Larch Forest Research Articles

Plant community structure and environmental factors regulate N-P stoichiometry of soil and leaves of larch forests in northern China

Plant community structure and environmental factors regulate N-P stoichiometry of soil and leaves of larch forests in northern China

Effects of salvage logging after forest fire on Siberian larch regeneration and ecosystem carbon stocks at the drought limit of the boreal forest in Mongolia

Post-fire salvage logging is widely applied in Mongolia's boreal forests with the intent to prevent intact forests from logging. The rationale behind this approach is the assumption that the additional disturbance caused by the removal of standing deadwood after stand-replacing fire is of no further significance for the already heavily disturbed ecosystem. However, while there is a global debate on effects of salvage logging for regeneration success, biodiversity, and soil health, little evidence has been collected from strongly drought-limited southern boreal forests of Central Asia. Comparing sites with and without salvage logging, we investigated forests of Siberian larch (Larix sibirica) ca. 20 years after stand-replacing fire and asked whether postfire salvage logging affected regeneration density, terminal shoot length and radial stem increment, ecosystem carbon stock densities, and reduced organic layer depth and compacted the soil. The biomass of the larch regeneration was significantly reduced by salvage logging, while tree growth was not affected. The ecosystem carbon stock density of burnt forest without salvage logging was 202 Mg C ha−1 and thus even in the lower range of intact larch forests from Mongolia, whereas burnt forests with salvage logging had organic carbon stock densities (104 Mg C ha−1) that were lower than those of unburned grasslands in the forest-steppe. These results show that removing deadwood from burnt forest is not insignificant, but has the potential to delay forest recovery and strongly reduces organic carbon storage. However, we did not find significant reductions in soil organic carbon stocks or soil compaction. Nonetheless, our findings raise the question of whether careful management of intact forests (especially by selective felling under a continuous-cover forestry regime) would be a more ecologically sustainable alternative than post-fire salvage logging.

The Adaptive Mechanism of Ginseng Rhizomes in Response to Habitat Changes

Panax ginseng, a perennial medicinal plant, utilizes its dried roots and rhizomes for medicinal purposes. Currently, in China, ginseng cultivation employs two methods: under-forest and farmland planting. These methods create distinct habitats, significantly influencing the ginseng’s rhizome morphology and, consequently, its economic value. In this study, two-year-old ginsengs were transplanted into farmland (TCG), a larch forest (TLCG) and a Quercus mongolica forest (TQCG) to analyze the differences in rhizome phenotypes caused by habitat changes. The results showed that there were significant differences in light intensity and the soil’s available phosphorus and potassium contents between farmland and forest environments. The differences in habitats led to different adaptability of the ginseng’s rhizome morphology. Compared with TCG, the rhizomes of TLCG and TQCG were significantly elongated by 48.36% and 67.34%, respectively. After the rhizomes’ elongation in TLCG and TQCG, there was an increase in indole-3-acetic acid (IAA) contents and a decrease in lignin contents. By analyzing the expression of key genes, we found that, compared with TCG, the expression of key enzymes of lignin biosynthesis genes such as PgCOMT and PgCCR4 were down-regulated. The difference in ginseng’s rhizome length is related to the signal transduction pathway of auxin and gibberellin. In addition, we preliminarily screened out transcription factors PgWRKY75, PgDIV, and PgbHLH93.1, which can actively respond to habitat changes and play important roles in the elongation of ginseng rhizomes. In summary, this study elucidates the phenotypic plasticity strategy of ginseng rhizomes in response to habitat changes and delineates the regulatory mechanism behind phenotypic adaptation, offering novel insights into ginseng’s morphogenesis.

Subfossil pollen spectra in the altitudinal belts of the Sikhote-Alin

This paper presents the characteristics and comparison of subfossil pollen spectra of modern plant communities in the altitudinal zones of the Northern Sikhote-Alin and the Southern Sikhote-Alin, using the cases of the Tordoki-Yani Mountain (absolute altitude 2090 m) and Oblachnaya Mountain (absolute altitude 1858 m). All pollen spectra from high mountains reflect the forests caused by long-distance transport of tree pollen. Due to the abundance of Picea pollen, the pollen spectra of the mountain tundra and upper part of the subalpine belts of the Northern Sikhote-Alin correspond to the most common type of vegetation at the upper forest borde r–the high-mountain spruce forest with Betula lanata, where Pinus pumila thickets can reach from the overlying belt. The largest amount of allochthonous pollen was found in the pollen spectra on the site without forest canopy. The pollen of broad-leaved trees was brought to high hypsometric levels by mountain-valley winds, rising air currents, from the underlying belts. The quantitative content of pollen of the main dominants of each altitudinal plant zone does not always accurately reflect the role of these taxa in the composition of the communities. The pollen productivity of Betula lanata exceeds the pollen productivity of the main forest forming species in all altitudinal zones, with the exception of the stone birch forests, therefore the share of its participation in the composition of the pollen spectra is overestimated. In the studied pollen spectra the content of Larix pollen is greatly underestimated compared to the role of this species in the forest stand, especially in soil samples from larch forest. It is associated with low pollen productivity, distribution and fossilization characteristics.

Abundance, habitat distribution and content of reserve energy substances in shrews (Sorex caecutiens, Sorex isodon) within the Seymchan-Buyundinskaya Depression (Upper Kolyma River region)

This research examined the influence of interspecific interactions among shrew species on their territorial distribution and trophic conditions within larch and poplar-chosenia forests along the upper Kolyma River. The study specifically analyzed the biotopic characteristics associated with the relative abundance and energy reserve content, including fat tissue mass and glycogen levels in the liver, of Sorex caecutiens and S. isodon. Fieldwork was conducted in the Seymchan- Buyunda depression during July and August in 2003 and 2010. A total of 1,588 individuals from both species were captured using pitfall traps. The assessment of energy reserve content in S. caecutiens (n = 736) and S. isodon (n = 113) was carried out between 2006 and 2010. The abundance of S. caecutiens in the examined habitats exhibited consistent trends and a strong correlation (RS = 0.95, p < 0.01). Conversely, S. isodon displayed asynchronous fluctuations in abundance across various habitats, likely attributable to competition with Laxmann’s shrew, which tends to displace S. isodon from its preferred larch forest during periods of elevated population density. The interannual variations in energy reserve content for both shrew species were remarkably similar, with no significant differences observed between habitats. The nature of these variations suggested insufficient feeding conditions for the animals during years of high overall abundance, with the dominant species, S. caecutiens, contributing most significantly to this phenomenon in both habitats of the upper Kolyma. The results indicate that interspecific relationships play a crucial role in shaping both territorial distribution and food availability for these shrew species.

Effects of Wildfire on the Adsorption-Desorption of Soil Free Amino Acids in a Dahurian Larch Forest in Northeast China

Effects of Wildfire on the Adsorption-Desorption of Soil Free Amino Acids in a Dahurian Larch Forest in Northeast China

Process‐Based Modeling of Ecosystem‐Level Monoterpene From a Japanese Larch (Larix kaempferi) Forest

AbstractGlobally, the emission of biogenic volatile organic compounds (BVOC) by plants represents the dominant source of volatile organic compounds emitted to the atmosphere. Monoterpenes, as the major BVOC group, can contribute to forming secondary organic aerosols and influence cloud properties. In this study, we developed a process‐based monoterpene module in the Vegetation Integrative SImulator for Trace gases (VISIT) model by considering the production, storage, and emission of monoterpene as three main processes. We further evaluated the modeled monoterpene emissions against the ecosystem‐level observation data at a half‐hour scale at a Japanese larch (Larix kaempferi) forest site on Mt. Fuji, Japan. The VISIT model performed with relatively higher accuracy with a Willmott's index of agreement at 0.61, a mean bias error (MBE) at 0.29, and a root mean squared error (RMSE) at 0.43, comparable to that of Model of Emissions of Gases and Aerosols from Nature model with a Willmott's index of agreement at 0.63, a MBE at 0.40, and a RMSE at 0.54. In a long‐term simulation under high CO2 emission scenarios, the ratio between monoterpene emission and gross primary production exhibited a stronger correlation with CO2 concentration than temperature. Our study provides a process‐based modeling approach for more accurately simulating monoterpene emissions from Japanese larch.

Natural Fires in the Larch Forest of the Cryolithozone: Monitoring and Firefighting Strategy under the Conditions of a Changing Climate

Natural Fires in the Larch Forest of the Cryolithozone: Monitoring and Firefighting Strategy under the Conditions of a Changing Climate

The Impacts of Phenological Stages within the Annual Cycle on Mapping Forest Stock Volume Using Multi-Band Dual-Polarization SAR Images in Boreal Forests

SAR images with two polarizations show strong potential for mapping forest stock volume (FSV) combined with limited samples. However, accurately mapping FSV still presents challenges in selecting the optimal acquisition date to obtain the SAR images during specific phenological stages within the annual forest cycle (growth and dormant stages). To clarify the impacts of phenological stages within the annual cycle on FSV mapping, SAR images with various polarization models and bands (Sentinel-1(S), GaoFen-3(GF-3 (G)) and ALOS-2(A)) were acquired within the growth and dormant stages of an annual cycle in a boreal evergreen coniferous forest (Chinese pine) and a deciduous coniferous forest (Larch). Subsequently, single-band (G, S, and A) and multi-band combined alternative variable sets (A + G, A + S, S + G, and A + S + G) were extracted within the same stage, respectively. Finally, the forward selection approach was utilized in conjunction with four different models (MLR, KNN, RF, and SVR) to obtain the most suitable variable sets and generate FSV mapping. The results demonstrated a strong correlation between the intensity of backscattering coefficients and the phenological stages of the forest. Within the dormant stage, there was a significant decrease in the gaps of backscattering coefficients obtained from the same polarization compared to those within the growth stage. Furthermore, the results also revealed that more signals from inside the canopy could be detected during the dormant stage in both evergreen coniferous forests and deciduous coniferous forests. Subsequently, the accuracy in mapping FSV obtained from single-band SAR images within the dormant stage are slightly higher than that within the growth stage, and the accuracy was still significantly affected by both overestimation and underestimation. Moreover, the combined effects of different bands significantly improve the reliability of mapped FSV. The rRMSE values in four multi-band combinations ranged from 22.37% to 29.40% for Chinese pine forests and from 21.27% to 34.38% for Larch forests, and the optimal result was observed from combinations of A + S + G acquired within the dormant stage. It is confirmed that SAR signal and their sensitivity to FSV depends on the stages of forest annual growth cycle. In comparison to the growth period, dual-polarization SAR data acquired during the dormant stage is more suitable for estimating FSV in boreal forests.

Controls over Fire Characteristics in Siberian Larch Forests

Controls over Fire Characteristics in Siberian Larch Forests

Assessing Larix principis-rupprechtii productivity and its determinants based on national forest inventory data in Hebei Province, China

Tree productivity is not only determined by stand structure, but also influenced by soil chemical properties, climate and topography. However, the relative importance of each indicator on larch (Larix principis-rupprechtii) productivity were uncertain. In this study, 76 pure larch forest plots were selected based on national forest inventory (NFI) data in Hebei Province, China. Structural equation model (SEM) was used to analyze the direct and indirect effects of stand structure, soil chemical properties, climate and topography on larch productivity, and to quantify the relative importance of each indicator in determining productivity. The results showed that stem volume growth (SVG) of larch was influenced by a combination of stand density, diameter at breast height (DBH), mean winter snow (PAS), annual temperature range (TD), slope, and alkali-hydrolysis nitrogen (AN). SVG tended to increase with decreasing stand density and AN content and increasing DBH. Stand density, DBH and AN were more important than PAS, TD, and slope in explaining SVG variation. The results can provide a scientific basis for adaptive management of larch forests.

Partition evapotranspiration into transpiration and evaporation in a natural boreal larch forest in China: A framework from concurrent eddy covariance systems

Partitioning forest ecosystem evapotranspiration (ET) into transpiration (T) and evaporation (E) has been widely discussed, as it is crucial for understanding hydrological processes and functions. However, quantifying the hydrological importance of the understory ecosystem is limited, particularly in China’s boreal forests. In this study, we first employed a framework with concurrent eddy covariance (EC) systems and the underlying water use efficiency (uWUE) method to partition ET in a natural boreal larch forest (Larix gmelinii) of China during the growing seasons of 2020 to 2022. The results showed that understory transpiration (Tu) and overstory transpiration (Tos) contributed 21.8 and 78.2% to T, respectively, while the contributions of understory evaporation (Eu) and overstory evaporation (Eos) to E were 41.2 and 58.8%, respectively. Understory evapotranspiration (ETu) contributed 32.6% to the total ET, suggesting the considerable importance of understory vegetation to water flux in the boreal larch forest. Interestingly, Tos and Eos had a similar contribution to ET. While the controlling mechanisms in Tu/T, Eu/E, and ETu/ET were more complex than those in Tu, Eu, and ETu, the leaf area index (LAI) of the overstory and solar radiation (SR) played greater roles in regulating each component and its respective ratios. Those results highlight the non-negligible role of understory vegetation in hydrological processes in boreal forests, which must be considered when managing or modelling forest-water relationships. Our study also demonstrates the effective utility of concurrent EC systems in partitioning ET in natural boreal forest ecosystems.

The Impact of Catastrophic Forest Fires of 2021 on the Light Soils in Central Yakutia

This paper presents the results of studying changes in the main parameters and properties of soils in larch and pine forests growing on sandy soils of the Lena-Vilyui interfluve of Central Yakutia, where catastrophic forest fires occurred in 2021. According to the remote monitoring information system of Rosleskhoz, in 2021, almost 8.5 million hectares of forests burned in Yakutia, which is considered as one of the largest forest fires in Russia and in the world in that year. After the fire passes through the forest floor, the content of organic matter decreases as a result of combustion processes. The acidity of the soil changes towards its alkalization due to the entry of combustion products. Changes in soil profiles occur; turbation processes begin more intensively, which in turn change the natural distribution of soil indicator values such as the organic carbon content, the pH, and the number of exchangeable bases. Due to the sharp increase in heat supply after a fire, the depth of seasonal thawing in the soils of burnt larch forests increases by a quarter and by twofold in pine forests. With the beginning of the thawing of the seasonally frozen layer, all the soils experience waterlogging, and ground water occurs above the permafrost.

Functional Diversity of Soil Microorganisms in Taiga Forests in the Middle and Late Stages of Restoration after Forest Fires

Fire can significantly affect the structure and function of forest soil microorganisms. Therefore, it is important to study the effects of different fire intensities on soil microbial carbon source utilization capacity in cold-temperate larch forests to protect and utilize forest ecosystems. In this study, we investigated the effects of different burning intensities on the carbon utilization capacity of soil microorganisms in fire sites from 2010 and 2000 using Biolog-Eco technology. Our findings revealed that (1) fire significantly increased soil pH, AN (available nitrogen), and AK (available potassium) (p < 0.05); (2) fire significantly increased the average color change rate (AWCD) of soil microorganisms (p < 0.05); (3) the Shannon index of soil microorganisms increased significantly, whereas the Simpson index and the McIntosh index decreased significantly after the fire—however, the McIntosh index in the 10M site was not altered; (4) the metabolic functions of soil microbial communities differed significantly among different fire intensities—MC (moisture content), TN (total nitrogen), and AK were the most influential soil environmental factors in the soil microbial community; and (5) mid-term fire restoration significantly increased microbial responses to carbohydrates, amino acids, esters, alcohols, amines, and acids, while late-fire burn sites significantly increased the microbial utilization intensity of amino acids, esters, and acids. In conclusion, fire significantly altered the functional diversity of soil microorganisms and microbial activities related to carbon source substrate utilization. Additionally, the ability of microorganisms to utilize a single carbon source substrate was also altered.

Post-fire succession of pseudo-taiga larch forest in the Tarvagatai Mountain range, Mongolia

Post-fire succession of pseudo-taiga larch forest in the Tarvagatai Mountain range, Mongolia

Soil Fungal Community Differences in Manual Plantation Larch Forest and Natural Larch Forest in Northeast China.

Soil fungal communities are pivotal components in ecosystems and play an essential role in global biogeochemical cycles. In this study, we determined the fungal communities of a natural larch forest and a manual plantation larch forest in Heilongjiang Zhongyangzhan Black-billed Capercaillie Nature Reserve and Gala Mountain Forest using high-throughput sequencing. The interactions between soil fungal communities were analysed utilising a co-occurrence network. The relationship between soil nutrients and soil fungal communities was determined with the help of Mantel analysis and a correlation heatmap. The Kruskal-Wallis test indicated that different genera of fungi differed in the two forest types. The results show that there was a significant change in the alpha diversity of soil fungal communities in both forests. In contrast, nonmetric multidimensional scaling (NMDS) analysis showed significant differences in the soil fungal community structures between the manual plantation larch forest and the natural larch forest. The soil fungal co-occurrence network showed that the complexity of the soil fungal communities in the manual plantation larch forest decreased significantly compared to those in the natural larch forest. A Mantel analysis revealed a correlation between the soil fungal co-occurrence network, the composition of soil fungi, and soil nutrients. The RDA analysis also showed that AN, TK, and pH mainly influenced the soil fungal community. The null model test results showed the importance of stochastic processes in soil fungal community assembly in manual plantation larch forests. Overall, this study enhances our understanding of the differences in soil fungal communities in manual plantation larch forests and natural larch forests, providing insights into their sustainable management. It also serves as a reminder that the ecological balance of natural ecosystems is difficult to restore through human intervention, so we need to protect natural ecosystems.

Holocene Sediments оf the Adycha River Valley, Yakutia

Palynological analysis of radiocarbon-dated sediments from floodplain deposits and peat bogs preserved in the terraces along the Adycha River, a tributary of the Yana River, document the regional presence of larch forests over at least the last 10 500 14C BP (12 500 cal BP). The Adycha records indicate that the most favorable climatic conditions during this interval occurred during the Early Holocene, persisting up to 8 200 14C BP (9 200 cal BP), and during the Middle Holocene between c. 6 000-5 100 14C BP (6 900-5 800 cal BP). Climatic warming also happened between 400-190 calendar years ago, following the cooling of the Little Ice Age. The expansion of Pinus pumila into the Yana River basin occurred c. 7 000 14C BP (7 800 cal BP). A date of 8 200 14C BP falls within an interval of global cooling, referred to as the Bond 5 event, as defined from North Atlantic marine deposits.

Dynamics of species diversity of the small mammal community in slope larch forests of Northern Coast of the Sea of Okhotsk

Dynamics of species diversity of the small mammal community in slope larch forests of Northern Coast of the Sea of Okhotsk

Fauna and Ecology of Macromycetes (Basidiomycota) in the Arctic Tree and Shrub Ecosystems of Central Siberia.

The research was aimed at studying the taxonomic diversity, habitat specialization, and trophic characteristics of mycobiota, including Basidiomycota, in the northern ecosystems of the Krasnoyarsk Krai (Central Siberia) near Norilsk. Larch forests and woodlands in the Siberian permafrost zone are distinctive and Basidiomycota, as a component of these ecosystems, plays an essential role in their functioning. Currently, there is a paucity of information about this group in Arctic ecosystems, both in terms of floristic and ecological aspects. Seventy species of macromycetes belonging to different trophic groups were discovered and identified. Only 15% of species occur regularly, while most species are found rarely or only once. The identified species belong to 44 genera, 25 families, and 8 orders, which are included in the class Agaricomycetes. The leading families in terms of the number of species are Russulaceae, Polyporaceae, Tricholomataceae, Suillaceae, Strophariaceae, and Cortinariaceae. Mycorrhizal fungi and wood decay fungi dominate the structure of mycobiota of the study area (the total share is 71%). The rest of the species (29%) are fungal decomposers inhabiting plant litter, the forest floor, and humus. The largest number of species occur in forest ecosystems, which are dominated by mycorrhizal and wood decay fungi (up to 70%), which are trophically associated with woody plants and debris. The fungal decomposers inhabiting plant litter, the forest floor, and humus dominate (about 80%) in the species composition of tundra, where, in the absence of woody substrate, wood decay fungi have not been found at all. The species richness of tree and shrub Arctic ecosystems is low, yet the taxonomical and ecological structure of Basidiomycota is similar to that observed in taiga and temperate forests. These data permit a more comprehensive description of the biodiversity of the Arctic and may prove useful in studying biological processes in these ecosystems.

Dynamics of Species Diversity in Small Mammal Communities in Slope Larch Forests on the Northern Coast of the Sea of Okhotsk

Dynamics of Species Diversity in Small Mammal Communities in Slope Larch Forests on the Northern Coast of the Sea of Okhotsk