Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-02 Cooperative journals: 《广西植物》
Abstract：为了解东兴金花茶幼苗对水分胁迫的适应能力和响应机制。以东兴金花茶一年生实生苗为材料，采用盆栽控水试验，研究不同控水时间处理对东兴金花茶幼苗的生理生态特性的影响。结果表明：随着控水时间的延长，水分胁迫的程度不断地加剧，东兴金花茶叶片净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）呈现显著下降趋势；胞间CO2浓度（Ci）先低后高的变化趋势，水分利用效率（WUE）成呈先高后低的变化趋势。土壤含水率和叶片相对含水量均呈现不断下降的趋势；丙二醛呈先降后升的变化趋势；东兴金花茶幼苗的荧光参数Fv/Fm和Fv/Fo呈现先增加而后不断下降趋势，分别从0.806下降至0.754和4.17下降至3.08；表明水分胁迫降低了PSII原初光能转化效率，光合作用原初反应过程受到抑制。基于水分胁迫的生理生态指标和叶片生物性状的变化表明：控水时间在4d情况下东兴金花茶可以提高自身水分利用效率来抵抗干旱，说明东兴金花茶幼苗对水分胁迫具有一定的适应性和响应机制。控水8~12 d，东兴金花茶的光合指标下降显著，土壤含水率下降至14.157%～15.065%，其叶片萎蔫、打卷，低于此水平东兴金花茶幼苗会因过度干旱而死亡，表明东兴金花茶幼苗对水分胁迫的耐受极限为土壤含水率的14.157%～15.065%。研究结果有助于营建适宜的环境以保证东兴金花茶的正常生长和繁殖，对东兴金花茶迁地保护、引种培育和回归自然具有重要的科学指导意义。
Subjects: Biology >> Botany >> Applied botany submitted time 2019-11-15 Cooperative journals: 《广西植物》
Abstract：桂林市龙胜县作为罗汉果的三大主产区之一，种植区土壤重金属含量及罗汉果质量，影响到该区罗汉果产业的健康发展。为探索龙胜县丘陵山区典型贫困村罗汉果园的安全性，研究了宝赠村典型罗汉果园土壤及罗汉果果实中砷、铜、锌、铅、镉、铬、汞7 种重金属含量，采用Hankanson 指数法分析了其潜在生态风险。结果表明：①龙胜丘陵山区罗汉果园土壤（0-10 cm，10-20 cm）重金属含量均达到国家农业用地土壤筛选值标准（GB15618-2018），其中0-10cm 土壤中砷、铜、锌、铅、镉、铬、汞的含量分别为3.67、18.00、58.39、17.01、0.10、28.57 和0.08 mg·kg-1，10-20cm 土壤中砷、铜、锌、铅、镉、铬、汞的含量分别为1.93、12.56、21.47、10.51、0.04、17.09 和0.02 mg·kg-1。②0~10 cm 和10~20 cm 土层中重金属的生态风险状况总体上处于轻微生态风险等级，综合生态风险指数分别为105.29 和38.96；0~10 cm 土层不同重金属潜在的生态风险顺序为汞>镉>铅>铜>砷>锌>铬，汞、镉的生态风险分别为50.16、42.05，在总重金属风险中贡献率分别占所有重金属的47.6%和39.9%，已达中等生态风险等级。在10~20 cm 土层，7 种重金属的生态风险大小关系为镉>汞>铜>铅>砷>铬>锌。③,研究区罗汉果果实中砷、铜、锌、铅、镉、铬、汞的含量分别为0.000 24、0.273、1.10、0.001 6、0.000 13、0.000 13 和0.000 12 mg·kg-1，其生态风险状况均处于轻微风险等级，7 种重金属的生态风险顺序为汞>铜>镉>锌>铅>砷>铬，综合生态风险指数为0.21193，几乎不存在生态风险。因此，在龙胜县丘陵山区典型贫困村宝赠村，推广种植的罗汉果达到了安全质量标准。
Subjects: Biology >> Botany >> Applied botany submitted time 2024-03-26 Cooperative journals: 《广西植物》
Abstract： To promote the restoration and reconstruction of ecosystem in the water-land ecotone, based on typical sample investigation, the variation patterns of vegetation species composition and diversity, and soil nutrients under different vegetation types were studied using Pearson correlation coefficient method and redundancy analysis method. The results were as follows: (1) There were significant differences in plant community structure and species diversity of different vegetation types (gravel zone, grass zone, shrub-grass zone, trees zone). As the submersed duration decreased, the water-land ecotone gradually evolved from scattered herbaceous plant communities to grass, shrub, and tree plant communities, and the α diversity of vegetation species (Shannon-Wiener index, Pielou index and Simpson index ) and vegetation coverage showed a gradually increasing trend, which were lowest value on the gravel zone and the highest on the trees zone. (2) There were significant differences in soil nutrient content among different vegetation types. With the decreased of submersed duration, soil organic matter content gradually increased, while soil water content, available nitrogen, available phosphorus, and available potassium showed a trend of first increasing and then decreasing, the maximum values of these nutrients mostly occurred in shrub-grass zone or trees zone, followed by grass zone, and gravel zone was the lowest. (3) Correlation and redundancy analysis showed that soil available nitrogen, available potassium, available phosphorus and organic matter were significantly positively correlated with various indicators of vegetation species α diversity, among which soil available nitrogen and available potassium had the strongest correlation with vegetation species diversity. In conclusion: different vegetation types in the Lijiang water-land ecotone have heterogeneous patterns of vegetation species composition and diversity as well as soil nutrients. Moderate submergence is beneficial for vegetation community aggregation and promoting soil nutrient accumulation. Herbaceous plants have stronger adaptability to moderate submergence environments. During the ecological restoration process of the Lijiang water-land ecotone, it is necessary to design restoration plans for different vegetation types and fully consider the relationship between vegetation species diversity and soil available nutrients.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-08-05 Cooperative journals: 《广西植物》
Abstract： Excentrodendron tonkinensis is a constructive species of karst seasonal rainforest and an obligate karst plant, which is also one of the national secondary key protected wild plant and an IUCN endangered plant, with high economic and ecological value. However, there is still a lack of understanding of how the potential suitable areas of Excentrodendron tonkinensis change in the context of global change and its key driving factors, which affect the scientific protection and utilization of Excentrodendron tonkinensis.To assess the impacts of climate change on the extents of the habitat of Excentrodendron tonkinensis, we used the Maximum-entropy model to analyze the potential changes in the geographical distribution in China of future climate scenarios SSP1-2.6 and SSP5-8.5), and tested the influence of the karst geological background distribution on predicting the suitable areas of karst obligate plants. The results show that: (1) in the case of adding karst geological background data, the average AUC of the prediction model for the suitable area is 0.997, which has a good prediction effect. And the model prediction results are strictly limited to the karst region, consistent with the characteristics of Excentrodendron tonkinensis which is karst obligate plant; (2) According to the fitting results of the model, the karst geological background, precipitation of warmest quarter(800-950 mm), and the min temperature of coldest month(7-11 ℃) are the key factors limiting the distribution of Excentrodendron tonkinensis; (3) with the increase of temperature in the future, the area of potential suitable areas for Excentrodendron tonkinensis would expand to higher latitudes karst areas. Large numbers of areas of stable habitats exist in parts of southwest Guangxi and southeastern Yunnan. These results suggest that the karst geological distribution is essential as predicting the potential geographic distribution of karst obligate plants such as Excentrodendron tonkinensis; if the temperature continues to rise in the future, its potential suitable areas will expand to high latitudes, and the degree of endangerment may be affected by climate, which means it is not obvious under the influence of climate changes; parts of southwestern Guangxi and southeastern Yunnan are suitable areas for the conservation and utilization of Excentrodendron tonkinensis under the climate changes in the future.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-06-29 Cooperative journals: 《广西植物》
Abstract： In order to study the adaptive strategy of dominant tree species in a karst seasonal rain forest to heterogeneous habitat conditions, seven dominant tree species in a virgin forest in Nonggang, China, were taken as the research objects. The leaf micromorphological indexes of adult individuals of each tree species and the photosynthetic indexes of leaves in the growing season of these trees were measured. The ecological adaptability of these leaf structural and functional indexes to the habitat gradient in the karst peak cluster depression landform was tested. The results were as follows: (1) Along the karst habitat gradient from depression to peak, nine leaf micro-morphological indexes, such as leaf compactness, palisade tissue thickness, cuticle thickness, and upper epidermis thickness, showed a significant upward trend, while leaf looseness showed a significant downward trend. (2) Along the karst habitat gradient from depression to peak, the light compensation point, dark respiration efficiency, and maximum transpiration rate of these leaves all showed a significant upward trend. However, the maximum water use efficiency, the maximum intercellular CO2 concentration, and the apparent quantum efficiency showed a significant downward trend. (3) Leaf compactness was positively correlated with photosynthetic and transpiration ability indexes. Leaf looseness was negatively correlated with these two types of indexes. The above results show that there is a trade-off relationship between photosynthetic efficiency and drought tolerance in leaf functional traits of dominant tree species in the karst seasonal rain forest. Trees distributed in the depressions have obvious adaptive characteristics to weak light. Trees distributed on the middle slopes show extensive habitat adaptability. Due to the limitation of strong light, high temperature and exposed rock, the trees distributed on the mountain peaks show strong drought adaptability and conservative ecological adaptive strategies.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-02 Cooperative journals: 《广西植物》
Abstract：该文报道了产自西藏自治区墨脱县境内的线柱苣苔属（Rhynchotechum）中国分布新记录——小花线柱苣苔(R. parviflorum Blume)。该种常生长在林中溪流附近的崖壁以及次生林下阴湿生境中。本种主要辨别特征为叶基本对生，花萼裂片被绢毛，花梗被黄褐色绒毛，花冠筒较小，子房具短柔毛，果无毛至微柔毛。印度学者于2020 年记载为印度新分布，而原始文献中记录的凭证标本采集点位于中国西藏自治区墨脱县境内，故对原文记述的产地信息提出质疑。同时，在前人的研究中部分馆藏的线柱苣苔属植物标本被认定为本种，在此一并提出该种在中国的分布地理信息和详细描述。
Subjects: Biology >> Botany >> Applied botany submitted time 2024-03-26 Cooperative journals: 《广西植物》
Abstract： Since the establishment of Anna in 1930, the taxonomic revisions of this genus have been infrequent. Early publications and revisions of Anna were based on specimens collected by foreign missionaries, which led to problems such as brief or inaccurate descriptions of traits and unclear species definition. When researching publication history, comparing morphology and investigating type locality of Anna ophiorrhizoides (Hemsl.) B. L. Burtt & R. A. Davidson and A. rubidiflora S. Z. He, F. Wen & Y. G. Wei, we found that Didymocarpus cavaleriei H. Lév. published by H. Léveillé in 1911 and Anna rubidiflora are actually the same species, and Didymocarpus cavaleriei was treated as a synonym of Anna ophiorrhizoides. After comparing the morphological characteristics of multiple populations of A. ophiorrhizoides and A. rubidiflora, it was found that the difference in their morphological characteristics lies in the corolla. It is not appropriate to use differences in corolla color as boundaries for the classificatory units of species. Taking into account the morphological characteristics and geographical distribution characteristics, it is proposed to treat Anna rubidiflora as a variety of Anna ophiorrhizoides. According to the regulations and suggestions in the 2018 International Code of Nomenclature for Algae, Fungi, and Plants (Shenzhen Code), we propose a new combination and a name at new rank——Anna ophiorrhizoides (Hemsl.) B. L. Burtt & R. A. Davidson var. cavaleriei（H.Lév.）X. X. Bai & F. Wen, and treat Anna rubidiflora as the synonym of the new combination.
Subjects: Biology >> Botany submitted time 2022-10-27 Cooperative journals: 《广西植物》
Abstract： Petrocodon Hance was one of the famous ornamental flowers, but most of them were assessed as extremely dangerous (CR), or at least above vulnerable (VU) due to climate turbulence and strong interference of human activities. To reconstruct the temporal and spatial changes of the potential suitable areas of Petrocodon since the last interglacial period, and explore the response of the suitable areas to environmental changes, which provided theoretical guidance for the origin of Petrocodon, the study of geographical differentiation, the conservation of unique germplasm resources in China, and the development and utilization of gardens. In this paper, combined with 120 distribution records and 17 environmental variables, the optimal MaxEnt model and geographic information technology (ArcGis) were used to simulate the suitable areas and distribution pattern of Petrocodon in China and Indo-China Peninsula. Based on stepwise multiple linear regression analysis, redundancy analysis and Monte Carlo test, the dominant factors affecting the current geographical distribution of Petrocodon were evaluated. The results were as follows: (1) The prediction accuracy of the optimized MaxEnt model was high, and the AUC value was greater than 0.96. The potential suitable areas of Petrocodon for the present distribution are continuous from southwest China to northern Vietnam, scattered in central and southern China and blocky in northern Myanmar, of which the southern Yunnan-Guizhou Plateau in China was the most suitable. (2) The environmental variables which restrict the geographical distribution of Petrocodon included precipitation of the driest month (bio14), precipitation of the warmest quarter (bio18), precipitation of the wettest quarter (bio16), SD of the temperature seasonality (bio4), min temperature of the coldest month (bio6) and altitude (alt). (3) Under the climate change scenario, the expansion and contraction areas of the suitable habitat of Petrocodon were located in the north and northeast of the current potential distribution area, which were sensitive areas susceptible to climate change. During the last interglacial period, the suitable area of Petrocodon expanded on a large scale, but there was almost no suitable distribution area of Petrocodon in the dry and cold environment during the last glacial maximum. After that, with the aggravation of climate warming, the suitable habitats of Petrocodon increased rapidly to high latitudes, while the suitable habitat in low latitudes decreased. (4) The centroid position of the suitable area for Petrocodon migrated northwards from Yongfu County, Guangxi (110.10� E, 24.69� N) to Chengbu County, Hunan (110.29� E, 26.05� N). To sum up, global warming has a positive impact on the potential distribution area of Petrocodon, but extreme warming will cause the suitable habitat of Petrocodon to shrink, and the niche of Petrocodon will narrow. Southwest China to northern Vietnam, which has the advantage of mature karst landform, may be its main refuge.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-02 Cooperative journals: 《广西植物》
Abstract：苦苣苔科原大花旋蒴苣苔(Boea clarkeana)为我国特有的复苏植物，在最近的修订中被并入套唇苣苔属(Damrongia Kerr)，更名为大花套唇苣苔(D. clarkeana )。本研究以大花套唇苣苔成熟种子为试验材料，通过观察钙盐和模拟干旱互作试验对其种子萌发和幼苗生长的影响，以期探究该植物对喀斯特特殊生境的适应机制。结果表明：钙盐及模拟干旱互作时，低浓度钙盐可减轻干旱对种子萌发和幼苗生长的抑制作用，并且低程度的干旱与低浓度的钙盐相互作用时反而会促进种子萌发和幼苗生长；低钙盐低旱复合条件对大花套唇苣苔生长的促进作用也体现了该物种对喀斯特地区保水性差的石灰岩土壤基质的专适性，也避免了和其他植物直接生态位的竞争。
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 2024-04-17 Cooperative journals: 《广西植物》
Abstract： Mangrove forests, characterized by high photosynthetic rates and low light compensation point, exhibit high Gross Primary Production (GPP), an important component of "blue carbon". Accurate estimation of regional GPP and quantification of its limiting factors are greatly significant for China to achieve its carbon neutrality goals. In this paper, we estimated the GPP of mangrove ecosystems in Hainan Island from 2016 to 2020 based on the Mangrove Vegetation Photosynthesis Light Use Efficiency (MVP-LUE) model using Sentinel-2 imagery and environmental data; and we also explored the spatiotemporal distribution pattern of GPP and its driving mechanism. The results were as follows: (1) During the study period, the annual GPP of mangrove ecosystems on Hainan Island showed an increasing trend, with higher GPP in the eastern than western regions and northern than southern regions. The mangroves distributed over a large area in northeastern Hainan Island dominate the temporal variation patterns at the whole island scale. However, distinct differences exist in the temporal dynamics across different regions of the mangrove ecosystem in Hainan Island. (2) In terms of the formation mechanism, the spatial and temporal distribution pattern of GPP of mangrove ecosystems on Hainan Island was driven by a combination of multiple meteorological factors. Seasonally within each year, during the transition from the dry season to rainy season, GPP was higher due to lower limitation from air temperature (Tair), and the promoting effects of photosynthetically active radiation (PAR) and sea surface temperature; in the middle of the dry season, low Tair imposed a serious limitation on GPP, but this Tair limitation was weakened with decreasing latitude. In the rainy season, higher cloud cover resulted in PAR becoming a limiting factor for GPP. At the end of the paper, we discussed the uncertainties and limitations of MVP-LUE, and the spatiotemporal distribution patterns of mangrove ecosystem GPP not only be constrained by environmental factors, but species composition and forest age structure can also be driving factors. The results of this study provide basic data to assess the contribution of regional mangrove forests to the global carbon cycle, and theoretical support to reveal the key environmental factors affecting mangrove ecosystem carbon dynamics.
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