Ecology and management of kermes oak (Quercus coccifera L.) shrublands in Greece: A review

Kermes oak (Quercus coccifera L.) shrublands occupy more than 0.4 million ha in Greece and are the typical browse rangelands for 4.5 million goats. Five "range types" of kermes oak were identified based on morphological differences. Clipping of kermes oak improves growth rate of twig length, increases the production of new twigs, and alters the nutritive value of browse. Kermes oak can withstand very heavy (100%) clipping of twigs for 2 consecutive years, yielding the highest growth rate and twig number. Browse production varies among different forms of kermes oak shrublands. The low form (0.5-0.8 m height) yielded the highest production (3,467 kg ha-1). Goat liveweight gain of tall form (2 m height) of kermes oak shrubland was 25 kg ha-1 yr-1; improved shrublands, by topping, produced double liveweight gain when their form was altered. Liveweight gain was almost quadrupled when kermes oak shrublands were converted to grasslands.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Efectos de la frecuencia de defoliación en la producción y el valor nutritivo de forraje de invierno de diferentes entradas de Agropyron cristatum (L.) Gaertn

The objective of this study was to evaluate the effect of different defoliation frequencies on winter forage production and nutritive value of improved population of Agropyron cristatum (L.) Gaertn. Four entries, a) base population, b) selected plants from mass honeycomb selection (MHS), c) selected plants from pedigree honeycomb selection (PHS) and d) selected plants from pedigree honeycomb selection using the combined criterion CC = x¯2 (1 – CV) / CV [PHS (CC)] were tested under four defoliation frequencies: 1) frequent, 2) moderate, 3) infrequent and 4) control. Dry matter production under moderate defoliation treatment was 9% and 107% respectively higher than frequent and infrequent the first harvest year, while the second harvest year the corresponding percentages were 26% and 44%. The selected populations of A. cristatum consistently exceeded in herbage production the base population under all defoliation treatments during winter. Among the selected entries, [PHS (CC)] had consistently higher DM production compared to MHS and PHS for the two experimental years. The CP content was significantly higher, while NDF, ADF and ADL contents were lower in the increased defoliation frequency compared to the control in both harvest years. There were no significant differences of the nutritive value among the entries (P > 0.05). Generally, herbage production of the moderate defoliation frequency was more stable through the years with relatively high nutritive value.El objetivo de este estudio fue evaluar el efecto de diferentes frecuencias de defoliación sobre la producción y el valor nutritivo de poblaciones mejoradas de Agropyron cristatum (L.) Gaertn. Se examinaron cuatro entradas: a) población base y plantas seleccionadas mediante b) selección masal en diseño «panal de abejas» (MHS), c) selección pedigree en diseño «panal de abejas» (PHS) y d) selección pedigree en diseño «panal de abejas» usando el criterio combinado CC= x¯2 (1 CV) / CV [PHS (CC)] bajo cuatro frecuencias de defoliación: 1) frecuente, 2) moderada, 3) infrecuente y 4) control. La producción de materia seca (MS) en el tratamiento de defoliación moderada fue un 9% y un 107% respectivamente más alta que en frecuente e infrecuente durante el primer año de recolección, mientras que durante el segundo año, los porcentajes correspondientes fueron 26% y 44%. Las poblaciones seleccionadas de A. cristatum sistemáticamente excedieron la producción de hierba de la población base en todos los tratamientos de defoliación durante el invierno. Entre las entradas seleccionadas, [PHS (CC)] presentó sistemáticamente una mayor producción de MS comparada con MHS y PHS en los dos años experimentales. El contenido de PB fue significativamente más alto, mientras que los de FND, FAD y LAD fueron más bajos en la frecuencia aumentada de defoliación comparada con el control, en ambos años de recolección. No hubo diferencias significativas en el valor nutritivo entre las entradas (P>0,05). En general, la producción de hierba en la frecuencia de defoliación moderada fue más estable a lo largo de los años, con un valor nutritivo más alto

Defoliation frequency effects on winter forage production and nutritive value of different entries of Agropyron cristatum (L.) Gaertn

Abstract The objective of this study was to evaluate the effect of different defoliation frequencies on winter forage production and nutritive value of improved population of Agropyron cristatum (L.) Gaertn. Four entries, a) base population, b) selected plants from mass honeycomb selection (MHS), c) selected plants from pedigree honeycomb selection (PHS) and d) selected plants from pedigree honeycomb selection using the combined criterion CC = x 2 (1 -CV) / CV [PHS (CC)] were tested under four defoliation frequencies: 1) frequent, 2) moderate, 3) infrequent and 4) control. Dry matter production under moderate defoliation treatment was 9% and 107% respectively higher than frequent and infrequent the first harvest year, while the second harvest year the corresponding percentages were 26% and 44%. The selected populations of A. cristatum consistently exceeded in herbage production the base population under all defoliation treatments during winter. Among the selected entries, [PHS (CC)] had consistently higher DM production compared to MHS and PHS for the two experimental years. The CP content was significantly higher, while NDF, ADF and ADL contents were lower in the increased defoliation frequency compared to the control in both harvest years. There were no significant differences of the nutritive value among the entries (P > 0.05). Generally, herbage production of the moderate defoliation frequency was more stable through the years with relatively high nutritive value. Additional key words: cool-season grasses, cutting frequencies, forage quality, sward management. Resumen Efectos de la frecuencia de defoliación en la producción y el valor nutritivo de forraje de invierno de diferentes entradas de Agropyron cristatum (L.) Gaertn El objetivo de este estudio fue evaluar el efecto de diferentes frecuencias de defoliación sobre la producción y el valor nutritivo de poblaciones mejoradas de Agropyron cristatum (L.) Gaertn. Se examinaron cuatro entradas: a) población base y plantas seleccionadas mediante b) selección masal en diseño «panal de abejas» (MHS), c) selección pedigree en diseño «panal de abejas» (PHS) y d) selección pedigree en diseño «panal de abejas» usando el criterio combinado CC = x 2 (1 -CV) / CV [PHS (CC)] bajo cuatro frecuencias de defoliación: 1) frecuente, 2) moderada, 3) infrecuente y 4) control. La producción de materia seca (MS) en el tratamiento de defoliación moderada fue un 9% y un 107% respectivamente más alta que en frecuente e infrecuente durante el primer año de recolección, mientras que durante el segundo año, los porcentajes correspondientes fueron 26% y 44%. Las poblaciones seleccionadas de A. cristatum sistemáticamente excedieron la producción de hierba de la población base en todos los tratamientos de defoliación durante el invierno. Entre las entradas seleccionadas, [PHS (CC)] presentó sistemáticamente una mayor producción de MS comparada con MHS y PHS en los dos años experimentales. El contenido de PB fue significativamente más alto, mientras que los de FND, FAD y LAD fueron más bajos en la frecuencia aumentada de defoliación comparada con el control, en ambos años de recolección. No hubo diferencias significativas en el valor nutritivo entre las entradas (P>0,05). En general, la producción de hierba en la frecuencia de defoliación moderada fue más estable a lo largo de los años, con un valor nutritivo más alto. Palabras clave adicionales: calidad del forraje, frecuencia de corte, herbáceas de climas templados, manejo de praderas

New Electrode and Electrolyte Configurations for Lithium-Oxygen Battery

Cathode configurations reported herein are alternative to the most diffused ones for application in lithium-oxygen batteries, using an ionic liquid-based electrolyte. The electrodes employ high surface area conductive carbon as the reaction host, and polytetrafluoroethylene as the binding agent to enhance the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) reversibility. Roll-pressed, self-standing electrodes (SSEs) and thinner, spray deposited electrodes (SDEs) are characterized in lithium-oxygen cells using an ionic liquid (IL) based electrolyte formed by mixing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt and N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl)imide (DEMETFSI). The electrochemical results reveal reversible reactions for both electrode configurations, but improved electrochemical performance for the self-standing electrodes in lithium-oxygen cells. These electrodes show charge/discharge polarizations at 60 °C limited to 0.4 V, with capacity up to 1 mAh cm−2 and energy efficiency of about 88 %, while the spray deposited electrodes reveal, under the same conditions, a polarization of 0.6 V and energy efficiency of 80 %. The roll pressed electrode combined with the DEMETFSI-LiTFSI electrolyte and a composite LixSn-C alloy anode forms a full Li-ion oxygen cell showing extremely limited polarization, and remarkable energy efficiency

A Long-Life Lithium Ion Battery with Enhanced Electrode/Electrolyte Interface by Using an Ionic Liquid Solution

In this paper, we report an advanced long-life lithium ion battery, employing a Pyr14TFSI-LiTFSI non-flammable ionic liquid (IL) electrolyte, a nanostructured tin carbon (Sn-C) nanocomposite anode, and a layered LiNi1/3Co1/3Mn1/3O2 (NMC) cathode. The IL-based electrolyte is characterized in terms of conductivity and viscosity at various temperatures, revealing a Vogel-Tammann-Fulcher (VTF) trend. Lithium half-cells employing the Sn-C anode and NMC cathode in the Pyr14TFSI-LiTFSI electrolyte are investigated by galvanostatic cycling at various temperatures, demonstrating the full compatibility of the electrolyte with the selected electrode materials. The NMC and Sn-C electrodes are combined into a cathode-limited full cell, which is subjected to prolonged cycling at 40 °C, revealing a very stable capacity of about 140 mAh g-1 and retention above 99 % over 400 cycles. The electrode/electrolyte interface is further characterized through a combination of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) investigations upon cell cycling. The remarkable performances reported here definitively indicate that IL-based lithium ion cells are suitable batteries for application in electric vehicles

Low-Polarization Lithium–Oxygen Battery Using [DEME][TFSI] Ionic Liquid Electrolyte

The room-temperature molten salt mixture of N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium bis(trifluoromethanesulfonyl) imide ([DEME][TFSI]) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is herein reported as electrolyte for application in Li–O2 batteries. The [DEME][TFSI]–LiTFSI solution is studied in terms of ionic conductivity, viscosity, electrochemical stability, and compatibility with lithium metal at 30 °C, 40 °C, and 60 °C. The electrolyte shows suitable properties for application in Li–O2 battery, allowing a reversible, low-polarization discharge–charge performance with a capacity of about 13 Ah g-1carbon in the positive electrode and coulombic efficiency approaching 100 %. The reversibility of the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) is demonstrated by ex situ XRD and SEM studies. Furthermore, the study of the cycling behavior of the Li–O2 cell using the [DEME][TFSI]-LiTFSI electrolyte at increasing temperatures (from 30 to 60 °C) evidences enhanced energy efficiency together with morphology changes of the deposited species at the working electrode. In addition, the use of carbon-coated Zn0.9Fe0.1O (TMO-C) lithium-conversion anode in an ionic-liquid-based Li-ion/oxygen configuration is preliminarily demonstrated

Ionic Liquid Electrolyte for Lithium Oxygen and Lithium Ion Oxygen Cell

The replacement of the combustion-engine by sustainable electric or hybrid vehicles, may effectively limit environmental issues such as the global warming greenhouse-gas emission and pollution [1-2]. Lithium-ion battery represents the most promising candidate due to its high energy density, conventionally of about 180 Wh kg-1 that may assure a driving range of 150 km by single charge, i.e. acceptable value, however far from that granted by the conventional combustion engine vehicles. The lithium oxygen system, can theoretically allow to obtain an energy density of 1000 Wh kg-1, i.e. a value that may increase the driving range by single charge [3]. The applicability of the lithium air batteries is limited by several drawbacks, such as the poor electrolyte stability, the short cycle life and the low energy efficiency due to high charge-discharge polarization [4]. A deep knowledge of the lithium-oxygen reaction mechanism [5] and the identification of a stable electrolyte [6] play important role fundamental in allowing the practical application of the system. Furthermore, the safety concerns associated to the reactivity of the lithium metal anode are still hindering the application of the lithium-oxygen battery [7]. We report a Li/O2 cell exploiting an ionic liquid(IL)-based, N-Methyl-N-Butyl-Pyrrolidinium Bis-(trifluoromethanesulfonyl)-Imide Lithium bis-(trifluormethanesulfonyl)-imide, Pyr14TFSI-LiTFSI electrolyte. The use of non-flammable IL-based electrolyte stable up to a 300-400 °C resulted in an improved safety level of the battery [8]. In addition, the ionic-liquid electrolyte allows a fast kinetics of the lithium oxygen electrochemical process, thus lead to an high energy efficiency. The results here obtained, and reported in summary in the figure evidence low cell polarization, most likely due to the reduced particle size of the discharged products [9]. The replacement of the reactive lithium metal by an alternative, safe anode material may be required to further enhance the lithium oxygen cell characteristics [10]. Herein, we employed an alternative, nanostructured tin-carbon composite instead of lithium metal, in lithium ion-oxygen cell characterized in terms of electrochemical properties, focusing particular attention to the study of the oxygen cross-over process

An advanced lithium-air battery exploiting an ionic liquid-based electrolyte

A novel lithium-oxygen battery exploiting PYR14TFSI-LiTFSI as ionic liquid-based electrolyte medium is reported. The Li/PYR14TFSI-LiTFSI/O2 battery was fully characterized by electrochemical impedance spectroscopy, capacity-limited cycling, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The results of this extensive study demonstrate that this new Li/O2 cell is characterized by a stable electrode-electrolyte interface and a highly reversible charge-discharge cycling behavior. Most remarkably, the charge process (oxygen oxidation reaction) is characterized by a very low overvoltage, enhancing the energy efficiency to 82%, thus, addressing one of the most critical issues preventing the practical application of lithium-oxygen batteries