Grasslands in ‘Old World’ and ‘New World’ Mediterranean‐climate zones: past trends,current status and future research priorities          下载免费PDF全文

C. Porqueddu  S. Ates  M. Louhaichi  A. P. Kyriazopoulos  G. Moreno  A. del Pozo  C. Ovalle  M. A. Ewing  P. G. H. Nichols 《Grass and Forage Science》2016,71(1):1-35

Despite their ecological, economic and social importance, grasslands in areas with Mediterranean climates continue to receive limited scientific, political and media attention. The main objectives of this review are to compare and contrast dryland grasslands in the ‘Old World’ regions of the Mediterranean basin (southern Europe, western Asia and North Africa) with those of ‘New World’ regions with Mediterranean climates (Australia and Chile) and to identify common research priorities. The common characteristics and differences in climate, soils, native vegetation, importance of the livestock sector and the socio‐economic background for the different Mediterranean environments are examined. Past trends and the current status of temporary and permanent Mediterranean grasslands are also described. Some common issues between these regions are as follows: (i) adaptation to climate change; (ii) increasing persistence and drought survival of both annual and perennial species; (iii) the important role of forage legumes; (iv) maintaining grassland plant diversity; and (v) improved ecosystem services, such as carbon sequestration, control of soil erosion and wildfires, and preservation of both wild and domestic biodiversity. The favourable climate in these regions, which allows year‐round grazing and the growth of legumes, should be exploited to improve the sustainability of grassland‐based, extensive farming systems and the quality of their animal products, while at the same time improving ecosystem services. The decreasing support for grassland research and development programmes requires increased international scientific and technical cooperation among the few institutions operating in the different Mediterranean‐climate areas of the World to provide innovative and sustainable solutions to farmers.  相似文献   

Testing the applicability of BIOME-BGC to simulate beech gross primary production in Europe using a new continental weather dataset     

Marta Chiesi  Gherardo Chirici  Marco Marchetti  Hubert Hasenauer  Adam Moreno  Alexander Knohl  Giorgio Matteucci  Kim Pilegaard  André Granier  Bernard Longdoz  Fabio Maselli 《Annals of Forest Science》2016,73(3):713-727

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Assessment of Anthropogenic Impacts on the Water Quality of Marreco River,Brazil, Based on Principal Component Analysis and Toxicological Assays     

Soraya Moreno Palácio  Fernando Rodolfo Espinoza-Quiñones  Aline Roberta de Pauli  Pitágoras Augusto Piana  Caroline Bressan Queiroz  Simony Camila Fabris  Márcia Regina Fagundes-Klen  Márcia Teresinha Veit 《Water, air, and soil pollution》2016,227(9):307

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Microhabitat effects on herbaceous nutrient concentrations at the community and species level in Mediterranean open woodlands: the role of species composition          下载免费PDF全文

V. Rolo  D. Rivest  M. L. López-Díaz  G. Moreno 《Grass and Forage Science》2015,70(2):219-228

The presence of a woody canopy in open oak woodlands affects not only the nutrition but also the species composition of the herbaceous community. Yet, the contribution of both effects (changes in nutrient concentrations and species composition) to total resources that are captured by the herbaceous community is not well understood. We assessed the mineral nutrition (N, P, K and Ca) of three herbaceous species and the herbaceous community as well as the species composition in contrasting microhabitats (beneath trees, beneath a leguminous shrub and in open spaces). Both trees and shrubs increased the nutrient concentrations of the herbaceous species that were studied, except for Taraxacum officinale. Their effects were less consistent when the entire community was considered and depended upon the nutrient being analysed. Species richness and N, P and K concentrations were positively associated, suggesting that more nutrients are captured by the herbaceous community as diversity increases. Our results suggest a close relationship between species composition and nutritional value at the community level that may explain the discrepancies observed between both levels of analysis (species vs. community). Thus, farm-level strategies based on the whole herbaceous community may overlook processes operating at the species level, which can be relevant to achieve sustainable management.  相似文献   

Ambient TSP concentration and dustfall variation in Urumqi,China     

XiaoXiao ZHANG  ;XiCHEN  ;YuHong GUO  ;ZiFa WANG  ;LianYou LIU  ;Cottle PAUL  ;ShengYu LI  ;HuaWei PI 《干旱区科学》2014,(6):668-677

Total suspended particulate(TSP, particle diameter≤100 μm) was the dominant air pollutant and significantly influenced local air quality. In this paper, we investigated the interannual and seasonal variations of TSP and dustfall of the atmosphere over Urumqi, the capital city of Xinjiang Uygur autonomous region, northwestern China, basing on environmental monitoring records and meteorological data from 1986–2012. The results showed that during the study period, annual average TSP concentration decreased from 716 to 260 μg/m3, with an average level of 422.9 μg/m3, while dustfall intensity reduced from 350.4 to 166.6 t/(km2?a), with an average level of 259 t/(km2?a). Over 50% of the annual pollution days were induced mainly by TSP. Spring and winter had relatively higher dustfall intensities, and dense traffic and residential areas had the highest dustfall intensities in the Urumqi metropolitan area. With an annual average precipitation of less than 300 mm, atmospheric particulates in Urumqi could be hardly removed through wet deposition. During spring and summertime prevailing winds from northwest and northeast could carry aeolian dust particles from sandy deserts to Urumqi. Aeolian dusts from deserts would remain to be a priority regarding air pollution control in arid oasis cities.  相似文献   

Conservation tillage: Short- and long-term effects on soil carbon fractions and enzymatic activities under Mediterranean conditions   总被引：2，自引：0，他引：2  

Sebastiana Melero  Rosa Lpez-Garrido  Jos Manuel Murillo  Flix Moreno 《Soil & Tillage Research》2009,104(2):292-298

Short- and long-term field experiments are necessary to provide important information about how soil carbon sequestration is affected by soil tillage system; such systems can also be useful for developing sustainable crop production systems. In this study, we evaluated the short- and long-term effects of conservation tillage (CT) on soil organic carbon fractions and biological properties in a sandy clay loam soil. Both trials consisted of rainfed crop rotation systems (cereal–sunflower–legumes) located in semi-arid SW Spain. In both trials, results were compared to those obtained using traditional tillage (TT). Soil samples were taken in flowering and after harvesting of a pea crop and collected at three depths (0–5, 5–10 and 10–20 cm). The soil organic carbon fractions were measured by the determination of total organic carbon (TOC), active carbon (AC) and water soluble carbon (WSC). Biological status was evaluated by the measurement of soil microbial biomass carbon (MBC) and enzymatic activities [dehydrogenase activity (DHA), o-diphenol oxidase activity (DphOx), and β-glucosidase activity (β-glu)].The contents of AC and MBC in the long-term trial and contents of AC in the short-term trial were higher for CT than TT at 0–5 cm depth for both sampling periods. Furthermore, DHA and β-glucosidase values in the July sampling were higher in the topsoil under conservation management in both trials (short- and long-term). The parameters studied tended to decrease as depth increased for both tillage system (TT and CT) and in both trials with the exception of the DphOx values, which tended to be higher at deeper layers.Values of DHA and β-glu presented high correlation coefficients (r from 0.338 to 0.751, p ≤ 0.01) with AC, WSC and TOC values in the long-term trial. However, there was no correlation between either TOC or MBC and the other parameters in the short-term trial. In general, only stratification ratios of AC were higher in CT than in TT in both trials. The results of this study showed that AC content was the most sensitive and reliable indicator for assessing the impact of different soil management on soil quality in the two experiments (short- and long-term).Conservation management in dryland farming systems improved the quality of soil under our conditions, especially at the surface layers, by enhancing its storage of organic matter and its biological properties, mainly to long-term.  相似文献   

骨骼肌电穿孔转基因技术研究进展     

皮文辉  宋志强  姬勇  刘守仁 《中国畜牧兽医》2009,36(12):187-191

目前,在大动物模型试验中,骨骼肌电穿孔转基因技术已被广泛用于转染一些功能基因,并能显著提高非病毒载体基因的转染效率。笔者就电穿孔促进基因通过细胞膜的可能机理及影响骨骼肌电穿孔转基因效率的关键因素（如物种、细胞直径、场强、脉冲参数、电极和电脉冲仪等）进行了综述。  相似文献   

抗菌肽饲料添加剂对小鼠巨噬细胞吞噬功能的影响   总被引：3，自引：0，他引：3  

王凯  罗杰东  周洪波  皮灿辉  彭永鹤  苏向东  李永新 《动物医学进展》2009,30(5)

对试验小鼠饲喂1‰和3‰抗菌肽饲料添加剂,鸡红细胞吞噬试验检测小鼠腹腔巨噬细胞吞噬功能,研究抗菌肽饲料添加剂对小鼠免疫功能的影响.结果表明,抗菌肽饲料添加剂可以显著提高小鼠腹腔巨噬细胞吞噬鸡红细胞的吞噬率和吞噬指数,增强小鼠非特异性免疫功能.  相似文献   

The horizontal barrier effect of stems on the foraging behaviour of cattle grazing five tropical grasses     

Marcelo A. Benvenutti  Iain J. Gordon  Dennis P. Poppi  Robert Crowther  Warwick Spinks  Fabiana C. Moreno   《Livestock Science》2009,126(1-3):229-238

The rate of nutrient intake (RNI) is a primary determinant of animal performance in grazing cattle and depends on both diet quality and instantaneous intake rate (IIR). In turn, diet quality and IIR are a function of the foraging behaviour of the animal (selectivity, bite mass and bite rate) and the characteristics of the sward. In this study we evaluated the effect of the stem density and the tensile resistance of stems on the foraging behaviour of cattle grazing tropical pasture species. The methodology involved the use of small sown microswards offered to tethered cattle. The experiment consisted of a factorial combination of five tropical grasses [Bothriochloa pertusa (Bp), Chloris barbata (Cb), Chloris gayana (Cg), Cynodon dactylon (Cd) and Heteropogon contortus (Hc)] and three stem densities (0, 400 and 800 stems m^− 2). Bp and Cd had stems of significantly lower tensile resistance (19 and 15 N respectively) (Group 1) than those of Cb, Cg and Hc (110, 211 and 167 N respectively) (Group 2). The steers avoided stems of Group 2 and thus, reduced bite area, bite mass, IIR and RNI as stem density increased. However, the animals did not avoid stems of Group 1 and there was no effect of stem density on any of the foraging behaviour variables when cattle grazed species in Group 1. These results confirm that RNI and plant part selection is closely associated with the tensile resistance of the stem.  相似文献   

Organic‐carbon fractions in an agricultural topsoil assessed by the determination of the soil mineral surface area     

Jean‐Marie Séquaris  Gregorio Guisado  Maria Magarinos  Carlos Moreno  Peter Burauel  Hans‐Dieter Narres  Harry Vereecken 《植物养料与土壤学杂志》2010,173(5):699-705

According to recent conceptual models, the organic carbon (OC) of soils can be divided into OC fractions of increasing stability from labile free OC to resistant OC associated with the soil mineral phase. In this study, we present a method for quantifying two OC fractions based on soil aggregate–size fractionation and the N₂ gas–adsorption method. For this purpose, we analyzed soil material of the plow layer of a Haplic Chernozem subjected to different fertilizer treatments (no fertilizer, mineral fertilizer, mineral and organic fertilizer). The total organic‐C concentration (TOC) and the clay content of the different size fractions were determined as well as the specific surface area (SSA_mineral) and the sample pore volume after thermal oxidation (OC‐free). The TOC of the different soil‐aggregate fractions was linearly related to SSA_mineral. Clay‐associated OC and nonassociated OC fractions of the different soil samples were quantified using two methods based on the OC surface loading at the clay fraction. The application of organic fertilizer increased the amount of nonassociated OC but hardly affected the concentration of clay‐associated OC. This finding agrees with previous studies on C dynamics in soils and indicates a finite capacity of soil materials to sequester OC. Even without any addition of organic fertilizer, the mineral phase of the analyzed soil material appears to be C‐saturated.  相似文献