Environmental gradients determining the distribution of benthic macroinvertebrates in Lake Takkobu, Kushiro wetland, northern Japan

Effects of environmental variables on the distribution of benthic macroinvertebrates inhabiting sediments were studied at 25 sites along the shoreline of Lake Takkobu in the Kushiro wetland of northern Japan in summer 2003. During the last decade, the lake’s status has undergone a drastic shift from clear water dominated by submerged macrophytes to turbid water dominated by phytoplankton. The canonical correspondence analysis showed that four environmental variables explained the significant variation in the macroinvertebrate species composition: submerged plant biomass, bottom sediment organic matter content (OMC), distance from the mouth of the Takkobu River, and bottom-layer pH. Five species of Chironomidae [Chironomus sp. (except plumosus group), Psectrocladius sp., Corynoneura sp., Parachironomus sp. arcuatus group, and Zavreliella sp.] occurred in sites with relatively lower pH and a high submerged plant biomass, whereas three species of Tubificidae (Tubifex tubifex, Aulodrilus limnobius and Aulodrilus sp.) and two of Chironomidae (Nanocladius sp. and Monodiamesa sp.) occurred in sites with high pH and little vegetation. The three Tubificidae species also preferred organic-rich sediments. Irrespective of aquatic vegetation, Sphaerium sp. (Bivalvia) and Monodiamesa sp. (Chironomidae) occurred in low-OMC sites, whereas Tanypus sp. (Chironomidae) preferred high-OMC sites. The number of macroinvertebrate taxa showed the highest correlation with the number of submerged plants, suggesting that macroinvertebrate species richness was related mostly to submerged plant species diversity in this lake. The quantity and species richness of submerged plants and OMC are thus important determinants of the community structure of macroinvertebrates inhabiting sediments in Lake Takkobu.     

北京地区黄檗分布与环境因子的关系

黄檗（Phellodendron amurense Rupr.）为我国二级重点保护野生植物,在北京地区黄檗多散生于阔叶林中,数量稀少。为了解北京地区黄檗分布与环境因子的关系,促进种群扩繁,在北京百花山、松山和雾灵山自然保护区共设置了12个20 m×20 m的样地,利用CCA分析方法对不同地点黄檗的生长分布状况与海拔、坡度、坡向、郁闭度、土壤pH值、碱解氮和土壤有机质等11个环境因子的关系进行了分析。结果显示,CCA排序第一轴主要反映了海拔、郁闭度和坡度的变化,第二轴主要反映了有机质含量、碱解氮含量、pH值和坡向的变化,其中海拔、碱解氮和土壤有机质是影响黄檗生长分布的重要环境因子,低海拔、低碱解氮含量以及土壤有机质高的地段适宜黄檗分布。对影响黄檗分布的环境因子进行定量分离,结果发现环境因子对黄檗样地物种分布的解释能力为84.5%,显示出较好的排序效果,黄檗分布点受人为干扰较少,其所在植物群落与环境保持了良好的对应关系;环境因子与物种分布呈显著相关（P=0.03）,表明CCA排序结果可以解释环境因子对物种分布的影响程度。     

武汉市城区苔藓植物多样性和分布及与环境因子的关系

对武汉市7个中心城区和部分远郊城区共26个样点73个样地的苔藓群落进行调查,采集苔藓植物样本共431份。经鉴定调查区内共有苔藓植物20科35属91种,其中狭叶小羽藓（Haplocladium angustifolium（Hampe et C.Muell.）Broth.）和钝叶绢藓（Entodon obtusatus Broth.）等为优势种,分布于其中的24个样点。多样性指数分析结果显示,位于青龙山国家森林公园的α多样性Patrick和Shannon-Wiener指数最高,说明该样点苔藓植物群落的复杂程度高,群落所含信息量大。Patrick指数与环境因子的Pearson相关性分析结果显示,土壤含水率和与主要干道距离是显著影响地面生苔藓植物多样性的环境因子,而显著影响树附生苔藓植物多样性的环境因子仅与距主要干道距离相关。用典范对应分析法（CCA）研究26个样点中苔藓植物的盖度与主要环境因子的关系,结果发现人为干扰程度、草本盖度、与城市主要干道的距离等对地面生和树附生苔藓植物的分布都有显著影响。其中地面生苔藓植物的分布受人为干扰和草本盖度影响最为显著;而树附生苔藓植物的分布受附生树干胸径及与主要干道距离影响最为显著。研究结果表明武汉市区苔藓植物的多样性和分布受人为干扰较大,树附生苔藓对汽车尾气等因素更为敏感。     

车八岭山地常绿阔叶林群落结构特征与微地形条件的关系

以车八岭国家级自然保护区南亚热带常绿阔叶林2hm2样地调查数据为基础,根据样方排列、海拔梯度变化及水分梯度理论潜在值从低到高的趋势将样地划分为5条样带,在由山脊至山谷的微地形变化范围内对群落结构进行全面分析,探讨群落内部结构变化规律及其影响因子。研究结果表明,海拔、坡位、坡向、坡度等山地微地形条件对群落结构及物种分布影响显著。从山脊至谷底变化过程中,各样带平均树高、平均胸径以及较大高度级和胸径级的物种个体比例减少,物种多样性呈现增加趋势。多响应置换过程(MRPP)分析表明各样带之间物种组成存在极显著差异(P0.0001),且样带主要物种及密度发生明显变化。通过物种与地形因子的典范对应分析(CCA)知,在同一区域内,物种随地形因子表现出不同的分布趋势,米锥(Castanopsiscarlesii)、甜锥(Castanopsis eyrei)、石栎(Lithocarpus glaber)等喜光的阳性树种在上坡位分布较多,枫香(Liquidambar formosana)、樟叶槭(Acer cinnamomifolium)等喜温暖湿润气候的物种则在下坡位样带为优势物种。揭示了山地常绿阔叶林群落特征对微地形变化的响应,对于区域生物多样性保护和植被恢复具有重要的理论和实践意义。     

舟山海域夏、秋季浮游动物的分布特征及其与环境因子的关系

为更好地了解舟山海域浮游动物的群落结构、生物量和丰度的时空分布特征及其与主要环境因子的关系,分别于2014年7月和10月进行了夏季、秋季两次生态综合调查,并用多维尺度分析法、典范对应分析法对浮游动物群落结构进行了研究。结果表明:夏季舟山海域调查的浮游动物有13类,64种,优势种为背针胸刺水蚤(Centropages dorsispinatus)、圆唇角水蚤(Labidocera rotunda)、中华哲水蚤(Calanus sinicus)、精致真刺水蚤(Euchaeta concinna)、百陶带箭虫(Zonosagitta bedoti)和真刺唇角水蚤(Labidocera euchaeta);秋季鉴定到浮游动物12类,45种,优势种为背针胸刺水蚤(Centropages dorsispinatus)、百陶带箭虫(Zonosagitta bedoti)、双生水母(Diphyes chamissonis)、瓜水母(Beroёcucumis)和中华哲水蚤。夏季浮游动物平均丰度及平均生物量(144.0 ind/m3和176.3 mg/m~3)都分别高于秋季(21.4个/m3和86.3 mg/m3);Shannon-Wiener多样性指数夏季(3.03)高于秋季(2.82),Pielou均匀度指数则是秋季(0.83)高于夏季(0.64);夏季不同区域浮游动物群落之间具有明显的差异,而秋季大部分站位群落之间差异不显著;温度、盐度、叶绿素a浓度和营养盐含量是影响舟山海域浮游动物分布的主要环境因子;与历史资料相比,舟山海域浮游动物丰度及生物量呈下降趋势,其优势种保持较稳定。     

荒漠啮齿动物群落与植物群落的对应分析

动物与其生存环境变量之间的关系一直是生态学家们广泛关注的问题.啮齿动物作为荒漠生态系统中重要的功能群,其数量大小和生态功能对生态系统的平衡和稳定具有重要意义.生境中的植被为啮齿动物提供赖以生存的食物资源和栖息地,了解啮齿动物群落与植被特征之间的关系对于理解动物群落变动规律具有重要意义.不同植被条件下啮齿动物群落的结构不同,Hernández等(2005)研究发现北美Chihuahuan荒漠的灌木生境中啮齿动物密度高于草地生境.     

贵州普定喀斯特石生藓类生态分布与环境因子的相关分析

苔藓植物与环境的相关性一直是苔藓生态学的研究热点,研究喀斯特石生苔藓分布与环境的关系,为深入石生苔藓植物生态学研究提供理论依据。选择贵州普定石漠化区域石生环境中的5个大样方25个小样方125个采集点进行调查,采集苔藓植物并测定收集了相关的环境因子数据。结果发现:(1)样方共采集到标本267份,经鉴定有石生藓类54种。其中,丛藓科、灰藓科为优势科(属数≥3),曲柄藓属、扭口藓属、真藓属等为优势属(种数≥3),丛藓、细牛毛藓、美灰藓、绿羽藓为优势种(次数≥3)。(2)运用典范对应分析(CCA)分析了影响该地区石生藓类分布的主要环境因素,发现石生藓类分布与坡度呈显著的负相关;与其它环境因子相关的重要性依次为岩面倾角、海拔、土壤中全钾含量、土壤厚度和pH。因此,研究环境因子对石生藓类分布的关系可以为石漠化综合治理以及石面绿化植物的筛选提供参考。     

浙江金华北山石生藓类分布与环境关系的排序分析

采用样方法调查了浙江金华北山石生环境30个样点167个样方,共记录86种,其中,丛藓科(Pottiaceae)、青藓科(B rachythec iaceae)、羽藓科(Thu id iaceae)和灰藓科(Hypnaceae)为4个大科,含的种数分别为11、11、10和8种。含种数较多的属为真藓属(Bryum)、凤尾藓属(F issidens)和青藓属(Brachythecium),分别含有7、7和6种。对86种藓类植物分布与环境关系的典范对应分析表明,海拔高度、水分条件和光照强度是影响金华北山石生藓类分布的主要环境因素。海拔决定藓类植被的类型,进而影响光照、岩表温度和水分条件。石面光洁度对石生藓类分布也有一定的影响,而石面坡度与其分布没有显著的相关性。     

Effects of scale-dependent factors on herbaceous vegetation patterns in a wetland,northern Japan

Herbaceous vegetation was examined in an Otanoshike wetland in northern Japan to clarify the relationships between vegetation patterns and environmental factors with different scales. Alders (Alnus japonica) have recently invaded and might modify the herbaceous vegetation. In total, 150 50×50cm plots were established on the transitional areas between alder thickets and grassy marshland. Cover was measured for the vascular plant taxa, and canopy area, number of stumps, number of mounds, water depth, elevation difference, litter thickness, soil organic matter, and soil pH were measured in each plot. TWINSPAN cluster analysis classified four vegetation groups: (i), grasslands represented by Phragmites australis, Trientalis europaea, Lythrum salicaria, and Hosta rectifolia; (ii), Calamagrostis langsdorfii, and Polygonum thunbergii grasslands with Spiraea salicifolia; (iii), reed swamp dominated by Phragmites australis, and (iv), marshland dominated by Carex lyngbyei. Canonical correspondence analysis indicated that water depth primarily divided vegetation groups 1–2 and 3–4. Alder established in drier sites mostly by re-sprouting, and the canopy affected light and soil conditions on the ground surface. The second axis of canonical correspondence analysis was related to the canopy area and soil pH, and explained the vegetation differentiation between groups 1 and 2, and groups 3 and 4. In conclusion therefore, scale-dependent or hierarchical variables affected the vegetation patterns in different ways, that is, the herbaceous vegetation was first differentiated by water depth that was corresponding to alder establishment on a large scale, and subsequent light and soil conditions were second determinants on a small scale.     

Benthic macroinvertebrate communities of intermittent streams in the middle reaches of the Guadiana Basin (Portugal)

The Guadiana River has an irregular hydrological regime, with severe droughts and floods, but little is known about how aquatic fauna respond to these natural events. Macroinvertebrate data and environmental information were collected at seven sites from three tributaries in the middle reaches of the Guadiana River, approximately every 3 months from April 1995 to April 1997. Despite considerable annual variation in discharge (related to duration of flood and drought periods), the number of macroinvertebrates found was consistently high. Diptera represented the major proportion of the benthic fauna (73.2%) followed by Ephemeroptera (10.3%), Coleoptera (4.1%) and Trichoptera (3.1%). Canonical correspondence analysis (CCA) was used to evaluate the relationships between taxa density and habitat variables. Generally, Plecoptera and Ephemeroptera were found in the upstream sampling sites. Wider and deeper sites were associated with the presence of Diptera and were least diverse. High values for both the Shannon-Wiener diversity index and the average score per taxon were usually found at upstream sites where Ephemeroptera and Plecoptera predominated. The data suggest that macroinvertebrates have a great capacity to recover rapidly from severe drought periods, both in terms of taxonomic diversity and number of individuals.     

Stock discrimination and connectivity assessment of yellowfin seabream (Acanthopagrus latus) in northern South China Sea using otolith elemental fingerprints

Connectivity between fish stocks is fundamental to the understanding of population dynamics and the implementation of sustainable fisheries management. Otolith microchemistry is a promising tool as it can provide information on the continuous growth of otoliths and the environmental effects on otolith composition. Such elemental fingerprints can help distinguish different stocks or life history stages, identify the origins or nursery areas of fish, and assess population structure. In this study, we examined the stock discrimination and spatial connectivity of cage-cultured and wild stocks of yellowfin seabream (Acanthopagrus latus) from the coastal waters of Shantou, Yangjiang, and Zhanjiang in China southern province Guangdong during 2012–2014, based on otolith trace-elemental signatures using multivariate statistical analysis and machine learning approaches. The concentrations of 13 elements (⁷Li, ²³Na, ²⁴Mg, ⁴⁰Ca, ⁵⁵Mn, ⁵⁶Fe, ⁵⁹Co, ⁵⁹Ni, ⁶⁴Cu, ⁶⁵Zn, ⁸⁸Sr, ¹²²Sb, and ¹³⁷Ba) in the natal spot of fish otoliths, representing the embryonic and paralarval stages of fish, were analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Stepwise discriminant analysis and random forests were used to distinguish the cultured and wild stocks of yellowfin seabream, and non-metric multidimensional scaling (NMDS) and cluster analysis were used to determine the spatial variation and connectivity of yellowfin seabream stocks. Overall, the cultured and wild stocks of yellowfin seabream could be identified with classification accuracy of 80.7% and 99.2% by using stepwise discriminant analysis and random forests respectively. When we compared site difference between cultured and wild stocks (site × stock interactions), the classification success was 60.4% for stepwise discriminant analysis and 85.7% for random forests. The misclassification of cultured and wild stocks within the three sites suggested the spatial connectivity between stocks and among sampling locations. Our findings suggested that the three wild stocks of yellowfin seabream from Guangdong coastal waters could be considered as one unit for management, and the difference between cultured and wild stocks was significant for yellowfin seabream from Shantou and Yangjiang, but less significant for yellowfin seabream from Zhanjiang. This study demonstrated that otolith elemental fingerprints can help improve our knowledge on the spatial connectivity, population structure, and life history of fish stocks, and random forests can be a useful tool for identifying cultured and wild stocks compared to the traditional stepwise discriminant analysis.     

富营养化城市湖泊武汉东湖沉积物微生物群体结构及空间变化研究(英文)北大核心CSCD

【目的】城市湖泊沉积物中的微生物群体是富营养环境生物修复的重要因素。本研究拟对中型富营养化湖泊——武汉东湖沉积物细菌群体结构及空间变化规律进行研究。加深对富营养湖泊微生物群体结构的理解,并为城市湖泊的保护和污染控制提供参考。【方法】采用16S r RNA基因RFLP分析和序列分析技术获得细菌群体系统发育信息。采用PCoA法分析武汉东湖沉积物细菌群体内以及与其它湖泊沉积物细菌群体间的相似性。采用CCA法分析环境因素对细菌群体的影响。【结果】武汉东湖沉积物细菌群体包含13个门和2个未知种群。PCoA分析进一步表明来自东湖3个子湖的细菌群体与其它地域富营养化湖泊的微生物种群结构相似,并区别于重度富营养化子湖庙湖的细菌群体。在庙湖中,我们发现了Thermogymnomonas类古菌的含量显著偏高。CCA分析表明细菌的分布与沉积物中碳、氮和磷元素的含量显著相关。【结论】本研究进一步确证了环境因素对细菌群体组成和分布的调节作用,加深了对富营养水体微生物群体结构的理解,并为城市湖泊的保护和污染控制提供了参考。     

地形因子对粤北山地森林不同生长型地表植物分布格局的影响

利用典范对应分析(CCA)方法研究了小地形变化对广东省车八岭国家级自然保护区山地常绿阔叶林不同生长型地表植物分布格局的影响.结果表明:坡向、坡度和坡位3个地形因子的综合作用对4种生长型地表植物(蕨类、木质藤本、草本和灌木)的分布格局均有显著影响.其中,坡向对4种生长型地表植物分布格局的影响均显著,坡度对灌木分布格局的影响显著,坡位对4种生长型地表植物分布格局的影响均不显著.从阴坡到半阴坡再到半阳坡,4种生长型地表植物的总个体数均逐渐减小,表明阴性植物在亚热带山地常绿阔叶林地表植物中占优势.大部分灌木属于阴性植物,其丰富度和多样性随坡向的变化趋势与总个体数一致.灌木对坡度的变化较敏感,在缓坡上数量较多.丘陵低山的坡位变化范围不大,对地表植物分布的影响不显著.在林分尺度上,地形因子在水平方向(坡向)上对地表植物分布格局的影响比垂直方向(坡度和坡位)大,反映出坡向是亚热带山地森林中影响水热条件的主要因子.     

象山港人工鱼礁区的网采浮游植物群落组成及其与环境因子的关系

根据2010年1月(冬)、4月(春)、7月(夏)和11月(秋)对象山港人工鱼礁区及其邻近海域的网采浮游植物样品,共鉴定出浮游植物8门74属220种,主要由硅藻(168种)和甲藻(38种)组成。春、秋、冬季全区浮游植物丰度(分别为67.85、65.88和56.77×104个/m3)显著高于夏季(7.19×104个/m3),优势种主要有琼氏圆筛藻(Coscinodiscus jonesianus)、大洋角管藻(Cerataulina pelagica)、洛氏角毛藻(Chaetoceros lorenzianus)和罗氏角毛藻(C.lauderi)等,其中琼氏圆筛藻为全年的优势种,且在春、冬季为该海域的绝对优势种。浮游植物群落参数(丰度、chl a浓度、种类数、Shannon-Wiener多样性、Pielou均匀度和Margalef丰富度等指数)和环境因子(温度、盐度、透明度、pH值、DO、悬浮物、DIN、PO4-P和SiO3-Si浓度)均存在极显著的季节变化(P<0.001),但区域(鱼礁区与对照区)间基本无显著差异。聚类、多维尺度和相似性分析结果也表明,浮游植物群落组成存在显著季节差异(P=0.001),但区域间无显著差异。可见,人工鱼礁投放对网采浮游植物群落无显著影响。究其原因:(1)可能是该海域人工鱼礁投放数量不多,仅有230个水泥鱼礁体(共5000空立方),建礁时间也较短,导致其生态效应在短期内难以显著体现;(2)对照区与人工鱼礁区的距离较近,且采样站位均靠近岛屿,潮流和岛屿对浮游植物的影响可能超过了人工鱼礁投放对其的影响。典范对应分析(Canonical correspondence analysis,CCA)显示,影响浮游植物群落的主要因子依次为温度、营养盐、盐度和悬浮物。     

武汉三角湖浮游甲壳动物群落结构

三角湖是长江中下游地区典型的小型城市湖泊,近年来其富营养化趋势明显。2014年7月至2015年6月对湖中浮游甲壳动物群落及其影响因子进行了调查,旨在为湖泊污染防治和生态修复提供依据。在三角湖共采集浮游甲壳动物9科17属22种。浮游甲壳动物全年平均密度为(3.7±3.6)ind/L,各月密度变化范围为0.6~13.1 ind/L,夏季和秋季密度较低,密度峰值出现在2月。浮游甲壳动物全年大部分时间(5、6月除外)以桡足类及无节幼体占优势,其比例为55.2%~95.4%。浮游甲壳动物物种丰富度变化范围为6~15,平均值为10±3,夏季浮游甲壳动物物种丰富度较低。浮游甲壳动物群落Simpson指数变化范围为0.76~0.90,平均值为0.80±0.04。Pearson相关分析表明,浮游甲壳动物总密度与水深呈显著负相关(r=﹣0.636,P0.05,n=11),显示季节性的水位波动影响浮游甲壳动物密度。典范对应分析(CCA)显示,水温和透明度是影响浮游甲壳动物物种组成季节变化的主要环境因子(P0.05)。高密度的鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)放养引起的摄食压力可能是三角湖浮游甲壳动物密度较低的主要原因之一。     

凉水自然保护区阔叶红松林林分空间结构特征及其与影响因子关系简

根据凉水自然保护区28块典型阔叶红松林样地的5个林分空间结构参数和18个影响因子数据,采用典范对应分析（CCA）方法,对凉水自然保护区阔叶红松林林分空间结构与影响因子间关系进行分析。研究结果表明：（1）研究区域阔叶红松林整体具有较好的林分空间结构,其水平分布格局主要表现为随机分布,树木生长整体处于中庸状态,林木的整体混交程度较高;（2）林分空间结构的CCA排序较好的揭示了该区林分空间结构与影响因子的关系;CCA第一排序轴反映了林龄、坡度、阔叶比和坡向的变化,第二排序轴反映了坡向、土壤有机质和平均胸径的变化,上述6因子的组合是决定林分空间结构特征的主要影响因子;（3）影响林分空间结构的变量中,地形、土壤和林分因子共解释了林分空间结构变化的59.20%,其中纯地形因子占30.68%,纯林分因子占19.01%,纯土壤因子占8.21%,未能解释部分为40.80%。     

太白山森林群落和林下草本物种变化的环境解释

采用典范对应分析(CCA)、Pearson相关分析、冗余分析(RDA)分别研究了不同环境因子对太白山森林群落及林下草本物种组成、多样性、功能性状等方面的影响。结果表明:(1)9种环境因子对于群落及林下草本物种的组成变化的解释程度不高,分别为23.9%和21.1%,但与海拔和土壤含水量紧密相关的CCA 1轴能大致区分高、中、低海拔样方的群落所有物种和草本植物的组成差异。(2)沿海拔梯度,群落所有物种的α多样性先增加后降低,林下草本物种α多样性沿海拔梯度有下降趋势,但二者都与坡度(Slope)及木本层盖度(WCD)无关。(3)海拔是决定森林群落及林下草本层物种功能性状值变化的主要因子,与海拔密切相关的RDA1轴能解释森林群落和林下草本物种性状值变化的71.2%和54.7%,林下草本植物与群落的最大株高(Hmax)变化模式不一致。     

黄河口及其邻近水域夏季鱼类群落空间格局及其与环境因子的关系

基于2013年夏季(6、7、8月)在黄河口及其邻近水域进行的渔业资源底拖网调查,应用多元分析方法研究了黄河口水域夏季鱼类群落空间结构,以及其与环境因子的关系.结果表明: 该海域夏季共捕获鱼类44种,隶属于11目25科40属,以暖温性和底层鱼类为主.经聚类分析,该海域夏季各月鱼类群落可大体划分为3个站位组.经单因子相似性分析(ANOSIM),黄河口不同水域鱼类群落物种组成存在显著差异.相似性百分比分析表明,矛尾虾虎鱼、斑鰶、短吻红舌鳎、蓝点马鲛和日本鳀等是各月份各站位组的典型种及造成不同站位组间群落差异的主要分歧种.典范对应分析(CCA)表明,影响夏季鱼类群落空间结构的主要环境因子为盐度、温度和深度.     

福建九龙江北溪浮游植物群落分布特征及其影响因子

分别于2011年枯水期(2月)、丰水期(5月)和平水期(10月),系统调查研究了福建九龙江北溪浮游植物群落组成、丰度的分布特征及其与环境因子的关系.共鉴定浮游植物107种,隶属于7门64属.不同水文期浮游植物主要优势种类不同,枯水期为马索隐藻和梅尼小环藻,丰水期为四尾栅藻和四角十字藻,平水期则演替为微小平裂藻.不同水文期浮游植物丰度变化明显,其平均值依次为枯水期(154.77×10⁴ cells·L^-1)>平水期(76.40×10⁴ cells·L^-1)>丰水期(45.40×10⁴ cells·L^-1).相关分析表明, 枯水期和平水期浮游植物丰度与铵态氮(NH₄⁺-N)呈显著正相关,丰水期浮游植物丰度与温度呈极显著正相关.典范对应分析(CCA)表明,水体温度是影响该水域浮游植物分布格局的重要因子,溶解态活性磷浓度也对浮游植物的分布有较大的影响.CCA排序图较好显示了浮游植物物种分布和环境因子之间的关系.     

Microbial community dynamics in mesophilic anaerobic co-digestion of mixed waste

This paper identifies key components of the microbial community involved in the mesophilic anaerobic co-digestion (AD) of mixed waste at Rayong Biogas Plant, Thailand. The AD process is separated into three stages: front end treatment (FET); feed holding tank and the main anaerobic digester. The study examines how the microbial community structure was affected by the different stages and found that seeding the waste at the beginning of the process (FET) resulted in community stability. Also, co-digestion of mixed waste supported different bacterial and methanogenic pathways. Typically, acetoclastic methanogenesis was the major pathway catalysed by Methanosaeta but hydrogenotrophs were also supported. Finally, the three-stage AD process means that hydrolysis and acidogenesis is initiated prior to entering the main digester which helps improve the bioconversion efficiency. This paper demonstrates that both resource availability (different waste streams) and environmental factors are key drivers of microbial community dynamics in mesophilic, anaerobic co-digestion.