Subjects: Biology >> Ecology submitted time 2021-06-17 Cooperative journals: 《干旱区地理》
Abstract： 通过梭梭林下黄花补血草种群发育和土壤种子萌发动态的野外调查以及模拟土壤结皮、 降水试验，研究了土壤结皮发育（无结皮覆盖土壤NSC、物理结皮覆盖的土壤PSC、生物结皮覆盖的土壤BSC)对其土壤种子萌发、幼苗死亡、种群特征的影响以及土壤结皮发育与模拟降水的相互作用，旨在为梭梭林下黄花补血草种群建植以及灌草结合的治沙模式提供理论依据。研究结果表明：（1）土壤结皮的发育可以促进黄花补血草土壤种子萌发，表现为BSC>PSC>NSC，且处理间差异极显著（P0.05）。（2）在15 mm模拟降水条件下，土壤结皮发育对种群密度和土壤种子萌发均具有显著促进作用，具体表现为PSC>BSC>NSC，且差异极显著（P0.05），而幼苗死亡率表现为NSC>BSC>PSC，且差异性极显著(PPSC>NSC，幼苗死亡率NSC>PSC>BSC。梭梭林下土壤结皮发育既增加了土壤表层水土 环境的稳定性，又增加了黄花补血草土壤种子基数，有利于土壤种子萌发和种群的更新和发育，而模拟降水可有效改善土壤水分条件，特别是结皮层土壤水分，为黄花补血草土壤种子萌发和种群更新提供了必要的物质基础和环境条件。
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/Significance] This paper proposes a new method to identify the growth points of technology fusion from the perspective of the dynamic evolution process of technology, aiming to identify the technology fusion fields with growth potential.[Method/Process] First, the study proposed two stages in the evolution path, summarized the evolution path of the technological fusion growth points, and summarized significant attribute characteristics according to the characteristics of the technological fusion growth points, and constructed an index system for recognition. Finally, calculating the changes of attributes on the evolution path realizes the identification of the technological fusion growth points.[Result/Conclusion] Through experiments and comparisons with existing studies, this method can effectively identify the growth points of technology fusion, and trace the origin and process of technology.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-19 Cooperative journals: 《计算机应用研究》
Abstract： Aiming at the time-consuming problem of traditional contour extraction method in building facade image processing, a building elevation contour extraction algorithm combined with visual saliency model and level set algorithm is proposed. First of all, using visual salient features and super pixel information to filter out the irrelevant background; secondly, it selects the significant blocks according to the building’s texture feature, with each super pixel block as a processing unit; finally, using the level set algorithm optimizes the resulting building area to obtain the final contour. The experimental results show that the processing speed of the proposed algorithm is effectively improved when the processing effect is equivalent, compared with the traditional contour extraction method.
Subjects: Library Science，Information Science >> Information Science submitted time 2017-12-05 Cooperative journals: 《数据分析与知识发现》
Abstract：【目的】解决在海量客户评论信息中抽取产品特征时噪声大的问题。【方法】运用 TF-IDF 和方差选择的 统计方法在众多初步提取出来的特征中进行选择, 设置阈值后将各自提取出来的特征取交进行过滤, 得到产品 特征集合, 根据基于矩阵和权重改进的 Apriori 算法产生频繁项集, 设定不同阈值得到最优特征集合, 实现对用 户评论中产品特征的自动提取。【结果】以手机评论文本为例, 从中抽取手机类的产品特征, 根据人工标注的 183 个特征和算法识别出来的特征, 查准率 P 为 72.44%, 查全率 R 为 77.59%, 综合值 F 为 74.93%。【局限】查准率 偏低, 存在人工标注特征错误的情况。【结论】实验结果表明, 在用统计方法和改进后的 Apriori 算法进行特征提 取时可以提高各性能指标。
Subjects: Civil Engineering and Building Construction >> Civil Construction Engineering submitted time 2017-12-05 Cooperative journals: 《土木建筑工程信息技术》
Abstract：在BIM技术的背景下，针对现有的BIM服务器多为C/S架构，对电脑软硬件有较高要求、无法跨平台等问题，实现BIM模型在Web端的重建，并实现了对模型的拾取，获取其属性。其方法主要分为两部分，第一部分实现BIM模型从Revit软件中的导出，第二部实现对其导出的模型信息在W eb端的三维交互，具有良好的用户体验。
Subjects: Library Science，Information Science >> Library Science submitted time 2023-08-27 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] It is of great significance to improve the existing problems of technical topic analysis in patents based on the LDA, which are low recognition, weak interpretability and fuzzy boundary division,to hold the technical hot spots and track the technological frontier. [Method/process] The international patent classification is introduced into the topic analysis in patents based on the LDA, and used as the language content of technical terms. The structure of WI (Word IPC) is trained to construct the WI-LDA model to achieve the identification and analysis of the subject of patent documents. [Result/conclusion] The case study of graphene field in Chinese patents and comparative study with traditional LDA models prove that the generalization ability of the WI-LDA model is strong, and the WI-LDA model can effectively reduce the difficulty of identification technical topic analysis in patents, increase the interpretability of topics and make the topic classification clearer.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Research on the identification method of University transferable patents is positive significance to improve the quality of patent push and promote the docking of university scientific research and social economy. [Method/process] Firstly, based on the literature research, we tested and determined the quantifiable identification index of patents, and combined with Bayesian theory to screen university transferable patents preliminarily. Then, we used the multiple correlation coefficient and coefficient of variation combination weighting method to calculate the weight of each identification index, and calculated the weighted comprehensive transfer probability of the remaining patents. Finally, we identified transferable patents according to the comprehensive probability value. In addition, we used university patents in the field of medical configuration products to test the method. [Result/conclusion] We use Bayesian theory and combination weighting method to calculate the comprehensive probability of university transferable patents through preliminary screening and secondary identification, this identification process not only ensures the accuracy of the results, but also takes into account the limitation of university patent management resources, which builds a good foundation for improving the quality of patent push.
Subjects: Biology >> Ecology submitted time 2018-01-20 Cooperative journals: 《生态学报》
Abstract：喀斯特区坡耕地水土及养分流失不仅是该区土地质量退化、土地生产力衰退主要原因，同时也是该区地下水质污染的重要因素。为揭示喀斯特坡耕地地表和地下二元空间结构下的土壤养分流失机制，以喀斯特坡耕地为研究对象，通过模拟其地表微地貌及地下孔（裂）隙构造特征，采用人工模拟降雨试验研究不同雨强下喀斯特坡耕地地表及地下水土及其氮、磷、钾流失特征。结果表明：（1）小雨强（50mm/h）和中雨强下（70mm/h），喀斯特坡耕地坡面产流主要以地下产流为主；大雨强下（90mm/h），地表径流高于地下径流；产沙方式则表现为由小雨的地表和地下产沙并重到中大雨强的地表产沙为主的一个转变过程。（2）在降雨侵蚀过程中，径流各养分输出浓度均表现出一定的初期冲刷效应，受土壤吸附作用影响，雨强对全钾（TK）和全氮（TN）的影响较全磷（TP）明显。（3）地表径流、地表泥沙和总泥沙各养分输出负荷均随雨强增大而增加，坡面径流泥沙总的TK输出负荷以泥沙为主，而TN和TP输出负荷则以径流为主；TP和TN在径流的输出负荷上以地下径流输出为主（其中TP地表负荷比在11.6%-46.2%，TN在7.0%-48.5%之间），而TK则以二者并重（地表负荷比在43.5%-57.0%之间）；各养分在泥沙的输出负荷上则均以地表泥沙流失为主，其负荷比均在54.5%以上。研究结果可为喀斯特区坡耕地水土流失及养分流失的源头控制提供基本参数和科学依据。
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] The core value of university libraries is first of all to maintain a high degree of consistency between service and needs. This paper tries to study how to develop strengths and avoid weaknesses, meet needs, diversify and implement patent services in various ways for university libraries. It is of great significance for university libraries to improve their service performances and highlight their missions.[Method/process] The paper is based on the analysis of user needs and service design, taking the patent service practices in the Intellectual Property Information Service Center of Shandong University of Technology as the example. The patent service orientation, content, and mode of university libraries have been discussed from three dimensions as the patent quality education combing popularization and improvement, the patent scientific research service with choosing to do something, and the information analysis and decision support for industry-academy-research policies.[Result/conclusion] High quality to meet user needs is the focus of patent services work in university library. In order to carry out patent service effectively, the library should be guided by rational orientations, supported by professionals, focused on patent education and guaranteed by effective mechanism.
Subjects: Biology >> Ecology submitted time 2017-11-23 Cooperative journals: 《生态学报》
Abstract：为探究干旱条件下，互叶醉鱼草（Buddleja alternifolia Maxim.）幼苗对重金属镉胁迫的生长及光合生理响应机制，以两年生互叶醉鱼草幼苗为试验材料，设置对照与干旱两个水分处理组（土壤相对含水率分别为：65%-60%，35%-30%），每个水分处理条件下再分别设置3个镉处理浓度（0.28、（0.6+0.28）、（1.2+0.28） mg/kg），共6个处理。测定不同水分及镉处理对互叶醉鱼草生长、生物量、光合参数及体内重金属含量的影响。结果表明：干旱与镉复合胁迫下植物的存活率为100%。镉胁迫、干旱与镉复合胁迫均不同程度抑制了互叶醉鱼草幼苗生长、生物量积累、植株的光合作用及叶绿素含量，且其光合和叶绿素含量的降幅明显大于单一镉胁迫。镉胁迫下，互叶醉鱼草幼苗单株最高镉富集量为69.33 mg/kg，而复合胁迫下单株最高镉富集量为50.68 mg/kg。以上结果表明：干旱胁迫能够加重镉胁迫对植物的影响，使复合胁迫下互叶醉鱼草生长、光合生理及镉富集能力下降。但单一镉胁迫下，互叶醉鱼草对镉具有更强的耐受性，并有较高的生物富集能力，且干旱与Cd复合胁迫下互叶醉鱼草幼苗仍有一定的镉积累量。因此在干旱半干旱区园林绿化以及Cd污染地区的生态建设中，互叶醉鱼草是一种具有巨大应用潜力和前景的灌木树种。
Subjects: Biology >> Ecology submitted time 2017-11-10 Cooperative journals: 《生态学报》
Abstract：为探究干旱条件下，互叶醉鱼草（Buddleja alternifolia Maxim.）幼苗对重金属镉胁迫的生长及光合生理响应机制，以两年生互叶醉鱼草幼苗为试验材料，设置对照与干旱两个水分处理组（土壤相对含水率分别为：65%-60%，35%-30%），每个水分处理条件下再分别设置3个镉处理浓度（0.28、（0.6+0.28）、（1.2+0.28） mg/kg），共6个处理。测定不同水分及镉处理对互叶醉鱼草生长、生物量、光合参数及体内重金属含量的影响。结果表明：干旱与镉复合胁迫下植物的存活率为100%。镉胁迫、干旱与镉复合胁迫均不同程度抑制了互叶醉鱼草幼苗生长、生物量积累、植株的光合作用及叶绿素含量，且其光合和叶绿素含量的降幅明显大于单一镉胁迫。镉胁迫下，互叶醉鱼草幼苗单株最高镉富集量为69.33 mg/kg，而复合胁迫下单株最高镉富集量为50.68 mg/kg。以上结果表明：干旱胁迫能够加重镉胁迫对植物的影响，使复合胁迫下互叶醉鱼草生长、光合生理及镉富集能力下降。但单一镉胁迫下，互叶醉鱼草对镉具有更强的耐受性，并有较高的生物富集能力，且干旱与Cd复合胁迫下互叶醉鱼草幼苗仍有一定的镉积累量。因此在干旱半干旱区园林绿化以及Cd污染地区的生态建设中，互叶醉鱼草是一种具有巨大应用潜力和前景的灌木树种。
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2024-04-24 Cooperative journals: 《中国全科医学》
Abstract： Background As revealed by previous studies，the head shaking tilt suppression test （HSTST）is associated with the vestibular cerebellum-mediated central storage mechanism and the video head impulse test（vHIT）is crucial for the diagnosis of vestibular diseases. Objective To explore the clinical application value of HSTST and vHIT in vestibular migraine（VM）and Meniere's disease（MD）. Methods Patients presenting with vertigo or dizziness as the primary complaint and diagnosed with VM and MD were selected from the Neurology Department of the Second People's Hospital of Guiyang from July 2021 to December 2022. After collecting their medical history and performing bedside examinations，pure tone audiometry test was conducted on those with hearing impairment. All patients completed vestibular function tests，including head shaking test （HST），HSTST，caloric test，and vHIT，were performed，followed by calculating the tilt suppression index（TSI）. Thenthe Clinical features and examination results of VM and MD patients with HST positive were compared，and the ROC curve of TSI was plotted to distinguish between the two groups of patients. Results Among the 50 VM patients involved in the study，22（44.0%） were HST positive，including 19（86.4%）exhibiting horizontal nystagmus and 3（13.6%）showing vertical nystagmus. Among the 45 MD patients，23（51.1%）were HST positive，all of whom were horizontal nystagmus. The analysis of the patients with HST positive showed that the female to male ratio in VM and MD patients was 4.5:1 and 1:1.3，respectively. The prevalence of family history of headaches was higher in VM patients compared to MD patients（P<0.05）. VM patients exhibited lower proportions of vomiting，tinnitus，ear tightness，and hearing loss symptoms（31.8%，18.2%，13.6%，13.6%）compared to MD patients（73.9%，100%，82.6%，100%），with a higher proportion of accompanying headache symptoms（77.3%） than MD patients（8.7%）（P<0.05）. Pure tone audiometry revealed a higher hearing loss rate in MD patients compared to VM patients（P<0.001）. Significant differences were observed in vHIT between VM and MD patients（P<0.05）. Then the TSI differed significantly between VM and MD patients ［（25.41±12.15）% and（78.71±13.76）%，respectively］（P<0.05）. From ROC curves，the area under the curve（AUC）was 0.962（95%CI=0.91-1.00）with a cut-off point at 0.66（sensitivity=0.90， specificity=0.95）. Conclusion Vestibular migraine primarily involves a central mechanism，and HSTST combined with vHIT can be used as auxiliary examination tools to differentiate diagnosis between VM and MD.
Subjects: Civil Engineering and Building Construction >> Civil Construction Engineering submitted time 2017-11-06 Cooperative journals: 《土木建筑工程信息技术》
Abstract：文基于Revit管线批量自动标注的实际工程要求，将平行管线标注分为无变径标注和有变径标注两类，并且阐述了会导致管线发生变径的三种情况 针对不同的管线排布情况分别采用了相对应的管线自动标注方法。本文还提出了一种利用引垂线的方法解决了多变径平行管线批量标注问题 实验结果表明，该类方法可以快 速高效地对管线进行标注，与传统的标注方法相比，简化了操作，提高了标注效率，为以后二次开发提供了一定的经验。
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-12-13 Cooperative journals: 《计算机应用研究》
Abstract： With the increasing popularization of intelligent terminal devices, information containing abundant extremely short text data, such as WeChat messages, online instant news and customers' comments on e-commerce websites have been experiencing explosive growth. In order to effectively extract the key features from the extremely short texts, this paper proposes an extremely short text classification model based on SVM. Firstly, by the data cleansing on the original data, the cleaned data is processed by the Jieba segmentation and TF-IDF. Then the (1-0) test verified the validity of the model. Finally, 9906 pieces of extremely short texts in Wuhu City Community management platform are used as the sample in this experiment. The results show that the proposed method can effectively improve classification accuracy compared to other traditional methods, such as Naive Bayes, Logistic regression and Decision tree. At the same time, the matching results in terms of misclassification and accuracy are more balanced.
Subjects: Biology >> Ecology submitted time 2017-03-08 Cooperative journals: 《生态学报》
Abstract：气候和土地利用变化是影响水资源变化最直接的因素。应用SWAT模型对干旱半干旱区小流域宁夏清水河流域径流进行多情景模拟预测，以历史气候要素变化趋势和CA-Markov模型分别设置未来气候和土地利用变化情景，以决定系数R2和Nash-Sutcliffe模型效率系数Ens（Nash-Sutcliffe efficiency coefficient）来衡量模拟值与实测值之间的拟合度，并评价模型在清水河流域的适用性。结果表明，韩府湾站在校准期和验证期的R2分别为0.80和0.71，Ens分别为0.77和0.69，泉眼山站在校准期和验证期的R2分别为0.66和0.63，Ens分别为0.62和0.56，表明构建的SWAT模型可以用于清水河流域的径流模拟。对未来气候和土地利用变化情景下径流的模拟结果显示，径流变化主要由降水变化主导，降水减少和气温升高的综合作用对流域径流变化影响最为显著；由于耕地和建设用地的增加，未来3种土地利用情景下流域径流量将均会呈现明显增加变化。与2010年相比，到2020年，自然增长情景流域径流将增加17.04%，林地保护情景径流将增加14.44%，规划情景径流将增加13.98%；综合降水、气温和土地利用的结合变化情景显示，未来流域径流将会有不同程度的下降，规划情景和气候变化的结合情景的径流下降最为明显，而有意增大林地和加强生态保护的林地保护情景对减缓流域径流下降具有一定作用。在气候变化的大背景下，根据水资源利用管理目标，可通过调整流域管理措施，特别是土地利用变化和改善区域小气候来减缓气候变化对流域水资源的负面效果，以此来改善流域径流和生态环境状况。
Subjects: Biology >> Ecology submitted time 2018-05-18 Cooperative journals: 《生态学报》
Abstract：为合理利用三峡库区消落带优良草本植物进行退化植被恢复，并探索恢复过程中草本植物的最佳混植比例，选取三峡库区消落带适生先锋草本植物牛鞭草（Hemarthria compressa）（H）和狗牙根（Cynodon dactylon）（C）为研究材料，于2016年4月29日在盆栽控制条件下设置3种不同水分条件（对照组——CK组、浅淹组——SF组、全淹组——TF组）、7种配置比例，每盆牛鞭草与狗牙根株数分别按2株进行递增与递减，具体的配比分别为H0C12，H2C10，H4C8，H6C6，H8C4，H10C2、H12C0，比较研究混植条件下牛鞭草与狗牙根在水淹环境中的生长及二者的竞争作用。研究发现：（1）无论在单植还是二者混植条件下，水分胁迫均显著降低狗牙根与牛鞭草生物量，且牛鞭草对水淹胁迫的响应更敏感；（2）狗牙根和牛鞭草的生长均具有明显的密度制约效应，但狗牙根的反应更为强烈；（3）不同水分与密度条件下，混植体系总相对生物量均大于1。在CK组，狗牙根与牛鞭草表现出竞争关系；在SF组和TF组，二者之间的竞争作用减小，表现出一定的促进作用。综合分析本试验不同水分与密度条件下牛鞭草与狗牙根的总生物量、根冠比、竞争系数（相对总生物量），发现常规供水处理下牛鞭草和狗牙根的最佳配置比例为H2C10，而浅水淹和深水淹处理下最佳配置比例为H8C4。研究结果可以为三峡库区消落带不同海拔位草本植被的恢复及管理提供依据，也为生态类型相同或相似地区人工恢复草本植被提供理论参考。
Subjects: Biology >> Botany >> Applied botany submitted time 2024-03-26 Cooperative journals: 《广西植物》
Abstract： Phosphorus (P) is one of the essential elements for plant growth and is a key factor in maintaining the productivity of subtropical forest ecosystems. Chinese fir (Cunninghamia lanceolata) is mainly distributed in subtropical areas of China, and its soil acidification and phosphorus utilization efficiency are low. It is of great significance to study the effect of Chinese fir plantation transformation on soil P for the stability of ecosystem and sustainable forest management. In this study, the rhizosphere soil and non-rhizosphere soil were collected from the replanted Chinese fir plantation, Castanopsis hystrix plantation, Mytilaria laosensis plantation and the mixed plantation of Castanopsis hystrix and Mytilaria laosensis on the cutting-blank of Chinese fir plantation in South Asia, and the effects of soil P component and transformation on the transformation of Chinese fir plantation into broadleaved forest were studied. The results showed that: (1) The content of microbial biomass phosphorus and the activity of acid phosphatase in rhizosphere and non-rhizosphere soil of the modified Castanopsis hystrix plantation, Mytilaria laosensis plantation and the mixed plantation of Castanopsis hystrix and Mytilaria laosensis were significantly higher than those of Chinese fir plantation. Soil total phosphorus of Castanopsis hystrix plantation and the mixed plantation of C. hystrix and Mytilaria laosensis was more easily converted to quick available phosphorus than those of Chinese fir plantation and Mytilaria laosensis plantation. (2) The contents of calcium chloride extraction phosphorus in rhizosphere and non-rhizosphere soil of Castanopsis hystrix plantation and the mixed plantation of Castanopsis hystrix and Mytilaria laosensis were significantly higher than those of Chinese fir plantation and M. laosensis plantation, and the contents of enzyme extraction phosphorus, hydrochloric acid extraction phosphorus and citric acid extraction phosphorus in rhizosphere and non-rhizosphere soil of Mytilaria laosensis plantation and Castanopsis hystrix/Mytilaria laosensis mixed plantation were significantly higher than those of Chinese fir plantation and Castanopsis hystrix plantation. (3) RDA results showed that soil water content and microbial biomass carbon were the key factors regulating P components in rhizosphere and non-rhizosphere soils, respectively. In summary, the transformation of Chinese fir plantation into broadleaved forest is conducive to the storage and supply of forest soil P, and this study provides an important scientific basis for tree species selection and management strategies to improve soil P availability in south subtropical plantations.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-06-17 Cooperative journals: 《广西植物》
Abstract：该文采用菌丝生长速率法，研究了山芝麻根、茎和叶不同溶剂萃取物在1.5 mg·mL-1 浓度下对10 种植物病原真菌菌丝生长的抑制活性，用孢子萌发法测试了山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病菌分生孢子萌发的抑制作用，用离体法测试了山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病的防治效果，并通过气相与质谱联用技术（Gas Chromatography-Mass Spectrometer，GC-MS）分析了山芝麻根石油醚相和乙酸乙酯相萃取物的主要成分，测试了其中8 种主要化合物对香蕉炭疽病菌菌丝生长的抑制活性。结果表明山芝麻各部分萃取相对10 种植物病原真菌菌丝生长均具有不同程度的抑制作用，其中，在1.5 mg·mL-1 浓度下，山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病菌菌丝生长的抑制率分别为87.00%和86.14%，其EC50 分别为0.062 mg·mL-1 和0.052 mg·mL-1；浓度在2 mg·mL-1、4 mg·mL-1、8 mg·mL-1时，山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病菌分生孢子萌发相对抑制率均在70%以上；在10mg·mL-1 浓度下，山芝麻根石油醚相和乙酸乙酯相萃取物对香蕉炭疽病的防治效果分别为72.32%和59.77%；通过气相与质谱联用技术对山芝麻根石油醚相和乙酸乙酯相萃取物进行了分析，其中，山芝麻根石油醚相萃取物中共鉴定出36 种主要化学成分，山芝麻根乙酸乙酯相萃取物中共鉴定出17 种主要化学成分，选取的8 种主要化合物中，在100 μg·mL-1 浓度下，邻苯二甲酸二异丁酯和邻苯二甲酸二丁酯对香蕉炭疽病菌菌丝生长显现较高的抑制活性，抑制率分别为65.12%和68.07%，EC50分别为56.66 μg·mL-1和37.04μg·mL-1。
Subjects: Biology >> Botany >> Applied botany submitted time 2024-01-03 Cooperative journals: 《广西植物》
QIN Huiting
YAN Jinliu
HUANG Haimei
LI Jiajun
XIANG Mingzhu
LI Changhang
HUANG Xueman
ZHAO Lijun
YOU Yeming
Abstract： Organic phosphorus (Po) is an important part of soil phosphorus reservoir. In order to investigate the effects of the soil Po fraction distribution properties in Pinus massoniana plantations after close to nature silviculture, we investigated the pure P. massoniana plantations (PP) and P. massoniana broad leaved mixed plantations (CP) after close to nature silviculture in southern subtropical China. After collecting 0~10 cm soil sample, it was screened into >2 mm, 0.25~2 mm and <0.25 mm particle size fractions using the dry sieving method. We measured the Po fraction, microbial biomass phosphorus (MBP) and acid phosphatase (ACP) activity in the bulk soil and aggregates to understand the distribution of the Po fraction and its drivers. The results were as follows: (1) Soil Po fractions changed in CP compared to PP, with highly recalcitrant organophosphorus (HRO P) and moderately labile organophosphorus (MLO P) markedly greater in the bulk soil and soil aggregates than in PP (P 0.05), while labile organophosphorus (LO P) and moderately recalcitrant organophosphorus (MRO P) were not significantly different in CP and PP. In addition, there was no consistent pattern of change in the Po fractions in the bulk soil and soil aggregates between PP and CP. (2) The size of the proportion of each form of Po in PP was HRO P>MRO P>MLO P>LO P, while CP was HRO P>MLO P>MRO P>LO P. (3) The MBP and ACP activity in CP was markedly greater than that of PP in the bulk soil and the soil aggregates, and there was a tendency for the ACP activity to increase with the decrease in the size of the aggregates. (4) Redundancy analysis revealed that soil available phosphorus (AP), mean weight diameter (MWD), MBP and total nitrogen (TN) were the main drivers of the soil Po fraction. In conclusion, the close to natural forest management model is beneficial to the accumulation and transformation of soil phosphorus in P. massoniana plantation. This study provides a theoretical basis for the improvement of soil quality and productivity in P. massoniana plantations.
Subjects: Biology >> Ecology submitted time 2018-05-10 Cooperative journals: 《生态学报》
Abstract：为探究三峡库区消落带原位人工种植的池杉（Taxodium ascendens）和落羽杉（Taxodium distichum）在该特殊生境下的适应机制，设置了浅淹（SS，海拔175m，对照）、中度水淹（MS，海拔170m）和深度水淹（DS，海拔165m）3个水淹处理组，测定了两树种在连续4个周期性水淹处理后的光合响应过程，并采用直角双曲线模型、非直角双曲线模型、直角双曲线修正模型和指数模型进行拟合，比较各模型拟合结果差异并选出最优模型，通过最优模型来分析水淹后落干期两树种的光合生理变化。结果表明：（1）不同模型间的光响应曲线拟合结果存在差异（PPn）的表现均为DS组 > MS组 > SS组。（3）中度水淹和深度水淹两树种的最大净光合速率（Pnmax）、表观量子效率（α）、光饱和点（LSP）均高于浅淹，而光补偿点（LCP）则显著降低。以上结果说明落干生长期两树种对强光和弱光的利用能力增强，水淹对两树种的光合潜力有一定的促进作用，这可能与其遭受水淹胁迫后的自我调节能力和光合补偿机制有关。由此表明，当生境发生不良变化时，植物的适应性变化往往表现为沿着有利于光合作用最大化的方向发展。
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