不同生境下假臭草生长特征分析

通过测定庄稼地、弃耕地、桉树林、公路边4种生境下假臭草叶面积(LA)、比叶面积(SLA)、LDMC和株高等形态特征、植株各构件生物量及生物量分配比和假臭草种群盖度、密度等种群数量性状,研究不同生境类型下假臭草个体的形态特征、生物量及生物量分配和种群生长状况的差异。结果表明:光照和土壤养分对假臭草的形态特征、生物量及生物量分配和种群数量性状的影响显著;低光照、高土壤养分生境下假臭草的LA、SLA、株高较高,假臭草叶片的LDMC较小,植株的花序数较少,生物量主要向叶和茎器官进行分配,根和花果器官的生物量分配则受到限制;高光照、养分贫瘠生境下假臭草的LA、SLA、株高较低,假臭草叶片的LDMC较大,生物量主要向根和花果器官进行分配,种群的盖度、密度、生物量和高度等种群数量性状较低,种群生长状况较差;高光照、肥沃养分生境为假臭草的最适生境,假臭草构件的资源配置较为优化,株高、基径粗、冠宽和花序数等形态指标较大,种群盖度、密度、生物量等种群数量性状较大,种群生长较好。     

不同生境下入侵种假臭草叶片的气孔特征

【背景】探讨入侵种假臭草不同生境下气孔的变化规律,揭示假臭草种群在不同生境下所采取的生长对策及适应机制,可为入侵生物的防治提供参考。【方法】采取光学显微镜系统观察桉树林、木薯地、弃耕地、公路边4种生境下假臭草叶片的气孔特征。【结果】光照和土壤肥、水条件对假臭草叶片的气孔孔径（横轴方向和纵轴方向）、单个气孔器面积、气孔器总面积、气孔密度及气孔指数的影响显著。低光照及肥沃、湿润土壤生境与高光照及贫瘠、干旱土壤相比,假臭草的气孔孔径（横轴方向和纵轴方向）、单个气孔器面积、气孔器总面积较大,气孔密度及气孔指数较小。【结论与意义】假臭草叶片气孔特征表现可塑性,说明其对异质环境具有一定的生态适应能力。     

空心莲子草在我国的适应性及入侵机制

空心莲子草是入侵我国的重要杂草之一,它在我国能广泛传播和迅速蔓延,与其自身特有的形态生理适应性、强大的繁殖特性和竞争力,以及传入地缺乏自然控制机制密切相关.空心莲子草从其原产地过渡到新的侵入地的过程中,在生态环境适应方面发生重大变化,产生一系列的形态结构、生理过程,以求适应陆地生活条件.其表型可塑性使得空心莲子草有更宽的生态幅,可利用的潜在资源范围也随之扩展;强大的营养繁殖能力,使其迅速产生大量的后代,在失去自然天敌调控的情况下,尤为适应其侵入种的生长、繁殖、发展和传播,种群数量的激增又会加速其传播扩散速度,导致空心莲子草爆发成灾.在综述空心莲子草在形态、生理、繁殖的适应性特征及天敌因素和入侵特性的基础上,根据前人的有关论述,分析了空心莲子草在我国的适应性特征及入侵机制,指出了空心莲子草在我国适应性及入侵机制应着重研究的方向,提出了综合治理和充分利用空心莲子草的对策.     

部分暖季型草坪草品种(系)在沿海滩涂的生长适应性及其对土壤盐度的影响

采用8个指标(密度、质地、均一性、盖度、耐旱性、萎蔫率、烧伤率及生长量)对12个暖季型草坪草品种(系)在江苏省沿海滩涂上的生长适应性进行了评价,并以电导率为指标分析了12个品种(系)对种植地土壤盐度的影响.结果表明,12个品种(系)8个评价指标的变异系数为32.51%～40.76%,差异不大;12个品种(系)在8个评价指标方面的排序不一致,但总体上各指标中得分最高的前3位均包含了海雀稗'P006'(Paspalum vaginatum 'P006' )和沟叶结缕草'Z014' (Zoysia matrella 'Z014' ),而得分最低的均为狗牙根[Cynodon dactylon (L. ) Pers. ]的品种(系).12个品种(系)中,海雀稗'P006'综合排名第1,生长适应性最好;沟叶结缕草'Z014'、结缕草'Z080'(Z. japonica 'Z080' )和中华结缕草'Z008' (Z. sinica 'Z008' )的综合排名分别为第2、第3和第4位,生长适应性也较好;而8个狗牙根品种(系)的得分排在第5至第12位,生长适应性较差.从2006年7月至2007年11月,12个品种(系)种植地的土壤平均电导率均随时间的延长出现一定的波动,但总体上呈现逐渐下降的趋势并达到相对一致的水平,且均明显小于空白地的土壤平均电导率.不同品种(系)对种植地土壤的脱盐作用有一定的差异,其中,狗牙根'C807'的脱盐效应最佳,在所有供试品种(系)中排序第1;而海雀稗'P006'和沟叶结缕草'Z014'也具有一定的脱盐效应,在所有供试品种(系)中分别排在第6和第7位.综合分析结果显示,海雀稗'P006'和沟叶结缕草'Z014' 对盐碱地的适应性较强并具有一定的脱盐效应,可作为滩涂绿化和盐碱地土壤改良的优良草种;而狗牙根'C807'可以作为滩涂绿化和土壤改良的先锋草种.     

红豆草中含晶细胞的形态学研究

红豆草（Ｏｎｏｂｒｙｃｈｉｃｖｉｃｉａｅｆｏｌｉａｓｃｏｐ．）植株的所有器官中都分布有含晶细胞,其结晶的类型主要为棱晶,此外还有砂晶。在营养器官中,含棱晶的细胞主要分布在维管组织之中或外围。横切面上,棱晶则几至几十块纵列成行存在,且常伴生于韧皮纤维旁,但每块棱晶各有一分室隔开;在茎的表皮下偶有与大型粘液细胞伴生的砂晶。花萼的表皮中偶有棱晶,花瓣表皮及雄蕊药隔中有砂晶;子房壁内表皮下一层细胞逐渐发育成含棱晶的连续细胞,同时子房维管组织中也形成大量棱晶。分析表明,结晶成分为草酸钙。     

不同生境下喜旱莲子草营养器官中抗氧化物质含量的比较

以水陆两种生境下生长的喜旱莲子草为实验材料 ,分别测定并比较了根、茎、叶可溶性蛋白及SOD、POD、Vc、GSH及绿原酸和类黄酮等抗氧化物质活性和含量 ,结果表明可溶性蛋白在叶中含量最高 ,并且水生环境中叶的含量高于陆生环境。除Vc外生态环境对各抗氧化物质含量影响具有一致性。水生环境下喜旱莲子草营养器官的抗氧化物质含量高于陆生环境下喜旱莲子草相应营养器官的含量。这是植物体内一种生理生化的生态适应     

模拟增温对青藏高原多年冻土区小嵩草和藏嵩草生长与抗氧化特征的影响

采用开顶式增温小室(OTCs)方法模拟气候变暖,分别选取青藏高原腹地风火山地区高寒小嵩草草甸和高寒藏嵩草沼泽草甸优势物种小嵩草和藏嵩草为研究对象,对比分析增温处理下两种优势物种叶片的形态与生理特征变化,从而探索高寒植物对气候变暖的内在响应机理.结果表明: 增温显著增加了小嵩草叶片长度(40.0%)和叶片数量(72.7%),也显著增加了藏嵩草株高(11.9%)和叶片长度(19.3%),促进了两种优势植物的形态生长和地上生物量增加.增温处理下小嵩草和藏嵩草叶片的膜透性(电导率),活性氧(过氧化氢和超氧阴离子自由基),超氧化物歧化酶、过氧化物酶、抗坏血酸过氧化物酶和过氧化氢酶活性,丙二醛含量均没有显著变化.但抗坏血酸和游离脯氨酸含量在藏嵩草叶片内分别显著增加了29.8%和53.8%,而在小嵩草叶片内没有明显变化.可见,增温下小嵩草和藏嵩草均能够维持正常的抗氧化水平,以维持该区域优势植物生长;但藏嵩草生理过程对增温更加敏感.     

高世代杉木种源在不同立地条件下的生长适应性

本文进行高世代杉木种源在不同立地条件下的栽植试验,调查二年生种源的生长状况,结果表明：在坡的下、中、上部,二年生高世代杉木种源的地径（或胸径）与树高平均生长量分别为4.08、3.82、3.56 cm和1.90、1.74、1.63 m。在不同立地条件下,地径（或胸径）、树高生长量存在显著差异。     

木本植物对喀斯特石质生境岩石形态结构的适应性

为弄清植物对喀斯特岩石形态结构的适应性,选择3种岩石类型及7种木本群落为研究对象,基于分形、空间句法理论研究岩石结构面孔裂隙形态结构及其与群落特征的关系。结果表明:石灰岩结构面孔裂隙间隙度大、白云岩居中、白云质砂岩小,分维数则反之;白云质砂岩结构面孔裂隙整合度、控制值、密度值大,白云岩居中,石灰岩小;白云岩生境下群落物种多样性及优势种碳、氮含量高、白云质砂岩次之、石灰岩低;分形与空间句法指数间呈显著相关关系,两者能较好的揭示岩石形态结构;总体上3种岩性生境下物种多样性及优势种碳、氮含量与岩石结构面孔裂隙分形及空间句法指数具较强相关关系;大致相同的环境下白云岩形态结构适宜植物生长、白云质砂岩次之、石灰岩差;研究岩石形态结构对喀斯特植被恢复具有重要意义。     

贵阳市10种观赏草基于AHP方法的观赏适应性综合评价

从观赏草观赏性出发,结合与适应性和生长繁殖相关的11个指标,通过层次分析法(AHP)对贵阳市引进的10个观赏草品种进行观赏适应性综合评价。结果表明,11个评价指标中,观赏草的株型、叶色、耐旱性所占权重均较大(＞0.1),是影响其观赏适应性的重要指标;通过建立评分标准后,得出10个品种的观赏性排名为火焰狼尾草、花叶蒲苇、紫叶狼尾草、矮蒲苇、新西兰亚麻、金叶苔草、粉黛乱子草、蓝羊茅、红巨人朱蕉、黄金苔草;生长适应性排名为矮蒲苇、花叶蒲苇、火焰狼尾草、紫叶狼尾草、新西兰亚麻、黄金苔草、粉黛乱子草、金叶苔草、红巨人朱蕉、蓝羊茅;最终综合评分观赏适应价值极好的(Ⅰ级＞4.30分)有花叶蒲苇、火焰狼尾草;观赏适应价值较好的(Ⅱ级3.56～4.30分)有矮蒲苇、紫叶狼尾草、新西兰亚麻、粉黛乱子草、金叶苔草;观赏适应价值一般的(Ⅲ级＜3.56分)有蓝羊茅、红巨人朱蕉、黄金苔草。     

威海天鹅湖大叶藻(Zostera marina)与日本鳗草(Zostera japonica)根际微生物群落结构及其驱动机制

[目的] 本文以威海天鹅湖大叶藻和日本鳗草根际沉积物为主要研究对象,探究不同生长时期的海草根际微生物群落结构多样性,并分析导致微生物群落结构差异的内在因素。[方法] 选取威海天鹅湖大叶藻和日本鳗草根际沉积物与非草区表层沉积物,采用高通量测序技术（Illumina MiSeq platform）解析海草不同生长时期下根际与非草区微生物群落特征。[结果] 微生物群落结构差异由海草生长时期以及海草是否定植共同驱动。在海草成熟期,丙酸菌属（Propionigenium）在大叶藻与日本鳗草根际有明显富集,其相对丰度分别为11.58%和14.26%;在海草幼苗期,脱硫球茎菌科（Desulfobulbaceae）在海草根际富集（大叶藻：2.299%,日本鳗草：4.092%）;在海草衰退期时,硫卵菌属（Sulfurovum）的相对丰度在根际较高（大叶藻：5.624%,日本鳗草：3.749%）。此外,海草生长时期对不同样品之间微生物群落结构差异的解释度最大（R²=0.20335,P=0.002）。PICRUSt2功能预测结果表明各功能基因在海草不同生长时期所呈现的趋势一致,但丰度上呈现出幼苗期 > 成熟期 > 衰退期的结果。[结论] 天鹅湖海草床沉积物微生物群落结构在海草不同生长时期呈现不同的多样性特征,具有明显的根际效应且不同种类海草的根际微生物群落无显著差异,不具有物种特异性。     

Carbon and nitrogen metabolism in the seagrass, Zostera marina L.: Environmental control of enzymes involved in carbon allocation and nitrogen assimilation

This study experimentally examined influences of environmental variables on the activities of key enzymes involved in carbon and nitrogen metabolism of the submersed marine angiosperm, Zostera marina L. Nitrate reductase activity in leaf tissue was correlated with both water-column nitrate concentrations and leaf sucrose levels. Under elevated nitrate, shoot nitrate reductase activity increased in both light and dark periods if carbohydrate reserves were available. When water-column nitrate was low, glutamine synthetase activity in leaf tissue increased with environmental ammonium. In contrast, glutamine synthetase activity in belowground tissues was statistically related to both nitrate and temperature. At the optimal growth temperature for this species (ca. 25 °C), increased water-column nitrate promoted an increase in glutamine synthetase activity of belowground tissues. As temperatures diverged from the optimum, this nitrate effect on glutamine synthetase was no longer evident. Activities of both sucrose synthase and sucrose-P synthase were directly correlated with temperature. Sucrose-P synthase activity also was correlated with salinity, and sucrose synthase activity was statistically related to tissue ammonium. Overall, the enzymatic responses that were observed indicate a tight coupling between carbon and nitrogen metabolism that is strongly influenced by prevailing environmental conditions, especially temperature, salinity, and environmental nutrient levels.     

山东荣成天鹅湖矮大叶藻种群的生态特征

在山东荣成天鹅湖发现较大面积的矮大叶藻,因天鹅湖独特的地理位置和矮大叶藻的高生物量,可以作为山东沿海矮大叶藻的典型代表.2011年9月至2012年10月,对天鹅湖东岸矮大叶藻及其生境进行了周年调查,初步掌握了该种的分布情况及其生境的生态特征.结果表明:矮大叶藻床沉积物成分以砂(81％)和粉砂(14％)为主,沉积物C、N含量在冬季最高,C/N秋季最高;矮大叶藻的密度、高度和地上生物量与水温显著相关(P＜0.05),生长呈现明显的季节变化,8-9月生物量最大.叶片的C、N含量及C/N因生长季节的不同而存在一定差异,C含量秋季显著高于春、夏季,N含量夏季显著低于春、秋季(P＜0.01),C/N夏季显著高于春季(P＜0.05).经估算,天鹅湖矮大叶藻的年固碳能力为111.4 g C·m-2.     

Specific growth rate as a determinant of the carbon isotope composition of the temperate seagrass Zostera marina

The seasonal variability of specific growth rate and the carbon stable isotope ratio (δ¹³C) of leaf blades (δ¹³C_leaf) of a temperate seagrass, Zostera marina (within 10 days old) were measured simultaneously, together with the δ¹³C of dissolved inorganic carbon (δ¹³C_DIC) at three sites in the semi-closed Akkeshi estuary system, northeastern Japan, in June, September, and November 2004. The δ¹³C_leaf ranged from −16.2 to −6.3‰ and decreased from summer to winter. The simultaneous measurement of the δ¹³C_leaf, growth rate, and morphological parameters (mean leaf length and width, mean number of leaves per shoot, and sheath length) of the seagrass and δ¹³C_DIC in the surrounding water allowed us to compare directly the δ¹³C_leaf and specific growth rate of seagrass. The difference in the δ¹³C of seagrass leaves relative to the source DIC (Δδ¹³C_{leaf − DIC}) was the least negative (−11 to −7‰) in June at all three sites and became more negative (−17 to −8‰) as the specific growth rate decreased. This positive correlation between Δδ¹³C_{leaf − DIC} and specific growth rate can be used to diagnose the growth of seagrasses. Δδ¹³C_{leaf − DIC} changed by −1.7 ± 0.2‰ when the leaf specific growth rate decreased by 1% d⁻¹.     

Using light-permeable grating to mitigate impacts of residential floats on eelgrass Zostera marina L. in Puget Sound, Washington

This study evaluated whether light-permeable deck grating could mitigate impacts of residential mooring floats constructed over eelgrass (Zostera marina L.) in Puget Sound, Washington. Eelgrass shoot densities in undisturbed control areas and underneath and adjacent to 11 residential floats (16–50% of each float was grated) were monitored prior to float installation and annually for 3 years following installation. Using linear regression analysis, a decline in eelgrass shoot densities relative to controls was detected underneath three floats (eelgrass was eliminated under only one float) and adjacent to two floats. When control data were used to represent 100% grated, there was a weak relationship between eelgrass bed quality and percent of the deck grated (r = 0.46, p = 0.032), but no relationship when the range of grating was 16–50% (p = 0.90). The percent of a float deck grated did not contribute significantly to a multiple regression model examining change in eelgrass density that included five other dependent variables associated with the design of the floats. We conclude that either there was no effect of grating up to 50% of a float deck or we could not detect an effect. We hypothesize that the large number of site and landscape scale variables associated with a float influenced the effect (and our ability to detect it) of any one variable (such as grating). Consequently, we recommend that managers manipulate as many attributes of a float as possible (including grating) in order to reduce risks to eelgrass.     

Effects of burial and erosion on the seagrass Zostera noltii

The effects of experimental burial and erosion on the seagrass Zostera noltii were assessed through in situ manipulation of the sediment level (− 2 cm, 0 cm, + 2 cm, + 4 cm, + 8 cm and + 16 cm). Shoot density, leaf and sheath length, internode length, C and N content and carbohydrates of leaves and rhizomes were examined 1, 2, 4 and 8 weeks after disturbance. Both burial and erosion resulted in the decrease of shoot density for all the sediment levels. The threshold for total shoot loss was between 4 cm and 8 cm of burial, particularly during the 2nd week. A laboratory experiment confirmed that shoots did not survive more than 2 weeks under complete burial. There was no evidence of induced flowering by burial or erosion. As well, no clear evidence was found of sediment level effects on leaf and sheath length. Longer rhizome internodes were observed as a response to both burial and erosion, suggesting a plant attempt to relocate the leaf-producing meristems closer to sediment surface or in search of new sediment avoiding the eroded area. The C content of leaves and rhizomes, as well as the non-structural carbohydrates (mainly the starch in rhizomes), decreased significantly along the experimental period, indicating the internal mobilization of carbon to meet the plant demands as a consequence of light deprivation. The significant decrease of N content in leaves, and its simultaneous increase in rhizomes, suggests the internal translocation of nitrogen from leaves to rhizomes. About 50% of the N lost by the leaves was recovered by the rhizomes. Our results indicated that Z. noltii has a high sensitivity to burial and erosion disturbance, which should be considered in the management of coastal activities.     

不同生境下景宁玉兰灌丛萌株形态及其生殖特征

景宁玉兰是萌生能力很强的灌木树种,为了解不同生境下景宁玉兰萌枝形态及其生殖特征,选择了灌丛(SH)、黄山松林(PTF)、落叶阔叶林(DBF)、杉木林(CLF)和林缘(FE)等5种坡向一致的生境类型,通过典型样地调查,比较分析了5种不同生境下景宁玉兰萌枝数量、大小、高度、枝系、开花及结实等性状。结果表明:(1)景宁玉兰在黄山松林下的分布密度最高,但5种生境下景宁玉兰每丛的萌枝数量没有差异,每丛最大萌枝基径对每丛萌枝数有一定影响,但最大萌枝高度与每丛萌枝数没有关系。在所有调查的景宁玉兰居群中,大于2根以上萌枝的灌丛达82.5%,说明萌生更新在种群繁衍中发挥着重要作用。(2)在落叶阔叶林下的萌枝基径显著小于其他生境(P0.05),黄山松林下一级枝粗度和长度显著小于其他生境(P0.05);灌丛中的总分枝率和逐步分枝率最高,灌丛和林缘生境的逐步分枝率(SBR2:3)高于其他生境。(3)生殖萌枝基径(r=0.320,P0.05)和高度(r=0.349,P0.05)与花量均呈显著正相关关系。杉木林下景宁玉兰生殖萌枝的花量显著高于黄山松林、落叶阔叶林和林缘生境(P0.05)。虽然黄山松林下景宁玉兰萌枝开花率及开花萌枝比例最低,但其果实大小、单果种子粒数及每丛结实率却较高(P0.05),(4)景宁玉兰对环境变化极为敏感,生境类型和海拔对萌枝形态和生殖性状均有一定影响。研究表明,景宁玉兰萌生特征主要受其内在生物学特性所控制,而萌枝形态及生殖特征则与其所处环境条件更为密切。     

Light adaptation and the role of autotrophic epiphytes in primary production of the temperate seagrass, Zostera marina L.

Photosynthetic features of Zostera marina L. and its autotrophic epiphyte community were investigated in a population inhabiting a shallow (1.3 m depth) water meadow in Great Harbor, Woods Hole, MA (U.S.A.). Photosynthesis versus irradiance (P-I) relationships were measured with respect to leaf age determined by the leaf position in the shoot bundle and by location of the tissue along the leaf axis. Therefore both age and light intensity gradients along the leaf axis were considered. The maximum photosynthesis (P_max) per dm² typically increased nearly two-fold along the leaf axis from leaf bases to apices. Photosynthetic rate on a chlorophyll (Chl) basis did not increase as dramatically along the leaf axis, and rates were usually lowest in tissues with the highest Chl content. The P-I relationships of leaves of different ages did not reveal photoinhibition even at light intensities > 1400 μE • m⁻² • s ⁻¹. Furthermore, no photoinhibition was observed in tissues from leaf blade bases, which never experienced high light levels (> 500 μE • m ⁻² • s⁻¹) in situ in Great Harbor. The initial slopes of the P-I curves and light compensation and saturation values varied along the leaf axis in relation to in situ light intensity gradients and in relation to leaf or tissue age. It appeared that leaf and/or tissue age was more important than light environment in determining P-I responses. The contribution of the autotrophic epiphyte community on Z. marina leaves to total photosynthesis per dm² was between 27 and 50%, and between 10 and 44% per mg chlorophyll. These levels of epiphyte photosynthesis can double the primary production of Z. marina leaves. No detrimental effects of epiphyte cover were realized in leaf maximal photosynthesis or P-I relationships. Non-epiphytized leaves and leaves from which epiphytes were removed showed essentially identical photosynthetic features. Light intensity and age gradients along the leaf axis control both the photosynthetic performance of the leaves and epiphyte biomass and photosynthesis.     

Suitability of Zostera marina populations for transplantation to the Wadden Sea as determined by a mesocosm shading experiment

As part of eelgrass re-establishment efforts in the Wadden Sea, five northwest European eelgrass (Zostera marina L.) populations were studied in a mesocosm filled with Wadden Sea water over a 2-year period. The original habitats of these populations varied with regard to salinity, tidal regime, latitude, substrate type and water nutrient content. The reproductive strategies ranged from semi-annual to perennial. Experimental parameters studied were: planting density (64 and 121 plants m⁻²) and irradiance corresponding to 75%, 89%, 95% and 98% light reduction at the bottom. Three out of five Z. marina populations were successfully transplanted. Planting density, although initially positively correlated, had no effect on final transplantation success. The populations maintained their original reproductive strategy. The reproductive strategy of the donor population did not show a clear correlation with transplantation success. The maximum light reduction tolerated at the bottom was 75%–89%. The populations did not differ in shading tolerance. Assuming a light attenuation coefficient in the Wadden Sea of k=2.0 m⁻¹, this corresponds to a maximum transplantation depth of between 0.45 m and 0.85 m below mean sea level. The differences in transplantation success, and the conservative reproductive strategy of different Z. marina populations, indicate genetic differences and/or low phenotypic plasticity. Moreover, this implies that the characteristics of a donor population must be carefully considered prior to transplantation.     

莲叶桐对热带珊瑚岛环境的生理生态适应性

为探究莲叶桐(Hernandia nymphaeifolia)对热带珊瑚岛季节性干旱、强光、盐碱等环境的生理生态适应性,该文对海南省文昌市试验苗圃(以下简称文昌苗圃)和移栽到热带珊瑚岛的莲叶桐的叶片形态解剖结构、抗氧化能力、抗逆渗透物质含量和光合色素等进行了研究.结果表明:(1)与文昌苗圃相比,莲叶桐在移栽到热带珊瑚岛...