湛江湾浮游植物优势种空间生态位

【目的】研究湛江湾浮游植物优势种生态位的资源利用状况及生态适应性,为评估该海域浮游植物的种群生存状况及污染治理提供基础资料和决策支撑。【方法】根据2021-2022年在湛江湾开展的四季浮游植物和环境因子调查结果,利用R语言相关程序包对生态位宽度、生态位重叠指数等生态位指标进行计算,对浮游植物优势种丰度与海水温度(t)、盐度(S)、pH,溶解氧(DO)、化学需氧量(COD)、无机氮(DIN,包括NO_(2)-N,NO_(3)-N,NH_(4)-N)、活性磷酸盐(SRP)质量浓度和氮磷摩尔浓度比(N/P)等主要环境因子进行冗余分析(RDA)。【结果与结论】共鉴定出浮游植物5门221种,硅藻种数最多。四季优势种共18种,均为硅藻,其中赤潮种类15种。与历史调查结果相比,湛江湾优势种既有交叉又有演替,历史上均出现过的优势种有7种,均为赤潮种,特别是中肋骨条藻(Skeletonema costatum)始终是主要优势种。通过对湛江湾浮游植物优势种生态位分析,生态位宽度与优势种丰度变异系数显著负相关(P<0.001)。结合RDA分析结果和物种生态位分化情况分析,种对之间生态位重叠值的高低与其同环境因子的相关性有较大关联,与同一环境因子有同向显著相关性的种对之间生态位重叠值较高,其他情况种对之间生态位重叠值较低。盐度、pH和SRP质量浓度则是影响湛江湾浮游植物优势种发展趋势的重要因素。SRP质量浓度和N/P浓度比是调查期间影响湛江湾浮游植物优势群落生长的竞争性因子。

江苏省湖泊水生植物优势种对氮、磷去除效果比较研究

为研究江苏省典型湖泊优势种对氮、磷的去除效果,选取江苏省6大典型湖泊白马湖、宝应湖、高邮湖、长荡湖、滆湖以及邵伯湖作为研究对象,针对该地区水生植物分布情况筛选出6种优势种,对地表Ⅴ类标准(TN:2 mg/L;TP:0.2 mg/L)水体中氮、磷的去除效果进行探究。调查结果表明:江苏省湖泊适应性较强的6种优势种分别为芦苇、茭草、穗状狐尾藻、轮叶黑藻、野菱、荇菜。净化试验表明:茭草和芦苇对TP、TN去除率较其他水生植物高,穗状狐尾藻去除氨氮效果最好。

新疆草地生物量优势植物地理分布特征

地理分布范围反映物种在一定空间中所占的分布面积,体现着物种适应环境的能力。以2011-2013年对新疆草地397个样地的调查数据为基础,集合全球生物多样性信息网络、中国数字植物标本馆收录的优势种植物分布点位数据,以及《新疆植物志》对其的记录信息,在ArcGIS软件上以县域为基本单位,用生物区划法计算新疆草地优势种地理分布范围并分析其在物种、功能群和分类水平上分布特征。结果显示:1)本研究所涉及的169种优势种植物,按地理分布范围可分为窄布种(0.15万~5.4万km^(2))]、中等分布种(5.5万~13.9万km^(2))、广布种(14.1万~30.8万km^(2))]和极广布种(31.5万~96万km^(2))] 4类。其中,窄布种、广布种和极广布种各包括42个优势种,而中等分布种有43个优势种。2)在科水平上,窄布种和中等分布种主要由菊科植物组成,而广布种和极广布种则由禾本科植物组成。3)在光合途径和生活型方面,窄布种、中等分布种、广布种和极广布种均由C4植物和多年生草本植物占主导。在生态型方面,窄布种主要由中生植物组成,而中等分布种、广布种和极广布种则由旱生植物组成。本研究为深入理解新疆草地优势种植物地理分布范围,提供了可视化的资料和数据支持。

蚂蚁河河岸缓冲带湿地优势种植物群落构建技术研究

通过对蚂蚁河河岸缓冲带湿地生态调查划分3种湿地类型。调查各湿地类型的主要群落建群优势植物。通过人工培养水质净化试验,确定各种优势植物的氮磷吸收效果。进行湿地植物群落构建,有效提高湿地群落生产力,增加对水体污染物吸收和阻控能力。

沉水植物对岩溶碳汇稳定性影响研究

岩溶碳汇是实现碳中和的重要手段,其稳定性是亟待解决的关键科学问题。地球上每年约45%的光合作用发生在水环境中,而岩溶区沉水植物如何影响岩溶碳汇稳定性仍不明确。以3条岩溶区河流中的沉水植物为研究对象,利用样方法、pH-drift技术和元素化学计量学,从定性和定量角度开展了沉水植物对岩溶碳汇稳定性的影响研究。结果表明:ZDR中沉水植物有8种,CTR中沉水植物有5种,HXR中沉水植物有7种,Shannon-Wiener多样性指数和Simpson优势度指数的趋势均为ZDR>HXR>CTR。在3条河流中沉水植物的优势种为苦草、海菜花、竹叶眼子菜和黑藻,且均具有利用HCO-3的能力。ZDR、HXR和CTR中沉水植物的年固碳量分别为8.56×10^(3)、4.83×10^(3)和3.88×10^(3) g·m^(-2)·a^(-1),平均值为5.76×10^(3) g·m^(-2)·a^(-1),分别是草地的37.65倍和人工林的40.56倍。3条河流中沉水植物多样性越高,其固碳量也越高。总的来说,在岩溶水生态系统中沉水植物发挥着碳泵的作用,进而提高了岩溶碳汇的稳定性。

黔西北铅锌矿区植物群落分布及其对重金属的迁移特征

重金属耐性植物和超富集植物的筛选、鉴定和驯化是植物修复技术研究与发展的关键。以黔西北4个不同恢复年限的铅锌矿为研究对象,通过群落生态调查利用聚类分析方法筛选出研究区域中重金属耐性植物优势种,并分析其对重金属Pb、Zn、Cu、Cd的迁移富集能力。结果表明:4个矿区共发现高等植物22种,分属13科21属,筛选出9种重金属耐性植物优势种,其中转运系数大于1的植物有:黄花蒿(Cu)、珠光香青(Zn)、大叶醉鱼草(Zn/Pb/Cd)、野艾蒿(Cu/Zn/Pb/Cd);没有富集系数大于1的植物。其中大叶醉鱼草具有耐贫瘠、耐旱、生物量大等优势,可将其作为典型的重金属耐性先锋植物,用于矿区废弃地的植物修复。

长江淡水潮汐湿地植物特性和植物群落演替研究——以镇江北固山湿地为例

镇江北固山湿地属于长江近河口段淡水潮汐湿地,植物群落基本保持原生演替的前期状况。根据对该湿地的实地观测研究,描述了河滨湿地植物的生长特性;结合湿地的水文特征刻画了湿地高等水生植物在时间、空间和景观上的生态过程;综合河滨湿地植物的生长特性及湿地的水文特征探讨了镇江淡水潮汐湿地的演变趋势。对湿地面临的问题进行了讨论,从而为长江淡水潮汐湿地的生态修复和增加生物多样性及湿地保护提供参考。

大庆萨尔图机场草本植物群落多样性调查及对鸟击防范的影响

在进行机场生态调研中,选择植物生长的不同时间段,利用样方法对大庆萨尔图机场围界内的草坪植物进行了群落多样性调查。调查显示,大庆萨尔图机场调查样方内有草本植物32种,分属于14科26属,含优势种8种。根据大庆萨尔图机场围界内草本植物的多样性特点,结合大庆萨尔图机场飞行区内鸟类活动的研究情况,分析不同区域、不同植物群落类型对机场内分布的昆虫、鸟类活动的影响及其相关性,从而得出大庆萨尔图机场不同区域植物群落对鸟类分布规律关系,为该机场制定科学有效的鸟击防范措施提供服务。

南太湖富营养化调查及评价

2009年4月至2010年4月,综合利用TN、可溶性无机氮(DIN)、叶绿素a(Chl-a)、透明度(SD)、TP和浮游植物等指标,通过参数法、综合营养状态指数法及浮游植物优势种法评价了南太湖富营养化水平。结果表明:(1)南太湖夹浦、新塘、小梅口、幻溇4个断面的TN质量浓度为1.80~2.53 mg/L,TP质量浓度为0.08~0.11 mg/L,DIN质量浓度为0.55~1.10 mg/L,Chl-a质量浓度为6.4~19.2μg/L。(2)夹浦、新塘和小梅口3个断面的综合营养状态均为轻度富营养,幻溇断面为中营养。南太湖综合营养状态水平呈现出由西南向东北逐级递减的趋势。(3)南太湖的浮游植物优势种的演替过程为鱼腥藻(Anabeana)→微囊藻(Microcystis)→拟浮丝藻(Planktothricoides),但均属于蓝藻。因此,浮游植物优势种法评价的南太湖富营养化水平为重富营养化,但该方法由于不确定性较大,一般只作为参考。

Hybrid Effects on the Release of Phytosiderophores in Winter Wheat (Triticum aestivum)

Fe (iron) deficiency is an important nutritional problem particularly in crop plants grown on calcareous soils. Phytosiderophore (PS) release has been suggested to be linked to the ability of graminaceous species and genotypes to overcome Fe_deficiency chlorosis. Thus, enhancing PS release is a critical step to improve Fe nutrition of plants grown on Fe stressed soils. The heterosis of PS release rate in common wheat was studied by analyzing PS release from roots of three hybrids and their four parents grown in Fe_deficiency nutrient solution under controlled environmental conditions. PS release rates were determined at two or three day intervals after onset of Fe_deficiency symptoms by the measurement of Fe mobilizing capacity of root exudates from freshly precipitated FeⅢ hydroxide. High amounts of phytosiderophores were released from the roots of all wheat genotypes under Fe_deficiency, and the amount progressively increased with the development of Fe_deficiency chlorosis. The results revealed that the hybrids had more sensitive feedback systems which secreted more phytosiderophores under Fe_deficiency than their parents. By analyzing the relationship between each hybrid and its parents, it was also found that the parents should be selected on the basis of the rate of PS release and the combining ability by using the heterosis to improve Fe utilizability of crop plants.

Relationship Between Heterosis and Endogenous Plant Hormones in Liriodendron

To investigate the possible involvement of endogenous plant hormones in heterosis of Liriodendron interspecific hybrid, growth traits and contents of endogenous GA 1/3 (gibberellin A 1, A 3), IAA (indole_3_acetic acid) and iPA (isopentenyl adenine) of tulip tree ( L. chinense (Hemsl.) Sarg.), yellow poplar ( L. tulipifera L.) and their interspecific hybrid ( L. chinense × L. tulipifera ) were examined. Results showed that: (1) the heterosis in height growth trait of the interspecific hybrid was mainly caused by the reletively greater elongation of internodes. Although the uppermost three internodes had the potential of elongation, the first one, which had the greatest elongation amount, contributed to the heterosis of the height growth trait; (2) the contents of endogenous GA 1/3 , IAA and iPA were greatly different among tulip tree, yellow poplar and their interspecific hybrid. All of the three interspecific hybrid families studied significantly contained higher amount of endogenous GA 1/3 and iPA in the uppermost first internode than their parental species. And thus, a correlation between the contents of endogenous GA 1/3 and iPA, and hybrid vigor for height growth trait in Liriodendron was observed; (3) the rankings of endogenous GA 1/3 and iPA contents in the uppermost first internode of three hybrid families studied were not similar to the ranking for height of 3_year_old trees. Therefore, the contents of endogenous GA 1/3 and iPA in the uppermost first internode could not be used in predicting hybrid vigor among hybrid families.

Investigation of Dominant Populations of Late-summer Phytoplankton and Comprehensive Nutritional Evaluation of Water Quality in Bailang Lake

[Objective] This study aimed to investigate the dominant populations of late-summer phytoplankton and conduct comprehensive nutritional evaluation of water quality in Bailang Lake. [Method] A series of water quality survey and phytoplankton sampling was conducted in Bailang Lake in September 2011, a total of four sam- pling points were set, to detect and analyze the total nitrogen, total phosphorus, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen and permanganate index in water samples and further conduct comprehensive nutritional evaluation of the water quality factors using comprehensive nutritional state index method. [Result] Water in Bailang Lake was neutral to slightly alkaline with pH of 8.57. The average water trans- parency was 0.4 m, with relatively high content of dissolved oxygen. The content of total nitrogen was relatively high of 3.043 mg/L averagely. Comprehensive nutritional evaluation showed that the water quality of Bailang Lake belonged to moderate eu- trophication. As can be seen from various comprehensive nutritional state indices TLI, the contribution of transparency, chlorophyll a and total nitrogen to the eutrophi- cation in Bailang Lake was the greatest, followed by the permanganate index and total phosphorus. Statistical analysis showed that the average weight-biomass of phy- toplankton in Bailang Lake was 6.442 mg/L, and the average was 146.46x104 individuals/ml. There were eight dominant species in Bailang Lake, including Scenedesmus, Tetraedron, Merismopedia sinica, Phormidium, Merismopedia, Tribonema, Chroomonas and Synedra. [Conclusion] This study provided data informa- tion for the environmental protection and fisheries production in Bailang Lake.

Analysis of the Species Dominance & Dominant on the Karst Mountain Grassland Plant Community

[Objective] The aim was to study the species,quantity and community traits of dominant plant in karst mountain grassland plant community so as to provide support for the vegetation restoration in karst mountain grassland.[Method] Standard plot sites investigation method was used study the quantity traits of different plant communities of different altitudes and slopes.[Result] The IV SDR4 were the highest in the all plot sites of plant community on the kasrt mountain grassland,but the IV SDR4 were showed a trend of decreasing with the increasing of the altitude.The dominant quantity was increasing with the altitude upward,so the altitude was the mostly factor for plant community construction.[Conclusion] Altitude was the main factor to influence the community structure of plant.

Fluorometric Discrimination Technique of Phytoplankton Population Based on Wavelet Analysis

The discrete excitation-emission-matrix fluorescence spectra (EEMS) at 12 excitation wavelengths (400, 430, 450, 460, 470, 490, 500, 510, 525, 550, 570, and 590 nm) and emission wavelengths ranging from 600-750 nm were determined for 43 phytoplankton species. A two-rank fluorescence spectra database was established by wavelet analysis and a fluorometric discrimination technique for determining phytoplankton population was developed. For laboratory simulatively mixed samples, the samples mixed from 43 algal species (the algae of one division accounted for 25%, 50%, 75%, 85%, and 100% of the gross biomass, respectively), the average discrimination rates at the level of division were 65.0%, 87.5%, 98.6%, 99.0%, and 99.1%, with average relative contents of 18.9%, 44.5%, 68.9%, 73.4%, and 82.9%, respectively; the samples mixed from 32 red tide algal species (the dominant species accounted for 60%, 70%, 80%, 90%, and 100% of the gross biomass, respectively), the average correct discrimination rates of the dominant species at the level of genus were 63.3%, 74.2%, 78.8%, 83.4%, and 79.4%, respectively. For the 81 laboratory mixed samples with the dominant species accounting for 75% of the gross biomass (chlorophyll), the discrimination rates of the dominant species were 95.1% and 72.8% at the level of division and genus, respectively. For the 12 samples collected from the mesocosm experiment in Maidao Bay of Qingdao in August 2007, the dominant species of the 11 samples were recognized at the division level and the dominant species of four of the five samples in which the dominant species accounted for more than 80% of the gross biomass were discriminated at the genus level; for the 12 samples obtained from Jiaozhou Bay in August 2007, the dominant species of all the 12 samples were recognized at the division level. The technique can be directly applied to fluorescence spectrophotometers and to the developing of an in situ algae fluorescence auto-analyzer for phytoplankton population.

Plant community composition and interspecific relationships among dominant species on a post-seismic landslide in Hongchun Gully, China

The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.

Changes in vegetation and soil properties following 6 years of enclosure in riparian corridors

Aims Riparian corridors play vital roles in the maintenance of biodiversity.Nonetheless,plant species diversity and vegetation coverage in riparian corridors are seriously threatened by increasing pressure owing to livestock consumption and anthropogenic disturbance;even the stability of river courses has been threatened.The establishment of enclosures is a widely used strategy to restore degraded grassland ecosystems,but its impact on degraded herbaceous riparian vegetation and soil properties remains unclear.The aim of this study was to evaluate whether species composition,richness,diversity,and soil properties can be recovered by the enclosure.Methods Twenty long-term monitoring sample plots were set in the Liaohe main stream river,Liaohe main stream river was enclosed for grazing and farmland exclusion in 2012.The height,coverage and individual numbers of plant were recorded for species richness and diversity evaluation from 2012 to 2017;soil nutrients were measured for comparative analysis in 2012 and 2017.We examined the effects of the establishment of enclosures on plant species diversity and soil properties from 2012 to 2017 in the riparian corridors of the Liaohe River system in China.Important Findings Plant species richness and diversity significantly increased from 2012 to 2017.The dominance of Asteraceae plants increased,while the abundance of Gramineae plants decreased over time.The difference in abundance increased each year since enclosure was implemented in 2012.The concentrations of phosphorus and potassium in the soil significantly decreased as a result of the combined effects of vegetation restoration and prohibition of farming practices following the establishment of enclosures.There was also a lag time related to the response of soil organic matter to the establishment of enclosures.In conclusion,our study provides new evidence regarding the response of species diversity,species composition and soil properties following riparian vegetation restoration efforts through enclosure development.

Herbivores alleviate the negative effects of extreme drought on plant community by enhancing dominant species

Aims Both extreme drought and insect herbivores can suppress plant growth in grassland communities.However,most studies have examined extreme drought and insects in isolation,and there is reason to believe that insects might alter the ability of grasslands to withstand drought.Unfortunately,few studies have tested the interactive effects of extreme drought and insect herbivores in grassland communities.Methods Here,we tested the drought–herbivore interactions using a manipulative experiment that factorially crossed extreme drought with the exclusion of insect herbivores in a temperate semiarid grassland in Inner Mongolia.Important Findings Our results demonstrated that both extreme drought and insect herbivores separately decreased total plant cover.When combined,insect herbivores reduced the impact of drought on total cover by increasing the relative abundance of drought-resistant dominant species.Our results highlight that the negative effect of extreme drought on total plant cover could be alleviated by maintaining robust insect herbivore communities.