Subjects: Biology >> Botany >> Applied botany submitted time 2024-01-03 Cooperative journals: 《广西植物》
Abstract： Taking Pinus elliottii and Liriodendron chinense artificial coniferous and broad-leaved mixed forest in the rocky desertification area of western Hunan Province as the research object, this paper provides a theoretical basis for vegetation restoration, plantation structure optimization, and soil improvement in this area. The stand structure and soil physicochemical properties of existing stands were analyzed using plant community analysis and field sampling detection methods. Winklemass 1.0 was used to calculate the spatial structure parameters of the stands, and three-dimensional discrete random variables were used to analyze the spatial distribution pattern of dominant species. The results show that: (1) 897 plants·hm-2 with DBH ≥ 2 cm in the stand, belonging to 15 families and 16 genera. The main forest layer is Pinus elliottii, with an average DBH of 32.3 cm and an important value of 44.2%; The secondary forest layer is the broad-leaved tree, with the majority of young and middle-aged trees. Cinnamomum camphora and Liriodendron chinense are the dominant species, with important values of 17.1% and 13.2% respectively. In addition, there are many alien regeneration species at the disadvantage niche. (2) The horizontal distribution pattern of trees tends to be random ( ̅=0.503); The overall trend of forest stands tends to transition towards mediocrity and disadvantage ( ̅=0.505); The degree of interspecific isolation is relatively high ( ̅=0.689), and the mixed forest is in good condition. Three-dimensional discrete random variables of spatial structure parameters show that 87.3% of Pinus elliottii is dominant and sub-dominant, 41.7% of Liriodendron chinense is sub-dominant, 26.9% is moderate, 23.5% of Cinnamomum camphora is moderate, 56.8% is inferior and absolute inferior. (3) The pH value of forest soil tends to be neutral; Compared with abandoned land, the bulk density, water capacity, porosity, organic carbon, total potassium, total nitrogen, and total phosphorus of the forest soil have significantly improved. However, the forest soil is still relatively barren, with local soil compaction and poor water retention ability. To sum up, after 43 years of growth of Pinus elliottii and Liriodendron chinense as pioneer species, the stand has a trend of succession to the uneven-aged forest and intensive mixed forest. However, the number of young and middle-aged broad-leaved trees in the forest is relatively large, and faults appear in the near mature forest. The elderly coniferous trees occupy the dominant ecological location. Needles need to be drawn to supplement the broad-leaved trees, interspersed to cultivate the broad-leaved trees, and select the inferior trees, to promote the structural succession of the forest with mainly sunny broad-leaved trees, followed by mesophytic and shade-tolerant broad-leaved trees.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-26 Cooperative journals: 《广西植物》
Abstract： In order to select superior clones with strong resin-producing capacity and high resin-quality from the existing fast-growing timber clones in seed orchard of Pinus elliottii, and to make high use of crop germplasm resource,36 clones in the first generation of slash pine seed orchard were used as materials to determine their resin yield, resin mass flow rate and DBH growth, and to analyze their resin composition by GC-MS. Based on the above indicators, correlation analysis and cluster analysis was used to comprehensively evaluate the production and quality of resin among 36 clones. The results were as follows: (1) There were a total of 21 pine resin components, including 8 monoterpenes and 13 diterpenes. (2) Correlation analysis showed that the resin mass flow rate (RMR) had significant and positive correlation with the total content of monoterpene, weakly negatively correlates to abietic-type resin acid, and not significantly correlated to pimaric-type resin acid. (3) Based on the cluster analysis results integrating four types of indicators as the total monoterpene content, resin mass flow rate, abietic-type resin acid and pimaric-type resin acid, 36 clones could be divided into three categories and the difference between each type is significant. The performance of Class 1 was much better than that of the other two categories. (4) There were 17 high-resin yield pine clones (ERM≥15.15) among 36 clones, and on the basis of this, four clones (6-44, 4-11-1, 1-38 and 3-64) display higher monoterpenes content, while four clones (4-11-1, 3-64, 2-0420, 3-468) showed higher contents of pimaric-type resin acid. And the content of abietic-type resin acid of clone 2-173 was the highest. In summary, a total of 21 pine resin components of P. elliottii were identified, and 36 clones were evaluated based on four indicators: the total monoterpene content, resin mass flow rate, abietic-type resin acid and pimaric-type resin acid. We not only analyzed qualitatively the resin composition but also evaluated quantitatively the resin-producing capacity of 36 clones in slash pine seed orchard. Our findings provide the scientific references for the targeted breeding of pine resin components and lay a foundation for subsequent heredity breeding and gene improvement of P. elliottii.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-06-05 Cooperative journals: 《广西植物》
Abstract： To investigate the effects of two different water sources, domestic sewage and nutrient solution, on the decomposition of residual roots and the transformation of chromium chemical forms in Cr6+ contaminated constructed wetlands, a micro Coix lachryma-jobi L constructed wetland was constructed to treat chromium containing wastewater [ using domestic sewage (DWS) and 1/2 Hoagland nutrient solution (HNS) as simulated solutions containing 0, 20, and 40mg· L-1Cr (VI), respectively]. By using the buried root decomposition method, we studied the decomposition dynamics of residual roots and the transformation pattern of chromium chemical forms.The results were as follows : (1) Under 20 and 40 mg· L-1 (Ⅵ) stress, the growth of Coix lacryma-jobi L was inhibited. The plant height and stem diameter of HNS treatment were greater than those of DWS treatment, but the plant height and stem diameter of HNS treatment were more inhibited by Cr (Ⅵ) than those of DWS treatment; (2) The decomposition rate of Coix lacryma-jobi L residual roots decreased with the increase of Cr (Ⅵ) concentration, and the decomposition rate of HNS treatment was higher than that of DWS treatment. After 60 days of decomposition, under DWS treatment, the residual root chromium content of 20 and 40 mg· L-1Cr (Ⅵ) treatment decreased by 11.7% and 8.09% respectively compared with that at the initial stage of root burial, while under HNS treatment, the residual root chromium content decreased by 15.8% and 18.42% respectively. The percentage of residual chromium in Coix lacryma-jobi L root residues at 20 and 40 mg· L-1 treatments decreased with the extension of root burial time, while the percentage of ethanol-extracted chromium and deionized water extracted chromium increased, and the percentage of acetic acid bound chromium increased significantly; (3) In the early stage of residual root decomposition, the COD, TN, NH4-N, and total chromium content in the effluent treated with HNS and DWS increased, and then decreased. The trend of change is consistent with the residual root decomposition process. HNS treated constructed wetlands are more efficient in removing chromium from wastewater. The research results indicate that after harvesting plants in constructed wetlands, root decomposition can quickly increase the chromium content in the effluent, and appropriately improve the nutritional status in wastewater, which can promote residual root decomposition and removal of chromium by wetlands.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-12-19 Cooperative journals: 《广西植物》
Abstract： Heavy metal pollution in Kandelia obovata ecosystem is an important part of coastal wetland research. In order to explore the health risk and heavy metal pollution of Kandelia obovata wetland of different origins in eastern Fujian，this study explored the content characteristics of heavy metals in surface sediments of different origins of Kandelia obovata wetlands and assessed their health risks in eastern Fujian by using the pollution load index method and human health risk assessment method. The results were as follows: (1) The average content of heavy metals in surface sediments of Kandelia obovata natural forest wetland was Zn（102.38 mg·kg-1）> Pb（101.53 mg·kg-1）> Cu（11.72 mg·kg-1）> Cd（0.91 mg·kg-1）. The order of heavy metal content in surface sediments of Kandelia obovata plantation was Zn （ 152.81 mg·kg-1）> Pb（105.83 mg·kg-1）> Cu（16.38 mg·kg-1）> Cd（1.33 mg·kg-1）. (2) The regional pollution load index (IPL zone) of heavy metals in surface sediments of Kandelia obovata natural forest was lower than that of Kandelia obovata plantation, and the corresponding pollution levels of Kandelia obovata plantation and natural forest were both 1, which belonged to moderate pollution. (3) The non-carcinogenic risk (Non carcinogenic Risk, RN) of heavy metals in surface sediments of Kandelia obovata wetland to adult males and adult females was lower than 1, and the non-carcinogenic risk to human body was very low. The RN of Pb element to children was higher than 1, it would cause non-carcinogenic risk to children. The carcinogenic risk (Cancer Risk, RI) of Cd to adult males, adult females and children was greater than 1.0×10-6, and there was a serious carcinogenic risk to the human body. The results indicate that heavy metal pollution of wetlands in eastern Fujian was serious. Therefore, we should control the pollutant emission around the wetland and purify the wetlands. In addition, adding the health risk assessment of heavy metals to the evaluation of Kandelia obovata wetland ecosystem will help to strengthen the ecological protection and risk management of Kandelia obovata.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-04-29 Cooperative journals: 《广西植物》
Abstract： In order to understand characteristics and significance of carbon (C), nitrogen (N), phosphorus (P) and stable carbon isotope composition (δ13C) in plant leaves of three typical aquatic plants under different growth environment, three life forms aquatic plants including emerging plant (Phragmites australis), emersion plant (Eichhornia crassipes) and submerged plant (Ceratophyllum demersumin) of the Huixian karst wetland are selected. The differences of carbon isotope compositions of interspecies and different habitat conditions were studied. The percentage of HCO3 － uptake from water by aquatic photosynthesis was estimated using the double-meta model. The results showed that: (1) the foliar δ13C of three diffirent plant life forms ranged from -28.47‰～-21.69‰ with an average of -24.83‰. There were significant differences between species, and its the sequence of relative value was Ceratophyllum demersum, Eichhornia crassipes and Phragmites australis. Among the three types of plants, Phragmites australis and Ceratophyllum demersum show the lowest and highest δ13 C, respectively. (2) For three types of halophytes，δ13C showed significantly positive correlations with foliar C, N, and P. The δ13C was also positively correlated with the contents of organic matter, available nitrogen, total nitrogen, available phosphorus and total phosphorus of sediment. All types of halophytes showed a negative correlation among δ13C, C/N, N/P, and C/P. The foliar N/P ratio of halophytes was 10.34, indicating a co-limitation by N and P for halophyte growth in the Huixian karst wetlands. These results suggested that three halophytes were adapted to environment through a high water use efficiency at the expense of decreased nitrogen use efficiency, and might improve C sequestration by increasing phosphorus use efficiency in the habitat of low water availability.The value of HCO3 － carbon sequestration by photosynthesis was 159.60 t·a-1·km-2 for Phragmites australis ,10.80 t·a-1·km-2 for Eichhornia crassipes, 9.24t·a-1·km-2 for Ceratophyllum demersum , with a mean value of 59.88 t·a-1·km-2. Different plant life forms, pathways of carbon fixation in photosynthesis and micro-environment were the important factors on affecting plant foliar δ13C in the Huixian karst wetland.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-01-12 Cooperative journals: 《广西植物》
Abstract：为了解湿地松‘松泰’小孢子叶球在发育过程形态是否有差异变化，明确其败育过程、败育方式及影响因素，为湿地松雄性不育品种利用和后期开展相关研究提供科学依据。以‘松泰’ s10败育系和s9可育系为材料，观察小孢子叶球形态发育变化；并对其小孢子叶球进行石蜡切片，在光学显微镜下观察小孢子发育过程。研究结果显示：s10败育系和s9可育系在小孢子母细胞减速分裂前无明显差异，小孢子叶球生长趋势也一致；四分体时期，s10小孢子细胞发育异常，小孢子叶球形态发育也出现异常，二者异常发育具有同步性；可育系从四分体到单核小孢子发育阶段的时间为5 d左右，而败育系持续发育长达20 d左右，持续时间为可育系的4倍。在此期间出现小孢子绒毡层细胞发育异常、降解缓慢，小孢子囊壁组织排列紊乱、降解延迟等现象，最后，s10形成异常二核花粉，且无花粉散出。因此推论s10小孢子败育的原因主要为：小孢子囊壁细胞发育异常，其小孢子叶球形态异常，相对应的其绒毡层在四分体时期发育异常，不能适时的分泌胼胝质酶来降解围绕着四分体的胼胝质壁，也不能适时地合成输送花粉形成所需能量物质，同时囊壁细胞出现降解延迟和层积，这一系列的异常变化导致不能形成正常四分体，从而使花粉败育。
Subjects: Biology >> Botany >> Applied botany submitted time 2020-01-12 Cooperative journals: 《广西植物》
Abstract：为使速生湿地松良种快速大规模繁殖，对其胚性愈伤组织进行诱导和增殖优化研究。该研究以1代湿地松种子园中10个速生湿地松优良无性系（基因型）的未成熟合子胚为外植体，系统研究了基因型、合子胚发育阶段、基本培养基、植物生长调节剂种类和浓度等不同因子对胚性愈伤组织诱导效率的影响，并探讨了胚性愈伤组织的增殖条件。结果表明：基因型、合子胚发育阶段、基本培养基及植物生长调节剂种类和浓度等均对胚性愈伤组织诱导有不同程度的影响。10个基因型均诱导出了胚性愈伤组织，其中以2号基因型诱导率最高，达到25.37%；合子胚发育阶段中，以处于多胚阶段的球果诱导率最高；5种基本培养基中，以在DCR基本培养基上诱导效果最佳；植物生长调节剂浓度及组合中以2,4-D 2.0 mg·L-1 + KT 2.5 mg·L-1诱导率最高，达到27.78%。湿地松胚性愈伤组织增殖的最佳培养基为在DCR基本培养基上添加0.5 mg·L-1 2,4-D、1.0 mg·L-1 KT、500 mg·L-1 CH和300 mg·L-1 L-谷氨酰胺。该研究为湿地松良种进一步开展成熟胚诱导及植株再生奠定了基础。
Subjects: Biology >> Botany >> Applied botany submitted time 2019-08-26 Cooperative journals: 《广西植物》
Abstract： As a critical part of wetland system in Guizhou plateau, lake Caohai plays important roles in the maintains of ecological balance,healthy and harmonious species diversity and the regional climate regulation. In order to stabilize the wetland and sustainable development resource,it is critical important to study the characteristics of heavy metals pollution in atmospheric deposition flux and pollution characteristics. By the susceptibility and tolerance of bryophytes to heavy metals, MossBag method was used to monitor the heavy metal pollution around the lake for seven heavy metals (Cu,Pb,Zn,Cd,Cr,As and Hg )analyses,and to provide a basic data for the ecological environment protection of Caohai.The contents of seven elements such as Cu, Pb, Zn, Cd, Cr, As and Hg were detected by ICP-MS and atomic fluorescence. The sediment flux was calculated. The principal component analysis and correlation analysis are applied to study their characteristicsand origin of such pollutants,while the ecological risks of these 7 heavy metals were evaluated using geoaccumulation index method. The study results showed that the heavy metals in atmospheric deposition fluxes of Caohai Lake was a significant difference. Among which Cu and Zn deposition fluxes are far higher Pb,Cd,Cr,As and Hg, reaching 21.43 μg•m-2•d-1 and 102.82 μg•m-2•d-1 with accounting for a large total deposition fluxes radio. The correlation analysis shows that there is a positive correlation between As and Cr, Zn and Cu, indicating they are from similar or same sources,with the same chemical and environmental behaviors.However,there is no significant correlation between other metals. Applying the geoaccumulation Index method,the following conclusions are reached: all seven heavy metals were seriously polluted, of which Cd was in the extremely high pollution level. Combing the study results with the characteristics and sources of heavy metal pollution around Caohai wetland, heavy metal pollutions were considered mainly caused by many factors,including industrial structure and production and life style, and even the leftover of primitive zinc smelting industry in the vicinity.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-06-17 Cooperative journals: 《广西植物》
Abstract：人为践踏对湿地苔藓地被的影响一直不清楚。以采自长白山区月亮湾湿地开阔地的红型和林缘的黄绿型中位泥炭藓（Sphagnum magellanicum）为实验材料，室内模拟人为践踏，使用便携式调制叶绿素荧光仪，测定其叶绿素荧光参数，研究不同践踏强度、不同践踏轮次下，两类中位泥炭藓的荧光参数响应情况。结果显示：践踏第二轮，红型中位泥炭藓的PSII实际光量子产量[Y（II）]和相对电子传递速率（ETR）随践踏强度增大而减小，而黄绿型的践踏组均大于对照组；践踏结束时，红型的Y（II）和ETR的践踏组均显著低于对照组，而黄绿型只有轻度践踏低于对照组；黄绿型泥炭藓践踏组的非调节性能量耗散量子产量[Y（NO）]甚至要低于对照组。研究表明，尽管泥炭藓属植物能耐受一定的践踏胁迫，但随着践踏轮次增多、强度增大，胁迫累积效应将强烈抑制其生长；多见于开阔地的红型泥炭藓对人为践踏的耐受能力低于林缘生境的黄绿型泥炭藓。湿地保护与管理中，应减少游人践踏干扰，尤其要严格控制开阔地生境的游人进入。
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