The effect of grassland renovation on soil mineral nitrogen and on nitrate leaching during winter

Renovation of grassland may increase the mineralization of organic material and leads to a high amount of mineral N in soil which can be leached in the winter period. Soil mineral N (SMN) in autumn and calculated nitrate leaching during winter were measured after the renewal of 8 y–old cut grassland on a sandy soil in NW Germany in 1999 to 2002. Several factors, which may influence the intensity of N mineralization, were investigated in the 2 years following renewal: the season of renovation (spring or late summer/early autumn), the technique (rotary cultivator or direct drilling), and the amount of N fertilization (0 or 320 kg N ha^–1 y^–1 in the 7 years before the renovation). Calculated nitrate‐N leaching losses during winter were significantly higher following renewal in early autumn (36–64 kg N ha^–1) compared to renewal in spring (1–7 kg N ha^–1). This effect was only significant in the first, not in the second winter after renovation. The renovation technique had a significant effect on the nitrate‐N leaching losses only in the first year after the renovation. Direct drilling led to higher leaching losses (35 kg N ha^–1) than the use of a rotary cultivator (30 kg N ha^–1) in the same year. Calculated nitrate losses (on average over 60 kg N ha^–1) were highest after renewal of N‐fertilized grassland in late summer/early autumn. To minimize N leaching losses, it would be more effective to plan grassland renewal in spring rather than in late summer/autumn. Another, however, less effective option is to reduce N fertilization before a renovation in autumn.     

Structure and functioning of earthworm communities in woodland flooding systems used for drinking water production

Earthworms are known to influence water infiltration in soils, but most of the existing knowledge relates to grasslands and arable systems; little is known on the role of earthworms for water infiltration in forests. We studied earthworm populations and water infiltration rates in woodland flooding sites used for groundwater recharge and the production of drinking water. Intensive flooding may detrimentally affect earthworm populations and simultaneously result in clogging of the topsoil, with the latter being a common problem in groundwater recharge systems. However, clogging does not occur at our study site, the “Lange Erlen” (Basel, Switzerland) and total earthworm numbers and biomass in flooded sites exceeded those of non-flooded sites (+51% and +71%, respectively). Total earthworm numbers (r = 0.85***), numbers of endogeic (r = 0.64*) and epigeic (r = 0.81**) earthworms and numbers of two species (Lumbricus rubellus, r = 0.62* and Allolobophora chlorotica, r = 0.77**) significantly correlated with water infiltration rates. The results suggest that short-term flooding (max. 10 days) interrupted by longer recovery periods favor earthworm populations which likely contribute to the long-term (ca. 100 years) sustainability of the studied forest groundwater recharge system and thereby to effective and cost efficient drinking water production.     

Impact of land use on soil organic carbon stocks in the humid tropics of NE Tanzania

The conversion of tropical forests to agricultural land use is considered as a major cause for a decline in soil organic carbon (SOC) stocks. However, the extent and impact of different land uses on SOC stock development is highly uncertain, especially for tropical Africa due to a lack of reliable data. Interactions of SOC with the soil mineral phase can modify the susceptibility of SOC to become mineralized. Pedogenic Fe‐, Al‐oxides and clay potentially affect SOC stabilization in highly weathered soils typically found in the humid tropics. The aim of our study was to determine the impact of different land uses on SOC stock on such soils. For that purpose, 10 pedologically similar, deeply weathered acidic soils (Acrisols, Alisols) in the Eastern Usambara Mountains (Amani Nature Reserve, NE Tanzania) under contrasting land use were sampled to a depth of 100 cm. The calculated mean SOC stocks were 17.5 kg C m^?2, 16.8 kg C m^?2, 16.9 kg C m^?2, and 20.0 kg C m^?2 for the four forests, two tea plantations, three croplands, and one homegarden, respectively. A significant difference in mean SOC stock of 1.3 kg C m^?2 was detected between forest and cropland land use for the 0–10 cm depth increment. No further significant impacts of land use on SOC stocks were observed. All soils have a clearly clay‐dominated texture. They are characterized by high content of pedogenic oxides with 29 to 47 g kg^?1 measured for the topsoils and 36 to 65 g kg^?1 for the subsoils. No positive significant relationship was found between SOC and clay content. Statistically significant positive relationships existed between oxalate‐extractable Fe, Al, and SOC content for cropland soils only. Compared to data published in literature the SOC stocks determined in our study were generally high independent of the established land use. It appears that efficient SOC stabilization mechanisms are counteracting the higher disturbance regime under agricultural land use in these highly weathered tropical soils.     

LPS-induced sickness behavior is not affected by selenium but is switched off by psychogenic stress in rats

Veterinary Research Communications - Sickness behavior (SB) is considered part of the adaptive behavioral and neuroimmune changes that occur in response to inflammatory processes. However, SB is a...     

Terrestrial ages of four allan hills meteorites: consequences for antarctic ice

The terrestrial ages of three Allan Hills meteorites are between 3 x 10(4) and 3 x 10(5) years and one is (1.54(-0.28)(+0.14)) x 10(6) years old. The Antarctic ice sheet is therefore older than (1.54(-0.28)(+0.14)) x 10(6) years and the meteorite accumulation process at Allan Hills probably began between 3 x 10(4) and 3 x 10(5)years ago.     

Cutaneous manifestations of neurological diseases: review of neuro-pathophysiology and diseases causing pruritus

Pruritus does not always originate from stimulation to the skin associated with primary dermatological disorders. It may be caused by neurological or behavioural disorders. The essential role of the nervous system in the control (enhancement and inhibition) of pruritus and its pathophysiology are presented. In order to allow differentiation between dermatological and neurological disorders, inherited or acquired peripheral neuropathies and central nervous disorders (Arnold-Chiari syndrome, seizure-related disorders, central nervous system tumours) that may induce itch are discussed.     

Stereotactic radiosurgery for treatment of osteosarcomas involving the distal portions of the limbs in dogs

Stereotactic radiosurgery (SRS) involves precise delivery of a single large dose of radiation to a designated tumor target. This report describes use of SRS in combination with a frameless stereotactic localization system to treat 11 dogs with appendicular osteosarcomas. Five dogs were treated with SRS alone; 6 were treated with a combination of SRS and chemotherapy. Overall median survival time was 363 days (range, 145 to 763 days), with 6 dogs still alive 90, 142, 234, 367, 633, and 763 days after SRS. Limb function was good or excellent in all 6 dogs that were still alive. Results in these dogs suggest that SRS may be a viable option for dogs with appendicular osteosarcoma, with the potential to provide long-term local tumor control and improvement in limb function, especially when combined with chemotherapy. Because of the destructive nature of osteosarcoma and limitations of SRS, dogs with tumors that are small and have caused minimal bone destruction would likely be the best candidates for this procedure.     

Political ecology of exurban “lifestyle” landscapes at Christchurch's contested urban fence

This paper examines the relationship of planning ideals of sharply defining edges between urban density and greenspace and alternative urban greening arrangements as they are manifested in a case study of exurban “lifestyle blocks” on the fringes of Christchurch, Aotearoa New Zealand. Exurban development outside Christchurch's urban growth boundary – called the “urban fence” – provides an example of tension between municipal attempts to curb sprawl and exurbanites’ desire to live in the dispersed settlements outside of urban boundaries. These struggles play out at different scales and in a range of different metropolitan contexts. This paper reports on the results of an ethnographic study of Christchurch urban fringe residents’ residential land-use narratives and practices. The paper focuses on landscape preferences and concerns of a sample of small-scale productive land users and explores the implications of their versions of urban greening in the context of policy visions for the urban edge. A political ecology interpretation highlights relationships in this case study between competing claims about fringe greening and fringe landscape practices. These contests over the landscapes of the urban edge illustrate ways that municipal and regional planning visions for the urban edge conflict with the ideals and practices of those residents and land use managers who might otherwise be some of the strongest supporters of urban greening initiatives. Competing discourses about the urban edge relate in different ways to concerns about abrupt urban containment and to practices that act on these concerns. I briefly discuss promising examples of edge greening in this case that may provide models for participatory management of contested and multi-use greenspace at the urban–rural fringe.     

Effect of oral supplementation of probiotic strains of Lactobacillus rhamnosus and Enterococcus faecium on the composition of the faecal microbiota of foals

Effects of probiotics on the intestinal microbiota of foals are yet insufficiently studied. The aim of this study was to investigate whether supplementation of Lactobacillus rhamnosus (DSM 7133) and Enterococcus faecium (DSM 7134) influences the bacterial composition of the faecal microbiota of foals. A total of 34 newborn foals were randomly assigned to the placebo group (PG, n = 16) and the treatment group (TG, n = 18). From day 1 to day 14 of life, foals orally received 3 ml of either a probiotic preparation (1.05 × 10⁹ CFU E. faecium and 4.50 × 10⁸ CFU L. rhamnosus) or placebo (carrier) once a day. Faeces were collected directly from the rectum immediately after birth (meconium) and at day 14 and day 56 of life. Samples of 12 foals per group were selected for microbiological analysis. DNA was extracted and used for polymerase chain reaction–denaturing gradient gel electrophoresis (PCR‐DGGE) and quantitative PCR. No DNA or amplicons were obtained from meconium. There were no differences in richness of bands and Shannon index of diversity regarding the Clostridium cluster XIVa between groups. Cluster analysis and principal coordinate analysis of DGGE data showed a clear effect of age. Band‐based similarity of bacterial clusters (Dice coefficient) decreased from day 14 to day 56 of life (p < 0.001) in PG foals only resulting in lower similarity in PG versus TG foals when 2 month old (p < 0.01). Five of thirty re‐amplified bands were identified on species level. Others were assigned either to family (mainly Lachnospiraceae) or genus level (Akkermansia). The bands related to Akkermansia muciniphila or Akkermansia spp. appeared almost in all DGGE profiles. Two‐week supplementation of the probiotic preparation to foals had no significant impact on the composition of the faecal microbiota but it appears to have prevented the reduction of bacterial similarity between 2 and 8 weeks of age observed in not treated foals.