Effect of desert soil algae on the stabilization of fine sands

Four filamentous cyanobacteria, Microcoleus vaginatus, Phormidium tenue, Scytonema javanicum (Kutz.) and Nostoc sp., and a single-celled green alga, Desmococcus olivaceus, all isolated from Shapotou (Ningxia Hui Autonomous Region of China), were batch cultured and inoculated onto unconsolidated sand in greenhouse and field experiments. Their ability to reduce wind erosion in sands was quantified by using a wind tunnel laboratory. The major factors related to cohesion of algal crusts, such as biomass, species, species combinations, bioactivity, niche, growth phase of algae, moisture, thickness of the crusts, dust accretion (including dust content and manner of dust added) and other cryptogams (lichens, fungi and mosses) were studied. The best of the five species were M. vaginatus and P. tenue, while the best mix was a blend of 80% M. vaginatus and 5% each of P. tenue, S. javanicum, Nostoc sp. and D. olivaceus. The threshold friction velocity was significantly increased by the presence of all of the cyanobacterial species, while the threshold impact velocity was notably increased only by the filamentous species. Thick crusts were less easily eroded than thin crusts, while biomass was more effective than thickness. Dust was incorporated best into Microcoleus crust when added in small amounts over time, and appeared to increase growth of the cyanobacterium as well as strengthen the cohesion of the crust. Microbial crust cohesion was mainly attributed to algal aggregation, while lichens, fungi and mosses affected more the soil structure and physico-chemical properties.

中国五倍子蚜虫冬寄主藓类植物的生理生态学研究

该项目以植物生理生态学（PlantPhysioecology）为研究方向，在藓类植物的光合特性及其与环境条件的关系，高温胁迫对藓类植物生理过程及生理生态学特性的影响，藓类植物光合作用与其水分含量和水势的关系等3个方面开展了大量深入的实验研究，取得了较好的实验结果.该项研究在苔藓植物生物学研究和冬寄主藓类植物人工培植方面既具有重要的理论意义，也具有重要的实际应用价值.

川西亚高山森林生态系统辐射传输研究

辐射传输研究是贯穿森林生态系统的纽带，太阳辐射为植物的生长发育提供光合能量、适宜的环境温度以及发育信息。一方面，气候变化使到达地面辐射能的质和量发生变化，影响到植被的生长发育，改变森林的结构，而森林结构的变化又会影响林冠内辐射能的分配和质量，这些变化会进一步影响到林下土壤温度，改变森林根系活性以及土壤营养转化的效率；连锁反应的结果有可能会使森林生态系统的生产力发生变化，改变碳素和氮素源库的调节方向，从而反馈影响地球气候系统。另一方面，人类作为生态系统的成员，必然需要森林生态系统为其提供更多的原材料和更好的生态服务功能，如何实现这些目标，就需要人类适度调整干预方式和频度，达到预期的目的。本文在建立适合于川西亚高山森林的叶面积测量技术、光照辐射模型和土壤温度变化模型的基础上，对川西亚高山地带森林生态系统的辐射传输特征进行了分析，并从森林结构的角度探讨了林分内的辐射分布以及对土壤温度的影响。主要成果如下： 1. 提出了一种照相法测量叶面积的方法。通过对摆放在平面上的叶片照相，利用投影变化，把非正射图像转化为正射图像，然后经过计算机图像处理得到每一片叶片的面积、周长、长度、宽度等信息。这种方法可使用户以任意方向和距离拍摄处于平面上的叶片，能同时处理大量的叶片，适于野外离体或活体叶片测量。叶片面积分辨率可调，分辨率可以与常用的激光叶面积仪相近甚至更高，而且叶片图像可以存档查询。 2. 提出一种模拟林内光照变化的模型。利用林冠半球照片，记录视点以上半球内的林冠构件空间分布，作为林冠子模型；天空辐射子模型采用国际照明委员会(CIE)的标准晴天和阴天以及插值模型。该模型能够模拟林下某一位点处的实时光斑变化。 3. 提出一种土壤温度变化模型。把土壤视为具有容量和阻力性质的结构，利用电阻和电容器件构建土壤能量分布模型。外界太阳辐射能经过植被以及其它一些能量分配器后进入土壤，其中有一部分转化为土壤势能，即土壤温度。土壤温度的变化类似于电池的充放电过程。在已知模型参数的情况下，可以从太阳辐射计算土壤温度的变化。在模型参数未知的情况下，通过输入和输出值推算模型的参数，而模型参数中的时间常数与土壤组成和含水量有关，这样就可以知道土壤水分的变化情况。 4. 从王朗亚高山森林典型样地林分结构的测量获得林地三维结构图、树冠形态、叶面积密度等参数，这些参数输入到Brunner (1998)开发的tRAYci 模型中计算出一段时间内林分任意位置处的光照值。与林下辐射计测量值以及半球照片计算结果的比较，该模型基本上能够满足对林分光环境了解的要求。 5. 从川西亚高山森林生产力的角度，探讨了森林生产力研究的方法以及川西地区的研究历史和成果，发现了其中的一些规律和问题，特别是在叶面积测量上，还没有使用标准的叶面积指数定义。综合来看，川西地区针叶林叶面积指数(单位土地面积上植物冠层总叶面积的一半) 应在4-5 之间。降雨丰富的华西雨屏带是川西地区森林生产力最高的地区，而向西北森林生产力逐渐降低。川西地区云冷杉林森林生产力平均约为600 gDM m-2 a-1，但是根据辐射能计算的潜在生产力则达到1800 gDM m-2 a-1。实际与潜在森林生产力的巨大差异说明其它因子对生产力的影响。 6. 王朗亚高山3 个典型森林林分中，白桦林样地(BF) 林下草本以糙野青茅、牛至、紫菀等喜阳性物种为主，林下透光度较高；冷杉林样地(FF) 林下透光度最低，以喜阴性物种水金凤、蟹甲草、囊瓣芹等为主；而云杉林样地(SF)林分林龄最大，林下透光度介于冷杉林和白桦林之间，草本层仍然以喜阴性物种东方草莓、紫花碎米芥、酢浆草等为主。冷杉林和云杉林的灌木层也很丰富，卫矛属、五加属、茶藨子属、忍冬属植物很丰富，而在白桦林则以栒摘要子属、榛子属、鹅耳枥属等植物为主。藓类植物在云杉林中最丰富，并且形成毯状层，其它两个林分则很稀少。3 个样地林分结构与林下光环境有很强的相关性，从光环境特征可以在一定程度上推测林分的结构。各样地单纯从乔木层材积推算的NPP 排列顺序为BF>FF>SF，与林下辐射透射率和林分年龄的顺序相同，暗示辐射对群落演替过程的驱动作用。 7. 用半球照相法测得BF、FF 和SF 3 个样地的有效叶面积指数以SF 样地最高，BF 最低。如果考虑针叶树叶片在小枝上的丛聚分布，利用北方针叶林的数值进行校正，则SF 样地LAI 显著增加(达到89%)，其它样地的LAI 基本不变甚至有所下降。校正后的数值与文献中地面测量的结果较相近，说明在使用半球照相法测量川西亚高山针叶林LAI 时必须加以校正。 8. 在3 个样地中，白桦、岷江冷杉和方枝柏种群为丛聚分布，紫果云杉在FF和SF 样地中基本上为随机分布。3 个物种出现丛聚分布的最短距离约为2m，在最短距离以内则为随机分布。最短距离可能与树冠大小有关，种子传播特征以及对光照的需求状况可能是造成这种分布格局类型的原因。 Radiative transfer plays a key role in forest ecosystems. Solar radiation providesenergy for photosynthesis, appropriate ambient temperature and development informationfor plants. However, quality and quantity of radiation reaching land surface are affected byweather and subsequently influence the growth and development of plants, which in turnchanges the budget of radiation in forest. Soil temperature changes with the variation ofradiation under forest canopy and influences the activity of roots and rate of nutrientturnover. Thus, any changes of radiation will induce chain reactions in the entireecosystem and display in the value of net primary productivity which will possibly shiftthe relationship between carbon source and sink at local or regional scale and feed back tothe global climate system. On the other hand, as a component of ecosystems, humanbeings of course need to demand more materials and better service from ecosystems. Forthese purpose, man must adapt their pattern and frequency of interference to ecosystems.This paper aims to research on the canopy structure, the radiation distribution and theirinfluence on soil temperature from the process of radiative transfer in subalpine forestecosystem of western Sichuan. The main results are: 1 Present a new photogrammetric method for leaf area. The main idea is to convertnon-vertically taken images of planar leaves to orthoimages through projectivetransformation. The resultant images are used to get leaf morphological parametersthrough image processing. This method enables users to take photos at almost anyorientation and distance if only the leaves are placed on same plane, and to processlarge quantity of leaves in a short time, which is suitable for field measurement. Theresolution of leaf area is adjustable to fit for special requirement. 2 A model using hemispherical photos combining with solar tracks and radiation courseis provided to simulate light variation in forest. The hemispherical photos of canopyrecord the real spatial distribution of each element of plants viewed from a point. Skyradiance is simulated with CIE standard clear sky or cloudy sky model. This modelcan be used to simulate real time light variation under canopy. 3 Present a soil temperature model. Soil could be regarded as a body of resistor andcapacitor. Some of the budget of solar radiation in soil body is transformed into soilpotential energy, the soil temperature. Variation of soil temperature is driven by solarradiation, vegetation, soil properties, etc. This model has two parameters, one of whichis time constant and is related to soil water content. The inversed model can be used tosimulate the variation of soil water. 4 By using model tRAYci developed by Brunner (1998), the 3-D distribution of light inthree subalpine forest stands of Wanglang Nature Reserve has been simulated andvalidated with value of radiometers in these stands. This model can basically satisfythe need for understanding light regimes of these stands. 5 Present some principles and questions of NPP (net primary of productivity) researchesin western Sichuan. The standard leaf area index (LAI) defined by Chen and Black(1997) has not been used in this region. Total leaf area and projected leaf area indexare still used in NPP researches which may differ around 1-fold in magnitude. Thestandard LAI which is a half of total leaf area above unit land area should be between4 and 5 for typical subalpine coniferous forest of western Sichuan concluded fromliteratures. The maximum forest NPP occurs in West China rain belt and decreasesnorthwestwards. Average NPP of spruce-fir forest in western Sichuan is about600gDM m-2 a-1, which is below the potential NPP of 1800gDM m-2 a-1 based onmeasured radiation in this region. The significant difference between potential and realNPP suggests that other factors influence the growth of stands. 6 In the three subalpine forest stands of Wanglang Nature Reserve, herbage layer ofAbstractbirch stand (BF) with age of 40 is dominated by heliophytes of Deyeuxia scabrescens,Origanum vulgare, Aster tongoloa etc.. However, both of the other two stands aredominated by shade tolerent species, such as Impatiens noli-tangere, Impatiensdicentra, Cacalia deltophylla and Pternopetalum tanakae etc. in fir stand (FF) withage of 180 and Fragaria orientalis, Cardamine tangutorum and Oxalis corniculata etc.in spruce stand (SF) with age of 330. Shrub species in the latter two stands arerelatively rich, typical dominant genera being Euonymus, Acanthopanax, Ribes andLonicera. Birch stand has relatively sparse shrubs dominated by genera of Cotoneaster,Corylus and Carpinus. Mosses are significant only in spruce stand. The canopystructure controls the light regime of stand, which influence the composition of herblayers beneath the canopy. This light regime-community structure relationship can beused to infer the herb community from canopy structure. The NPP derived from timbervolume of arbor layer of the three stands decreases from BF to SF, which is in thesame order of transmitted total radiation under canopy and age of these stands,suggesting the driving effect of radiation in the succession of community. 7 The highest effective LAI of the three stands obtained by hemispherical photos is inplot SF and lowest in plot BF. After rectification of the clumping effect of leaves onshoot, the real LAI in plot SF increases significantly (89%) and approximate to theaverage LAI of coniferous forest in western Sichuan. Therefore, the LAI obtainedfrom hemispherical photos needs rectification for clumping effect. 8 Spatial distribution pattern for Betula platyphylla, Abies faxoniana and Sabinasaltuaria is clumpy, but Picea purpurea almost random in plot FF and SF. The shortestdistance for clumpy distribution for Betula platyphylla and Sabina saltuaria is 1.5m,and 2m for Abies faxoniana. And random pattern for these trees is exhibited within thisrange which almost coincides with the diameter of crown. Seed dispersalcharacteristics and light requirement may be the reason for different spatial pattern.

川西地区几种优势苔藓植株元素含量及其时空差异性

揭示苔藓植株元素含量及其时空差异性是深入开展利用苔藓植物指示环境和筛选理想监测藓种的科学基础。采用微波消解（ICP-AES）方法对九寨沟自然遗产地原始林景点停车场周围三个采样带：I为停车场植被小岛（PS），向外约120 m半径为II带（D120），再向外距离约1,000 m为III带（D1000）和3个方向上的大羽藓和毛尖青藓2种苔藓中13种元素（A1, S, Ca, P, Cu, Fe, K, Mg, Mn, Pb, Ni,Zn和Cd）含量进行了测定和比较，并对采自边坡方向（PS-3）上2005和2007年的4种苔藓植物（南木藓、大羽藓、平藓和厚角絹藓）也进行了13种元素含量的测定和比较。同时对九寨沟自然遗产地、黄龙自然遗产地、夹金山和梦笔山的冷杉原始林4个地区的3种苔藓中（大羽藓、锦丝藓和塔藓）的A1、Ca、Cu、Fe、K、Mg、P、Zn、C和N 10种元素含量进行测定和比较。 对大羽藓和毛尖青藓2种苔藓植物内13种元素的测定发现：1）同种苔藓对不同元素的富集能力不同。A1、Ca、K、Mg和P的元素含量在苔藓中的富集较其他元素的要高。2）不同种苔藓植物对同种元素的富集能力不同，毛尖青藓较大羽藓能够监测出更多的元素；对于被检测出的元素，毛尖青藓监测出的累积量大于大羽藓，其中累积量最大的元素是Ca为10 874.286 μg.g-1.year-1，最小的是Cu元素为5.438 μg.g-1.year-1。对05年和07年的平藓、大羽藓、南木藓和厚角絹藓元素含量的测定表明：元素在两年中的积累量是不同的。综合分析表明，苔藓生物监测方法可有效监测景点停车场机动车尾气中排放出的典型元素（如Cu、Pb、Ni、Zn、Cd等）含量，而毛尖青藓较大羽藓能更可靠的监测九寨沟自然遗产地单景点汽车尾气金属元素种类及其排放量。 对4个地区3种苔藓10种元素监测发现：1）Ca、Mg、Zn、K和Cu元素在黄龙地区的含量高于在其它地区的含量；P元素在梦笔山地区的含量为最高；Fe和Al元素在夹金山地区的含量高于在其它地区的含量。2）C元素在其它因素一致的情况下，进行不同年龄间的元素含量比较，结果显示元素含量在各年龄间并不存在明显的差异性；N元素含量与年龄的差异出现在黄龙林下及林窗的塔藓、九寨沟林下的锦丝藓及塔藓和梦笔山的塔藓中，而在锦丝藓中未出现元素含量与年龄的差异性；塔藓能检测出更多的元素种类其含量与年龄间存在显著差异，锦丝藓检测到的元素种类次之；除锦丝藓（锦丝藓在林窗中几乎检测不到元素含量与年龄间的差异性）外，其他两种藓在林窗中能检测出的元素种类大于在林下的检测种类。3）元素含量与生境间存在差异性的元素分别有：黄龙大羽藓中的Ca、P和Mg元素；九寨锦丝藓中的Zn元素；夹金山塔藓中的Al、Fe和Zn元素；梦笔山大羽藓中的Al、Fe和Mg元素及锦丝藓中的Ca元素。4）区域、年龄和生境因素对苔藓植株元素含量均达到了显著水平，但两两之间及三者之间的交互作用由于元素种类的不同存在差异。综合分析表明，苔藓植物中的元素含量受年龄、区域的影响较生境的更大。 The revelation of mosses elements content and its spatiotemporal differences is the scientific foundation of moss monitoring. To determine the feasibility of moss monitoring metal depositions derived from travel bus emiss ions in scenic spot, we collected one year-growth samples of two mosses Brachythecim piligerum and Thuidium cymbifolium with different distance (island center, 120m，1000m ) and different direction (north, south and east) far from parking site island from Yuanshilin Spot at Jiuzhaigou World Nature Heritage in the Western Sichuan of China and determined thirteen element （A1, S, Ca, P, Cu, Fe, K, Mg, Mn, Pb, Ni, Zn, Cd）contents by ICP-AES analysis method. And picked 4 kinds of mosses (Macrothamnium macrocarpu m（Reinw. etHornsch.）Fleisch.，Thuidium cymbifolium，Entodon concinnus (De Not.) Par., Neckera pennata) from the direction PS-3 in 2005 and 2007, determined 13 element contents. Collected 3 kinds of moss (Thuidium cymbifo lium, Actinothuidium Hookeri (Mitt.) and Hyolcomium splendens (Hedw.) from Jiuzhaigou natural heritage, Huanglong natural heritage, Mt. Jiajin and Mt. Mengbi in primeval forest with two habitat (undergrowth and forest gap), determined element contents of A1, Ca, Cu, Fe, K, Mg, P, Zn, C and N. We found that, 1) The elements content are difference in same type of moss. Content of A1, Ca, K, Mg and P are higher than others. 2) While the contents of A1, S, Ca, P, Cu, Fe, K and Zn had significant correlation with the different distances from parking site, the nearer the distance was, the more accumulation was; 2) Comparing to Thuidium cymbifolium, Brachythecium piligerum can test more elements which contents show the significant correlation with distances. And Brachythecium piligerum can have greater element accumulation than Thuidium cymbifolium. The element contents in two years (2005 and 2007) are different. The present study found that moss can reliably bio-indicate metal deposition from traffic emissions in one scenic spot and Brachythecium piligerum is a good moss for bio-indicating element content from traffic emissions at Jiuzhaigou World natural Heritage. Determined the 10 element contents in 4 areas through 3 kinds of moss we found that, 1) Ca, Mg, Zn, K and Cu element content is higher in the Huanglong area than in other areas, The P element content in Mt. Jiajin is higher than other areas, Fe and Al element content is higher in the Mt. Jiajin than in other areas. 2) The content of C had no significant correlation with age. As for N, this significant correlation found in Hyolcomium splendens (Hedw.) with 2 habitat in Huanglong, Actinothuidium Hookeri (Mitt.) and Hyolcomium splendens (Hedw.) with undergrowth in Jiuzhai, Hyolcomium splendens (Hedw.) in Mt. Mengbi. The types of elements which content showt he significant correlation are most in Hyolcomium splendens (Hedw.) and least in Thuidium cymbifolium. Except Actinothuidium Hookeri (Mitt.), the types of elements that content had significant correlation with age in forest gap are more than in undergrowth. 3) The elements which content had significant correlation with habitat are P, Ca and Mg in Thuidium cymbifolium in Huanglong, Zn in Actinothuidium Hookeri (Mitt.) in Jiuzhai, Al, Fe and Zn in Hyolcomium splendens (Hedw.) in Mt. Jiajin, in Mt. Mengbi Al, Fe and Mg in Thuidium cymbifolium and Ca in Actinothuidium Hookeri (Mitt.). 4）The region, the age and the habitat factor has coeffect element content. The correlationship between element contents and the age, the region is closer than habitat.

Application of static and dynamic enclosures for determining dimethyl sulfide and carbonyl sulfide exchange in Sphagnum peatlands: Implications for the magnitude and direction of flux

A static enclosure method was applied to determine the exchange of dimethyl sulfide (DMS) and carbonyl sulfide (OCS) between the surface of Sphagnum peatlands and the atmosphere. Measurements were performed concurrently with dynamic (flow through) enclosure measurements with sulfur-free air used as sweep gas. This latter technique has been used to acquire the majority of available data on the exchange of S gases between the atmosphere and the continental surfaces and has been criticized because it is thought to overestimate the true flux of gases by disrupting natural S gas gradients. DMS emission rates determined by both methods were not statistically different between 4 and >400 nmol m−2 h−1, indicating that previous data on emissions of at least DMS are probably valid. However, the increase in DMS in static enclosures was not linear, indicating the potential for a negative feedback of enclosure DMS concentrations on efflux. The dynamic enclosure method measured positive OCS flux rates (emission) at all sites, while data using static enclosures indicated that OCS was consumed from the atmosphere at these same sites at rates of 3.7 to 55 nmol m−2 h−1. Measurements using both enclosure techniques at a site devoid of vegetation showed that peat was a source of both DMS and OCS. However, the rate of OCS efflux from decomposing peat was more than counterbalanced by OCS consumption by vegetation, including Sphagnum mosses, and net OCS uptake occurred at all sites. We propose that all wetlands are net sinks for OCS.

苔藓碳氮稳定同位素对环境条件和大气氮沉降的指示研究

苔藓植物由于具有特殊的形态结构和生物学性质而被广泛应用于环境变化和大气沉降的指示和监测，而稳定同位素（如13C、15N、34S）是辨识环境体系中物源走向以及研究植物和环境关系的可靠技术。本论文正是结合苔藓生物指示方法和稳定同位素示踪技术，开展了苔藓碳氮同位素指示环境条件和大气氮沉降的初步研究。通过不同环境条件下苔藓同位素的对比研究，揭示了苔藓碳氮同位素对环境因子和氮沉降变化的响应机制。进而应用石生苔藓碳氮元素含量和同位素，并结合光合色素含量等参数，对贵阳地区的大气氮沉降进行了详细研究，深化了苔藓同位素方法在环境监测和大气氮沉降研究中的应用，并为城市氮污染的防治提供了地球化学依据。获取了一些有意义的发现和创新点。 1. 不同生长条件下苔藓元素含量和同位素的变化及其意义 即使在同一地点，苔藓13C会由于水分条件和光照条件的差异而发生明显变化，而树冠对大气沉降物质的长期截留吸收会使下方苔藓氮硫含量偏低以及同位素偏负，其同位素效应还与树冠类型和树冠厚度有关。因此，应用苔藓元素含量和同位素指示区域环境和大气沉降时应尽量消除生境差异的影响，受生长条件影响或歪曲了的苔藓指示信息可能导致在解释环境变化和大气沉降时得出错误的结论，相对而言，开阔地的石生苔藓是较可靠的指示工具。利用同位素方法探讨苔藓记录信息的差异是本研究的创新点之一，目前国内外尚无相关的报道，这深化了苔藓碳氮同位素对环境条件和大气输入响应机制的认识，同时还为苔藓同位素研究大气沉降提供了采样指导。 2. 不同地区苔藓新老组织碳氮含量和同位素组成特征 贵阳市区苔藓碳含量高于贡嘎山地区，而13C明显偏负，表明城市苔藓受人为CO2排放的影响，而非污染区苔藓13C能够响应海拔和年均温度的差异。贵阳市区苔藓氮含量较高反映其氮沉降高于贡嘎山地区，明显偏负的15N值主要指示了城市废水氨释放的影响。不同地区苔藓新生组织的碳氮含量总体高于衰老组织，但同位素没有明显变化，反映了生理功能的衰退和部分元素向新生组织迁移会导致老组织碳氮含量降低，但不会明显改变其碳氮同位素记录，新组织氮含量较可靠地反映了氮沉降的水平（贵阳市约为30.18 kg/ha/yr，贡嘎山地区约为8.46 kg/ha/yr）。本研究扩展了苔藓同位素对不同地区环境因子和氮沉降差异的响应状况，并首次探讨了苔藓衰老对其碳氮含量和同位素记录的影响，为深入理解非维管植物衰老过程的碳氮同位素分馏奠定基础。 3. 贵阳地区大气氮沉降的空间分布 根据大气氮沉降和苔藓氮含量之间的定量关系（y=0.052x+0.7325），可以利用石生苔藓氮含量（0.85% ~ 2.97%）计算贵阳地区的大气氮沉降。贵阳地区的氮沉降（0.91 kg/ha/yr ~ 44.69 kg/ha/yr）总体已经超过最易受影响的陆地生态系统的氮沉降负荷值（5 kg/ha/yr ~ 10 kg/ha/yr），市区氮沉降平均值（29.21±6.17 kg/ha/yr）与前期监测值（30.18kg/ha/yr）基本一致，高于酸性针叶林和落叶林的氮沉降负荷值（15 kg/ha/yr ~ 20 kg/ha/yr）。而农村地区氮沉降平均值（14.31±5.11 kg/ha/yr）与贵州农村地区铵沉降的平均值（14.3 kg/ha/yr）吻合。本研究首次根据石生苔藓氮含量量化了氮沉降的水平和空间分布，对大气氮沉降生态环境影响的评价以及喀斯特地区脆弱生态系统的保护具有重要意义。 4. 贵阳地区大气氮沉降的主要来源和主要形态 贵阳地区石生苔藓15N值（-12.50‰ ~ -1.39‰）呈明显的双峰分布模式（-12‰ ~ -6‰和-5‰ ~ -2‰），表明该地区的氮沉降存在两个主要来源。市区明显偏负的苔藓15N值（平均-8.87±1.65‰，<5km; -8.59±2.28‰，5 km ~ 10km）主要反映城市废水和人畜排泄物NH3的影响，而往外到农村较高的苔藓15N值（平均-3.83±0.82‰ ~ -2.48±0.95‰，>15km）主要指示了农业NH3的贡献。根据市区苔藓和雨水15N值计算，市区氮沉降中铵态氮的贡献约占76%，硝态氮约为23%，贵阳地区的氮沉降以铵沉降为主。本研究首次发现了以铵沉降为主的城市地区苔藓15N值市区偏负、农村偏正的变化规律，这与氮沉降以硝态氮为主的城市苔藓15N变化（市区偏正、农村偏负）相反。此外，根据苔藓15N随大气沉降中铵态氮和硝态氮比值的变化规律，贵阳地区苔藓氮含量和15N的变化主要由两种不同铵源（城市铵和农业铵）的变化所控制，贵阳苔藓氮含量和15N的空间变化可以进一步作为铵沉降变化的证据。 5. 贵阳地区主要大气氮源（铵）的沉降机制与模式 贵阳市区往外石生苔藓氮含量随离市中心的距离呈指数降低（y=1.5e-0.13x+1.26），而15N值随距离对数升高（y=2.54Ln(x)-12.23），揭示了城市来源的铵沉降从市区往外随距离指数降低，其分布模式为点源模式，贵阳市区可被视为贵阳地区的一个点状氨源。而农村地区苔藓氮含量不随距离而变化、15N值不存在明显差异，反映了农业氨的面源分布模式。通过极限法计算苔藓氮含量和15N随距离变化的函数，氮沉降在离市中心17.2km以内以城市铵为主，以外以农业铵为主，城市铵的影响范围总体小于41km，城市铵随离市中心距离的变化关系为y=56.272e-0.116x-0.481。此外，贵阳市区往外不同方向的苔藓氮含量和15N随距离的变化梯度存在差异，表明城市铵向周边不同方向的传输具有非均一性，这主要与不同方向的地形条件、地表植被状况、风向、城市化程度等差异有关。本研究首次通过苔藓监测证实以铵沉降为主的城市，城市铵沉降的分布呈点源模式，并通过苔藓氮含量和15N的变化得出了城市铵的定量分布、沉降机制和影响因素。 6. 贵阳地区石生苔藓碳含量和13C值的变化及其意义 贵阳地区石生苔藓碳含量（34.47% ~ 52.76%）从市区到农村随距离指数降低（y=9.206e-0.042x+38.024），并与氮含量存在正相关关系，表明大气氮输入具有增加苔藓碳含量的作用。苔藓13C值（-30.69‰ ~ -26.96‰）从市区到农村随距离逐渐升高（y=0.674Ln(x)-30.03），反映了城市人为CO2的影响逐渐减小。此外，苔藓13C随碳氮含量增加而降低，碳氮同位素存在正相关关系，反映了石生苔藓光合作用与氮素吸收相互制约，市区较高的氮沉降或铵沉降增强了苔藓光合作用和碳代谢，使苔藓在固碳过程中发生更大的13C分馏。本研究首次发现了城市地区较高的氮沉降能够促进石生苔藓光合固碳能力，苔藓13C值能够指示城市人为CO2的影响以及氮沉降的生物效应。 7．其它创新之处 为深入认识城市地区氮沉降的变化及其生物响应，本研究还对石生苔藓光合色素含量进行了分析，首次探讨了石生苔藓光合生理参数和碳氮含量、碳氮同位素之间的关系。市区苔藓光合色素含量高于农村地区，叶绿素含量与碳氮含量存在正相关关系，表明光合色素分析可以反映环境胁迫状况、苔藓固碳能力和氮素营养状况。叶绿素含量与13C值呈负相关关系指示了氮沉降增强石生苔藓光合作用的机制。

Relacje między zgrupowaniami ameb skorupkowych, roślinnością i parametrami siedliskowymi torfowisk minerotroficznych Wielkopolski

Wydział Biologii: Instytut Biologii Środowiska/Zakład Hydrobiologii

Phytochrome diversity in green plants and the origin of canonical plant phytochromes.

Phytochromes are red/far-red photoreceptors that play essential roles in diverse plant morphogenetic and physiological responses to light. Despite their functional significance, phytochrome diversity and evolution across photosynthetic eukaryotes remain poorly understood. Using newly available transcriptomic and genomic data we show that canonical plant phytochromes originated in a common ancestor of streptophytes (charophyte algae and land plants). Phytochromes in charophyte algae are structurally diverse, including canonical and non-canonical forms, whereas in land plants, phytochrome structure is highly conserved. Liverworts, hornworts and Selaginella apparently possess a single phytochrome, whereas independent gene duplications occurred within mosses, lycopods, ferns and seed plants, leading to diverse phytochrome families in these clades. Surprisingly, the phytochrome portions of algal and land plant neochromes, a chimera of phytochrome and phototropin, appear to share a common origin. Our results reveal novel phytochrome clades and establish the basis for understanding phytochrome functional evolution in land plants and their algal relatives.

The origin and evolution of phototropins.

Plant phototropism, the ability to bend toward or away from light, is predominantly controlled by blue-light photoreceptors, the phototropins. Although phototropins have been well-characterized in Arabidopsis thaliana, their evolutionary history is largely unknown. In this study, we complete an in-depth survey of phototropin homologs across land plants and algae using newly available transcriptomic and genomic data. We show that phototropins originated in an ancestor of Viridiplantae (land plants + green algae). Phototropins repeatedly underwent independent duplications in most major land-plant lineages (mosses, lycophytes, ferns, and seed plants), but remained single-copy genes in liverworts and hornworts-an evolutionary pattern shared with another family of photoreceptors, the phytochromes. Following each major duplication event, the phototropins differentiated in parallel, resulting in two specialized, yet partially overlapping, functional forms that primarily mediate either low- or high-light responses. Our detailed phylogeny enables us to not only uncover new phototropin lineages, but also link our understanding of phototropin function in Arabidopsis with what is known in Adiantum and Physcomitrella (the major model organisms outside of flowering plants). We propose that the convergent functional divergences of phototropin paralogs likely contributed to the success of plants through time in adapting to habitats with diverse and heterogeneous light conditions.

Contributions to the bryological flora of the tropical and subtropical forests from the Argentina (Bryophyta, Musci).

The authors present here a list of 32 mosses belonging to 15 families: Brachytheciaceae, Cryphaeaceae, Entodontaceae, Hedwigiaceae, Hypnaceae, Leptodontaceae, Meteoriaceae, Neckeraceae, Pilotrichaceae, Polytrichaceae, Pterobryaceae, Racopilaceae, Rigodiaceae, Stereophyllaceae, and Trachypodaceae, all collected in the mountainous forests of the Yungas of the NW of the Argentina (Jujuy, Salta, Catamarca and Tucumán provinces), and also in the rainforests from the NE of the country (Misiones province). Eight species: Atrichum polycarpum, Chrysohypnum elegantulum, Pilosium chlorophyllum, Pilotrichella flexilis, Porotrichodendron lindigii, Pseudotrachypus martinicensis, Steerecleus scariosus, and Thamnobryum fasciculatum are new records for the bryologic flora from Argentina. Braunia imberbis and Squamidium brasiliense are two new records for the bryophytic flora of the Catamarca province; Porotrichodendron superbum is new for the Salta province, while Forsstroemia coronata is the first record for the Catamarca and Jujuy provinces. Aerolindigia capillacea, Braunia reflexifolia, Chryso-hypnum diminutivum, Meteorium deppei and Meteoridium remotifolium are five new citations for the Jujuy province, and Schoenobryum concavifolium is new for the bryophytic flora of the Misiones province. Many studied species occur more frequently in the Yungas than in the NE rainforests; others show separated distribution but live in both areas, the Yungas and Paranaense area, and others are more or less restricted to the Paranaense rainforest of the NE of Argentina. The taxonomy of species is updated, and comments are included on bibliographical precedents, ecology and chorology of each taxon.

Flora y vegetación briofítica de la Sierra del Relumbrar (SO de Albacete, España)

Heras-Ibáñez. J. de las, J., Ros. R. M.~ & Guerra, J. Bryophyiic flora and vegetation of ¡he Sierra del Relumbrar (SW of A/bace¡e, Spainj Lazaroa 11: 149-175 (1989). A brophytic and phytosociologic study of the Sierra del Relumbrar (SW of Albacete, Spain) is made. The caíalogue presenís 136 taxa (23 liverworts and 133 mosses). It includes 34 new [br Albacete province and 19 [br he SE ol? Spain. Bryophytic conirnunities are analysed. Sorne of ihem can be assignated to previously known associations in the Iberian Peninsula and a new one is described.

Biomonitoring of air pollutants by using lichens (Evernia prunastri) in areas between Kenitra and Mohammedia cities in Morocco.

In this study, Evernia prunastri, a lichen growing in its natural habitat in Morocco was analysed for the concentration of five heavy metals (Fe, Pb, Zn, Cu and Cr) from eleven sites between Kenitra and Mohammedia cities. The control site was Dar Essalam, an isolated area with low traffic density and dense vegetation. In the investigated areas, the concentration of heavy metals was correlated with vehicular traffic, industrial activity and urbanization. The total metal concentration was highest in Sidi Yahya, followed by Mohammedia and Bouznika. The coefficient of variation was higher for Pb and lower for Cu, Zn and Fe. The concentrations of most heavy metals in the thalli differed significantly between sites (p<0.01). Principal component analysis (PCA) revealed a significant correlation between heavy metal accumulation and atmospheric purity index. This study demonstrated also that the factors most strongly affecting the lichen flora were traffic density, the petroleum industry and paper factories in these areas. Overall, these results suggest that the index of atmospheric purity and assessment of heavy metals in lichen thalli are good indicators of the air quality at the studied sites.

Development of microsatellites for the peat moss Sphagnum capillifolium using ISSR cloning

Sphagnum mosses are major components of peat bogs but populations of many species are under threat due to habitat fragmentation resulting from the cutting of peat for fuel. We have used an intersimple sequence repeat (ISSR)-based cloning method to develop nine polymorphic nuclear microsatellites for the peat moss species Sphagnum capillifolium. Between three and seven alleles per locus were detected in a sample of 48 haploid gametophytes and levels of gene diversity ranged from 0.5391 to 0.7960. These represent the first microsatellite markers developed for this important genus and most also exhibited cross-species amplification across a range of common Sphagnum species.

A 1300-year multi-proxy, high-resolution record from a rich fen in northern Poland:Reconstructing hydrology, land use and climate change

Here we present the first high-resolution multi-proxy analysis of a rich fen in the central-eastern European lowlands. The fen is located in the young glacial landscape of the Sta{ogonek}zki river valley. We investigated the fen's development pathways, asking three main questions: (i) what was the pattern and timing of the peatland's vegetation succession, (ii) how did land use and climate affect the succession in the fen ecosystem, and (iii) to what degree does the reconstructed hydrology for this site correlate with those of other sites in the region in terms of past climate change? Several stages of fen history were determined, beginning with the lake-to-fen transition ca. AD 700. Brown mosses dominated the sampling site from this period to the present. No human impact was found to have occurred until ca. AD 1700, when the first forest cutting began. Around AD 1890 a more significant disturbance took place-this date marks the clear cutting of forests and dramatic landscape openness. Deforestation changed the hydrology and chemistry of the mire, which was revealed by a shift in local plant and testate amoebae communities. We also compared a potential climatic signal recorded in the peat profile before AD 1700 with other sites from the region. © 2013 John Wiley & Sons, Ltd.

Protestantism, Spectacle, Motherhood and Vice: Dublin's New Pleasure Gardens

In 1748, Bartholomew Mosse, a curious combination of surgeon, obstetrician and entertainment impresario, established a pleasure garden on the northern fringes of Dublin. Ostensibly designed to fund the construction of a maternity hospital to be located adjacently, Mosse’s New Pleasure Gardens became one of the premier leisure resorts in Dublin. This was to have a profound effect on the city’s urban form. Within a few years the gardens became an epicentre of speculative development as the upper classes jostled to build their houses in the vicinity. Meanwhile, the creation nearby of Sackville Mall, a wide and generous strolling ground, established a whole section of the city dedicated to haute spectacle, display and leisure. Like other pleasure gardens in the British Isles, Mosse’s venture introduced new, commodified forms of entertainment. In the colonial context of eighteenth-century Ireland, however, ‘a land only recently won and insecurely held’ (Foster, 1988) by the Protestant Anglo-Irish settler class, the production of culture and spectacle was perhaps more significant than elsewhere. Indeed, the form of Mosse’s gardens echoed the private city gardens of a key figure in the Anglo-Irish aristocracy, while the hospital itself was constructed in a style of a Palladian country house, symbol of colonial presence in the countryside. However, like other pleasure gardens, the mix of music and alcohol, the heterogeneous crowd culled from across social and gender boundaries, and a landscape punctuated with secluded corners, meant that it also acquired a dubious reputation as a haunt of louche and illicit behaviours. The curious juxtaposition between a maternity hospital and pleasure garden, therefore, begins to assume other, hitherto hidden complexities. These are borne out by a closer examination of the architecture of the hospital, the shape of its landscape and the records of its patrons and patients.