix kaempferi seedlings using morphological and physiological parameters

The frequency and severity of drought are expected to increase due to climate change; therefore, drought tolerance of tree species should be considered before planting for maximal survival in the field. In this study, we examined the response of drought stress in two of the most popular plantation species: Sargent cherry (Prunus sargentii) and Japanese larch (Larix kaempferi) based on the morphological and physiological characteristics. These plantation species are widely planted in central and northern Asia, especially in Japan and Korea, and also widely used for plantation purpose in northern Europe. Three different irrigation regimes of control (CT; 100% precipitation (P)), light drought (LD; 40% reduction of P), and heavy drought (HD; 80% reduction of P) were applied at the experimental site of Mt. Jiri, the Republic of Korea. For morphological responses, both species experienced a significant decrease in leaf size in drought conditions; however, Sargent cherry and Japanese larch experienced reduced leaf width and length, respectively. On the other hand, leaf mass area (LMA, g cm−2) increased and branch growth decreased in both species under drought conditions. As physiological responses, drought stress significantly decreased maximum photosynthesis rate (Amax) and electron transfer rate (Jmax) for both species, while stomatal conductance (Gs) at Amax significantly decreased only in Sargent cherry. Drought significantly reduced predawn (ΨPD), midday leaf water potential (ΨMD), and transpiration in Sargent cherry but not in Japanese larch. In mid-summer, carbon isotopic composition (δ13C) significantly decreased in Sargent cherry but only showed a reduction tendency in Japanese larch. However, the changes of δ13C were not significant in early summer or mid-fall. In the present study, both species showed isohydric and anisohydric characteristics, but Sargent cherry showed greater anisohydric behavior with a steeper slope (Y = 2.132X) and Japanese larch showed more isohydric behavior with a shallower slope (Y = 1.722X). Our results highlight that both species altered their morphological and physiological responses under drought stress; however, the Japanese larch showed greater resistance and resilience in morphological and physiological responses, and in plant-water relations. Therefore, Japanese larch would be more beneficial for plantations in water deficit regions than Sargent cherry.

Severe insect defoliation at different timing affects cell wall formation of tracheids in secondary xylem of Larix kaempferi

Severe insect defoliation induced non-lignified tracheids and thin-walled latewood tracheids in the defoliation year in Larix kaempferi. These anomalous tracheids had heterogenous lignin deposition of S2 layer. Severe insect defoliation induces the formation of light ring consisted of thin-walled latewood tracheids in larch trees, which would affect wood quality. However, the identity of the secondary wall layers affected by insect defoliation remains unclear. The aim of this study is to clarify the effects of insect defoliation on the formation of secondary cell walls of tracheids in Larix kaempferi with focus on the defoliation timing. We observed by light microscopy and transmission electron microscopy (TEM) the secondary cell walls of tracheids produced in a defoliation year in L. kaempferi trees on which needles were attacked in July (gypsy moth, GM samples) or August (larch sawfly, LS samples). Light microscopy observations revealed that GM samples produced non-lignified tracheids in the transition zone between earlywood and latewood, as well as thin-walled latewood tracheids, and non-lignified tracheids were observed near the cambial zone in LS samples following defoliation for two consecutive years. TEM observations revealed that the tracheids in both samples had anomalous layers in secondary walls such as thin S2 layers with heterogeneous lignin deposition. The production of non-lignified tracheids corresponded to defoliation date in both samples, unlike changes in the layer composition of anomalous tracheids. Our study suggests that changes in wood structure depend on the date of insect defoliation and that insect defoliation affects the formation of secondary cell walls of tracheids, presumably in response to inadequate photosynthate supply as a result of defoliation.

Species- and elevation-dependent productivity changes in East Asian temperate forests

The velocity and impact of climate change on forest appear to be site, environment, and tree species-specific. The primary objective of this research is to assess the changes in productivity of five major temperate tree species (Pinus densiflora, PD; Larix kaempferi, LK; Pinus koraiensis, PK; Quercus variabilis, QV; and Quercus mongolica, QM) in South Korea using terrestrial inventory and satellite remote sensing data. The area covered by each tree species was further categorized into either lowland forest (LLF) or high mountain forest (HMF) and investigated. We used the repeated Korean national forest inventory (NFI) data to calculate a stand-level annual increment (SAI). We then compared the SAI, a ground-based productivity measure, to MODerate resolution Imaging Spectroradiometer (MODIS) net primary productivity as a measure of productivity based on satellite imagery. In addition, the growth index of each increment core, which eliminated the effect of tree age on radial growth, was derived as an indicator of the variation in primary productivity by tree species over the past four decades. Based on our result from NFI plots and increment core data sets, the productivity of PD, QV, and QM in LLF was relatively higher than those in HMF, while LK and PK in HMF were more productive than lowland ones. Our analysis of the increment core data revealed a contrasting pattern of long-term productivity changes between coniferous and oak tree species. While the productivity of oak tree species tended to increase after the 1990s, the productivity in coniferous forests tended to decrease. These differences across forest types and their altitudinal classes are also noticeable from the MODIS product. The results of our study can be used to develop climate-smart forest management strategies to ensure that the forests continue to be resilient and continue to provide a wide range of ecosystem services in the Eastern Asian region.

Effects of Cutting, Pruning, and Grafting on the Expression of Age-Related Genes in Larix kaempferi

Grafting, cutting, and pruning are important horticultural techniques widely used in the establishment of clonal forestry. After the application of these techniques, some properties of the plants change, however, the underlying molecular mechanisms are still unclear. In our previous study, 27 age-related transcripts were found to be expressed differentially between the juvenile vegetative (1- and 2-year-old) and adult reproductive (25- and 50-year-old) phases of Larix kaempferi. Here, we re-analyzed the 27 age-related transcripts, cloned their full-length cDNA sequences, and measured their responses to grafting, cutting, and pruning. After sequence analysis and cloning, 20 transcription factors were obtained and annotated, most of which were associated with reproductive development, and six (LaAGL2-1, LaAGL2-2, LaAGL2-3, LaSOC1-1, LaAGL11, and LaAP2-2) showed regular expression patterns with L. kaempferi aging. Based on the expression patterns of these transcription factors in L. kaempferi trees subjected to grafting, cutting, and pruning, we concluded that (1) cutting and pruning rejuvenate the plants and change their expression, and the effects of cutting on gene expression are detectable within 14 years, although the cutting seedlings are still maturing during these years; (2) within three months after grafting, the rootstock is more sensitive to grafting than the scion and readily becomes mature with the effect of the scion, while the scion is not readily rejuvenated by the effect of the rootstock; and (3) LaAGL2-2 and LaAGL2-3 are more sensitive to grafting, while LaAP2-2 is impervious to it. These findings not only provide potential molecular markers to assess the state of plants but also aid in studies of the molecular mechanisms of rejuvenation.