贵州麻若平台泥炭藓沼泽中泥炭藓持水特性及其与土壤营养元素关系研究

泥炭藓属(Sphagnum)植物的持水特性在泥炭湿地形成过程中起着重要作用,研究其与土壤营养元素之间的关系有助于地区湿地保护和退化湿地的修复。以贵州麻若平台分布的泥炭沼泽为对象,采用方差分析、相关性分析和冗余分析等方法对沼泽内泥炭藓的生物量、蓄水量、吸水率和土壤营养元素含量等进行研究。结果显示,该区域泥炭藓物种组成主要包括狭叶泥炭藓(Sphagnum cuspidatum Ehrh.)、多纹泥炭藓(Sphagnum multifibrosum X. J. LiM. Zang)和卵叶泥炭藓(Sphagnum ovatum Hampe.) 3种,狭叶泥炭藓为优势种,占泥炭藓总盖度的87.2%。沼泽中泥炭藓的生物量为(0.62±0.01) kg/m~2,自然蓄水量为(9.42±0.45) kg/m~2,饱和吸水率达1827.41%±34.56%,说明泥炭藓具有很强的持水能力。RDA分析表明,泥炭藓的生物量、饱和吸水量和饱和吸水率主要受沼泽土壤总钾、总磷、有效磷、有效氮、有效钾的影响,泥炭藓的鲜重、自然蓄水量和自然吸水率受土壤pH和水位的影响较大。泥炭藓的生物量、饱和蓄水量、饱和吸水率与土壤总钾含量呈正相关,与土壤总磷、有效磷、总钾、有效氮、总氮、有机质含量呈负相关,说明土壤总磷、有效磷、有效钾、有效氮、总氮、有机质对沼泽中泥炭藓的持水能力具有抑制作用。     

贵州麻若平台泥炭藓沼泽中泥炭藓持水特性及其与土壤营养元素关系研究

泥炭藓属（Sphagnum）植物的持水特性在泥炭湿地形成过程中起着重要作用,研究其与土壤营养元素之间的关系有助于地区湿地保护和退化湿地的修复。以贵州麻若平台分布的泥炭沼泽为对象,采用方差分析、相关性分析和冗余分析等方法对沼泽内泥炭藓的生物量、蓄水量、吸水率和土壤营养元素含量等进行研究。结果显示,该区域泥炭藓物种组成主要包括狭叶泥炭藓（Sphagnum cuspidatum Ehrh.）、多纹泥炭藓（Sphagnum multifibrosum X.J.Li&M.Zang）和卵叶泥炭藓（Sphagnum ovatum Hampe.）3种,狭叶泥炭藓为优势种,占泥炭藓总盖度的87.2%。沼泽中泥炭藓的生物量为（0.62 ±0.01）kg/m²,自然蓄水量为（9.42 ±0.45）kg/m²,饱和吸水率达1827.41%±34.56%,说明泥炭藓具有很强的持水能力。RDA分析表明,泥炭藓的生物量、饱和吸水量和饱和吸水率主要受沼泽土壤总钾、总磷、有效磷、有效氮、有效钾的影响,泥炭藓的鲜重、自然蓄水量和自然吸水率受土壤pH和水位的影响较大。泥炭藓的生物量、饱和蓄水量、饱和吸水率与土壤总钾含量呈正相关,与土壤总磷、有效磷、总钾、有效氮、总氮、有机质含量呈负相关,说明土壤总磷、有效磷、有效钾、有效氮、总氮、有机质对沼泽中泥炭藓的持水能力具有抑制作用。     

三种泥炭藓对干旱及植物相互作用的形态响应

泥炭藓是泥炭地中的优势植物,常面临干旱的威胁,并分化为藓丘种、丘间种甚至丘坡种,其形态特征如何响应种间相互作用和干旱胁迫还鲜有人知。以藓丘种大泥炭藓(Sphagnum palustre)、尖叶泥炭藓(S.capillifolium)和丘间种喙叶泥炭藓(S.fallax)为材料,在模拟湿润和干旱条件下,对人工构建的苔藓群落进行室内培养实验,分析干旱及植物相互作用对3种泥炭藓生物量生产、高增长、侧枝生产与水细胞体积百分比(HCP)的影响。结果表明:干旱对于3种泥炭藓的生物量生产、高增长、侧枝生产均有抑制效应,并促进了2个藓丘种HCP的增加;邻体抑制了藓丘种大泥炭藓的生物量生产与侧枝生产,并使藓丘种尖叶泥炭藓的HCP明显下降;在HCP性状上,干旱与邻体存在交互作用。研究表明,2类泥炭藓能够通过调整形态特征来适应干旱以及植物相互作用,藓丘种较强的耐旱能力应归因于其能通过增加HCP来提高储水能力。     

毕节吞天井边缘地带不同郁闭度环境对泥炭藓叶绿素荧光特性及蓄水量的影响

为了丰富对泥炭藓的生长环境认识,探究其对冲蚀型喀斯特天坑形成的可能影响,并寻找对其更适合的生长条件,采用梯度划分法,以采自毕节吞天井边缘地带不同郁闭度环境下生长的泥炭藓(Sphagnum palus?tre)为实验材料,分别测出其叶绿素荧光参数及蓄水量,探究不同郁闭度环境下泥炭藓的光合能力和持水能力。结果显示:①随着郁闭度的增大,泥炭藓的初始荧光(F^o)和最大荧光(F^m)均显著增大,分别由224.67上升至264,716上升至785.33。PSⅡ最大光化学效率(F^v/F^m)先降低后趋于平稳,光化学淬灭系数(qP)显著增大,由0.17上升至0.46。非光化学淬灭系数(NPQ)显著减小,由1.57下降至0.8。光合电子传递速率(ETR)显著增大,由5.72上升至9.68。②随着光照减弱,泥炭藓的吸水率和蓄水量显著升高,其中,自然吸水率由14.36上升至26.37,饱和吸水率由21.7上升至27.01;自然蓄水量由3032.97上升至12816.01,饱和蓄水量由4576.34上升至13175.97。③泥炭藓虽具有良好的耐光性,但高郁闭度环境,更有利于其叶绿素的积累,增强光合作用,提高生物量的积累,进而获得更强的蓄水能力。此外,不同植物种群之间的竞争会抑制泥炭藓的生长,分享土壤水分,而充足的水分是泥炭藓生存极为重要的条件。④泥炭藓良好的持水特性和吸水作用,在减缓地表径流上具有重要作用,在地质过程中起减慢的作用。而不同郁闭度环境下泥炭藓持水性的不同,也在一定程度上影响了水流的分配规律,从而对冲蚀型天坑的形成产生影响。     

鄂西七姊妹山泥炭藓沼泽植物多样性

以湖北宣恩县七姊妹山泥炭藓沼泽植被为研究对象,对其物种组成、群丛类型、植物群落生物量、物种重要值及多样性特征进行了分析.结果表明,该沼泽物种组成较为丰富,共计41科65属94种;沼泽植被可区分为9个群丛,其中泥炭藓(Sphagnum palustre ssp. palustre)、野灯心草(Juncus sethuensis)和堇菜(Viola verecunda)为9个群丛共有种.在9个群丛中,大理苔草-泥炭藓群丛(Ass.Carex taliensis-Sphagnum palustre ssp.palustre)的生物量最高,亮鞘苔草-泥炭藓群丛(Ass.Carexfargesii-Sphagnum palustre ssp.palustre)的生物量最低;泥炭藓的生物量占其所在群丛总生物量的74.78%-91.18%.泥炭藓的平均盖度为88.6%,在其中7个群丛中,泥炭藓的重要值大于其他物种的重要值.在群丛物种多样性指数中,丰富度指数(R)最高的为西南小叶地笋 庐山蔗草一泥炭藓群丛(Ass.Lycopus coreanus vat.cavaleriei Scirpus lushanensis-Sphagnum palustre ssp.palustre),优势度指数(C)最高的为亮鞘苔草-泥炭藓群丛,多样性指数(H')最高的为西南小叶地笋 野灯心草-泥炭藓群丛(Ass.Lycopus coreanus vat.cavaleriei Juncus setchuensis-Sphagnum paslustre ssp.palustre),均匀度指数(J)最高的为野灯心草 宜昌苔草-泥炭藓群丛(Ass.Juacus setchuensis Carex alliFormis-Sphagnum palustre ssp.palustre).     

遮阴对两种泥炭藓植物生长及相互作用的影响

以大泥炭藓和喙叶泥炭藓为材料,研究遮阴对其生长及植物相互作用的影响.结果表明:在单种群中,遮阴处理明显促进了大泥炭藓的高生长,但对喙叶泥炭藓的生长以及大泥炭藓生物量和分枝数未产生影响;在混合群中,喙叶泥炭藓抑制了大泥炭藓生物量和分枝数的增长,而大泥炭藓对喙叶泥炭藓的生长无影响.随遮阴胁迫的增加,邻体对喙叶泥炭藓竞争加剧,当胁迫进一步增强,邻体效应有转变为正相互作用的趋势,但邻体对大泥炭藓的效应始终为竞争,未随胁迫增加而变化.     

火烧高温对泥炭藓孢子萌发力影响的模拟实验

作为生态系统稳定性维持的一个重要因素,火对泥炭地优势植物泥炭藓(Sphagnum)孢子库的影响尚不清楚.以采自长白山区泥炭地的泥炭土和3种泥炭藓的成熟孢子为实验材料,室内模拟火烧,以此设置不同温度水平(20、40、60或100℃,持续0.5、1、2、4或10 min),对泥炭藓孢子进行热激处理,经萌发实验后,研究火烧高温对孢子萌发率的影响.结果显示,火烧期间各层土温随深度而递减,表层泥炭可达300℃的极端高温,而1 cm深温度仅为70℃,体现出泥炭土良好的热缓冲性;40℃的热激可使锈色泥炭藓(S.fuscum)与中位泥炭藓(S.magellanicum)孢子萌发率提高20%与50%;60℃的热激使尖叶泥炭藓(S.capillifolium)孢子的萌发率提高1倍;100℃热激对3种泥炭藓孢子萌发则有强烈的抑制作用.研究表明,泥炭藓孢子耐受高温的能力有限,但土壤中的孢子凭借泥炭的良好热缓冲性,可以躲避火烧高温造成的致命伤害,适度的热激甚至能提高其萌发力,对其在火后的建植及种群的长存可能有重要意义.     

水位控制对农田泥炭藓产量的影响

为明确不同水位控制下农田土壤因子与泥炭藓产量之间的关系,解析影响泥炭藓产量的主要土壤因子,以贵州省龙里县水苔村种植年限相同的泥炭藓为研究对象,分析不同水位条件下泥炭藓生理生态指标与土壤因子的特征,并结合冗余分析,讨论水位和土壤因子的交互作用对泥炭藓生理生态指标的影响。结果表明：水苔村种植泥炭藓有1科1属5种,其中泥炭藓原亚种(Sphagnum palustre L. ssp.palustre)为优势种。泥炭藓生理生态指标均随水位升高逐渐上升,表明高水位有利于泥炭藓生长;土壤含水量(SWC, Soil Water Content)和孔隙度(STP, Soil Porosity)随水位升高逐渐增大,表明水位升高有助于增强土壤透水、透气及蓄水保墒能力;总氮(TN, Total Nitrogen)、总磷(TP, Total Phosphorus)、总钾(TK, Total Potassium)、有效磷(AP, Available Phosphorus)随水位升高逐渐降低,表明水位升高加速氮磷钾等营养元素淋失;脲酶(URE, Urease)和过氧化氢酶(CAT, Catalase)随水位升高逐渐...     

模拟氮沉降对鄂西南贫营养泥炭地两种藓类植物生长与分解的影响

以泥炭藓属(Sphagnum)植物为优势种的贫营养泥炭地是陆地生态系统重要的碳汇,其优势植物的生长与分解动态关系着贫营养泥炭地碳汇潜力,但有关氮沉降对贫营养泥炭地优势藓类植物生长与分解的影响还存在很大争议,并且氮沉降对亚热带贫营养泥炭地优势藓类植物生长与分解的研究鲜有报道。该研究以鄂西南贫营养泥炭地为研究对象,通过原位喷洒不同浓度的NH4Cl溶液,采用生物量收割法和分解袋法,探讨模拟氮沉降对泥炭藓(S.palustre)与金发藓(Polytrichumcommune)生长及分解的影响。研究结果表明:(1)氮沉降对两种藓类植物生长高度与生物量均有明显的影响,且两种藓类植物生长存在一定的氮沉降阈值,约为3g·m^–2·a^–1;(2)氮沉降对两种藓类植物生长影响程度不同,金发藓对氮沉降的响应灵敏度要大于泥炭藓;(3)高浓度氮沉降(6和12g·m^–2·a^–1)抑制了泥炭藓分解,低浓度氮沉降(3g·m^–2·a^–1)对泥炭藓分解的影响取决于分解时间,而所有浓度氮沉降均抑...     

东北哈泥泥炭地不同泥炭藓属植物高光谱特征

泥炭藓是北方泥炭地的优势植物,其高光谱特征研究很少。本研究采用高光谱遥感技术,对不同水位埋深条件下(藓丘及丘间)生长的相同种类泥炭藓植物,及同一水位埋深条件下的不同种类泥炭藓植物的光谱特征进行研究。结果表明,不同种类泥炭藓属植物的光谱反射特征具有明显种间差异,主要反映在绿峰、红边的差异上。由于水分条件差异,生长在高丘和低丘的锈色泥炭藓、泥炭藓及中位泥炭藓在可见光和近红外波段的光谱反射率均具有显著差异,高丘的泥炭藓属植物的反射率均高于低丘的泥炭藓属植物。本研究所获得的东北地区哈泥泥炭地几种泥炭藓属植物的详细光谱信息,可以为高分辨率航空影像和卫片解译泥炭藓湿地提供地面基础。     

Vegetation changes of a Danish mire 1957–1981

A Danish mire influenced by culture until ca. 100 years ago and since then with incipient growth of Betula pubescens , was analyzed in 1957 and 1981 with regard to height of the Betula trees and cover percentage of plant species in the field layer. In 1957, every m2 along a 110 m transect was examined; in 1981 only 56 m2 representatively selected from the transect were examined. Betula showed considerable changes with a net intake of 10 trees (23%) and a net loss of 23 trees (52%), i.e. a net loss of 13 trees (30%). The mean height of the trees has, however, increased by 80 cm and the sum of the height of the trees per m2 by 29 cm. An increased total cover was found for Em–petrum nigrum, Molinia coerulea , and Erica tetralix , and a decreased total cover for Calluna, Sphagnum magellanicum, S. nemoreum, S. rubellum, Hypnum cupressi–forme, Pleurozium schreberi , and Aulacomnium palustre. An almost unchanged total cover was found for Eriophorum vaginatum, E. angustifolium, Sphagnum recurvum, Andromeda polifolia, Drosera rotundifolia , and Oxycoccus palustris. On the basis of quantitative changes in the individual plots, a specific index of change is calculated, decreasing in the order Empetrum > Sphagnum magellanicum > S. recurvum = Molinia > Calluna > Hypnum cupressiforme > Pleurozium schreberi> Oxycoccus palustre> Sphagnum nemoreum = S. rubellum = Eriophorum vaginatum = E. angustifolium > Aulacomnium palustre > Erica> Drosera > Andromeda. Analyses from 1981 demonstrate that usually the light conditions and/or the water content and rarely the bulk density of the soil is correlated with the change in cover of the individual species. For some species it is also shown that the change is correlated with the strongly increased cover of Empetrum in particular. The changes are finally illustrated by showing the position of the species along ecological gradients in 1981.     

The interaction between epiphytic algae, a parasitic fungus and Sphagnum as affected by N and P

We report the effects of fertilisation with N and P on the infection of Sphagnum by its fungal parasite Lyophyllum palustre, the expansion of epiphytic algae and the interaction between the latter two from 1998 to 2001. We added 40 kg N ha⁻¹ yr⁻¹ or 3 kg P ha⁻¹ yr⁻¹ in a full factorial design at 4 field sites. In a greenhouse experiment we reinoculated Sphagnum to verify the identity of the fungus and its necrotic effect on Sphagnum .
Lyophyllum palustre was responsible for the necrosis of Sphagnum in our experiments. Adding N induced complete necrosis of Sphagnum cuspidatum by L. palustre , whereas adding P decreased the area of necrotic tissue. Disease severity was related to the N concentration in the Sphagnum capitula. In Sphagnum magellanicum and S. papillosum , infection with L. palustre resulted in defoliation of stem sections. Adding N stimulated the expansion of algae at all sites, reducing the volume of photosynthetic tissue in Sphagnum. The density of the film of algae in the treatments receiving N was a function of the frequency of defoliated Sphagnum stems.
We conclude that infection with parasitic fungi and, in humid environments, the expansion of epiphytic algae, may aggravate the impact of increased N deposition or of other ecosystem disturbances that affect nutrient availability.     

贵州泥炭藓属植物物种多样性研究

对采自贵州各地的150余份泥炭藓属植物标本进行整理,发现其中的拟狭叶泥炭藓和吕宋泥炭藓为贵州首次发现,至此,贵州有泥炭藓属植物18种1亚种和1变种。列入中国红色名录中的多纹泥炭藓在贵州的分布除原记录安顺地区外,这次研究还发现在贵州的麻江和雷公坪2个地方亦有分布。     

长白山哈泥泥炭地七种苔藓植物生态位

采用Levins和Pianka公式,对哈泥泥炭地7种苔藓植物的生态位进行了研究.结果表明：7种苔藓在泥炭的全氮、全磷、Ca²⁺、K⁺、沼泽水的pH和电导率、乔木郁闭度、灌木盖度以及水位埋深9个环境因子梯度上的平均生态位宽度排序为：沼泽皱缩藓＞喙叶泥炭藓＞中位泥炭藓＞尖叶泥炭藓、桧叶金发藓＞大泥炭藓＞锈色泥炭藓.锈色泥炭藓倾向于特化种,沼泽皱缩藓倾向于泛化种.在各种环境因子中,以电导率平均重叠值最高,水位埋深、乔木郁闭度、pH和灌木盖度梯度上平均重叠值最低,是影响苔藓分布的主要环境因子.多数苔藓在这4个梯度上产生生态位分异.少数苔藓种对在所有环境因子梯度重叠值均较高,是由于苔藓之间存在水分协作关系.这为苔藓植物的种间竞争提供了间接证据.     

A contribution to the Sphagnum (Sphagnaceae) flora of Paraguay

The genusSphagnum is reviewed for Paraguay, with an emphasis on recent collections. Five species and one variety are recognized:S. perichaetiale Hampe,S. magellanicum Brid.,S. pulchricoma C. Müll.,S. itabense Crum & Buck, sp. nov.,S. flaccidum Besch., andS. flaccidum var.lindmanii (Warnst.) Warnst.Sphagnum flaccidum is redescribed; it is illustrated, as areS. perichaetiale andS. itabense.     

Externally held water – a key factor for hair lichens in boreal forest canopies

Lichens hold water inside (internal pool) and outside their body (external pool). Yet, external pool size is not known in hair lichens dominating boreal forest canopies. Here we quantify morphological traits and internal/external water in two widespread Bryoria species along Picea abies canopy-height gradients: Bryoria fuscescens at 5–20 m and Bryoria capillaris at 15–20 m. Dry mass and specific thallus mass (STM) of intact B. fuscescens increased with height, while STM of individual branches did not. Maximum water holding capacity (mg H₂O cm⁻²) increased with height, but did not differ between the species. Bryoria had much larger external (79–84% of total) than internal water pools, trapping water by dense clusters of thin, overlapping branches. They thus increase water storage in boreal forest canopies and influence hydrology. High external water storage extends hydration periods and improves lichen performance in upper canopies, and thereby contributes to the success of these hair lichens.     

Branch sacrifice: cavitation-associated drought adaptation of riparian cottonwoods

In their native riparian zones (floodplains), Populus deltoides (prairie cottonwood) and P. fremontii (Fremont cottonwood) commonly experience substantial branch die-back. These trees occur in semi-arid areas of North America and unexpectedly given the dry regions, they are exceptionally vulnerable to xylem cavitation, drought-induced air embolism of xylem vessels. We propose that the vulnerability to cavitation and branch die-back are physiologically linked; drought-induced cavitation underlies branch die-back that reduces transpirational demand enabling the remaining shoot to maintain a favorable water balance. This proposal follows field observation along various western North American rivers as precocious branch senescence, the yellowing and death of leaves on particular branches during mid- to late summer, was common for P. deltoides and P. fremontii during hot and dry periods of low stream-flow. Branches displaying precocious senescence were subsequently dead the following year. The proposed association between cavitation, precocious senescence and branch die-back is also supported by experiments involving external pressurization of branches to about 2.5 MPa with a branch collar or through an adjacent cut-branch. The treatments induced xylem cavitation and increased leaf diffusive resistance (stomatal closure) that was followed by leaf senescence and branch death of P. deltoides. P. trichocarpa (black cottonwood) appeared to be less affected by the pressurization treatment and this species as well P. angustifolia (narrowleaf cottonwood) and P. balsamifera (balsam poplar) seldom display the patchy summer branch senescence typical of P. deltoides and P. fremontii. ’Branch sacrifice’ describes this cavitation-associated senescence and branch die-back that may provide a drought adaptation for the prairie and Fremont cottonwoods. Received: 13 May 1999 / Accepted: 4 November 1999     

Neurovascular territories of the external and internal oblique muscles

The purpose of this study was to document the extent of the arteries supplying the external and internal oblique muscles and the connections among the vascular territories. Ten adult human cadavers underwent whole-body arterial perfusion (200 ml/kg) with a mixture of lead oxide, gelatin, and water, through the carotid artery. The external and internal oblique muscles were dissected and subjected to radiography. The vasculature of each muscle was analyzed by using the paper template technique. The areas of the vascular territories of the individual intercostal arteries within the external oblique muscle varied from 9 to 22 percent. The area of the vascular territory of the muscular branch of the deep circumflex iliac artery was 5 to 18 percent. The ascending branch of the deep circumflex iliac artery supplied a mean of 35.7 percent of the vascular territory of the internal oblique muscle. The lower six posterior intercostal arteries supplied a mean of 48.5 percent. The lateral branches of the deep inferior epigastric artery supplied a mean of 15.8 percent. This information provides the basis for the design of external and internal oblique muscle flaps for functional muscle transfer.