Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-13 Cooperative journals: 《广西植物》
Abstract： The purpose of this study is to explore the survival strategy of Phoebe bournei seedlings in natural communities under extremely low light environment. 2-year-old seedlings of P. bournei were used as experimental materials to study the effects of different treatments were measured by simulating different light environments (100%, 35% and 10% light transmittance) on leaf morphology, anatomical structure and photosynthetic physiological characteristics of P. bournei seedlings, and to explore the internal relationship between seedling morphology, physiological plasticity and light adaptation. The results were as follows: (1) The leaf length, leaf width, leaf area and specific leaf area (SLA) of seedlings increased with the decrease of light intensity; The leaf thickness, palisade tissue thickness, Thickness ratio of palisade tissue to sponge tissue of 10% light transmittance were the minimum. (2) The net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), light utilization efficiency (LUE), photochemical quenching coefficient (qp), non photochemical quenching coefficient (NPQ), effective photosynthetic quantum yield (Fv'/Fm') and potential photochemical efficiency (Fv/Fo) of 35% light transmittance were significantly higher than those of 100% and 10% light transmittance. (3) Chlorophyll a, Chlorophyll b, Carotenoids, total chlorophyll and Fv/Fm all increased with the decrease of light intensity, but chlorophyll a/b decreased with the decrease of light intensity. (4) The plasticity index of seedling structure and physiology showed that photosynthetic pigment content characteristics>morphological characteristics>photosynthetic characteristics>anatomical structure characteristics>chlorophyll fluorescence parameter characteristics, among which, the plasticity index of leaf area, SLA, Pn, Gs, LUE and photosynthetic pigment content ranged from 0.455 to 0.755. To sum up, P. bournei seedlings are not suitable to grow under full light, and perform well under about 35% light transmittance; under extremely low light with 10% light transmittance, P. bournei leaves can improve light energy capture by increasing leaf area, SLA, Pn and photosynthetic pigment content; the seedlings of P. bournei mainly adapt to the low light environment by adjusting the plasticity of photosynthetic pigment content and morphology, coordinating with the changes of anatomical structure, photosynthetic physiology and chlorophyll fluorescence parameter plasticity. This study can provide theoretical basis, management and selection of light environment of P. bournei for the future cultivation.
Subjects: Biology >> Botany submitted time 2022-08-30 Cooperative journals: 《广西植物》
Abstract： How plants change functional traits to adapt to the environment has always been the focus of ecology. In order to explore the adaptive strategies of plant leaves in different succession stages of Maolan Karst forest, taking the dominant species in five different succession stages ( herb, shrub, shrub-arbor, arbor and climax community) in Maolan Nature Reserve as the research object, the leaf functional properties and soil physical and chemical properties of dominant plants in different succession stages were measured. The results showed that : ( 1 ) With the positive succession of vegetation, soil total nitrogen content ( STN ), soil organic matter content ( SOM ) and soil water content ( SWC ) gradually increased, soil total phosphorus content ( STP ) and soil total potassium content ( STK ) first increased and then decreased, and soil pH value showed a decreasing trend as a whole. ( 2 ) With the positive succession of vegetation, leaf area ( LA ), leaf dry matter content ( LDMC ), leaf thickness ( LT ) and leaf carbon content ( LCC ) gradually increased. On the contrary, specific leaf area ( SLA ) and leaf potassium content ( LKC ), leaf nitrogen content ( LNC ) increased first and then decreased, and leaf phosphorus content ( LPC ) decreased first and then increased.( 3 ) Redundant analysis showed that plants were mainly distributed in the environment of high soil pH and relatively low STK, STP, SWC, SOM and STN in the early succession stage. Plant leaves in the community took high SLA, LNC and LPC, and low LA, LDMC, LT and LWC. Plants in the late succession stage were mainly distributed in the environment of high soil moisture and nutrients. LDMC, LT, LA and LWC showed an upward trend compared with the early succession stage, and SLA, LNC and LPC showed a downward trend compared with the early succession stage. In conclusion, with the forward succession of vegetation, plants adapt to the environment by changing functional traits, and leaf functional traits change from open strategy in the early succession to conservative strategy in the late succession.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-02-25 Cooperative journals: 《广西植物》
Abstract：探讨不同耕作方式的土壤矿质元素含量变化特征，旨在促进火龙果生长发育和品质改良。研究区采用套种紫花苜蓿（Medicago sativa）、施用有机肥、施用化肥与农药、地膜覆盖和无措施 5 种耕作方式，以每种方式土壤的 22 种矿质元素为评价指标，比较不同耕作方式的矿质元素含量差异，阐明土壤矿质元素之间的相关关系。结果表明：与无措施相比，其他耕作方式的 Ca、Si、Mn 等元素含量呈增加趋势，Fe、Mg、Al 等元素含量则降低，Na含量无显著差异；施用有机肥的矿质元素含量最丰富，地膜覆盖次之，套种紫花苜蓿最低；相关性分析表明火龙果地土壤矿质元素间多存在显著相关性，Al、Si、S、Ni 与其他元素的相关性较密切，其次为 Fe、Mg、Na、Mn、Cu、Co，均达到显著或极显著水平；Ca、Fe、Mg、Mn、Cu、Zn 和 B 之间多呈负相关，存在拮抗效应。干热河谷石漠化区在火龙果栽培时，应首选有机肥作为养分添加方式；并及时补充不同耕作方式造成的土壤矿质养分亏缺，尤其是 Fe、Mg、Al、Na、Cu、Zn 等元素。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-07-23 Cooperative journals: 《广西植物》
Abstract： As the aging and degradation of Zanthoxylum planispimum var. dintanensis has affected the rocky desertification control, and in order to discuss the reason of aging and degradation of Zanthoxylum planispimum var. dintanensis, and realize the stabilization of forest stand and sustainable management, this paper took aging degraded plants with typical symbol of yellow blooms and normally grown plants as the research objects and adopted soil agrochemistry and environmental mineralogy methods to analyze mineral element content in root-zone soil of different plants, evaluate integrated soil quality and to reveal the mineral element mechanism of aging and degradation of Zanthoxylum planispimum var. dintanensis. The results shows that (1) C, P, K, S, Se, Sr, Mo and oxide in root-zone soil of normally grown plants were generally higher than the content in aging degraded plants, while total nitrogen, rapidly available phosphorus, available nitrogen, Cu, Pb, Zn and Cr had no significant difference, and other elements had no obvious change rule. It indicates that mineral elements are one of the causes of the aging and degradation of Zanthoxylum planispimum var. dintanensis. Available contents of elements also had an impact on plant growth, which indicates that we should improve availability of nutrients when managing the Zanthoxylum planispimum var. dintanensis. From the perspective of plant nutrition demand, all major, medium and micro elements had a dominant effect on soil quality. In the management of soil fertility, we should not only focus on a large number of elements. (2) Root-zone soil quality indexes manifested that the highest plant was No. 3 normally grown plant and the lowest plant was No. 1 aging degraded plant, suggesting that soil quality influences the aging and degradation of Zanthoxylum planispimum var. dintanensis. But the soil quality is not the only cause of aging degradation of Zanthoxylum planispimum var. dintanensis, and more comparative studies of soil microbes and plant hormones should be conducted. (3) When managing the Zanthoxylum planispimum var. dintanensis in forest stand, cultivate good soil structure, make sure the comprehensiveness and proportionality of soil nutrient, and pay attention to deficit effect caused by low mineral elements, and it is necessary to make sure the appropriate nutrient concentration and ratio to increase the absorption capacity of the plant.
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