| 1. |
- Ayuke, Fredrick, et al.
(författare)
-
Effects of biocontrol bacteria and earthworms on the severity of Alternaria brassicae disease and the growth of oilseed rape plants (Brassica napus)
- 2017
-
Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 117-118, s. 63-69
-
Tidskriftsartikel (refereegranskat)abstract
- Biological control of plant diseases through the addition of microbial biocontrol agents and the promotion of earthworms can be an environmentally friendly alternative to the chemical control of plant diseases. However, possible risks with biocontrol agents and their interactions with earthworms and other soil biota have not been well studied. The aim of this study was to assess whether the beneficial bacterium Bacillus amyloliquefaciens and the earthworms Aporrectodea caliginosa or Aporrectodea longa could reduce disease in oilseed rape (Brassica napus) challenged with the pathogen Alternaria brassicae. Plant growth and productivity were measured as plant survival, height, biomass, and flower development as well as disease index. A second objective was to assess whether the presence of the bacterium at high concentrations would influence the survival, growth, and reproduction of the earthworms. One outdoor and one greenhouse experiment were performed with Br. napus plants challenged with AL brassicae inoculated to the plant leaves in the presence or absence of Bacillus amyloliquefaciens inoculated to the root environment and in the presence or absence of earthworms (Ap. caliginosa or Ap. longa) added to the soil. All treatments were replicated three times. In the outdoor experiment, inoculation with AL brassicae reduced the growth of plants and the addition of Ap. caliginosa increased plant height. In the greenhouse experiment, pairwise comparisons of plants challenged with AL brassicae showed that treatment with B. amyloliquefaciens led to significantly lower disease index than the treatment with Ap. caliginosa plus B. amyloliquefaciens, while other treatments had intermediate disease indices. The addition of AL brassicae or B. amyloliquefaciens increased the survival and mass increment of Ap. caliginosa as a main effect when used separately but not when used in combination.This study did not give any clear indication of the usefulness of B. amyloliquefaciens for biocontrol of plant pathogens such as AL brassicae when growing plants in natural soil. In addition, no significantly positive effects from the tested earthworm species were seen.
|
|
| 2. |
- Elfstrand, Sara, et al.
(författare)
-
Carbon routes from decomposing plant residues and living roots into soil food webs assessed with C-13 labelling
- 2008
-
Ingår i: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 40:10, s. 2530-2539
-
Tidskriftsartikel (refereegranskat)abstract
- This field experiment investigated how C from fresh organic amendments and from a growing leek crop was allocated into different soil microbial and faunal groups in an arable field. A C-13-enriched red clover green manure was incorporated in one treatment, while the growing leek crop was pulse labelled with (CO2)-C-13 in another. Incorporation of C-13 into microbial fatty acids, micro- and macroarthropods, enchytraeids and earthworms was determined on several occasions during the growing season in order to determine whether different groups or species of microorganisms and fauna were specialised on either the decomposing green manure material or root-derived C. Compound-specific stable isotope ratio analysis showed fatty acid markers of actinomycetes and Gram-positive bacteria to be more strongly linked to C originating from the decomposing green manure material, whereas the marker for arbuscular mycorrhizal fungi was more linked to C from the growing leek crop. In contrast, several markers for Gram-negative bacteria were the most C-13-enriched and had incorporated more C-13 than the other phospholipid fatty acids in both treatments, indicating a general dominance irrespective of C source. Most soil fauna seemed to derive their C directly or indirectly from the decomposing plant material, while C from the growing crop appeared to be of secondary importance in this agroecosystem. (C) 2008 Elsevier Ltd. All rights reserved.
|
|
| 3. |
- Ericson, Lars, et al.
(författare)
-
Bevara de värdefulla skogar som ännu finns kvar i Sverige
- 2017
-
Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN Debatt: Sverige har åtagit sig att skydda 20 procent av landets land- och sötvattensområden till 2020. Men hittills har bara 4–5 procent av den omfattande produktiva skogen bevarats. För att nå de demokratiskt beslutade målen måste Skogsstyrelsens beslut om stopp för inventering av nyckelbiotoper hävas, skriver sju forskare.
|
|
| 4. |
- Friberg, Hanna, et al.
(författare)
-
Contribution of anecic and epigeic earthworms to biological control of Fusarium graminearum in wheat straw
- 2021
-
Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 166
-
Tidskriftsartikel (refereegranskat)abstract
- Earthworms have proved to contribute to plant health indirectly, by improvement of soil physical and chemical properties, as well as directly, through suppression of plant pathogens. Fusarium Head Blight, caused primarily by Fusarium graminearum, is one of the most important cereal diseases, with severe detrimental effects on yield and grain quality worldwide, and significant effect on grain safety due to the accumulation of mycotoxins produced by the fungus. Earthworms could reduce the residue-borne inoculum density of F. graminearum through different mechanisms, including direct competition by residue consumption, growth inhibition caused by the earthworm coelomic fluid, mechanical disruption of fungal hyphae, and burying crop residue which reduce the chances for the fungus to release spores for head infection. Thus, the aim of this study was to assess the effects of anecic and epigeic earthworms on wheat straw and on F. graminearum inoculum. For this, PVC cylinders (microcosms 14.5 cm diameter, 30 cm height) were filled with moist soil mix, wheat straw was evenly distributed on the soil surface (inoculated with Fusarium, soil microorganisms or sterile) and three earthworm species (Aporrectodea longa, Lumbricus rubellus or Lumbricus terrestris) were tested. Since the response of earthworms may change according to conditions of soil moisture and food availability, two different experiments were arranged. The first Experiment represented a sub-optimal situation for earthworms regarding soil moisture and feeding conditions, which was obtained by scarce watering of the microcosms with a consequent decrease in soil water content during incubation, and by not adding cow manure as supplementary food source. In the second experiment, soil was enriched with cow manure as feed for the earthworms and soil moisture was maintained above 25%. Results from qPCR analysis revealed that F. graminearum inoculum on straw was reduced to undetectable amounts by L. rubellus and A. longa when the feeding conditions were limited, while no significant differences compared with the control without earthworms were found when earthworms had high food availability (alpha = 0.05). Straw coverage on soil surface was reduced by L. rubellus (epigeic) in both experiments (p < 0.0001), while A. longa (anecic) just did so under optimal conditions. L. terrestris (anecic), only tested under optimal conditions, reduced soil cover significantly more than the other two species (p < 0.0001). Negative effect of this fungus was not observed on the studied earthworms. Both anecic and epigeic earthworms tested showed potential to contribute to biological control of F. graminearum in wheat straw. This control may occur by reducing straw on surface, reducing the pathogen inoculum on straw, or both, depending on the environmental conditions and their response according to their ecological group and species. The possibilities to optimize earthworm capacity for biological control of fungal diseases in practical agriculture, under changing weather and organic matter supply conditions, are discussed.
|
|
| 5. |
|
|
| 6. |
- Hinners, Linda, 1971-
(författare)
-
De fransöske handtwerkarne vid Stockholms slott 1693–1713 : Yrkesroller, organisation, arbetsprocesser
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis deals with French sculptors and painters active around 1700 at the Royal Palace in Stockholm. They were summoned from Paris by the architect Nicodemus Tessin the younger (1654–1728). This study analyses the Frenchmen’s professional roles, how Tessin organised their work and the working methods applied in the decoration of the Gallery of Charles XI and the adjoining parade rooms. It also involves questions concerning the artist’s roles and the status of artistic professions at the early modern period.The artisans were a group of some fifteen sculptors, painters, founders and a goldsmith. Several of them were accompanied by family members, some of whom were active in the workshop. In France these sculptors and painters had worked in the Bâtiments du Roi and particularly at the Gobelins. Although they were not part of the artistic elite at the Académie Royale de Peinture et de Sculpture they had vital knowledge in classical pattern/design, le bon goût and drawing. The artisans were also members of the guild system and were thus permitted to accept private commissions.My aim has been to clarify the artisans’ background in Paris and the recruitment undertaken by the diplomat Daniel Cronström (1655–1719). With regard to their activities in Sweden, it has been important to clarify their conditions in the building organisation at the Royal Palace, including social contexts such as their family situation and the possibility to practise their Catholic faith. Equally important is the professional relationship between the Frenchmen and Tessin, who was appointed Superintendent in 1697. Through detailed archival studies, the working practices and the creative process are analysed, especially the collaboration between Tessin and the painter Jacques Foucquet and the sculptors René Chauveau (1663–1722) and Jacques Foucquet (1639–1731).
|
|
| 7. |
- Lagerlöf, Jan
(författare)
-
Abundance and diversity of soil mite (Acari) communities after conversion of tropical secondary forest into rubber plantations in Grand-Lahou, Cote d'Ivoire
- 2017
-
Ingår i: Ecological Research. - : Wiley. - 0912-3814 .- 1440-1703. ; 32, s. 909 - 919
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this investigation was to understand the modification of mite communities and soil physico-chemical parameters after conversion of secondary forests into rubber plantations and how these change with the aging of the plantations. The sampling was performed in a humid period and samples were taken from three of each age of secondary forests, 7-year-old rubber plantations, 12-year-old rubber plantations and 25-year-old rubber plantations. We hypothesized that the stress imposed on mite communities during site preparation and planting would be compensated for by the reduction of the soil degradation index as the rubber plantations age. Across the 12 sampling areas, 120 soil cores were taken at 10 cm soil depth over a 40 m transect. Soil physico-chemical parameters were characterized and soil mites were extracted with a modified Berlese-Tullgren funnel over the course of 10 days. The results showed that conversion of secondary forests into rubber plantations leads to a modification in the density of mites (-60 and +1%), species richness (-48 and -15%), water content (-62 and -31%), soil organic carbon (-67 and -51%) and total nitrogen (-64 and -52%) respectively after about 7 and 25 years of conversion. The investigation pointed out an improvement in soil ecological quality with the aging of rubber plantations over time and this was characterized by an increase in the density of mites (+150%), species richness (+63%), water content (+84%), organic carbon (+50%) and total nitrogen (+33%) in the 25-year-old plantations compared to the 7-year-old plantations.
|
|
| 8. |
- Lagerlöf, Jan
(författare)
-
Abundance and diversity of soil mites (Acari) along a gradient of land use types in Taita Taveta, Kenya
- 2011
-
Ingår i: Tropical and Subtropical Agroecosystems. - 1870-0462. ; 13, s. 11-26
-
Tidskriftsartikel (refereegranskat)abstract
- The abundance and diversity of soil mites was monitored along a gradient of land use types (LUTs) during the wet seasons in soils of Taita Taveta, Kenya. Sampling of mites from soils was carried out in eight LUTs which included maize-based system (Zea mays), coffee (Coffea arabica), horticulture, napier grass (Pennisetum purpureum), fallow, pine (Pinus patula), cypress (Cypressus lusitanica), natural forest. LUT significantly influenced abundance, richness and diversity of the soil mites. During the short rains the diversity of soil mites increased in the order napier ,maize-based system, horticulture, coffee, fallow, natural forest, pine forest, cypress plantation while the long rains season abundance increased in the order maize-based system, coffee, horticulture, napier, natural forest, fallow, pine forest, cypress forest. Higher abundance, richness and diversity of the mites was observed in the less disturbed forest ecosystems unlike the agro-ecosystems, which are often disturbed with intensive cultivation A total of 37 families were recorded with 20 oribatid families, 10 mesostigmatid families and 7 prostigmatid families. The families that ranked highest in abundance across the LUT were Scheloribatidae, Oppidae (Oribatida) and Rhodacaridae (Mesostigmata). Land use type influenced significantly (P<0.05) the abundance and diversity of soil mites where intensification lowered the diversity and abundances resulting in less complex mites community structures
|
|
| 9. |
- Lagerlöf, Jan
(författare)
-
Can litter production and litter decomposition improve soil properties in the rubber plantations of different ages in Cte d'Ivoire?
- 2018
-
Ingår i: Nutrient cycling in agroecosystems. - : Springer Science and Business Media LLC. - 1385-1314 .- 1573-0867. ; 111, s. 203-215
-
Tidskriftsartikel (refereegranskat)abstract
- Litter production and litter decomposition influence the availability of nutrients in the soil. The investigation aimed at characterizing the dynamics of leaf litter decomposition, and soil physico-chemical and biological parameters in rubber plantations of different ages. During a 12-months' period, field studies were done in 7-, 12-, and 25-year-old rubber plantations. For measuring of litter decomposition and input from aboveground, 324 litter bags and 27 litter traps (1 m x 1 m) were placed in 3 sampling areas per age class of rubber plantations. The soil parameters were also characterized. The results showed that the annual litter production and the amounts of organic carbon in leaves increased with the aging of the plantations. The annual decomposition constant (k) ranged from 0.0381 +/- 0.0040 year(-1) in the 25-year-old plantations to 0.0767 +/- 0.0111 year(-1) in the 7-year-old plantations. The annually decomposed litter mass varied between 2.7 +/- 0.3 t ha(-1) year(-1) in the 12-year-old plantations to 4.2 +/- 0.3 t ha(-1) year(-1) in the 25-year-old plantations. The soil of the 25-year-old plantations showed higher values of most physico-chemical and biological variables as compared to the 7-year-old plantations: annual litter production (+ 32%), annual litter mass decomposed (+ 11%), annual carbon (+ 15%) and nitrogen (+ 11%) inputs, soil organic carbon (+ 52%), total nitrogen (+ 32%), soil organic matter (+ 52%), soil water content (+ 74%), and the total density of soil invertebrates (+ 121%). The results indicate an improvement of soil properties with the aging of the rubber plantations and the importance of this agricultural system for carbon sequestration.
|
|
| 10. |
- Lagerlöf, Jan
(författare)
-
Changes in mite richness and diversity along a gradient of land-use intensity from mid-west Ivory Coast
- 2017
-
Ingår i: Tropical Ecology -Allahabad-. - 0564-3295. ; 58, s. 497-506
-
Tidskriftsartikel (refereegranskat)abstract
- The conversion of natural forest to agricultural land, and different management practices contribute extremely to soil physico-chemical and biological degradation. One of the key factors influencing this alteration is land use intensity. The objective of this study was to evaluate the changes in soil mite abundance, richness and diversity orchestrated by land use intensification. Eight agroecosystem with an increased land use intensity index were selected: Primary forest - Secondary forest - Multi-species planted trees - 10-year old teak plantations 4-year old teak plantations - Cocoa plantations - Recurrent fallows - Mixed crops fields. On each land use type 5 grills point were sampled. The results showed that soil mite density decreased significantly (P < 0.05) from Primary forest to Mixed crops field, showing that mite abundance was hugely influenced by the degree of agroecosystem stability. The average number of species per sampling point varied significantly (P = 0.0013) from Primary forest (9.6 +/- 0.8) to Mixed crops fields (1.4 +/- 0.5). The same pattern was observed with the Shannon index, which was ranked between Primary forest (2.92 +/- 0.21) and Mixed crops fields (0.45 +/- 0.28). Cumulative alpha diversity varied from 5 species in Mixed crops fields to 22 species in Primary forest. The beta diversity (turnover or dissimilarity) were generally high and varied from 42.3% (Primary forest and Secondary forest) to 82.3% (Multi-species planted trees and Mixed crops fields). The results demonstrated that higher was the land use intensity index, the lower were the mite abundance, diversity and species richness. Interactions between mite abundance and diversity and trophic resource characteristics, shade and soil organic carbon is discussed.
|
|
