Litter decomposition in Mediterranean ecosystems: Modelling the controlling role of climatic conditions and litter quality

2011 ◽  
Vol 49 ◽  
pp. 148-157 ◽  
Author(s):  
Guido Incerti ◽  
Giuliano Bonanomi ◽  
Francesco Giannino ◽  
Flora Angela Rutigliano ◽  
Daniela Piermatteo ◽  
...  
2007 ◽  
Vol 13 ◽  
pp. 103-105
Author(s):  
T. Osono

Fungal endophytes of grasses affect ecosystem processes through mutualistic interactions with host plants, but how grass endophytes affect litter decomposition remains unclear. In this study, previously published data on litter quality and decomposition of grasses are summarised and effects of fungal endophytes of grasses on litter quality and decomposition are reviewed to discuss possible roles of endophytes in decomposition. Aboveground litters of grasses have relatively low nitrogen (N) and lignin contents and show slow increase of N and lignin contents during decomposition. Endophyte-infected litter have slightly lower N contents than non-infected litter, but the differences so far reported were not statistically significant. A negative effect of grass endophytes on litter decomposition rates was demonstrated, but the effect of endophyte infection on decomposition was not as strong as the effects of other biological and environmental factors. This suggests that grass endophytes have a relatively minor effect of on litter quality and decomposition, but more studies are necessary to verify this tentative conclusion. Keywords: decomposition, lignin, litter, nitrogen


2016 ◽  
Author(s):  
E.F. Leifheit ◽  
M.C. Rillig

AbstractArbuscular mycorrhizal fungi (AMF) have been shown to positively and negatively affect plant litter decomposition. The use of litter types with different quality and different observation periods might be responsible for these contradictory results. Therefore, we performed a 10-week laboratory experiment with 7 litter types differing in their C:N ratio, and tested for effects of litter quality and the presence of AMF on litter decomposition. We found that decomposition of plant litter with higher C:N ratios was only beginning and was stimulated by AMF, whereas decomposition of plant litter with lower C:N ratios had already progressed and was decreased by AMF. With this study we show that not only litter quality is important for effects of AMF on litter decomposition, but also the stage of litter decomposition.


Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Cristina Mihaescu ◽  
Daniel Dunea ◽  
Adrian Gheorghe Bășa ◽  
Loredana Neagu Frasin

Phomopsis juglandina (Sacc.) Höhn., which is the conidial state of Diaporthe juglandina (Fuckel) Nitschke, and the main pathogen causing the dieback of branches and twigs of walnut was recently detected in many orchards from Romania. The symptomatological, morphological, ultrastructural, and cultural characteristics, as well as the pathogenicity of an isolate of this lignicolous fungus, were described and illustrated. The optimum periods for infection, under the conditions prevailing in Southern Romania, mainly occur in the spring (April) and autumn months (late September-beginning of October). Strong inverse correlations (p < 0.001) were found between potential evapotranspiration and lesion lengths on walnut branches in 2019. The pathogen forms two types of phialospores: alpha and beta; the role of beta phialospores is not well known in pathogenesis. In Vitro, the optimal growth temperature of mycelial hyphae was in the range of 22–26 °C, and the optimal pH is 4.4–7. This pathogen should be monitored continuously due to its potential for damaging infestations of intensive plantations.


2016 ◽  
Vol 135 (5) ◽  
pp. 849-856 ◽  
Author(s):  
Michiru Kasahara ◽  
Saori Fujii ◽  
Toko Tanikawa ◽  
Akira S. Mori

PEDIATRICS ◽  
1963 ◽  
Vol 31 (6) ◽  
pp. 909-918
Author(s):  
Nathan B. Talbot

WHILE MEDICAL HISTORIANS cannot provide us with accurate statistics concerning the incidence of rickets and scurvy in centuries past, they leave little room for doubt about the high prevalence of these disorders prior to the advent of modern scientific medicine. Thus, Castiglione has written that in the sixteenth century scurvy raged throughout northern Europe, in Scandinavia, on the shores of the Baltic, and in the interior of Germany. It is interesting to note, however, that Jacques Cartier, whose sailors had been ravaged by scurvy, learned in 1536 from the Indians that the malady could be cured by juices of the almeda tree. This was 200 years before James Lind demonstrated the curative effects of lemon juice in his treatise on scurvy published in 1753 and almost 400 years before ascorbic acid, which was isolated by Szent-Gyorgi in 1928, was recognized to be vitamin C by Waugh and King in 1932. Rickets, likewise, was occurring in a large portion of children prior to the discovery of the existence of vitamin D by Hess, Steinbock, and Windaus in 1918, of its therapeutic value by Mellanby in 1919, of the equivalent role of sunlight by Hess in 1921, and of the chemical composition of the vitamins by Windaus in 1922. But 200 years earlier Friedrick Hoffman had the answer to the control of this disease almost in hand. He attached much importance to climatic conditions as a factor in rickets, noting that if anything is specially powerful in producing this affliction, it is a surrounding atmosphere of cold foggy air. He cited as striking evidence of this the famous emporium of England, London, which he found to be specially apt to produce and foster this disease.


2021 ◽  
pp. 1-12
Author(s):  
Zalmen Henkin

Abstract Encroachment of woody plants into grasslands and subsequent brush management are among the most prominent changes occurring in arid and semiarid ecosystems over the past century. The reduced number of farms, the abandonment of marginal land and the decline of traditional farming practices have led to encroachment of the woody and shrubby components into grasslands. This phenomenon, specifically in the Mediterranean region, which is followed by a reduction in herbage production, biodiversity and increased fire risk, is generally considered an undesirable process. Sarcopoterium spinosum has had great success in the eastern Mediterranean as a colonizer and dominant bush species on a wide variety of sites and climatic conditions. In the Mediterranean dehesa, the high magnitude and intensity of shrub encroachment effects on pastures and on tree production were shown to be dependent on temporal variation. Accordingly, there are attempts to transform shrublands into grassland-woodland matrices by using different techniques. The main management interventions that are commonly used include grazing, woodcutting, shrub control with herbicides or by mechanical means, amelioration of plant mineral deficits in the soil, and fire. However, the effects of these various treatments on the shrubs under diverse environmental conditions were found to be largely context-specific. As such, the most efficient option for suppressing encroachment of shrubs is combining different interventions. Appropriate management of grazing, periodic control of the shrub component, and occasional soil nutrient amelioration can lead to the development of attractive open woodland with a productive herbaceous understory that provides a wider range of ecological services.


2021 ◽  
Vol 18 (1) ◽  
pp. 52-65
Author(s):  
P. N. Mikheev

The article discusses issues related to the impact of climate change on the objects of the oil and gas industry. The main trends in climate change on a global and regional (on the territory of Russian Federation) scale are outlined. Possible approaches to the identification and assessment of climate risks are discussed. The role of climatic risks as physical factors at various stages of development and implementation of oil and gas projects is shown. Based on the example of oil and gas facilities in the Tomsk region, a qualitative assessment of the level of potential risk from a weather and climatic perspective is given. Approaches to creating a risk management and adaptation system to climate change are presented.


2013 ◽  
Vol 16 (8) ◽  
pp. 1045-1053 ◽  
Author(s):  
Pablo García-Palacios ◽  
Fernando T. Maestre ◽  
Jens Kattge ◽  
Diana H. Wall

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