Although vegetation restoration is a prevalent ecological remediation strategy in degraded areas of southern China, whether restoration models effectively enhance soil quality remains a subject of considerable interest. Studies on soil nutrient status and balance from soil microbial indicators and extracellular enzymes may provide insights into quantitative evaluation of vegetation restoration effects. To investigate the influence of different vegetation restoration patterns on soil nutrient conditions in subtropical red soil erosion areas, soil sampling and investigation were conducted in the following areas representing various vegetation restoration stages: 3a mixed Cunninghamia lanceolata and Mytilaria laosensis forest (BMF), 5a Dendrocalamopsis oldhami forest (BA), 17a mixed Pinus massoniana and Cunninghamia lanceolata forest (CMF), 37a mixed Pinus elliottii and Schima superba forest (CBM), as well as tree-free grass slope indicating non-restoration pattern (CK). Through measurements of soil physicochemical properties, microbial biomass, and extracellular enzyme activities, we calculated soil nutrient stoichiometric ratios, extracellular enzyme vector traits, as well as microbial stoichiometric imbalance, microbial nutrient use efficiency, and threshold element ratios. Redundancy analysis (RDA) was employed to identify key microbial and enzymatic indicators that played a dominant regulatory role in soil physicochemical properties under different vegetation restoration models. The results revealed that soil carbon (C), nitrogen (N), the soil C/N, C/P, and N/P ratios (SC/N, SC/P, and SN/P, respectively), as well as soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN), all increased significantly with vegetation restoration processes. An asynchronous trend along restoration chronosequence was shown in some indicators, such as microbial biomass stoichiometric traits and imbalance, as well as soil enzyme parameters. Among different modes, BA mode exhibited the lowest microbial biomass, especially in terms of MBC, soil microbial N/P ratio imbalance (N/Pimb), and vector length (VL), making it a less desirable vegetation restoration option; the BMF mode exhibited P limitation as indicated by extracellular enzyme activity C/P ratio (EEAC/P) and soil microbial threshold C/P ratio (TERC/P); the CBM mode demonstrated favorable performance proved by MBC, EEAC/P, soil microbial threshold C/N ratio (TERC/N), and TERC/P. Redundancy analysis identified MBC, N/Pimb, EEAC/P, VL, TERC/N, and TERC/P as key microbial and enzymatic indicators influencing soil physicochemical properties. These findings suggest that soil nutrient conditions could be better examined by integrated assessment with soil microbe biomass, enzymes and their stoichiometry. Restoration duration significantly influenced the soil nutrient status and balance of the 37a mature plantation, enabling it to surpass other planting modes. Vegetation composition also plays a typical role especially in juvenile stage in anthropic vegetation restoration processes.

The disposal of urban tree litter as waste has significant implications for material cycles, energy flows, and global climate change within urban ecosystems. However, the species-specific contributions of urban trees to atmospheric CO2 emissions through soil respiration (RS) remain poorly understood. This study investigates the effects of litter management on RS dynamics in urban green spaces, focusing on six common species (Mangifera indica, Ficus microcarpa, Cinnamomum camphora, Bauhinia purpurea, Triadica sebifera, and Celtis sinensis) in Fuzhou, China. Three litter treatments—litter retention (CK), litter removal (RL), and litter doubling (DL)—were established to monitor monthly RS fluctuations. Results indicate that DL significantly increased RS rates, while RL reduced them. The increase in RS due to litter addition was more pronounced than the decrease caused by litter removal for most species. RS rates exhibited a unimodal seasonal pattern, peaking in summer. Furthermore, litter treatments influenced the temperature sensitivity coefficient (Q10), with F. microcarpa showing the highest average Q10 (4.16) and M. indica the lowest (1.88). This study underscores the critical role of litter input in modulating RS in urban green spaces and highlights the joint but asymmetric effects of soil temperature and moisture on RS dynamics.

Although leveraging the interaction with endophytic fungi is an efficient and environment-friendly strategy for plants to enhance growth and resistance, how different endophyte species influence host plants' resilience in adverse conditions remain comparatively unclear. In order to explore the effect of endophytic fungi on the aluminum resistance of woody host plants, Vernicia montana seedlings were subjected to different aluminum concentrations (T0, T1, T2, T3, T4) in this study. The aluminum contents in roots, leaves and rhizospheric soil of V. montana seedlings were determined after applying endophyte suspensions of Pestalotiopsis (NP), Alternaria (LA), Penicillium (QP), Coniothyrium (DC) and Thermophilic (ST) spp. The results showed that aluminum stress treatment, endophytic fungi treatment and their interaction had significant effects on aluminum content in leaves, aluminum content in roots, aluminum content in rhizospheric soil, and the transport and retention rate of aluminum ions in soil-root-leaf. With the increase of aluminum concentrations, the aluminum content in leaves of V. montana increased in the endophyte treatments of LA and ST, decreased in CK, NP and DC, or had marginal variation in QP treatment. Compared with T0, four endophyte treatments of LA, QP, DC and ST significantly reduced root aluminum content under T4 concentration (P < 0.05), contrary to the results of NP treatment. Endophyte treatments significantly increased root aluminum content of V. montana under T1 concentration (P < 0.05). The foliar Al content in fungi-inoculated seedlings was significantly lower than that of the non-inoculated ones under T0 and T3 levels (P < 0.05), the LRR is less than 1, while the opposite trend was observed under T2 and T4 treatments. The aluminum transport coefficient TFsoil-root and TFroot-leaf increased in different proportions under the same aluminum concentration. The findings indicate that the application of endophytic fungi change the aluminum contents and transport from rhizospheric soil, roots to leaves. The specific effects of endophytic fungi vary with the degree of aluminum stress and the fungi genus. The study proves that inoculation of endophytic fungi can improve the aluminum tolerance of host plants, and thereby play an important role in promoting the sustainable development of forestry.

Plants respond to variations in soil nutrient distribution and the presence of neighboring plants, yet consensus is lacking on the impact of naturally heterogeneous soil nutrient environments on plant competition. This study employs pot experiments to simulate homogeneous and heterogeneous forest soil nutrient environments and designs neighbor competition experiments for Vernicia montana, Cunninghamia lanceolata, and Phoebe bournei, to assess the impact of neighbor competition on these seedlings from the perspective of root morphology and foraging ability in different nutrient environments. The results reveal that when faced with heterogeneous nutrient environments or competitive settings, V. montana primarily utilized morphological and physiological plasticity, such as increasing root morphological indicators and concentrating more nutrients in the underground part, to enhance its adaptability and achieve competitive advantages. C. lanceolata and P. bournei mainly depended on physiological plasticity, like increased root nutrient concentration, when they were co-planted with other species. Compared to interspecific competition, intraspecific competition had a significant inhibitory effect on V. montana, especially under heterogeneous nutrient conditions, with notable reductions in root morphological indicators and root N, P concentration in mono-culture. Nutrient heterogeneity also altered the effects of interspecific competition on C. lanceolata and P. bournei. When mixed-planted with C. lanceolata or P. bournei, V. montana exhibited stronger competitive ability in both nutrient environments. The effects of mixed planting on C. lanceolata and P. bournei were significantly different between the two nutrient environments, in that homogeneous nutrient environment favored the growth and nutrient absorption of C. lanceolata, while heterogeneous nutrients generally benefited P. bournei. Most research on seedling competition is conducted under homogenous nutrient environments, and the results may not accurately reflect in-situ competition, potentially obscuring the scientific implementation of forestry management. Taking into account competition under unevenly distributed soil resources will help in optimizing tree species selection and cultivation methods, thereby improving the adaptability and ecological benefits of forests.

The effects of different tree stands of Schima superba, Alnus formosana, and Castanopsis fissa on activated aluminum in acidic soils were evaluated in Jianyang District, Nanping City, Fujian Province, China. The contents of exchangeable aluminum, monomeric hydroxyl aluminum, acid soluble inorganic aluminum, and humic acid aluminum in rhizosphere and bulk soils of different stands were measured to compare the effects of different tree species on the content and proportion of activated aluminum in soil. The results showed that: compared with those in rhizosphere soils of S. superba and A. formosana, the contents of exchangeable aluminum in rhizosphere soils of C. fissa reduced by 54.48% and 38.93%, while those of monomeric hydroxyl aluminum increased by 47.43% and 32.56%, respectively. A. formosana had the highest content of acid-soluble inorganic aluminum in bulk soils among the three stands; in A. formosana stands, there were significant differences in the contents of hydroxyl aluminum, acid soluble inorganic aluminum, and humic acid aluminum between rhizosphere and bulk soils. There were also significant differences in exchange aluminum contents of S. superba stands and in acid-soluble inorganic aluminum contents of C. fissa stands, in rhizosphere and bulk soils; and the proportions of exchangeable aluminum and monomeric hydroxyl aluminum differed between the three stands, with the proportion of exchangeable aluminum content being in the order of S. superba＞ A. formosana＞ C. fissa, while that of monomeric hydroxyl aluminum content was in the order C. fissa＞ S. superba＞ A. formosana. Therefore, the contents of activated aluminum in soil were affected by the rhizosphere environment and tree stand types.

为探究种间竞争对木麻黄和台湾相思生长的影响,利用相邻混植和独立盆栽试验测定木麻黄和台湾相思生长和养分含量的变化,分析两者的种间竞争差异.结果表明,混植对木麻黄树高和根冠比影响显著(P<0.05),但对地径无显著影响(P>0.05).与单植栽培方式相比,混植栽培方式下木麻黄树高和地上生物量分别增加57.28％、20.92％,而根总长、根总表面积以及根总体积分别减少62.67％、51.25％和285.19％;混植对台湾相思树高影响显著(P<0.01),对其地径、根冠比无显著影响(P>0.05);在混植栽培方式下,台湾相思树高、地径、总生物量、根总长、根总表面积以及根总体积分别减少119.17％、17.72％、35.75％、11.15％、33.79％和44.62％.根系在磷信号刺激下,仅有台湾相思L4和SA4径级增加;木麻黄叶中Na含量降低81.63％,而P元素和K元素分别增加11.38％、12.30％,根中Na、P、K元素含量分别减少26.17％、28.29％和21.45％.台湾相思叶中Na、K元素含量分别降低6.23％、7.78％,P元素增加7.55％,根中Na、P、K元素含量分别增加24.81％、22.05％、24.53％.木麻黄和台湾相思在混植栽培方式下,均通过改变自身形态或营养成分抑制对方,说明邻株竞争可以改变沿海人工林中植物的适应性和群落结构,也表明植物根系在邻株竞争中存在重要作用.因此,研究结果可为沿海防护林的更新恢复和经营管理提供理论指导.

Acacia confusa is an important species in coastal shelter forests. In order to explore the effects of salt and phosphorus fertilization on leaf photosynthesis and nutrient characteristics of the seedlings. NaCl solutions were configured in the concentrations of 0% (B0), 0.2% (B1), 0.4% (B2), 0.6% (B3) and 0.8% (B4), and superphosphate solutions in the concentrations of 0 g·kg-1(P0), 0.5 g·kg-1(P1), and 1.5 g·kg-1(P2). The photosynthesis and nutrient characteristics of the seedlings were determined after being watered by the six combined solutions of salt-phosphorus coupling fertilization. The results were as follows: (1) Salt stress significantly inhibited the growth and development of the seedlings, and the higher the salt content, the greater the effect. Phosphorus application under low-salt stress was unfavorable to the growth of the seedlings, while phosphorus application under medium-high one significantly slowed down the inhibition of the seedling growth. (2) The greater the salt stress, the higher the effects on the photosynthesis of the seedlings. The stomatal closure degree of phosphorus application increased under low and medium salt stress, which aggravated the effect of salt stress on photosynthesis of the seedlings. Appropriate phosphorus application under high-salt stress could significantly improve the photosynthetic capacity of the seedlings. (3) Salt stress significantly reduced chlorophyll content and caused harm to photosystem II. Phosphorus fertilization on the seedlings under low-salt stress had adverse effects on chlorophyll synthesis. Appropriate fertilization of phosphorus in high-salt stress could increase chlorophyll synthesis, stabilize cell membrane structure, and improve the potential photosynthetic capacity of leaves. (4) Salt stress had strong interference on the contents of Fe, Mn, Na, Cu and other metal elements in leaves. Phosphorus application under salt stress could effectively promote the absorption of some elements by seedlings. In conclusion, phosphorus application after salt stress can improve the photosynthesis and nutrient absorption ability of A. confusa seedlings on the whole. The results provides a theoretical basis for improving the salt tolerance and phosphorus utilization rate of A. confusa, and have guiding significance for the sustainable management of coastal shelter forests.

【Objective】 This study purposes to explore the effects of single endophytic fungus and mixed endophytic fungi on the growth and photosynthesis of Cunninghamia lanceolata seedlings. 【Method】 The endophytic fungi isolated from the root, stem and leaf samples of Chinese fir with robust growth and no diseases and insect pests were used as inoculated seedlings. The growth characteristics and photosynthetic physiological indexes of C. lanceolata seedlings were determined by inoculating the single or mixed growth promoting fungi. 【Result】 Four endophytic fungi Trichoderma spirale（S10）, Hypoxylon（S22）, Colletotrichum gloeosporioides（S24） and Umbelopsis dimorpha（S38） were successfully colonized in the root of C. lanceolata seedlings. Through the analysis of seedling height diameter, aboveground and underground biomass, root to shoot ratio and other growth characteristics, it can be seen that: single strain S24and mixed strains S10×S22 and S22×S38 significantly promoted the growth of seedling height and ground diameter of C. lanceolata seedlings. Compared with CK group, the growth rates of single strain S24 on seedling height and ground diameter of C. lanceolata seedlings were 2.99% and 15.66%, respectively.The growth rates of seedling height and ground diameter for mixed strains were 13.81% and 3.04%, respectively, for S10×S22, and 18.99% and 11.01%, respectively, for S22×S38. The aboveground and underground biomass growth rates of individual strains S22, S24 and S38 were S22（22.86% and 58.57%）、S24（18.94% and 53.74%）and S38（15.87% and 57.40%）, respectively, compared with CK group. By analyzing chlorophyll content, chlorophyll fluorescence parameters（F0、Fv/Fm） and other photosynthetic characteristics, it can be seen that: single strain S38 and mixed strains S10×S38 and S22×S24 significantly increased the chlorophyll content of seedlings at 45-60 d stage. Compared with CK group, chlorophyll content of C. lanceolata in S38 and CK group were 11.15%higher. The growth rates of mixed strains were as follows: S10×S38（2.25% and 17.53%）and S22×S24（10.72% and 13.51%）. C. lanceolata seedlings inoculated with single strain S24 and mixed strain S22×S38 had a lower F0 value than that inoculated with other strains. The Fv/Fm value ranged from 0.80 to 0.85 across all treatments. 【Conclusion】 These results indicated that both single endophytic fungus and mixed endophytic fungus inoculations significantly improved the biomass and photosynthesis of C. lanceolata seedlings, and could effectively promote the growth of C. lanceolata seedlings. The growth promotion effect of mixed endophytic fungi was stronger than that of single endophytic fungus.

【Objective】The differences in leaf nutrient content and nutrient resorption efficiency of different canopies of A. montana forest were analyzed, and the relationship between A. montana leaf nutrient resorption efficiency and nutrient contents in leaves and soil was studied.【Method】The Aleurites montana forest, planted after the coniferous forests with low production being cut down and cultivated as ecological forest conforming to the nature, was taken as test materials. The contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in leaves of the upper and lower canopies of A. montana were determined in the peak vegetative period (July) and the defoliating period (October).【Result】The macronutrients N, P, K, Ca and Mg in senescent leaves were significantly lower than those in mature leaves and there was no nutrient enrichment in senescent leaves. The N contents of mature and senescent leaves in the upper canopy were significantly higher than those in the lower canopy. The K content in mature leaves of upper layer was significantly higher than that in the lower canopy. Ca resorption efficiency was significantly lower than that of other nutrients, with only 14.935 (±3.191) %. In addition, the resorption efficiency of Mg in the lower canopy was significantly higher than that in the upper canopy. There was no significant difference in the resorption efficiencies of other nutrients between upper and lower canopies. There was a significant negative correlation between K resorption efficiency and K content in mature and senescent leaves, and a significant positive correlation between Ca resorption efficiency and Ca content in mature leaves. There was a significant positive correlation between N resorption efficiency and soil hydrolyzed nitrogen. The K resorption efficiency was negatively correlated with soil total K content, but positively correlated with soil available K content.【Conclusion】The nutrient contents in senescent leaves of A. montana were significant lower than those in mature leaves, and there was a certain correlation between nutrient resorption efficiency and nutrients in leaves and soil. The study results could provide a scientific basis for further exploring the nutrient cycling mechanism of ecological public welfare forests.

Understanding how natural disasters affect soil quality and how it recovers is essential to improve soil management. We studied the effects of the 2010 Nanping landslides (China) on soil quality. We conducted an observational study using three levels of disturbance (‘destroyed’, ‘recovering’, and ‘undisturbed’). The ‘destroyed’ areas were sampled immediately after the landslide and the others were sampled 7 years later. To assess the consistency of landslide-induced effects, we sampled these levels of disturbance in three forest types (Cunninghamia lanceolata conifer forest, Phyllostachys heterocycla bamboo forest, and secondary evergreen broadleaf forest). In total, 81 soil samples were collected and analyzed for 26 soil indicators. A minimum data set (MDS) was identified that represented the physical, chemical, and biological properties of the soils. Indicators in the MDS were then weighted and summed together to calculate a soil quality index (SQI) for each category and a total SQI. The landslide strongly affected all aspects of soil quality. After seven years of natural recovery, most aspects of soil quality were significantly improved but remained lower than in ‘undisturbed’ sites. Recovery was faster for biological than physical or chemical properties. Recovery was slower in bamboo forests than in other forest types, suggesting that human interventions could accelerate post-landslide soil recovery in bamboo forest. Our results provide fundamental data for evaluating impacts of natural disasters on soil and rates of natural recovery.

为了明晰福建省千年桐(Vernicia montana Lour.)人工林碳储量的变化规律及碳库分配格局,采用空间代替时间的方式,对南平市林龄2、3、5、7和9a的千年桐人工林乔木层(包括树干、树枝、树叶和树根)、灌木层、草本层、凋落物层及0～ 100 cm土层的碳含量和碳储量及其所占比例进行了比较,并对各林分的总碳储量及分配格局进行了分析.结果 表明:林龄2a的林分中树根碳含量最高(584.63 g· kg-1),树叶碳含量略低;林龄3、5和9a的林分中树干碳含量最高,分别为536.34、406.44和636.95 g· kg-1;林龄7 a的林分中树干、树枝、树叶和树根的碳含量差异较小.并且,林龄2、3和9 a的林分中乔木层碳含量最高,分别为537.68、467.77和529.35 g· kg-1.各土层碳含量的平均值为11.30～21.42 g· kg-1,总体上随林龄增长而升高.各林分的总碳储量为105.60～214.60 t·hm-2,总体上随林龄增长而升高.各林分的植被层碳储量为23.89～85.13 t·hm-2,占总碳储量的17.27％～ 39.67％,其中,乔木层、灌木层、草本层和凋落物层的碳储量分别为21.11～75.78、0.96～2.46、0.27～0.56和1.55～6.33 t·hm-2,分别占总碳储量的14.60％～ 35.31％、0.72％ ～ 1.14％、0.22％ ～0.26％和1.46％ ～2.95％.各林分的土壤碳储量为81.71～129.47 t·hm-2,占总碳储量的60.34％～ 82.74％.随林龄增长,除林龄2a的林分外,其余林龄林分的土壤碳储量占总碳储量的比例降低,而植被层碳储量占总碳储量的比例却升高.综上所述,千年桐人工林碳储量分配比例从大到小依次为土壤、乔木层、凋落物层、灌木层、草本层,且总碳储量总体上随林龄增长而升高.

为明晰自毒胁迫下内生真菌对宿主杉木生理过程的影响,探讨利用内生真菌缓解杉木自毒作用的可能,在课题组前期已获得2株对杉木幼苗有促生作用的内生真菌(CG2柱孢属Cylindlrocarpon sp.、aJ4毛霉属Mucor sp.)基础上,测定不同浓度(0、40、80、120 mg/L)化感物质混合(邻羟基苯甲酸:肉桂酸= 4:1混合液)胁迫下,感染(EI)与未感染(CK)内生真菌的杉木植株在不同胁迫时期(0、30、45、60 d)的生理生化指标,比较分析不同菌株处理(单菌与两者混合菌株Ca)对杉木幼苗的影响.结果表明:内生真菌侵染并未显著提高杉木幼苗叶绿素a、b含量;aJ4、CG2菌株侵染能在一定程度上缓解杉木幼苗化感物质的混合胁迫,在轻度、中度、重度及胁迫中期、后期(0 mg/L 45 d,80 mg/L 45-60 d,120 mg/L 60 d)下有明显的效果,表现在与CK杉木幼苗相比,EI杉木幼苗初始荧光参数(Fo)显著降低,最大光化学效率(F/Fm)及潜在光化学活性(Fv/F.)显著增加;EI杉木幼苗仅能在低浓度及短期内缓解化感物质混合胁迫对杉木植株细胞膜的损害,降低丙二醛(MDA)及相对电导率含量,提升杉木幼苗SOD、POD活性;与CK杉木幼苗相比,El杉木幼苗苗高、地径生长量增加显著.可见,2种内生真菌及其混合菌侵染处理能在一定程度上缓解不同浓度杉木化感物质混合胁迫对杉木幼苗生理及酶活性的损害,提升杉木幼苗抗逆性,但菌株间存在显著差异(P＜0.05),aJ4、CG2菌株侵染效果显著强于Ca菌株(P＜0.05),表明混合菌株之间可能存在拮抗作用;本研究可为筛选优势菌株和深入理解逆境下内生真菌与杉木的共生机制提供数据基础,同时也为缓解杉木连栽障碍,促进杉木人工林可持续经营提供新思路.

The optimization of regional land use structures and functions and the sustainable use of the ecological environment are very important in the process of urbanization. In this study, based on the Landsat 7+ETM images of Nanping City from 2015, the object-oriented land use classification method was used to calculate the value of ecosystem services in Nanping City and various counties (districts).The spatial distribution characteristics between the levels of population urbanization, spatial urbanization, economic urbanization, and living urbanization and the value of ecosystem services were quantitatively analyzed by utilizing spatial measurement methods. The impact of the levels of four types of urbanization on the spatial distribution of ecosystem services values was explored using the bivariate spatial autocorrelation method. The results showed that there was a significant negative spatial correlation between population urbanization and the total value of ecosystem services. Specifically, the negative correlation between population urbanization and food production services was the most significant. Additionally, there was a certain positive correlation between economic urbanization and waste disposal services. Further, the bivariate LISA figures between different urbanization levels and the values of ecosystem services showed that a high urbanization-low ecosystem services value (High-Low) appeared in Jian’ou and Shaowu, while the regions of Guangze and Shunchang reflected a low urbanization-high ecosystem services value (Low-High).The findings of this study can provide information for decision-making regarding the sensible use of regional land resources and the improvement of ecological and environmental quality.

选取福建省北部8年林龄的杉木(Cunninghamia lanceolata)纯林、千年桐(Aleurites montana)纯林及杉木-千年桐混交林(杉桐混交林),通过测定土壤pH值、根际及非根际土壤交换性铝、单聚体羟基铝、酸溶无机铝、腐殖酸铝含量,探讨不同林分根际与非根际土壤活性铝形态分布特征.研究结果表明:(1)3种林分土壤pH值在3.76-4.33之间,杉桐混交林土壤pH值显著高于两种纯林.(2)3种林分中,杉桐混交林的交换性铝含量显著高于杉木纯林,酸溶无机铝含量显著低于杉木和千年桐纯林,根际土单聚体羟基铝含量与两种纯林无显著差异.(3)同种林分间,千年桐纯林、杉桐混交林的根际土交换性铝及单聚体羟基铝含量均显著低于非根际土,杉木纯林根际土4种活性铝含量与非根际土均无显著差异.(4)不同土壤的交换性铝和单聚体羟基铝总量占活性铝总量的6.09％-16.17％,交换性铝含量与土壤pH值均呈现显著负相关(P＜0.05).综上,相较两种纯林,杉桐混交林能显著降低土壤酸度及酸溶无机铝含量,对交换性铝含量有一定的提升作用,但并未显著影响土壤中单聚体羟基铝及腐殖酸铝含量;结果可为闽北酸性红壤区人工林经营管理、土壤铝毒害防治及生态环境恢复提供理论依据.

为微生物与植物互作关系的生产应用提供理论基础,浇施菌液并接种5株内生真菌(NG1、CG5、AJ6、AJ14和AJ13)于低磷胁迫下的杉木幼苗(Cunninghamia lanceolata),15 d后进行低磷胁迫试验,测定杉木植株的电导率、丙二醛、超氧化物歧化酶和可溶性蛋白等生理生化指标,分析内生真菌对杉木抗逆性的影响,筛选低磷胁迫下适宜杉木的内生真菌.结果 表明:正常条件下,菌株NG1、AJ6和AJ14能有效提高植株电导率;轻度低磷胁迫条件下,菌株AJ14能较好地保护植株生长;中度低磷胁迫条件下,各菌株在胁迫中前期均能显著缓解磷胁迫;重度低磷胁迫条件下,菌株A J6和AJ14表现良好,能有效缓解逆境对植株的伤害.在不同低磷胁迫梯度下,5株溶磷菌均能在胁迫15～45 d显著缓解低磷环境对植株的危害.与未接种处理的杉木幼苗相比,菌株NG1、AJ6、CG5、AJ14以及AJ 13均显著提高SOD活性,对杉木幼苗均有一定的抵御低磷胁迫的作用,以菌株AJ14效果最佳.菌株AJ6和AJ14在低磷胁迫下能有效提高可溶性蛋白含量.综合各项指标,菌株NG1和AJ6一定程度上能够缓解低磷胁迫对杉木植株的影响.

为了解闽北山地针阔混交林的养分循环,以7-9年生不同坡位(上坡、中坡、下坡)的杉木(Cunninghamia lanceolata)-千年桐(Aleurites montana)混交林的鲜叶、凋落叶及0-10 cm土壤层的养分含量为研究对象,分析不同林龄、不同坡位的碳(C)、氮(N)、磷(P)含量及化学计量比差异,探讨杉桐混交林随林龄和坡位变化的化学计量特征.结果表明:(1)两种树种C、N、P含量基本表现为叶片＞凋落叶＞土壤,且在3个库之间差异显著.(2)混交林叶片N含量较低、P含量较高,凋落叶N、P含量均较低,土壤C、N含量较高而P含量偏低,叶片中较高的P含量是对土壤中相应养分含量缺乏的适应策略.(3)千年桐叶片的C、N、吸杉木的N、P均表现为9年生最高,凋落叶随林龄变化与叶片完全一致;混交林土壤P含量随林龄增加而增大.(4)混交林土壤有机C含量、N含量随坡位变化表现为上坡＞中坡＞下坡.结合本项目组的前期研究发现,该研究区幼龄期受N和P的共同限制,而在中龄期受N限制减缓,仅受P元素的限制,表明混交林对林木的养分限制状况有一定的改善作用;结果可为我国南方地区针阔叶混交林的可持续经营提供科学依据.

[Objective]The present investigation was undertook in order to probe into the effects of en-dophytic fungi on photosynthetic performance of Casuarina equisetifolia seedlings,and to improve the productivity of the seedlings.[Method]28 strains of endophytic fungi were inoculated to Casuarina equi-setifolia seedlings by using two different inoculation methods which were dipped the seedling root in sus-pension (S) and irrigated the potted seedling with suspension (P). Relative chlorophyll content and the main chlorophyll fluorescence parameters of the seedlings were determined by SPAD-502 chlorophyll meter and Handy FluorCam respectively.[Result]In the case of using S method ,the SPAD value of strain No. 46 increased significantly by 31.34% compare with CK,the Fm and Fv of strain No. 16 had the most significant difference compare with CK,moreover,they are 2.13 and 2.21 times as much as CK. However,in the case of using P method,different strains had no effect on seedlingsˊ SPAD.[Conclusion]It is deduced that endophytic fungi could improve relative chlorophyll content and the main chlorophyll fluorescence parameters of Casuarina equisetifolia seedlings,and thus improve the productivity of the seedlings. However different inoculation methods and different strains have different impact on photosynthetic performance.

[目的]对千年桐(Aleurites montana)内生真菌进行分离鉴定,初步筛选具有较高溶磷活性的内生真菌.[方法]从福建省南平市建阳区的外墩采育场、湖桥工区和书坊林场的千年桐根、茎、叶中分离纯化得到内生真菌.根据菌落在根、茎、叶中出现频率及其直径生长速度筛选优势菌株,进一步对优势菌进行溶磷能力的定性测定.[结果]共分离出155株菌株,其中茎内生真菌60株(38.71％)、叶50株(32.26％)、根45株(29.03％).湖桥样地采集的内生真菌数量最多、外墩样地最少.选出25株优势菌株,经形态学和18 SrDNA分子鉴定分别为毛霉菌属(Mucor sp.)、青霉属(Penicillium sp.)、拟盘多毛孢属(Pestalotiopsis sp.)、生赤壳属(Bionectria sp.)、木霉属(Trichoderma sp.)、嗜热真菌属(Thermomyces sp.)、链格孢属(Alternaria sp.)、盾壳霉属(Coniothyrium sp.)和镰刀菌属(Fusarium sp.).对优势菌株溶磷效果的试验表明,具有较强溶磷活性的菌株分属青霉属(Penicillium sp.)和嗜热真菌属(Thermomyces sp.).[结论]千年桐内生真菌数量在不同地点和不同器官间分布各有不同,初步确定千年桐内生真菌菌属组成,得到具有较强溶磷活性的菌株分属青霉属(Penicillium sp.)和嗜热真菌属(Thermomyces sp.).

以漳江口红树林的秋茄(Kandelia candel)、木榄(Bruguiera gymnorrhiza)、桐花树(Aegiceras corniculatum)和老鼠筋(Acanthus ilicifolius)为研究对象,对其根、茎、叶中的碳(C)、氮(N)、磷(P)含量以及生态化学计量学特征进行分析.结果 表明:秋茄、桐花树、老鼠簕3种植物各器官中的C含量均表现为茎、叶显著大于根,秋茄、木榄、桐花树3种植物的N、P含量均表现为叶＞茎＞根;桐花树、老鼠筋不同器官的C含量变异系数均表现为根＞叶＞茎,秋茄、木榄、老鼠筋3种植物N含量的变异系数均表现为根、茎大于叶,秋茄、木榄、桐花树3种植物P含量的变异系数均表现为根、茎大于叶;秋茄、木榄、老鼠筋C∶N的变异系数为根、茎大于叶;4种植物中,老鼠筋根、叶的P含量显著高于其他3种植物,茎的P含量略高于其他3种植物,根C、N、P与叶C、P的变异系数均大于其他3种植物;4种红树植物叶的C∶N∶P质量比(151∶9∶1)显著小于根(187∶4∶1)和茎(239∶5∶1),叶的C、N和P的生态化学计量特征相对稳定.分析红树植物不同器官养分元素间的分配规律,可为大尺度的红树林生态化学计量学研究提供理论基础,并为红树植物的保护与可持续经营提供科学依据.

文章说明了在高速国际化背景下,高等院校研究生课程教学团队应该对学校国际化建设中的资源和平台进行多维融合并利用优势资源提升研究生课程的教学质量和效果.文章以学术英语课程的改革实践为例,具体介绍了如何利用平台和资源优势,将研究生学术英语课程的教学内容、授课形式和考核方式分别与国际化建设过程中的外教资源、创新理念、学术平台进行多维融合,达到培养高层次、国际化专业人才的课程目标.学术英语课程教改实践的成功为其他研究生专业课程提供了很好的借鉴和参考,也是高校国际化建设成果的有机体现.