Kaempferi Plantations Research Articles

Soil available phosphorus and pH are key factors affecting the site index of Larix kaempferi plantations in China

Assessing the quality of forest sites is crucial for evaluating the potential productivity of forests and formulating effective management strategies. Therefore, it is essential to understand how environmental variables affect the site quality. This study focuses on quantifying the effects of 44 different environmental variables including climate, topography, and soil properties on the site index of Larix kaempferi plantations in three different climate regions in China, utilizing the random forest algorithm. L. kaempferi site index was determined from stem analysis data by felling dominant trees from 51 even-aged stands. The results indicated that the proposed random forest model explained ~59.47% of site index variations. Among many environmental variables, available phosphorus, pH, degree-days above 5°C (DD5), and spring mean maximum temperature (Tmax_MAM) had significant effects on the site index (P < 0.05), and the importance of soil chemical properties generally exhibits relatively larger effects on the site index than climate variables and topography variables. The partial dependence analysis revealed that the L. kaempferi plantations had maximum values at ~30 mg/kg of available phosphorus in the first soil layers, 30 mg/kg of available phosphorus in the second soil layers, 20 mg/kg of available phosphorus in the third soil layers, the DD5 between 2,600and 3,000°C, and Tmax_MAM ~15°C. Our findings attempt to provide a better understanding of the site–growth relationship.

Study on the relationship between net primary productivity and site quality in Japanese larch plantations in mountainous areas of eastern Liaoning.

Plantation forests enhance carbon storage in terrestrial ecosystems in China. Larix kaempferi (Lamb.) Carrière (Lamb.) (Larix olgensis Henry) is the main species for afforestation in the eastern Liaoning Province. Therefore, it is important to understand the correlation between the site class and carbon sink potential of Larix kaempferi plantations in Liaoning Province for afforestation and carbon sink in this area. The model was fitted using three classical theoretical growth equations: the Richards model, the Korf model, and the Hossfeld model. This study used the forest resource inventory data for management in Liaoning Province in 2011 to build six dynamic height-age models for a Larix kaempferi plantation in Dandong City regardless of base-age. The optimal model derived by the generalized algebraic difference approach (GADA) method was compared with the model derived by the algebraic difference approach (ADA) method. The superiority of GADA was demonstrated by comparison. The Levenberg-Marquardt algorithm was used to fit the model. The statistical and biological characteristics were considered synthetically when comparing the models. The best model was screened out by statistical analysis and graphic analysis. The results show that the differential height-age model derived from Richards equation can well explain the growth process of Larix kaempferi in Dandong City, Liaoning Province under different conditions. The site index model based on Richards equation and derived by GADA was used to calculate the site class of a Larix kaempferi plantation in Dandong City. The net primary productivity (NPP) value from the past ten years was extracted from the MOD17A3HGF data set. Spearman correlation analysis and Kendall correlation analysis were used to show that there is a significant positive correlation between NPP value and site class of Larix kaempferi plantation in Dandong City. Among them, the highest growth occurred in 2016; NPP increased by about 3.914 gC/m2/year for every two increases in height-age grade; the lowest increase in NPP was in 2014; NPP increased by about 2.113 gC/m2/year for every two increases in height-age grade; and for every two increases in height-age grade in the recent ten years, the average NPP value increased by about 2.731 gC/m2/year.

Prediction model for the quantity and density of first-order branches of Larix kaempferi in eastern area of Liaoning Province, China.

As an important branch characteristic factor, the quantity of branches could influence crown structure, tree growth, and wood quality. Taking Larix kaempferi plantation in Dagujia Forest Farm, Qingyuan County, Liao-ning Province as the research object, we developed a mixed effect prediction model of the first-order branches quantity of L. kaempferi including sprouting branches based on the negative binomial distribution model, and a mixed effect prediction model of the first-order branches density of L. kaempferi including sprouting branches based on the negative exponential model. The results showed that the mixed effect model considering sample level as the random effect effectively decreased the heteroscedasticity and autocorrelation. The fitting goodness was better than the traditional model. The quantity of the first-order branches increased with increasing crown ratio. The mixed effect model with the basic model intercept of the first-order branches quantity as the random effect parameter was determined as the optimal model, with Ra2=0.552 and the RMSE=7.242. As for the density of the first-order branches, the heteroscedasticity and autocorrelation were also reduced when the random effect was added. The density of the first-order increased with increasing crown ratio. The mixed effect model with the basic model intercept of the first-order branches density model and branch depth as random effects was determined as the optimal model, with Ra2=0.792 and the RMSE=4.447. The model for branch quantity and density of L. kaempferi constructed would lay an important foundation for making scientific forest management plans and improving wood quality.

Tree age affects carbon sequestration potential via altering soil bacterial community composition and function.

Among various factors related to the forest carbon pool, the tree stand age, which interacts with soil organic matter, decomposition rates, and microbial activity, is essential and cannot be disregarded. However, knowledge about how tree phases influence soil carbon sinks is not adequate. This study sampled Larix kaempferi (Japanese larch) plantations with different tree stand ages to investigate the temporal dynamics of soil carbon sink in the forest. Physiochemical analyses and high-throughput sequencing results further revealed the interactions of tree stands and their related rhizosphere microbiome. It was found that microbial composition and metabolic activity were significantly affected by different tree ages, whose structures gradually diversified and became more stable from young to mature forests. Many keystone taxa from the phyla Chloroflexi, Proteobacteria, Acidobacteriota, and Nitrospirota were found to be associated with carbon transformation processes. Interestingly, the carbon resource utilization strategies of microbial groups related to tree ages also differed, with near-mature forest soils showing better labile carbon degradation capacity, and mature forests possessing higher degradation potential of recalcitrant carbon. Age-altered tree growth and physiology were found to interact with its rhizosphere microbiome, which is the driving factor in the formation and stability of forest soil carbon. This study highlighted that the tree age-associated soil microbiomes, which provided insights into their effects on soil carbon transformation, were significant in enhancing the knowledge of carbon sequestration in L. kaempferi plantations.

Responses of the Crown Shape of Larix kaempferi Plantations to Site Index in Subtropical Areas of China

This study addresses how site index may affect crown shape by developing a crown shape regression model for the planted L. kaempferi at high altitudes in the subtropical climate of China. A total of 9241 branches from 78 trees, including 39 dominant trees and 39 intermediate trees, were measured in Hubei Province, southern China. The branch characteristics, including branch length, branch angle, and branch chord length of all living branches, were measured by felling trees. The models that showed good performance in crown shape modeling were used and compared in the present study. The goodness of fit statistics and stability of parameter estimation of the modified Kozak equation were better than those of the segmented polynomial equation. A nonlinear mixed-effect crown shape model was developed based on the modified Kozak equation. In addition to the tree level variables of diameter at the breast height (DBH), crown ratio (CR), and tree height-to-DBH ratio, an attempt was made to incorporate the site index into the crown shape model for the planted L. kaempferi. However, the site index was not a significant variable in the crown shape model. The purpose of our study was to lay the foundation for further study of the growth of the trees and the effects of crown morphology on stem growth in the future.

The responses of soil microbial characteristics to nitrogen addition and biochar amendment in a Larix kaempferi plantation

Nitrogen (N) deposition is an important environmental factor that can change soil chemical properties. It can also alter the characteristics of microbial communities. The incorporation of biochar into soils is considered a potential strategy to enhance carbon (C) storage in soil and modify the impacts of N deposition. However, the impacts of biochar on the microbial characteristics of soil after short-term N deposition in subtropical plantations remain poorly understood. Here, we investigated the effects of biochar application (0, 5, 10 t ha−1) on soil chemical traits and microbial characteristics (extracellular enzyme activities, microbial community and microbial biomass) in a Larix kaempferi plantation in Shennongjia, China, under N addition (0, 50, 100 kg N ha−1 yr−1) during two growing seasons. We found that simulated N deposition significant increased soil total nitrogen (TN), nitrate nitrogen (NO3−-N) and total phosphorus (TP) concentrations, while heavy N deposition (100 kg N ha−1 yr−1) significant decreased soil microbial biomass nitrogen (MBN) concentration and β-glucosidase (β-GC) activity. Biochar amendment significantly increased soil microbial biomass, TN and soil organic carbon (SOC) concentrations. Both N addition and biochar amendment significantly altered Ascomycota and Basidiomycota relative abundance, with biochar amendment increasing Ascomycota relative abundance and decreasing Mortierellomycota relative abundance under heavy N deposition. Fungal diversity showed a positive correlation to TN, TP and NO3−-N concentrations, but a negative correlation to MBN. Biochar addition inhibited the increase in soil NO3−-N concentration caused by high N addition in the plantation, and influenced the change in the composition of microbial community caused by N addition. Our piecewise structural equation model suggested that N addition affected MBN and fungal diversity directly or indirectly via its effects on soil enzyme activities and properties. In contrast, there were no significant direct or indirect effects on bacterial diversity among all factors. These results improve our understanding of the influence and mechanisms of N addition and biochar amendment on soil microbial characteristics in subtropical coniferous plantations in the short term, and can provide a valuable reference for predicting the future effects of N deposition on soils in this region’s plantation.

Disentangling the direct and indirect effects of canopy and understory vegetation on the foraging habitat selection of the brown bear Ursus arctos

Elucidating the factors affecting the foraging habitat selection of wildlife can further our understanding of the animal–habitat relationships and inform wildlife conservation and management. Canopy and understory vegetation may directly or indirectly affect the foraging habitat selection of carnivores through changes in habitat structure and prey availability, respectively; however, the relative importance of these two effects remains largely unknown. Dwarf bamboo Sasa kurilensis is a predominant understory plant that suppresses regeneration in the forests of northern Japan. The purpose of this study was to disentangle the direct and indirect effects of canopy forest type Larix kaempferi plantation versus natural mixed forest) and dwarf bamboo on foraging habitat selection of a large carnivore, the brown bear Ursus arctos. In the Shiretoko World Heritage, brown bears dig for cicada nymphs during summer. We evaluated the frequency of brown bear foraging on cicadas by investigating traces of digging for cicada nymphs. A structural equation model was used to statistically disentangle the direct and indirect effects of vegetation. Our results demonstrated that canopy and understory vegetation directly and indirectly affected foraging habitat selection of brown bears. Dwarf bamboo negatively affected cicada nymph density, which positively affected brown bear digging. This suggests that dwarf bamboo also had indirect negative effects on brown bears. Forest type had significant direct and indirect effects via change in cicada nymph density on foraging behavior in brown bears. Forestry managers in northern Japan, including the study site, try to remove dwarf bamboo for assisting natural regeneration. Removal of dwarf bamboo by scarification might not only promote natural regeneration, but also provide a beneficial foraging habitat for bears.

Hydrological effects of litter and soil layers of Larix kaempferi plantation in subtropical regions

Hydrological effects of litter and soil layers of Larix kaempferi plantation in subtropical regions

Effects of Randomized Management on the Forest Distribution Patterns of Larix kaempferi Plantation in Xiaolongshan, Gansu Province, China

Patterns of tree distribution are an important attribute of forest structure and directly affect the health and stability of forest ecosystems. This paper studied the effects of forest management on the forest distribution pattern of Larix kaempferi plantations with an aim to improve the quality of the spatial structure of plantations by providing scientific grounds for near-nature distribution pattern adjustment. We set up 15 long-term positioning and monitoring plots of 20 m × 20 m of L. kaempferi plantations in Xiaolongshan, Gansu Province, China, based on the Clark and Evans index, and applied the structure analysis method of the neighboring tree relationship to determine the standard angle of the uniform angle index of regularly distributed plantation forests. The changes in forest distribution patterns were compared before and after randomized management (R1 (dumbbell-shaped random unit), R2 (torch-shaped random unit) and R1:R2 = 1:2 models) and underlayer tending and unmanaged control (CK). The results showed that (1) Under different management modes, the distribution patterns obtained by the Clark and Evans index and the mean values of the uniform angle index were entirely the same; all stand patterns were evenly distributed. (2) Regardless of randomized management or underlayer tending, the number of trees in the even distribution was the largest, accounting for more than 40%. (3) The mean values of the uniform angle index of most stands increased obviously after randomized management, among which the R1 and R2 stands showed an upward trend, while the R1:R2 = 1:2 stands showed a slight decrease. However, the mean values of the uniform angle index of the stands with underlayer management showed a decreasing trend. (4) The proportion of random trees in most stands increased significantly after randomized management, increasing by 1%~19% compared with that before adjustment, while the proportion of random trees in the underlayer tending treatment decreased by 2%~10%. Our results suggest that (1) The method based on the modified uniform angle index standard angle could effectively improve the accuracy of the distribution pattern of individual trees in plantation forests and further improve the accuracy of the overall stand pattern quantitatively. (2) Randomized management significantly increased the proportion of random trees in the stands, which accelerated the evolution of the forest distribution pattern of the L. kaempferi plantation to a random distribution.

The potential role of an alien tree species in supporting forest restoration: Lessons from Shiretoko National Park, Japan

Restoring forests has recently received considerable attention in the context of sequestering carbon and supporting biodiversity. Although considering alien species as a tool for natural forest restoration still remains controversial, harnessing alien species when they are already present in an ecosystem might result in overall benefits for nature and society. In this study we evaluated whether the presence of an alien tree species supports or hinders the establishment of naturally regenerating forests in Shiretoko National Park, Japan. In particular, we focused on Larix kaempferi, which is widely present yet non-native to the region, and examined how this alien species affects two factors influencing the success of restoration: wind disturbance and deer herbivory. We examined the following effects of L. kaempferi plantations on natural regeneration: (1) the windbreak function for protecting native tree growth and (2) the nursery function to promote the regeneration of native tree saplings and seedlings under high herbivory pressure. We assessed tree height and regeneration, using large-scale remotely sensed data and terrestrial inventory data in five major vegetation types. We found that L. kaempferi plantations can protect native species from predominant winds. Additionally, L. kaempferi canopy cover promoted abundance and species richness in understory saplings and seedlings compared to other vegetation types such as primary and secondary forests, even under excessive browsing pressure. No regenerating L. kaempferi individuals were observed during the field census, suggesting the species is likely not invasive in our study system. The positive relationship between alien tree species and the regeneration of native tree assemblages emphasizes that existing alien species have the potential to act as nurse plants. Our findings imply that the presence of alien species can contribute to natural forest restoration by improving the local environmental conditions for native species in the short-term. Given the multiple ecological and social needs in our changing world, careful consideration is required to evaluate the long-term consequences of alien species. Especially in ecosystems in which alien species have already established, using their positive functions rather than swiftly eradicating them from the landscape might be beneficial for long-term restoration goals. We conclude that managers need to be aware of the context-dependency of alien species to make restoration more effective.

Temporal effects of thinning on the composition and growth of regenerated woody plants in Larix kaempferi plantations

Understanding the temporal effects of thinning on the composition and growth of regene-rated broadleaved woody species in coniferous plantations can provide profound references for promoting the conversion of monoculture plantations into mixed conifer-broadleaved forests, which could solve the problem that the production and ecological functions of monoculture plantations cannot be balanced. We compared the composition of regenerated woody plant species in Larix kaempferi plantation with short-term (1-3 years), medium-term (4-9 years) and long-term (>9 years) after thinning. Furthermore, we selected three regenerated tree species with higher importance value and reciprocal symbiosis with L. kaempferi, which differed in shade tolerance, including shade-intolerant species Quercus mongolica, intermediate shade-tolerant species Acer mono, and shade-tolerant species Tilia mandschurica. We analyzed the relationships between light conditions (i.e., canopy density) and the growth (i.e., base diameter and height) of those species in L. kaempferi plantation with different terms after thinning. The results showed that 46 species of regene-rated broadleaved woody plants were recorded in thinned plantations. The common and dominant tree in different terms after thinning was A. mono, and the shrub species were Lonicera japonica and Euonymus alatus. With the increasing time after thinning, species richness of regenerated trees decreased, but the ratio of tree to shrub species increased and the intermediate shade-tolerant tree species took the dominant position. The temporal effect of thinning on the growth of three tree species was affected by shade tolerance ability. Basal diameter and height of T. mandschurica were higher than those of Q. mongolica and A. mono. With the increases of time after thinning, basal diameter of T. mandschurica and height of A. mono were more sensitive to light, indicating that there were respectively "a shade tolerance strategy" and "a shade avoidance strategy" to adapt to the post-thinning environment. The effects of thinning on the composition and growth of regenerated broadleaved woody species in L. kaempferi plantations were significantly time-sensitive. When deve-loping thinning measures to promote the regeneration of broadleaved trees in plantations, we should consider to extend the thinning interval appropriately to ensure the growth of broadleaved tree seedlings (e.g., T. mandschurica and A. mono) and accelerate their migration into the canopy layer. This would promote the formation of mixed conifer-broadleaved forests and eventually realize the sustainable development of plantations.

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.

Effects of forestry practices on habitat variables and mammal abundance in a Japanese larch plantation

Forestry practices can lead to changes in wildlife habitat that could have lasting effects on the distribution of species. Hence, the aim of this study was to determine the effects of forestry practices on habitat variables and habitat use by mammals in three different stands (control, clear-cut and clear-cut with reserves) in a Japanese larch Larix kaempferi plantation from April to October in 2016 and 2017. We recorded the presence of field signs for the following six mammal species: Korean hare Lepus coreanus, raccoon dog Nyctereutes procyonoides, Eurasian badger Meles meles, water deer Hydropotes inermis, roe deer Capreolus pygargus and wild boar Sus scrofa. Habitat variables significantly differed among three stands. Field sign (feces, foot prints and feeding signs) abundances of mammals showed significant differences between the control and clear-cut stands. Moreover, field sign abundances of all species were highest in the clear-cut with reserves stand. We calculated the impact of clear-cutting on habitat use by mammals using GLMMs. Both clear-cutting in the models were significant and had positive coefficients on habitat use by Korean hare, raccoon dog, deer and wild boar. In Eurasian badger models, only clear-cutting with reserves show positive impacts on habitat use. Habitat selection by forest edge species such as Korean hare and deer showed dependence on understory structure. Abundant understory in the clear-cut with reserves stand may not only provide vegetative food and cover for herbivores but also small prey species for omnivores and carnivores. The results of our study show that forest understory is one of the most instrumental factors mitigating the effects of clear-cutting on habitat use by mammal and it should, therefore, be given due importance in forestry practices.

DBH growth for three years after thinning on even-aged Pinus koraiensis and Larix kaempferi plantations in South Korea

This study was conducted to determine the effects of different thinning intensities on the DBH growth of Pinus koraiensis and Larix kaempferi trees. Permanent monitoring plots were installed in 26 P. koraiensis plantations and 36 L. kaempferi plantations in 2012 and 2014, respectively. To evaluate the effect of thinning intensity, each plot consisted of three square or rectangular plots; control or non-thinned, light thinning, in which 20% of the total basal area was removed, and heavy thinning, in which 40% of the total basal area was removed. The mean DBH increments for 3 years were computed and compared across thinning intensities. Other factors, such as slope, altitude, or stand density, were compared across thinning treatments to understand why DBH increment did not follow thinning intensity. Overall mean DBH increment for 3 years after thinning was affected by different thinning intensities: heavy thinning > light thinning > control. ANOVA showed that there was a significant difference in DBH increment among thinning intensities in both species. Also, Duncan’s multiple range test showed that all thinning treatments were significantly different from each other. Other factors that affect DBH besides thinning intensity were identified, such as residual basal area, slope gradient, and aspect.

Effects of N-fixing tree species (Alnus sibirica)on amino sugars in soil aggregates of Larix kaempferi plantation in eastern Liaoning Province, China.

Soil microbial residues are important components of soil stable carbon (C) pools. How N-fixing tree species influence microbial residues in soil aggregates in larch plantations is still unclear. To determine the effects of N-fixing tree species on the distribution of microbial residues in different aggregates, we compared the distribution of amino sugars, biomarker of microbial residues, among aggregates in a pure larch (Larix kaempferi) plantation and a mixed plantation of larch (Larix kaempferi) and alder (Alnus sibirica) in eastern Liaoning Province. The results showed that alder did not affect the distribution of amino sugars, but significantly increased amino sugars content in soil aggregates. The total amino sugars in different soil aggregates were enriched by 130%-170% in the mixed larch plantation compared with those in pure larch plantation. The contributions of glucosamine, galactosamine and muramic acid to the increases of total amino sugars caused by alder introduction were 66.5%-66.9%, 30.0%-30.6% and 2.5%-3.2%, respectively. Alder introduction significantly accelerated the glucosamine/muramic acid ratios in >2000 μm and <250 μm aggregates, but not in 250-2000 μm aggregates. Moreover, alder introduction increased the microbial contribution to soil organic C in all aggregates, but did not influence this contribution among aggregates, indicating that the effects of alder introduction on microbial contribution to aggregates were homogeneous.

Different responses in leaf-level physiology to competition and facilitation under different soil types and N fertilization

Knowledge of how competition and facilitation affect photosynthetic traits and nitrogen metabolism contributes to understanding of plant-plant interaction mechanisms. We transplanted two larch species, Larix kaempferi and L. olgensis, to establish intra- and interspecific interaction experiments under different types of soil. Experiment 1: Two different soil types were selected, one from a c. twenty years old L. kaempferi plantation (named larch soil) and another from a secondary natural forest (named mixed forest soil). The experiment included three types of plant interactions (L kaempferi + L. kaempferi, L. olgensis + L. olgensis, and L. kaempferi + L. olgensis) and two soil types. Experiment 2: N fertilization was applied to larch soil. The experiment included the same three types of plant interactions as in Experiment 1 and two N treatments. The growth of L kaempferi was negatively affected by larch soil and accelerated by N fertilization, particularly under interspecific interaction. The effects of soil type combined with plant-plant interactions or N fertilization influenced the chlorophyll pigment content, net photosynthetic rate (Pn), photosynthetic N use efficiency (PNUE) and total non-structural carbohydrates of leaves (TNC). Chl a/Chl b (ratio of chlorophyll a to chlorophyll b) was higher when the growth of L. kaempferi was facilitated by the presence of L. olgensis in mixed forest soil. However, the ratio significantly declined when L. kaempferi confronted strong competition from L. olgensis in larch soil without N fertilization. Under N fertilization in larch soil, Chl a/Chl b of L. olgensis significantly increased by the presence of L. kaempferi. Plant-plant interactions and soil types affected the number of chloroplasts, especially in L. kaempferi, which had a greater number of chloroplasts under interspecific interactions than in monoculture when growing in mixed forest soil. L. olgensis enhanced its ability to absorb N-NO3− under interspecific interactions in larch N- soil, while L. kaempferi enhanced its ability to absorb N-NH4+ under interspecific competition in mixed forest soil. Competition or facilitation modified the photosynthetic traits and nitrogen metabolism depending on the type of soil. Differences in these physiological processes contribute to divergent performance among individuals growing under interspecific or intraspecific competition, or in isolation.

赤杨对辽东落叶松人工林土壤氨基糖积累的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 赤杨对辽东落叶松人工林土壤氨基糖积累的影响 DOI: 10.5846/stxb201705150897 作者: 作者单位: 沈阳农业大学;沈阳农业大学,中国林业科学研究院森林生态环境与保护研究所,沈阳农业大学,沈阳农业大学,沈阳农业大学,沈阳农业大学,沈阳农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 东北低山丘陵区大流域尺度防护林体系景观格局调控技术（2015BAD07B030103） Effects of N-fixing tree species (Alnus sibirica) on amino sugars in the soils of a Larix kaempferi plantation in eastern Liaoning Province, China Author: Affiliation: Shenyang Agricultural University,,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:微生物残留物是土壤稳定性碳库的重要组成部分，然而其对固氮树种的响应还不清楚。以辽东山区日本落叶松（Larix kaempferi）人工纯林和落叶松-赤杨混交林为研究对象，以氨基糖作为微生物残留物的生物标识物，研究了赤杨对落叶松人工林根际和非根际土壤氨基糖积累的影响。结果表明，混交林中落叶松根际和非根际各氨基糖单体含量均显著高于纯林，说明赤杨引入有利于土壤微生物残留物的积累。其中，混交林落叶松根际及非根际土壤氨基糖葡萄糖含量分别比纯林高出99.5%（P<0.01）和154%（P<0.01）；胞壁酸含量分别比纯林高出66.1%（P<0.01）和132.3%（P<0.01）。赤杨引入对氨基葡萄糖/胞壁酸比值的影响不显著，但显著增加氨基糖对土壤有机碳的贡献。冗余度分析表明全氮是驱动土壤中氨基糖发生变化的主要因子。表明赤杨引入显著提高微生物固持的土壤碳库和有机碳稳定性，这对落叶松人工林合理经营具有重要意义。 Abstract:Microbial residues are an important component of soil stable carbon (C) pools. However, their response to N-fixing tree species is still unclear. The present study investigated the effects of alder (Alnus sibirica) on microbial residues (as indicated by amino sugars) in the rhizosphere and non-rhizosphere soils of a larch (Larix kaempferi) plantation in eastern Liaoning Province, China. The contents of individual amino sugars significantly increased in the larch rhizosphere and non-rhizosphere soils in the mixed plantation relative to the pure plantation, indicating that alder benefits microbial residue accumulation. Specifically, the glucosamine (GluN) contents were 99.5% (P<0.01) and 154% (P<0.01) higher in the larch rhizosphere and non-rhizosphere soils in the mixed plantation than in the pure plantation, respectively, while the muramic acid (MurN) contents in the rhizosphere and non-rhizosphere soils were 66.1% (P<0.01) and 132.3% (P<0.01) higher in the mixed plantation than in the pure plantation, respectively. We found that alder had no effect on the GluN/MurN ratio, but significantly enriched the amino sugar proportion of soil organic C. Redundancy analysis revealed that total nitrogen was the dominant factor driving changes in amino sugars. This study indicates that alder would significantly stimulate the microbial fixation of C and the stability of soil organic C, which means that it plays a vital role in managing larch plantations. 参考文献 相似文献 引证文献

Influence of tree thinning on the abundance of mammals in a Japanese larch Larix kaempferi plantation

ABSTRACTWe examined the influence of tree thinning on the abundance of mammals in a Japanese larch Larix kaempferi plantation in Mt Gariwang, Pyeongchang, South Korea. In 2014 and 2015, from April to October, we recorded the presence of tracks as a proxy for abundance, for the following seven mammalian species: Korean hare Lepus coreanus, raccoon dog Nyctereutes procyonoides, Siberian weasel Mustela sibirica, Eurasian badger Meles meles, water deer Hydropotes inermis, roe deer Capreolus pygargus, and wild boar Sus scrofa. We also assessed how the intensity of tree thinning affected vegetation cover; there were significant differences in number of standing trees, basal area, coverage of vegetation layers, and number and volume of downed trees among the control, moderately thinned, and intensively thinned stands. We found significant differences in the abundance of tracks among the stands for three mammal species. In four mammal species, the abundance of track was significantly correlated with volume of downed trees, coverage of ground vegetation, number of downed trees, and number of standing trees, according to stepwise analysis. The presence and abundance of mammals is linked to habitat variables and forest managers should consider how habitat modifications will affect wildlife.

Influence of soil qualities on intra- and interspecific competition dynamics of Larix kaempferi and L. olgensis

Forest management has potential to detrimentally impact long-term plantation productivity. Establishment of mixed plantations and fertilization are two important management approaches when trying to maintain soil qualities and productivity. In this study, two types of experiments were conducted to investigate the influence of soil qualities on intra- and interspecific competition dynamics in two larch species. Experiment 1: We transplanted two deciduous larch species, Larix kaempferi and L. olgensis, to study intra- and interspecific competition dynamics in two different types of soil: one from a c. twenty years old L. kaempferi plantation (named larch soil) and another from a secondary natural forest (named mixed-forest soil). Experiment 2: Effects of N fertilization on the competition dynamics of the two larch species were tested in the larch soil. In the experiment 1, we hypothesized that the growth of L. kaempferi in the larch soil under no fertilization is inhibited when competing with L. olgensis, and their competition relationships may be different in the mixed-forest soil. In both species, the starch and TNC (total non-structural carbohydrate) concentrations of roots and shoots were significantly higher in the mixed-forest soil when compared to the concentrations in the larch soil without N fertilization (N−). The relative competition intensity (RCI) was affected by the soil type. RCI of L. olgensis was higher than that of L. kaempferi in the larch soil N- condition, and RCI of L. kaempferi was higher than that of L. olgensis in the mixed-forest soil in 2015. However, the RCI values did not show significant differences in 2014. In the experiment 2, L. kaempferi showed superior competitiveness in the larch soil N+ condition, with the highest RCI value in 2014, but the RCI value of L. kaempferi declined while the RCI value of L. olgensis increased from 2014 to 2015. Both experiments indicated that the benefiting species had higher element (C, N and P) and non-structural carbohydrate (starch and soluble sugar) content accumulation ratios from 2014 to 2015. We found that competition relationships changed between years and depending on conditions. We suggest that mixed plantations and N fertilization together could effectively promote the productivity of Larix.

Biomass, carbon storage and nutrient characteristics in Larix kaempferi plantations at diffe-rent stand ages

Based on 7-, 17-, 30-, and 40-year-old Larix kaempferi plantations, this paper studied the influence of tree age on biomass, carbon storage and nutrient characteristics. There was significant difference in biomass and nutrient concentration of stem, bark, needle, branch and root at different development stages at individual tree level. The biomass of each organ showed a trend of increase with the increasing age. The concentrations of N, P, K decreased, Mg concentration increased at first and then decreased, and Ca concentration continued to rise with the increasing age. There was significant difference in biomass of each organ for dominant, intermediate and suppressed trees, but no significant difference in nutrient concentration. It indicated that nutrient concentration of each organ was not affected by competition. At stand level, the total biomass, carbon storage and nutrient accumulation increased with the increasing age. Compared with young stand, the growth rate of biomass, carbon storage and nutrient accumulation were increased by 217%, 218% and 56% in mature stand, respectively. It indicated L. kaempferi had a high nutrient use efficiency, and could utilize less nutrient to produce more dry matter. Except that the accumulation of P and K had a slight decrease in pre-mature stand (30 years old), other elements increased with the increasing age. N mainly concentrated in needle, Ca concentrated in stem, K and Mg concentrated in root and P was distributed evenly in different organs. The annual accumulation rates of biomass, carbon and nutrient of L. kaempferi stands decreased with the increasing age, from 7.16 t·hm-2, 3.40 t·hm-2 and 104.64 kg·hm-2 for young stand to 3.99 t·hm-2, 1.89 t·hm-2and 28.64 kg·hm-2 for mature stand, respectively. It indicated that L. kaempferi plantations had great carbon sequestration potential and high nutrient consumption during young and middle ages.