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Specific root length of Japanese larch (JL) and hybrid larch (HL) seedlings grown at soil temperatures of 7, 15, and 25°C for 16 weeks. Different letters indicate an intraspecific statistical difference in means (P = 0.05). An asterisk indicates a significant difference (P \ 0.05) between the two species under the same temperature conditions
Source publication
We studied the effects of soil temperature (7, 15, and 25°C) on the growth and photosynthesis of seedlings of the Japanese
larch (Larix kaempferi) and its hybrid larch (L. gmelinii×L. kaempferi) to simulate early stages of regeneration after disturbance. At a soil temperature of 7°C, the root length per unit root
biomass, chlorophyll concentration,...
Contexts in source publication
Context 1
... (5.6 ± 1.0) differed significantly (P \ 0.01) from values at 15°C (16.7 ± 2.1) and 25°C (15.2 ± 4.0). A similar response to temperature was found in the hybrid larch, for which the root area was higher at 15°C (10.6 ± 2.8) and 25°C (10.8 ± 2.8) than at 7°C (4.4 ± 0.5). Consequently, the SRL (i.e., the root length per unit root biomass, cm mg -1 ; Fig. 1) at 7°C was markedly lower in the Japanese larch than in the hybrid larch throughout the growing season. The SRL values of the Japanese larch were 2.58, 2.80, and 3.51 at below- ground temperatures of 7, 15, and 25°C, respectively. The SRL values of the hybrid larch were 2.85, 2.45, and 2.90 at temperatures of 7, 15, and 25°C, ...
Context 2
... though larches can acclimate to cool climatic conditions (Gower and Richards 1990), the biomass of the two larch seedlings increased markedly with increasing temperature (Fig. 1). However, the P sat of Japanese larch seedlings at a below-ground temperature of 15°C was higher than that of seedlings grown at a 25°C soil tem- perature. As a result, their size and biomass were larger at a below-ground temperature of 15°C than at 25°C, which may be attributed to the suppressed root respiration at lower temperatures. ...
Context 3
... to low soil temperature reduces root extension through low photosynthetic capacity as found in several plants ( Domisch et al. 2001;Halter et al. 1997;Koike et al. 2003;Larcher 2003;Landhäusser et al. 2001;Korotkii et al. 2002;Qu et al. 2004b). Moreover, at a soil tem- perature of 7°C, the Japanese larch had a smaller SRL than the hybrid larch (Fig. 1). SRL reflects the ability of a plant to compete for resources such as nutrients and water ( Qu et al. 2003). Plants can increase their capacity for nutrient and water uptake by producing a longer root for a given root mass, i.e., by increasing their SRL ( Kroon and Visser 2003). The higher SRL of the hybrid larch at a lower soil ...
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Traditional nursery culture of Changbai larch (Larix olgensis Henry) in Northeast China requires up to a 2-year nursery production period. The high cost of seedling culture for this duration has been identified as a constraint. As a potential means to help to shorten the cultural period, we evaluated growth, biomass accumulation, and nitrogen (N) u...
Citations
... For non-mangrove terrestrial plants, previous studies have demonstrated that root-zone cooling often decreased root growth (Hogue and Neilsen 1986;Karlsson and Nordell 1996;Domisch et al. 2001;Alvarez-Uria and Körner 2007; Communicated by Julie Zinnert. Qu et al. 2009;Nagasuga et al. 2011), nutrient uptake and transport (DeLucia et al. 1992; Karlsson and Nordell 1996;Dong et al. 2001;Weih and Karlsson 2001;Warren 2009), leaf area (DeLucia et al. 1992; Karlsson and Nordell 1996;Weih and Karlsson 2001;Nagasuga et al. 2011;Kuwagata et al. 2012), and photosynthetic activity (DeLucia 1986;Sawada et al. 1987;Day et al. 1991;DeLucia et al. 1992;Schwarz et al. 1997;Cai and Dang 2002;Dang and Cheng 2004;Shimono et al. 2004;Zhang and Dang 2005;Rogiers and Clarke 2013). These studies often detected clear negative effects of root-cooling below about 15°C. ...
Air temperature regulates the photosynthesis and growth of mangrove plants, but the effect of soil (root-zone) temperature is unclear. To clarify the mechanisms underlying change in mangrove growth in relation to soil temperature, we examined how root-zone cooling inhibited the photosynthesis and growth of Kandelia obovata Sheue, H.Y. Liu & J. Yong, which is a relatively cold-tolerant mangrove species. We collected K. obovata propagules in a subtropical region and planted them in sand-filled pots in a glasshouse. The seedlings were divided into two groups, with soils completely submerged in 20°C or 30°C water. The relative growth rate of K. obovata seedlings was lower at a soil temperature of 20°C than of 30°C, and K. obovata leaves had significantly lower maximum carboxylation rates (Vcmax) at a soil temperature of 20°C than of 30°C. Vcmax was significantly positively correlated with the leaf NO3–N content, root length, and leaf sugar and starch contents, suggesting that the carboxylation capacity of K. obovata was regulated by inorganic nitrogen availability rather than by negative feedback regulation associated with end-product accumulation. Our results suggest that the growth and photosynthesis of mangrove species in a subtropical region are reduced not only by low air temperature, but also by low soil temperature. These findings partly support the hypothesis that the distribution of mangrove plants is affected by sea surface temperature (which affects the soil temperature), and that their latitudinal limits often coincide with a winter sea surface temperature of 20°C.
... Variation of light-saturated photosynthetic rate (P sat ) at ambient (left) in short-and long-shoot needles at larch canopy and no variation of P max at CO hybrid larch shows greater photosynthetic starch accumulation capacity than in Japanese larch [29]. ...
Larch species are widely distributed in the northern hemisphere where permafrost and seasonal frozen soil exist. This species with heterophyllous shoots has been intensively planted in northeast Asia as well as in northeast China as the principal afforestation species for restoring agricultural lands to forests from 1999. Although approximately 15 species exist in the northern hemisphere and they are easy to hybridize. Among them, Japanese larch grows the fastest and was exported to Europe as a breeding species from early 20s. Although Japanese larch is tolerant to cold, it suffered from various biological stresses. After nearly 40 years of vigorous breeding effort, hybrid larch F1 (Dahurian larch × Japanese one) was developed with simple propagation methods. With the use of free-air CO2 enriched (FACE) systems, we revealed growth responses of the F1 and its parent larches to environmental conditions. From experiments, F1 showed high responses to elevated CO2 and O3 but not so much to N loading. As future perspectives for larch plantations as an important eco-environmental resource, we expect to afforest F1 seedlings infected with ectomycorrhizae (e.g., Suillus sp.) for efficient afforestation at nutrient-poor sites and at the same time for the production of delicious mushrooms.
... There was a significantly exponential relationships between soil temperature at 5 cm depth and R Mic (R 2 = 0.702). Thus, the soil temperature is the most important factor that influences root growth (Qu et al. 2009) and soil microbial respiration (Liang et al. 2010;Karhu et al. 2014;Li et al. 2017). With increasing global temperatures, we might predict an increasing soil CO 2 efflux contributed by soil. ...
PurposeSoil microbes contribute significantly to soil respiration (SR) in boreal forests; however, there is limited knowledge on microbial contributions from long field investigations. The objective of this study was to estimate soil microbial respiration, as well as its primary controlling factors, for a period of three consecutive years. Materials and methodsA trenching method was used to distinguish soil microbial respiration (RMic) in a 55-year-old mature Japanese larch (Larix kaempferi) plantation in Northern Japan; the soil in which developed originally from volcanic soils containing pumice. We used a portable CO2 detection system to measure the soil respiration rate during the growing season. Environmental factors, soil physiochemical characteristics, and soil microbial biomass carbon and nitrogen (MBC and MBN) were analyzed to explain the seasonal variations of SR and RMic. Results and discussionThe results showed that the estimated contribution of soil microbes to SR was 78, 62, and 55% during the three successive years, respectively. Respiration attributable to decomposition of aboveground litter contributed approximately 19% to SR. The major environmental factor that affected RMic was soil temperature at 5 cm depth, which accounted for more than 70% of the seasonal variation in RMic observed. There were close relations among MBC, MBN, and soil water content, but the soil water content showed no significant relation with RMic. Conclusions
The RMic to SR varied from 78 to 55% following 3 years of trenching treatments. Our results demonstrated the important role of soil microbes on soil respiration in this larch forest. Soil temperature was the major positive factor that influenced RMic, while soil water content had no significant effect. Global warming will increase the loss of C into the atmosphere by increasing the RMic, and could accelerate climate change.
... They also act as an interface between soil and the plant body (e.g., Fitter and Hay 2002). Most roots of woody plants have high plasticity to soil properties, such as soil moisture content (e.g., Koike et al. 2003), nitrogen availability (Qu et al. 2003), temperature of rhizosphere (Korotkii et al. 2002;Qu et al. 2009;Kajimoto 2010) and other factors. The growth dynamic of roots is strongly affected by atmospheric conditions (Wang et al. 2015a), as in the case of the Aspen FACE (Pregitzer and Tlhelm 2013). ...
Key message
The CO
2
effect on the root production of a broad-leaved community was insignificant when grown in brown forest soil, however, it was positively large when grown in volcanic ash soil.
Abstract
We evaluated the root response to elevated CO2 fumigation of 3 birches (Betula sp.) and 1 deciduous oak (Quercus sp.) grown in immature volcanic ash soil (VA) or brown forest soil (BF). VA is a nutrient-poor, phosphorus-impoverished soil, broadly distributed in northern Japan. Each species had been exposed to either ambient (375–395 μmol mol−1) (aCO2) or elevated (500 μmol mol−1) (eCO2) CO2 during the daytime (more than 70 μmol m−2 s−1) over 4 growing seasons. The results suggest that eCO2 did not cause an increase in total root production when the community had grown in fertile BF soil, however, it did cause a large increase when the community was grown in infertile VA soil. Yet, carbon allocation to plant roots was not affected by eCO2 in either the BF or VA soils. Rhizo-morphogenesis appeared to occur to a greater extent under eCO2. It seems that the saplings developed a massive amount of fine roots under the VA and eCO2 conditions. Unexpectedly, eCO2 resulted in a larger total root mass when the community was grown in VA soil than when grown in BF soil (eCO2 × VA vs. eCO2 × BF). These results may hint to a site-specific potential of communities to sequester future atmospheric carbon. The growing substance of plants is an important factor which root response to eCO2 depends on, however, further studies are needed for a better understanding.
... Soil temperature in the mounding (0-3 cm) treatment reached 27°C (data not shown), a value well above the optimal soil temperature for root growth of European larch (20°C) (Kozlowski et al. 1991). Similarly, root growth of Japanese larch is known to decline at soil temperatures [25°C (Qu et al. 2009). Given the close phylogenetic relationship of hybrid larch to these species (Bergès and Chevalier 2001), we expected that for shallow-planted seedlings (especially in mounds), high soil temperatures would have impaired root functions, including water absorption (Boucher et al. 2001). ...
Some site preparation is generally recommended to enhance the growth and survival of planted and naturally regenerated seedlings, but it must be justified both economically and environmentally. More severe preparation is thought to be necessary for intensive plantation silviculture, e.g., using fast-growing, ameliorated stocks, especially in boreal ecosystems. Although not justified scientifically, deep-planting of seedlings is often discouraged and may even be financially penalized in eastern Canada. We thus evaluated early seedling growth and survival of hybrid larch (Larix 9 marschlinsii Coaz) in an experiment including mechanical site preparation and planting depth treatments. Our results suggest that satisfactory early hybrid larch establishment and growth could be met using low environmental impact or low cost treatments (such as soil inversion using an excavator or single-pass disk trenching), and that deeper planting has no negative effect. Structural equation modelling (SEM) was used to explore causal relationships between factors influencing seedling performance at the local scale (planting microsites), including soil moisture, soil temperature, surrounding vegetation, and seedling nutrition. SEM analysis supported the absence of overall differences among treatments, while also highlighting the negative impact of increased soil water content where drainage was suboptimal, as well as the unexpected positive impact of increased competition on growth mostly through seedling nutrition, among others. These early observations will need to be confirmed over a longer period, as well as with a more comprehensive assessment of site environmental conditions and competition intensity.
... Also, the high sand temperature was not probably a factor influencing seedling growth. Higher soil temperatures than 15°C can inhibit the root elongation of larch species (Qu et al. 2009). Charcoal can generate heat through the adsorption of far infrared radiation (Tai et al. 1999) and charcoal produced at high temperatures can generate more heat through the greater adsorption of far-infrared radiation than charcoal generated at low temperature (Reeves et al. 2008). ...
Fires burn forest with spatially heterogeneous intensity and charcoals generated at various temperatures during fires exhibit
variable physical and chemical characteristics. These variable properties of charcoal may, in turn, influence germination
and growth of tree seedlings. To examine the effects of different charcoal properties on the growth of Gmelin larch (Larix gmelinii) seedlings, we conducted an experiment with larch-branch-derived charcoals produced at 400°C (low charcoal) and 800°C (high
charcoal); charcoal was combined with sand at three different rates (5%, 20% and 50%, v/v charcoal in sand). The high charcoal had no significant effects on any measured property while the low charcoal application
stimulated growth and the effect increased with the addition rate. The low charcoal application resulted in the greater available
P content, a lower N/P in needles and the greater growth of seedlings than high charcoal application. The growth of seedlings
was not affected by the application of the high charcoal at any rate probably because the high charcoal inhibited the seedling
growth due to its high pH. These results indicate that charcoal produced at different temperatures during forest fires can
affect the growth of Gmelin larch seedlings differently.
KeywordsCharcoal–Charring temperature–Gmelin larch (Larix gmelinii)–P availability–Forest fire
For sustainable use and suitable management of larch plantations, we must clarify the ecophysiological responses of larch
species to environmental changes. The physical environment has been changing dramatically, e.g., increase in atmospheric CO2 concentration ([CO2]), nitrogen (N) deposition, and atmospheric ozone concentration ([O3]), and these changes may negatively affect growth of larch species. This review summarizes the previous experimental studies
on the ecophysiological responses of larch species to elevated [CO2], soil acidification, elevated [O3], and N load. Based on the advanced studies, although elevated [CO2] will stimulate the productivity of larch, increase of [O3] and severe soil acidification will reduce it. Increase of N deposition, at least, will not negatively affect larch productivity.
Finally, we propose the future direction for investigation to understand the mechanism of the responses of larch species and
to predict the associated risk.
