Large‐scale identification of hot spots for soil carbon demand under climate change and bioenergy production          下载免费PDF全文

Uwe Franko  Felix Witing  Greta Jäckel  Martin Volk 《植物养料与土壤学杂志》2015,178(2):199-208

Global change scenarios predict an increased risk for declining amounts of soil organic matter (SOM) for Central Germany. Within this region the production of bioenergy is one important strategy to counteract the rising anthropogenic CO₂‐emissions. Both issues have a close connection: SOM is an important basis for soil productivity and requires a steady reproduction flux. Bioenergy production requires productive soils and partly consumes plant biomass C. Therefore, the available amount for SOM reproduction is reduced. This study provides a methodology for the large‐scale identification of areas with possible conflicts between bioenergy production and SOM reproduction based on (1) the prediction of climate change impact on SOM reproduction and (2) an analysis of the regional distribution of biogas plants. With the C demand index (CDI) and the capacity index (CAP), two indicators were developed which enable the identification of hot spots of high carbon demand for SOM reproduction due to climate change and the usage of bioenergy. As a result of low data requirements, the indicators are widely applicable and transferable to other large‐scale studies. The proposed methodology was applied to Central Germany as a pilot region. Results indicate a growing demand (10–40%) of fresh organic C from biomass for SOM production in comparison to the current level. The analysis reveals that the bioenergy C demand is not evenly distributed within the study region. It also shows some regional clustering. Furthermore, the analysis identifies certain hot spots of a high C demand, where a high capacity of biogas production may conflict with rising demands for biomass to mitigate climate change effects on SOM storage. The hot spot areas—identified and selected on a large scale—can subsequently be analyzed in more detail on a local to farm scale by using high‐resolution data and models which enable the quantification of soil C dynamics.  相似文献   

Effects of autumn tillage and residue management on soil respiration in a long‐term field experiment in Sweden          下载免费PDF全文

Veera Kainiemi  Johan Arvidsson  Thomas Kätterer 《植物养料与土壤学杂志》2015,178(2):189-198

Several previous field studies in temperate regions have shown decreased soil respiration after conventional tillage compared with reduced or no‐tillage treatments. Whether this decrease is due to differences in plant residue distribution or changes in soil structure following tillage remains an open question. This study investigated (1) the effects of residue management and incorporation depth on soil respiration and (2) biological activity in different post‐tillage aggregates representing the actual size and distribution of aggregates observed in the tilled layer. The study was conducted within a long‐term tillage experiment on a clay soil (Eutric Cambisol) in Uppsala, Sweden. After 38 y, four replicate plots in two long‐term treatments (moldboard plowing (MP) and shallow tillage (ST)) were split into three subplots. These were then used for a short‐term trial in which crop residues were either removed, left on the surface or incorporated to about 6 cm depth (ST) or at 20 cm depth (MP). Soil respiration, soil temperature, and water content were monitored during a 10‐d period after tillage treatment. Respiration from aggregates of different sizes produced by ST and MP was also measured at constant water potential and temperature in the laboratory. The results showed that MP decreased short‐term soil respiration compared with ST or no tillage. Small aggregates (< 16 mm) were biologically most active, irrespective of tillage method, but due to their low proportion of total soil mass they contributed < 1.5% to total respiration from the tilled layer. Differences in respiration between tillage treatments were found to be attributable to indirect effects on soil moisture and temperature profiles and the depth distribution of crop residues, rather than to physical disturbance of the soil.  相似文献   

Long-term dynamics of pelagic fish density and vendace (Coregonus albula (L.)) stocks in four zones of a lake differing in trawling intensity     

T. J. Marjomäki  M. Huolila 《Ecology of Freshwater Fish》2001,10(2):65-74

Abstract – An 11-year time series of hydroacoustic fish density estimates and fisheries statistics of vendace ( Coregonus albula (L.)) from four zones of a lake differing in trawling intensity was analyzed in order to test the hypothesis that intensive trawling has detrimental effects on pelagic fish stocks, especially vendace recruitment. The standardized fish density estimate in trawled zones showed no decrease in comparison to the non-trawled zone. No signs of recruitment failure associable with trawling intensity were found. The growth of vendace at the end of the study period was slower than that at the beginning, indicating a higher density, most clearly so in the zone with highest trawling intensity. No significant correlations were detected between 3-year mean trawling intensity and yield per unit effort of over-1-year-old vendace or fish density in any zone. Thus, no evidence to support the hypothesis was found. This was suggested to be due to density-dependent compensatory processes in recruitment and/or natural mortality effectively counteracting the population change induced by exploitation. ^Note  相似文献   

Joint ventures in private forestry in Ireland     

Aine Ni Dhubhain  Thomas Kavanagh 《Small-Scale Forestry》2003,2(1):9-19

A study was conducted with the objective of obtaining a profile of farmers who have participated in the Farm Partnership Scheme in Ireland. This scheme is a joint venture between Coillte (The Irish Forestry Board) and farmers. Under the terms of the scheme, Coillte is responsible for the establishment, management and harvesting of the forest plantation on the farmer’s land. The farmer retains ownership of the land, receives premium payments and shares in the harvesting profits. Fifty farmers who joined the Farm Partnership Scheme between 1993–1997 were interviewed in 1999 and a detailed questionnaire was completed. Survey results indicate that the typical farm partner was male, married and aged 50 years or older. Over half of those surveyed had an off-farm job. The most popular reason for farmers opting to participate in the Farm Partnership Scheme was that they did not have sufficient time to undertake the establishment and management of a forest plantation themselves. The average size of forest established under the scheme was 23.7 ha, with Sitka spruce the most popular species planted. The average annual payment under the scheme was €8077. For 46% of those surveyed, the returns from the Farm Partnership Scheme comprised all of their farm income.  相似文献   

Book Review: <Emphasis Type="Bold">The Ethics of Food: A Reader for the Twenty-First Century</Emphasis>. Edited by Gregory E. Pence,Lanham, Massachusetts: Rowman and Littlefield Publishers,Inc., 2002, 350 pp., ISBN 0742513343     

Ben Mepham 《Agriculture and Human Values》2005,22(3):365-365

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Five-year Surveillance of Small Mammal Abundance in Scandinavian1     

A. Myllymki  E. Christiansen  L. Hansson 《EPPO Bulletin》1977,7(2):385-396

A large-scale surveillance system was established in 1971. It was based on the practical needs for information on the fluctuation in numbers of harmful rodents and the desirability of forecasts. The sampling method used was the Small Quadrat Method (SQM). The annual surveys covered about 50 localities in Norway, Sweden and Finland, the total number of SQ's being over 2,000, and the total number of specimens caught approaching 18,000. In terms of numbers, the dominant rodent species were Microtus agrestis (L.) and Clethrionomys glareolus (Schreber), the former clearly dominating in Finland, the latter in most regions of the other 2 countries. In southern Sweden and Norway, Apodemus species were also relatively abundant, as was Sorex araneus L. in certain regions. During the 5-year period under study, the numbers of M. agrestis peaked twice (1972 and 1975) in Finland but only once in Sweden and Norway. The peak years of C. glareolus mosdy coincided with those of M. agrestis but, in some areas, were slightly earlier. Fluctuation in numbers of Insectivora did not seem to be correlated with that of the rodents. The usefulness of the SQ indices as a basis of short-term forecasts is apparent, while criteria for long-term forecasts require further analysis.  相似文献   

Resistance to triforine: A nonexistent problem?     

A. Fuchs  S. P. de Ruig  J. M. van Tuyl  F. W. de Vries 《European journal of plant pathology / European Foundation for Plant Pathology》1977,83(1):189

Permanent resistance to triforine in Cladosporium cucumerinum was obtained after UV irradiation of spore suspensions and selection of resistant strains in the presence of triarimol or triforine. About 50 strains were examined for mycelial growth on malt agar, viability upon routine subculturing, growth and inhibition by triforine in thin-layer chromatographic bioassays, and virulence towards cucumber seedlings. In addition, sporulation and spore germination, as well as effects of ergosterol were investigated in a restricted number of strains. Although all strains differed considerably from each other in these characteristics, they were quite similar in a reduced overall-fitness. These triforine-resistant mutants of C. cucumerinum might, therefore, have a greatly reduced chance of survival in competition with the wild-type strain, as was actually demonstrated for two strains in greenhouse experiments with mixed-inoculations of cucumber seedlings. Such a reduced chance of survival might also explain why under practical conditions development of resistance to triforine has not been observed yet.The triforine-resistant C. cucumerinum strains showed cross-resistance to a number of systemic fungicides known or supposed to inhibit ergosterol biosynthesis, viz. Denmert, fenarimol, imazalil, triadimefon and triarimol. The practical implications and potential hazards of such cross-resistance for the use of already established fungicides are discussed.  相似文献   

Characterization of fenarimol-resistant mutants of Aspergillus nidulans     

M. A. de Waard  S. A. Gieskes 《European journal of plant pathology / European Foundation for Plant Pathology》1977,83(1):177

The fitness of twelve fenarimol-resistant mutants of Aspergillus nidulans was tested with respect to spore germination, germ tube elongation, hyphal growth and sporulation. Half of the strains tested were isolated on triarimolcontaining media. The other strains were selected on imazalil-or cycloheximide-containing media (Van Tuyl, 1977).A number of mutant strains produced spores with unimpaired viability on synthetic medium. In other strains a reduction in spore viability was noticed. The rate of germ tube elongation of all resistant mutants was significantly lower than that of the wild-type strain. Mutant strains with a low degree of resistance always had an almost normal mycelial growth rate, whereas growth of some of the strains with a relatively high degree of resistance was significantly slower. Spore production on malt agar was highest in the wild-type strain and was found to be lower in fenarimol-resistant mutants. In most of the mutant strains tested a high degree of cross-resistance between fenarimol, imazalil and triadimefon was established; in some of them cross-resistance to these chemicals was low or even absent.Possible implications of the results described for the chance of development of resistance in phytopathogenic fungi to sterol biosynthesis-inhibiting fungicides are discussed.  相似文献   

Täuschende Forstinsekten     

Gäbler  Hellmuth 《European Journal of Forest Research》1939,61(4):97-104

European Journal of Forest Research -  相似文献   

Demonstration of two different H2-oxidizing activities in soil using an H2 consumption and a tritium exchange assay     

Veronika Häring  Ralf Conrad 《Biology and Fertility of Soils》1994,17(2):125-128

H₂-oxidizing activities were assayed in slurries of four soils by measuring the consumption of H₂ and the exchange of ³H₂ with H₂O at increasing mixing ratios of H₂ or ³H₂. Both H₂ consumption and ³H₂ exchange were abolished by autoclaving or the addition of formaldehyde. The rates of H₂ consumption and ³H₂ exchange were proportional to the quantity of soil used. Both activities increased with increasing concentrations of H₂ or ³H₂ and displayed biphasic kinetics, demonstrating the existence of two different H₂-oxidizing activities, one with a relatively low K _m and V _max, and a second with a relatively high K _m und V _max. The first type of activity was characteristic of abiontic soil hydrogenases, and the second of aerobic H₂-oxidizing bacteria. In contrast to H₂ consumption, which required the presence of either O₂ or ferricyanide, ³H₂ exchange operated equally well without an external electron acceptor. The ³H₂ exchange assay may thus be particularly useful for enrichment of soil hydrogenases which have not yet been isolated and for which no natural electron acceptor is known.  相似文献