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Traits of an invasive grass conferring an early growth advantage over native grasses

Journal of Plant Ecology 2016年第6期9卷 672-681页

作者： Lara G.Reichmann Susanne Schwinning h.wayne polley Philip A.Fay Department of Integrative Biology University of Texas at AustinAustinTX 78712USA USDA-ARS Grassland Soil and Water Research Laboratory808 E Blackland RoadTempleTX 76502USA Department of Biology Texas State UniversitySan MarcosTX 78666USA

Aims Invasive species often have higher relative growth rates(RGR)than their native *** use efficiency,total leaf area and specific leaf area(SLA)are traits that may confer RGR differences between natives and invasives,but trait differences are less prominent when the invasive species belongs to the same plant functional type as the dominant native ***,we test if traits displayed soon after germination confer an early size ***,we predicted that invasive species seedlings grow faster than the natives because they lack trade-offs that more strongly constrain the growth of native *** We quantified plant morphological and physiological traits and RGR during early seedling growth at high and low nutrient levels in three dominant perennial native C_(4) grasses:Panicum virgatum L.(switchgrass),Schizachyrium scoparium(Michx.)Nash(little bluestem)and Andropogon gerardii Vitman(big bluestem);and a perennial C_(4) exotic invasive grass,Sorghum halepense(L.)Pers.(Johnsongrass).Important Findings After 2 weeks of growth,Johnsongrass seedlings had greater biomass,SLA and photosynthetic nitrogen use efficiency,but lower leaf N concentrations(%leaf N)and root:shoot ratio than *** growth continued,Johnsongrass more quickly produced larger and thicker leaves than the natives,which dampened the growth advantage past the first 2 to 3 weeks of *** in carbon gain appears to be the best explanation for the early growth advantage of *** natives,growth was constrained by an apparent trade-off between allocation to root biomass,which reduced SLA,and production of leaves with high N content,which increased carbon *** Johnsongrass,root:shoot ratio did not interact with other traits,and%leaf N was decoupled from RGR as a result of a trade-off between the positive indirect association of%leaf N with RGR and the negative direct association of%leaf N with RGR.

关键词： biomass allocation invasive plants RGR Sorghum halepense trade-offs trait development

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Productivity of well-watered Panicum virgatum does not increase with CO_(2) enrichment

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Journal of Plant Ecology 2012年第4期5卷 366-375页

作者： Philip A.Fay h.wayne polley Virginia L.Jin Michael J.Aspinwall USDA-ARS Grassland Soil and Water Research Laboratory 808 E Blackland RdTempleTX 76502USA USDA-ARS Agroecosystem Management Research 137 Keim HallUniversity of Nebraska-LincolnLincolnNE 68583USA Section of Integrative Biology 1 University StationC0930University of Texas at AustinAustinTX 78712USA

Aims Rising atmospheric CO_(2) has been shown to increase aboveground net primary productivity(ANPP)in water-limited perennial grasslands,in part by reducing stomatal conductance and transpiration,thereby reducing depletion of soil ***,the benefits of CO_(2) enrichment for ANPP will vary with soil type and may be reduced if water limitation is *** is known about CO_(2) effects on ANPP of Panicum virgatum,a perennial C4 tallgrass and potential bioenergy *** hypothesized that if water limitation is minimized,(i)CO_(2) enrichment would not increase *** ANPP because photosynthetic rates of this C4 grass would not increase and because decreased transpiration at elevated CO_(2) would provide little additional benefit in increased soil moisture and(ii)soil type will have little effect on *** CO_(2) responses because of high overall soil *** Growth and leaf physiology of *** cv.‘Alamo’were studied as plants established for 4 years on silty clay and clay soils along a 250 to 500 ll l-1 gradient in atmospheric CO_(2) located in central Texas,*** were watered to replace evapotranspiration,fertilized with NO_(3)Nh_(4) and P_(2)O_(5) and clipped to standard height during *** Findings ANPP increased through the third year of *** moisture(0–20 cm),ANPP,tiller numbers and leaf area index were 8–18%higher on the clay than on the silty clay *** did not increase with CO_(2) except in the planting ***,biomass removed with clipping strongly increased with CO_(2) in years 2 and 3,suggesting that CO_(2) enrichment increased the early-to mid-season growth of establishing *** but not later regrowth or that of fully established ***,CO_(2) enrichment differentially affected two components of ANPP in years 2 and 3,increasing tiller mass and reducing tiller *** reallocation of resources in clipped *** suggested increased meristem limitation of productivi

关键词： switchgrass bioenergy resource allocation tillering meristem limitation

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Species-specific,pan-European diameter increment models based on data of 2.3 million trees

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Forest Ecosystems 2018年第3期5卷 277-295页

作者： Mart-Jan Schelhaas Geerten M hengeveld Nanny heidema Esther Thurig Brigitte Rohner Giorgio Vacchiano Jordi Vayreda John Redmond Jaroslaw Socha Jonas Fridman Stein Tomter heino polley Susana Barreiro Gert-Jan Nabuurs Wageningen University and Research Wageningen Environmental Research(WENR)Droevendaalsesteeg 36708PB WageningenThe Netherlands Wageningen University and Research BiometrisDroevendaalsesteeg 16708PB WageningenThe Netherlands Wageningen University and Research Forest and Nature Conservation Policy GroupDroevendaalsesteeg 36708PB WageningenThe Netherlands Swiss Federal Institute for Forest Snow and Landscape Research WSLResource AnalysisZuercherstrasse 111CH-8903 BirmensdorfSwitzerland European Commission Joint Research CentreDirectorate DSustainable Resources-Bio-Economy UnitIspraItaly CREAF 08193 Cerdanyola del VallesSpain Univ Autonoma Barcelona 08193 Cerdanyola del VallesSpain Forest Service Department of AgricultureFood and the MarineJohnstown Castle EstateCo.WexfordIreland Department of Biometry and Forest Productivity Institute of Forest Resources ManagementFaculty of ForestryUniversity of Agriculture in KrakowAI.29Listopada 4631-425CracowPoland Swedish University of Agricultural Sciences (SLU) 90183 UmeaSweden Norwegian Institute of Bioeconomy Research P.O.Box 115N-143 1AsNorway Thunen Institute Institute of Forest EcosystemsAlfred-Mo1ler-Strabe 1Haus41/4216225 EberswaldeGermany Forest Research Centre (CEF) Instituto Superior de AgronomiaUniversidade de LisboaTapada da Ajuda1349-017Lisbon.Portugal Wageningen University and Research Forest Ecology and Forest Management GroupDroevendaalsesteeg 36708PBWageningenThe Netherlands

Background: Over the last decades, many forest simulators have been developed for the forests of individual European countries. The underlying growth models are usually based on national datasets of varying size, obtained from National Forest Inventories or from long-term research plots. Many of these models include country-and location-specific predictors, such as site quality indices that may aggregate climate, soil properties and topography effects. Consequently, it is not sensible to compare such models among countries, and it is often impossible to apply models outside the region or country they were developed for. however, there is a clear need for more generically applicable but still locally accurate and climate sensitive simulators at the European scale, which requires the development of models that are applicable across the European continent. The purpose of this study is to develop tree diameter increment models that are applicable at the European scale, but still locally accurate. We compiled and used a dataset of diameter increment observations of over 2.3 million trees from 10 National Forest Inventories in Europe and a set of 99 potential explanatory variables covering forest structure, weather, climate, soil and nutrient ***: Diameter increment models are presented for 20 species/species groups. Selection of explanatory variables was done using a combination of forward and backward selection methods. The explained variance ranged from10% to 53% depending on the species. Variables related to forest structure(basal area of the stand and relative size of the tree) contributed most to the explained variance, but environmental variables were important to account for spatial patterns. The type of environmental variables included differed greatly among ***: The presented diameter increment models are the first of their kind that are applicable at the European scale. This is an important step towards the development of a new ge

关键词： European forests Diameter increment model Climate change Growth modelling National forest inventory

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对避免产科硬膜外麻醉时导管误入静脉的策略的评估——一项对随机对照性研究的系统综述

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麻醉与镇痛 2010年第4期6卷 1-13页

作者： Jill M. Mhyre Mary Lou V. h. Greenfield Lawrence C. Tsen Linda S. polley 张晓怡(译) 杭燕南(校) Department of Anesthesiology Ann Arbor Michigan of Anesthesiology Perioperative and Pain Medicine Hospital Harvard Medical School Boston Massachusetts Department Brigham and Women's The University of Michigan health System Ann Arbor Michigan of Anesthesiology Perioperative and Pain Medicine Hospital Harvard Medical School Boston Massachusetts 不详

背景我们在本综述中对产妇腰段硬膜外麻醉时导管放置，以降低其误入静脉风险的7种策略进行了系统回顾。方法我们在多个数据库中搜索了从1966年12月至2007年10月期间，关于评价避免产妇腰段硬膜外导管置管误入静脉方法的所有前瞻性、随... 详细信息

背景我们在本综述中对产妇腰段硬膜外麻醉时导管放置，以降低其误入静脉风险的7种策略进行了系统回顾。方法我们在多个数据库中搜索了从1966年12月至2007年10月期间，关于评价避免产妇腰段硬膜外导管置管误入静脉方法的所有前瞻性、随机对照试验。对于已经发表的研究采用质量评估工具进行评价，并且通过研究结果的合并来考察这些预防误入硬膜外静脉方法的有效性。结果在检索90项研究后，有30项试验（n=12738例）被选入。5种策略能有效防止硬膜外导管误入静脉丛：操作时采取侧卧位而不是坐位[6项试验，质量评分为35％（标准差11％），比值比为0．53（95％置信区间为0．32～0．86）]；在置管前通过穿刺针预注入液体[8项试验，质量评分为48％（标准差18％），比值比为0．49（95％置信区间为0．25—0．97）]；使用单孔而非多孔导管[5项试验，质量评分为30％（标准差6％），比值比为0．64（95％置信区间为0．45—0．91）]；使用有金属线包埋的聚氨酯导管而不是聚酰胺导管[1项试验，质量评分为31％，另加4篇未评分的摘要，比值比为0．14（95％置信区间为0．06—0．30）]；导管置入深度≤6cm[2项试验，质量评分为47％（标准差11％），比值比为0．27（95％置信区间为0．10—0．74）]。而采用旁正中法进针和更细的穿刺针及导管型号都不能降低置管误入静脉的风险。结论可以通过患者的侧卧体位、椎管内预注液体、单孔导管、包埋金属的聚氨酯导管，以及置管深度≤6cm等方法来降低产科腰段硬膜外麻醉置管中导管误入静脉的风险。总之，低质量的研究文章削弱了上述结论的可靠性。

关键词：腰段硬膜外麻醉随机对照试验硬膜外静脉导管误入系统综述评估工具产科质量评分

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小鼠神经再生的检测(下)(英文)

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河南大学学报（医学版） 2013年第2期32卷 77-83页

作者：潘宝晗约翰W.格里芬迈克A.波里保罗N.霍夫曼默汗默德h.法拉约翰霍普金斯医学院神经科美国马里兰州巴尔的摩21205 约翰霍普金斯医学院神经科学系美国马里兰州巴尔的摩21205 约翰霍普金斯医学院病理科美国马里兰州巴尔的摩21205 约翰霍普金斯医学院眼科美国马里兰州巴尔的摩21205

神经系统疾病是人类疾病最复杂的一大类。由于神经系统的特殊发育和组织构造,从神经科学的基础科研到临床诊断治疗都极为困难。神经再生和神经退行性病变的研究是当代科学研究的最热门领域之一,但是实验研究进展缓慢,尤其是可转化为临... 详细信息

神经系统疾病是人类疾病最复杂的一大类。由于神经系统的特殊发育和组织构造,从神经科学的基础科研到临床诊断治疗都极为困难。神经再生和神经退行性病变的研究是当代科学研究的最热门领域之一,但是实验研究进展缓慢,尤其是可转化为临床应用的知识更少。主要原因之一是我们一直缺乏直观易行的动物模型。我们课题组的努力方向之一是开发新的实验模型。最近几年我们已经取得了很多新进展,先将有关内容总结如下。

关键词：胸外侧神经皮大肌皮感觉神经神经再生神经变性神经即溶接头

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小鼠神经再生的检测(上)(英文)

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河南大学学报（医学版） 2013年第1期32卷 1-10页

神经系统疾病是人类疾病最复杂的一大类。由于神经系统的特殊发育和组织构造,从神经科学的基础科研到临床诊断治疗都极为困难。神经再生和神经退行性病变的研究是当代科学研究的最热门领域之一,但是试验研究进展缓慢,尤其是可转化为临... 详细信息

神经系统疾病是人类疾病最复杂的一大类。由于神经系统的特殊发育和组织构造,从神经科学的基础科研到临床诊断治疗都极为困难。神经再生和神经退行性病变的研究是当代科学研究的最热门领域之一,但是试验研究进展缓慢,尤其是可转化为临床应用的知识更少。主要原因之一是我们一直缺乏直观易行的动物模型。我们课题组的努力方向之一是开发新的试验模型。最近几年我们已经取得了很多新进展,先将有关内容总结如下。

关键词：胸外侧神经皮大肌皮感觉神经神经再生神经变性神经即溶接头

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