Cunninghamia Lanceolata Plantation Research Articles

Effect of Stand Density and Soil Layer on Soil Nutrients of a 37-year-old Cunninghamia lanceolata Plantation in Naxi, Sichuan Province, China

In order to study the characteristics of soil nutrient elements and the changes in biomass under different densities and soil layers of forest stand, this paper considers Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) density test forests with five densities (A: 1667 trees·ha−1; B: 3333 trees·ha−1; C: 5000 trees·ha−1; D: 6667 trees·ha−1; E: 10,000 trees·ha−1) as the research objects, located in Naxi District, Sichuan Province, China. Eleven soil physical and chemical property indicators, understory vegetation, and litter biomass were measured. The results were as follows: (1) The stand density had a significant effect on the soil nutrient content, understory vegetation, and litter biomass. A low density is conducive to the accumulation of soil organic matter, hydrolytic N, available P, available K, and total Ca. (2) With the increase in soil depth, the contents of soil organic matter, total N, hydrolytic N, and total P decreased gradually; pH and total Ca decreased gradually; and available P showed a trend of decrease-up-decrease. The soil layers had no significant effect on the total K, total Fe, and total Mg concentrations. (3) Low density (density A or B) was found to be beneficial to the growth of undergrowth vegetation and forest trees, the return of nutrients, long-term soil maintenance, and the stable high yield of Chinese fir plantations.

Characteristics of soil microbial biomass carbon and nitrogen and its seasonal dynamics in four mid-subtropical forests

Taking evergreen broad-leaved forest in mid-subtropical areas, and its converted Phoebe bournei, Phyllostachys heterocycla and Cunninghamia lanceolata plantations as research objects, microbial biomass carbon (MBC) and nitrogen (MBN) in the surface (0-10 cm) and deep soil layer (40-60 cm) were measured by chloroform fumigation and extraction method, with their seasonal dynamics and the relationships with soil physicochemical properties in four types of forests being investigated. The results showed that the MBC and MBN in the surface soil was the highest in the evergreen broad-leaved forest, followed by P. bournei, P. heterocycla and C. lanceolata plantations, with that in the former three being significantly higher than in C. lanceolata plantion. There was no significant difference in the MBC and MBN contents in the deep soil layer among the four types of forests, while those in surface soil were significantly higher than in the deep soil layer. The MBC and MBN contents showed obvious seasonal dynamics, with highest values in summer and lowest in winter presenting a single peak change pattern. MBC and MBN had significantly positive correlations with soil total carbon (TC), total nitrogen (TN) and temperature, but significantly negative correlation with soil bulk density. The conversion of evergreen broad-leaved forest to the three plantation resulted in lower MBC and MBN in the surface soil to some degree, with C. lanceolata plantation being the first to be affected, but little change occurred in the deep soil layer. The quantity and quality of litter, contents of TC, TN and soil temperature were the key factors driving the differences of MBC and MBN contents and their seasonal dynamics of the four types of forests.

杉木人工林下原生与引入树种叶性状变异特征

PDF HTML阅读 XML下载 导出引用 引用提醒 杉木人工林下原生与引入树种叶性状变异特征 DOI: 10.5846/stxb201809202054 作者: 作者单位: 中国林业科学研究院亚热带林业研究所,中国林业科学研究院亚热带林业研究所,中国林业科学研究院亚热带林业研究所,中国林业科学研究院亚热带林业研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2017YFC0505500，2017YFC0505502） Variations in leaf traits of native and introduced tree species in Cunninghamia lanceolata plantations Author: Affiliation: Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Research Institute of Subtropical Forestry,Chinese Academy of Forestry 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:叶性状在表征植物资源利用和生存策略方面具有重要作用。构建异龄复层林是改造人工纯林的有效措施，探究引入与原生树种叶性状变异有利于林下伴生树种的筛选。研究了引入乔灌木树种（如闽楠、蚊母树等13个树种）与原生乔灌木树种（苦槠、红紫珠等6个树种）的叶片形态、光合色素、碳氮磷生态化学计量和非结构性碳水化合物特征。结果表明：（1）总体上引入与原生乔木和灌木树种的叶形态性状差异较小，原生乔木的叶长和比叶面积显著小于引入树种与原生灌木。引入与原生树种间光合色素具有显著差异，引入乔木叶绿素含量显著高于原生乔木，不同功能群植物的比叶面积.叶绿素关系格局存在策略位移现象。引入树种叶碳含量显著大于原生树种，叶氮和叶磷含量显著大于原生乔木；引入树种和原生灌木的碳、氮、磷养分含量的变异系数较大；引入与原生树种叶碳氮磷生态化学计量没有一致变化规律。引入灌木叶可溶性糖含量、原生灌木淀粉含量均显著高于乔木树种，灌木的非结构性碳水化合物总量也显著高于乔木。（2）引入与原生树种叶性状呈显著协同变化趋势。所有叶性状中，比叶面积、叶绿素含量、叶氮含量、叶磷含量在乔木和灌木中均呈极显著正相关关系。主成分分析显示，引入乔木和灌木树种的叶性状接近，引入树种与原生灌木之间叶性状差异相对较小，但与原生乔木间的叶性状差异较大。总体上引入树种的叶性状与原生树种具有趋同适应特征，但不同生活型植物叶性状在林下弱光环境中仍产生一定分异，引入灌木可能比引入乔木更适应杉木林下生境。 Abstract:Leaf traits of plants play crucial roles in determining resource utilization and survival strategies. Single-layered monoculture plantations are converted to multi-layered mixed plantations is an effective measure to improve plantation quality. To study the variation of the leaf traits of introduced and native species is beneficial to select the associated tree species under forest. This study assessed the traits of leaf morphology, photosynthetic pigments, carbon, nitrogen and phosphorus ecological stoichiometry, and non-structural carbohydrates of introduced arbors and shrubs species (such as Phoebe bournei and Distylium racemosum) and native arbors and shrubs species (such as Castanopsis sclerophylla and Callicarpa rubella). The results showed that leaf length and specific leaf area of native arbors were significantly smaller than those of the introduced species and native shrubs, and the other leaf morphological traits were little difference between introduced and native species. Photosynthetic pigment content differed markedly between the introduced and native species, and the chlorophyll content of native arbors was significantly lower than that of the introduced arbors. The relationship of specific leaf area and chlorophyll varied among different functional groups. The leaf carbon content of the introduced tree species was distinctly higher than that of the native tree species, and the leaf nitrogen and phosphorus contents were significantly higher than those of the native arbors. The coefficients of variation of nutrient contents of the introduced species and native shrubs were higher than that of the native arbors. The variations in leaf carbon, nitrogen, and phosphorus eco-stoichiometry differed in the introduced and native tree species. The soluble sugar content in the introduced shrubs and the starch content in the native shrubs were markedly higher than those of arbors, and the content of the non-structural carbohydrates in the shrubs was distinctly higher than that in the arbors. The leaf traits of the introduced and native tree species showed a significant synergistic change. For the arbor and shrub species, there was a marked positive correlation among the leaf area, chlorophyll content, and leaf nitrogen and phosphorus contents. Based on principal component analysis (PCA), the leaf traits were similar between the introduced arbors and shrubs. The differences of leaf traits were relatively smaller between introduced tree species and native shrubs, while there was a large difference between introduced tree species and native arbors. The leaf traits of introduced and native tree species showed convergent adaptation. However, the leaf traits of different life forms still had some differences in the low-light environment. The introduced shrubs may be more suitable for the understory environments in Cunninghamia lanceolata. 参考文献 相似文献 引证文献

Effects of precipitation exclusion and warming on soil soluble carbon and nitrogen in a young Cunninghamia lanceolata plantation

Soil soluble carbon and nitrogen play important roles in soil carbon and nutrient cycles and are highly sensitive to climate change, as they can be directly used by microorganisms. We used Tension Lysimeter to collect soil solution in 50% precipitation exclusion (P) and warming (5 ℃) plus 50% precipitation exclusion (WP) treatments in a 2 year-old Cunninghamia lanceolata plantation in subtropics, to examine the effects of precipitation and temperature on soil soluble carbon and nitrogen concentrations in soil profile. Results showed that neither P treatment nor WP treatment changed seasonal dynamics of soil dissolved organic carbon (DOC) concentration, with maximum value at October among all treatments. DOC concentration was increased in both P and WP treatments in the whole soil profile, especially in 60 cm soil depth. Compared with the control, DOC concentration was increased by 30.4%-88.7% and 32.8%-137.6% in P and WP treatments, respectively, with the most obvious difference being found in October. DOC concentration was decreased with the increases of soil depth in the control, but no significant difference among different soil layers were found in P and WP treatments. NO3--N concentration was increased by 221.1%-931.0% in WP treatment. Therefore, precipitation reduction might increase losses of C and N from soil solution in subtropical forest, due to improvement of soil permeability by the increases of fine roots grown into deep soil, which might stimulate soil microorganism activities and soil organic matter decomposition. Furthermore, warming would exacerbate the risk of C and N losses.

Effects of precipitation reduction on the composition and stability of soil organic matter in a young Cunninghamia lanceolata plantation.

It is hard to predict the response of soil organic matter (SOM) to global climate change due to its heterogenous chemical structure. With the development of molecular techniques to identify the structure, sources and stages of SOM degradation, long-standing questions regarding the composition and stability of SOM might be resolved. To investigate the effects of changes in precipitation patterns on the stability of SOM, we analyzed the specific compositions and extent of degradation of SOM using biomarkers, in a young Cunninghamia lanceolata plantation after reducing 50% of precipitation (P) for two years. The results showed that precipitation reduction (P-treatment) significantly reduced the levels of free lipids. Relative to control (CT), P-treatment decreased short-chain n-alkanoic acids (C16-18) and terpenoids and steroids by 62.8% and 19.1%, respectively. However, P-treatment did not significantly change the concentrations of other aliphatic compounds. Although there was no observable difference in the total lignin content between treatments, P-treatment significantly reduced the acid to aldehyde ratios for syringyl [(Ad/Al)s] and vanillyl [(Ad/Al)v]. Thus, the labile compositions of SOM were accelerated to decomposition under rainfall pattern change. Although the recalcitrant compositions (lignin) were relatively stable, their long-term stability should be further monitored.

Dynamics of nutrient concentration and microbial community composition during fine root decomposition in subtropical Mytilaria laosensis and Cunninghamia lanceolata plantations.

We conducted a 12-month fine root decomposition experiment under 19-year-old Mytilaria laosensis and Cunninghamia lanceolate plantations to explore the dynamics of nutrient concentration and microbial community composition. The aim of this study was to provide insights into nutrient cycling under plantations with different tree species. Our results showed that the initial concentrations of phosphorus (P) and potassium (K) were significantly higher in the fine root of M. laosensis than those in C. lanceolata, which significantly decreased with decomposition. Nitrogen (N) concentration in fine roots of both species increased with decay time. The variation of N concentration in fine root of C. lanceolata lagged behind that in M. laosensis. During the decomposition, magnesium (Mg) concentration in fine root of C. lanceolata showed no significant changes, but that of M. laosensis decreased at the initial decay stage and increased thereafter and was significantly lower than that of C. lanceolata at the 8th month. The ratio of fungi to bacteria (F/B) of both species decreased at the initial stage and then increased, with significantly higher F/B in fine root of M. laosensis than that of C. lanceolate after one-year decay. Redundancy analysis (RDA) showed that changes in N and K concentrations and C/N ratio explained 37.2%, 14.5% and 14.8% of the variations in microbial community composition of C. lanceolata fine root respectively. However, during the decay of M. laosensis fine root, concentrations of Mg and K were key factors, accounting for 35.9% and 17.6% of the variations in microbial community composition, respectively. We concluded that other nutrients beyond N, such as Mg, might also be an important factor affecting root decomposition in different tree species.

Effects of short-term warming and nitrogen addition on the quantity and quality of dissolved organic matter in a subtropical Cunninghamia lanceolata plantation.

Increasing temperature and nitrogen (N) deposition are two large-scale changes projected to occur over the coming decades. The effects of these changes on dissolved organic matter (DOM) are largely unknown. This study aimed to assess the effects of warming and N addition on the quantity and quality of DOM from a subtropical Cunninghamia lanceolata plantation. Between 2014 and 2016, soil solutions were collected from 0–15, 15–30, and 30–60 cm depths by using a negative pressure sampling method. The quantity and quality of DOM were measured under six different treatments. The spectra showed that the DOM of the forest soil solution mainly consisted of aromatic protein-like components, microbial degradation products, and negligible amounts of humic-like substances. Warming, N addition, and warming + N addition significantly inhibited the concentration of dissolved organic carbon (DOC) in the surface (0–15 cm) soil solution. Our results suggested that warming reduced the amount of DOM originating from microbes. The decrease in protein and carboxylic acid contents was mostly attributed to the reduction of DOC following N addition. The warming + N addition treatment showed an interactive effect rather than an additive effect. Thus, short-term warming and warming + N addition decreased the quantity of DOM and facilitated the migration of nutrients to deeper soils. Further, N addition increased the complexity of the DOM structure. Hence, the loss of soil nutrients and the rational application of N need to be considered in order to prevent the accumulation of N compounds in soil.

中亚热带不同森林更新方式生态酶化学计量特征

PDF HTML阅读 XML下载 导出引用 引用提醒 中亚热带不同森林更新方式生态酶化学计量特征 DOI: 10.5846/stxb201803130498 作者: 作者单位: 福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院,福建师范大学地理科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41401346，31670620）；海峡联合基金项目（U1505233） Patterns of eco-enzymatic stoichiometry in mid-subtropical forest regeneration Author: Affiliation: School of Geography, Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,School of Geography, Fujian Normal University,Fujian Normal 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:了解土壤生态化学计量特征对预测不同生态系统养分变化、功能以及植物生产力具有重要意义。森林更新是维持中亚热带森林生态系统可持续发展的重要手段。选取福建省三明市陈大林业采育场3种不同森林更新方式进行研究，包括米槠次生林（SF）、米槠人工促进天然更新林（AR）和杉木人工林（CF），测定其土壤理化性质及土壤3种酶，计算酶化学计量。结果显示：1）AR的土壤总氮、全磷、铵态氮含量以及含水量最高（P < 0.05），土壤有效磷的含量则是CF最高（P < 0.05）；2）生态酶化学计量结果表明AR的土壤微生物处于氮限制状态，CF的土壤微生物处于磷限制状态；3）冗余分析表明，土壤含水量和铵态氮是驱动不同森林更新方式土壤生态酶化学计量变异的重要环境因子。研究表明，人促更新方式更有利于土壤有效氮的积累，而人工林则有利于土壤有效磷积累，这可能与造林树种有关。土壤生态酶化学计量更易受到土壤含水量以及有效性养分的驱动，而与土壤化学计量未呈现良好的耦合性。 Abstract:Understanding the characteristics of soil ecological stoichiometry is important for predicting nutrient changes, plant productivity, and ecosystem functions in different ecosystems. Forest regeneration is an important approach to accomplish sustainable development of mid-subtropical forest ecosystems. Therefore, in this thesis, three contrasting ways of forest regeneration were selected for study in the Chenda state-owned forestry farm in Fujian; namely, Castanopsis carlesii forest (SF), human-assisted naturally regenerated Castanopsis carlesii forest (AR), and Cunninghamia lanceolata plantation (CF). Additionally, different physical and chemical soil properties were examined, along with three types of soil enzymes, and eco-enzymatic stoichiometry was calculated. Our results revealed the following:1) the soil contents of total nitrogen, total phosphorus, ammonium nitrogen, and moisture were the most significant in the human-assisted naturally regenerated Castanopsis carlesii forest(P < 0.05), while soil content of available phosphorus was the highest in the Cunninghamia lanceolata plantation(P < 0.05); 2) according to the eco-enzymatic stoichiometry calculation, the state of soil microorganisms were restricted by nitrogen availability in the human-assisted naturally regenerated Castanopsis carlesii forest, and by phosphorus availability in the Cunninghamia lanceolata plantation; 3) as redundancy analysis showed, the content of soil moisture and ammonium nitrogen are important environmental factors that influence the eco-enzymatic stoichiometry of different forest regeneration methods. Generally, human-assisted natural regeneration is more beneficial to soil mineral nitrogen accumulation, while artificial forest regeneration is conducive to accumulation of available phosphorus in the soil, which may be related to the tree species selected for afforestation. Soil eco-enzymatic stoichiometry is more likely to be driven by soil moisture content and nutrient availability than by soil stoichiometry. 参考文献 相似文献 引证文献

Assessing influence of simulated canopy nitrogen deposition and understory removal on soil microbial community structure in a Cunninghamia lanceolata plantation

Assessing influence of simulated canopy nitrogen deposition and understory removal on soil microbial community structure in a Cunninghamia lanceolata plantation

Effects of nitrogen deposition on diversity and composition of soil bacterial community in a subtropical Cunninghamia lanceolata plantation.

The increasing rate of atmospheric nitrogen (N) deposition has become the focus of research attention. Soil bacterial community plays an important role in soil nutrient cycling. We stimulated N deposition at the Forest Ecosystem of Fujian Normal University and Global Change Research Station in Chenda Town, Sanming City in the Fujian Province of China. We examined the effect of N deposition on the structure and composition of soil bacterial community using 16S rDNA amplification sequencing. The results showed that short-term addition of N had no significant effect on the soil bacterial diversity and composition, but high N treatment significantly affected therelative abundance of individual bacterial species, which increased the abundance of Copiotrophic group and decreased that of the corresponding Oligotrophic group, indicating that changes in soil bacterial nutrient strategies were driven by the availability of nutrients. Enhanced understanding of the responses of soil bacterial community and nutrient distribution pattern to rapid N deposition could improve the prediction ability about the future environment.

增温和施氮对亚热带杉木人工林土壤溶液养分的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 增温和施氮对亚热带杉木人工林土壤溶液养分的影响 DOI: 10.5846/stxb201704290787 作者: 作者单位: 福建师范大学,福建师范大学,福建师范大学,福建师范大学,福建师范大学,福建师范大学,福建师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31670620，U1505233）；福建省科技厅科技项目（2016R1032-2） The effects of warming and nitrogen addition on soil nutrients in the soil solutions from a subtropical Cunninghamia lanceolata plantation Author: Affiliation: Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University,Fujian Normal University Fund Project: the national natural science foundation of china（31670620；U1505233）；Fujian Provincial Department of science and technology project(2016R1032-2) 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:在增温和氮沉降等气候变化背景下，土壤溶液养分元素供应是否平衡对加速或减弱土壤养分循环起着至关重要的作用。为探究增温和施氮对亚热带杉木人工土壤溶液养分动态的影响，分别于各样地的0-15、15-30cm和30-60cm土层安装土壤溶液采集器。利用真空泵的负压原理采集土壤溶液，对其有机组分及无机组分进行了两年的动态监测。结果显示：增温及增温+施氮显著增加了各土层溶解性总氮（DTN）及硝态氮（NO3-）浓度，而施氮促进了植被对其的大量吸收而未呈现显著的促进作用。整体而言，短期增温和施氮处理显著降低了可溶性有机碳（DOC）浓度，对土壤溶液K+、Ca2+、Na+、Mg2+等离子含量影响较小。但相比于施氮，增温对土壤溶液中矿质元素的影响远大于施氮。增温导致的土壤孔径增大，通透性增强可极大地促进Fe3+、Al3+淋溶，同时导致表层Na+、Mg2+离子含量显著降低。增温+施氮交互作用对土壤溶液各养分的影响存在叠加效应，但并不是增温和施氮单因子的简单累加，要深入了解土壤养分对未来气候变迁的内部机制需进一步长期监测。 Abstract:Climate change can alter soils by causing warming and nitrogen deposition. It is not clear whether the nutrient supply balance in the soil solution plays an important role in accelerating or weakening soil nutrient cycling. The aim of this study was to analyze the effects of warming and nitrogen addition on nutrients in the soil solutions taken from a subtropical Cunninghamia lanceolata plantation. Soil solution collectors were installed at soil depths of 0-15, 15-30, and 30-60cm in every sample plot. The soil solutions were collected using the negative pressure supplied by a vacuum pump, and the dynamic changes to the organic and inorganic components were analyzed for two years. The results showed that warming and warming+N addition significantly inhibited the dissolved total nitrogen (DTN) and NO3- concentrations in all the soil layers, and N addition had no significant effect on them due to the increase in mass vegetation absorption of these nutrients. In general, the short-term treatments of warming and N addition significantly decreased the concentrations of dissolved organic carbon (DOC), but had little effect on the K+, Ca2+, Na+, and Mg2+ concentrations in the soil solution. However, the effect of warming on the mineral elements in the soil solution was much greater than that of N addition. Warming increased the soil pore-size and permeability, which greatly promoted Fe3+ and Al3+ leaching and decreased Na+ and Mg2+ concentrations in the surface soil. The interaction between warming and N addition may have a combined effect that is more than the simple addition of a single factor. Therefore, further long-term monitoring to understand the internal mechanism of soil nutrient response to future climate change is needed. 参考文献 相似文献 引证文献

The effects of different human disturbance regimes on root fungal diversity ofRhododendron ovatumin subtropical forests of China

Ericoid mycorrhizal associations are a symbiotic relationship between soil fungi and ericaceous plants. Diversity of fungi associated with hair roots of ericaceous plants may vary as a result of frequent disturbances by human activities. The fungal diversity and communities associated with hair roots of Rhododendron ovatum were investigated along a human disturbance gradient in subtropical forests of China. Nine hundred fungal operational taxonomic units were determined by high-throughput sequencing, including different phyla such as Ascomycota, Basidiomycota, Zygomycota, Chytridiomycota, and Glomeromycota. The dominant phylum in Cunninghamia lanceolata plantations and old-growth forest was Ascomycota, while Basidiomycota was the dominant phylum in secondary forests. The indicator species analyses showed that more pathogenic indicator fungi appeared in the disturbed forests, whereas more putative ericoid mycorrhizal fungi existed in the old-growth forests. Principal component analysis also showed that the fungal communities in the hair roots of R. ovatum were distinct between natural forests and plantations, suggesting that the fungal communities associated with hair roots of R. ovatum after logging were resilient and could recover to predisturbance status. The results of envfit analysis showed that performance of host plants rather than accompanying plant community and soil parameters of plots was the key determinant of the root-associated fungal community of R. ovatum.

Variations of water use efficiency and foliar nutrient concentrations in Cunninghamia lanceolata plantations at different ages

We studied water use efficiency (WUEi), nitrogen (N) and phosphorus (P) status of leaves at different leaf ages (current year, 1-, 2-, and 3-year-old foliage) as well as their relationships in a subtropical chronosequence of Chinese fir (Cunninghamia lanceolata) forests (3-, 8-, 14-, 21- and 46-year-old). The results showed that foliar WUEi varied significantly with foliar age in the order of current year foliage > 1-year-old foliage > 2-year-old foliage > 3-year-old foliage, while stand age had no significant impact on foliar WUEi. Foliar N/P ranged from 11.4 to 19.6 and was higher in younger and older stands than in stands at the fast-growing stage. The foliar N and P concentrations tended to display similar trends with foliar ages in the order of current year foliage>1-year-old foliage>2-year-old foliage>3-year-old foliage. WUEi did not change significantly with stand ages, probably because the photosynthetic rates and stomatal conductance decreased simultaneously with stand age. There was no relationship between WUEi and foliar N. WUEi had significant positive correlation with foliar P and significant negative correlation with foliar N/P. It is indicated that foliar P concentration would be a key factor affecting WUEi with increasing atmospheric N deposition in subtropical forests.

Seasonal dynamics of soil mineral nitrogen pools and nitrogen mineralization rate in different forests in subtropical China

We conducted an in situ incubation experiment to determine soil mineral N (NH4+-N and NO3--N) concentrations and soil net N mineralization rates (net ammonification rate and net nitrification rate) using close-top PVC tubes in three adjacent forests (natural forest, Castanopsis kawakamii and Cunninghamia lanceolata plantation) from September 2014 to August 2015 in subtropical China, investigating the effects of forest type and season on soil inorganic N concentrations and soil net N mineralization rates. Results showed that soil NO3--N was the dominant form in mi-neral N pool in all three forests, and the proportion of NO3--N to soil inorganic N content ranged from 55.1% to 87.5% and from 56.1% to 79.1% in natural forest and Cunninghamia lanceolata plantation, respectively. The effects of forest types on soil mineral N pool were only significant on soil NO3--N, and the concentration of NO3--N in Castanopsis kawakamii was significantly lower than in the other two forests. The NO3--N and mineral N pool varied seasonally in all forests, and were higher in dormant season (October to February) than in growing season (March to September). Soil nitrification rate was very low in the whole year in all three forests and soil net ammonification was the major process of soil net mineralization. Tree species significantly affected soil net ammonification rate, and the value under Chinese fir was significantly lower than the other two fore-sts. The seasonal patterns of the soil net ammonification rate were not similar in all the three forests, but with the lowest value occurring in November and February in the following year. Analysis using variance of repeated measures indicated that soil mineral N concentrations and soil N mineralization rates were significantly affected by forest type and season, and correlation analysis showed that soil mineral N and soil N mineralization rate were significantly affected by water moisture and temperature, and the effects of litter on soil N mineralization rate were mainly through quality control, ra-ther than the quantity control.

Conversion Parameters for Stand Biomass Estimation of Four Subtropical Forests in Southern China

Even though the National Forest Resource Inventory (NFRI) does not provide detailed forest biomass information directly, the NFRI data are useful for estimating forest biomass and carbon stocks by using conversion parameters. However, the accuracy and errors of this approach for estimating the stand biomass of subtropical forests remain unclear. In this study, we selected four typical subtropical forests (Cunninghamia lanceolata plantation, Pinus massoniana evergreen coniferous forest, Choerospondias axillaris deciduous broadleaved forest, and Lithocarpus glaber–Cyclobalanopsis glauca evergreen broadleaved forest) in Dashanchong Forest Park to calculate the biomass expansion factor (BEF) and the root:shoot ratio (R). Our results showed that the average BEF values for the four forests were 1.144, 1.301, 1.592 and 1.396, respectively, while the average R values were 0.197, 0.192, 0.226 and 0.221, respectively. These results may be important for estimating forest biomass in the subtropical zone of southern China.

Responses of soil organic carbon and its labile fractions to nitrogen and phosphorus additions in Cunninghamia lanceolata plantations in subtropical China.

A series of nitrogen (N) and phosphorus (P) addition experiments using treatments of N0(0 kg N·hm-2·a-1), N1(50 kg N·hm-2·a-1), N2(100 kg N·hm-2·a-1), P (50 kg P·hm-2·a-1), N1P and N2P were conducted at Cunninghamia lanceolata plantations in subtropical China. The responses of soil organic carbon (SOC), particulate organic carbon (POC) and water-soluble organic carbon (WSOC) to the nutrient addition treatments after 3 years were determined. The results showed that N and P additions had no significant effects on SOC concentration in 0-20 cm soil layer, while P addition significantly decreased soil POC content in 0-5 cm soil layer by 26.1%. The responses of WSOC to N and P addition were mainly found in 0-5 cm soil layer, and low level N and P addition significantly increased the WSOC content in 0-5 cm soil layer. Nitrogen addition had no significant effect on POC/SOC, while the POC/SOC significantly decreased by 15.9% in response to P addition in 0-5 cm soil layer. In 5-10 cm and 10-20 cm soil layers, POC/SOC was not significantly altered in N and P addition treatments. Therefore, the forest soil C stability was mainly controlled by P content in subtropical areas. P addition was liable to cause the decomposition of surface soil active organic C and increased the soil C stability in the short term treatment.

Effects of nitrogen deposition on the concentration and spectral characteristics of dissolved organic matter in soil solution in a young Cunninghamia lanceolata plantation.

To study the effects of nitrogen deposition on the concentration and spectral characteristics of dissolved organic matter (DOM) in the forest soil solution from the subtropical Cunninghamia lanceolata plantation, using negative pressure sampling method, the dynamics of DOM in soil solutions from 0-15 and 15-30 cm soil layer was monitored for two years and the spectroscopic features of DOM were analyzed. The results showed that nitrogen deposition significantly reduced the concentration of dissolved organic carbon (DOC), and increased the aromatic index (AI) and the humic index (HIX), but had no significant effect on dissolved organic nitrogen (DON) concentration in both soil layers. There was obvious seasonal variation in DOM concentration of the soil solution, which was prominently higher in summer and autumn than in spring and winter.Fourier-transform infrared (FTIR) absorption spectrometry indicated that the DOM in forest soil solution had absorption peaks in the similar position of six regions, being the highest in wave number of 1145-1149 cm-1. Three-dimensional fluorescence spectra indicated that DOM was mainly consisted of protein-like substances (Ex/Em=230 nm/300 nm) and microbial degradation products (Ex/Em=275 nm/300 nm). The availability of protein-like substances from 0-15 cm soil layer was reduced in the nitrogen treatments. Nitrogen deposition significantly reduced the concentration of DOC in soil solution, maybe largely by reducing soil pH, inhibiting soil carbon mineralization and stimulating plant growth. In particular, the decline of DOC concentration in the surface layer was due to the production inhibition of the protein-like substances and carboxylic acids. Short-term nitrogen deposition might be beneficial to the maintenance of soil fertility, while the long-term accumulation of nitrogen deposition might lead to the hard utilization of soil nutrients.

不同温度条件下亚热带森林土壤碳矿化对氮磷添加的响应

不同温度条件下亚热带森林土壤碳矿化对氮磷添加的响应

可溶性有机质输入对杉木人工林表层土壤有机碳矿化的激发效应

可溶性有机质输入对杉木人工林表层土壤有机碳矿化的激发效应

近自然化改造对马尾松和杉木人工林生物量及其分配的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 近自然化改造对马尾松和杉木人工林生物量及其分配的影响 DOI: 10.5846/stxb201704030573 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中央级公益性科研院所基本科研业务费专项资金（CAFYBB2014QA033）；广西林业科技项目（桂林科字[2016]第37号）；广西自然科学基金项目（2014GXNSFBA118100） Effects of close-to-nature transformation on biomass and its allocation in Pinus massoniana and Cunninghamia lanceolata plantations Author: Affiliation: 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:近自然化改造作为森林新增碳汇的最有希望的选择之一，将如何通过改变林分结构影响林分生物量和生产力进而影响林分固碳能力和潜力目前尚不清楚，因此，了解近自然化改造对人工林生物量及其分配的影响，对人工林生态系统碳管理具有重要意义。以马尾松近自然化改造林（P （CN））、马尾松未改造纯林（P （CK））、杉木近自然改造林（C （CN））和杉木未改造纯林（C （CK））4种人工林为研究对象，采用样方调查和生物量实测的方法，分析4种林分生物量差异，旨在揭示近自然化改造对马尾松和杉木人工林生物量及其分配的影响。结果表明：马尾松杉木人工林近自然化改造通过调整林分结构显著提升马尾松和杉木人工林生物量和生产力，8a后马尾松和杉木林分生物量分别增加46.71%和37.24%。乔木层生物量在林分生物量总量中占主导地位（95.48%-98.82%），并对林分生态系统总生物量变化起决定性作用。林分生物量和生产力的增加主要因为近自然化改造改变了林分群落结构，进而提高了乔木层生产力。研究结果表明，合理的经营措施不仅可以改善林分结构，提升林分生产力，并可为增强植被固碳能力创造有利条件。 Abstract:Close-to-nature transformation is considered one of the most promising options for creating new forest carbon sinks, but the mechanism by which it influences the biomass by changing the forest structure and thereby influencing the ability and potential of the forest for carbon sequestration remains unclear. Therefore, there is an urgent need to understand these key effects of close-to-nature transformation on the biomass for carbon management in plantation ecosystems. Based on a close-to-nature forest of Pinus massoniana plantation (P(CN)) and an unimproved pure stand of P. massoniana (P(CK)), and a close-to-nature stand of Cunninghamia lanceolata (C(CN)) and an unimproved pure stand of C. lanceolata (C(CK)) as the research objects, the biomass and allocation difference of the four forest types were studied using the method of quadrat sampling combined with biomass measurement, aiming to reveal the influence of close-to-nature transformation on forest biomass and its allocation patterns in P. massoniana and C. lanceolata plantation. The results indicated that the biomass and productivity of P. massoniana and C. lanceolata plantations can be significantly increased by close-to-nature transformation, and the biomass of P. massoniana and C. lanceolata forest stands can be increased by 46.71% and 37.24%, respectively, after 8 years. The biomass of the arborous layer dominates the total biomass (95.48%-98.82%), which plays a vital role in the overall change in forest stand ecosystem biomass. The increase in biomass and productivity in the forest is mainly due to the change in the forest stand community structure, which increases the productivity of the arborous layer. Taken together, the results indicate that reasonable management measures can not only improve stand structure and productivity, but also create favorable conditions that enhance vegetation carbon fixation capacity and potential. 参考文献 相似文献 引证文献