Natural revegetation of indigenous roadside vegetation by propagules from topsoil

Road construction degrades large areas of indigenous vegetation. Better understanding of ecosystem restoration after degradation will require development and assessment of improved restoration techniques. The potential of natural revegetation based on propagules from topsoil as a restoration technique, to achieve succession towards indigenous vegetation, is not fully understood and accepted as an alternative method for vegetation establishment. The aim of this study was to evaluate this restoration technique by comparing different topsoils with respect to their potentials for revegetation and to describe the early succession on these topsoils by recording change in vegetation cover and the number of species.The study road RV23 is situated in south-east Norway and runs mainly through mixed, mostly coniferous forest. The topsoil (the upper 30 cm) was removed before road construction started, stockpiled during the construction period and then redistributed on the road verge afterwards. In 1999, 10 macroplots of 25 m² were placed randomly on selected topsoils of different qualities, to represent the soil variation in the study area. The soil quality varied from organic-rich to organic-poor soils. Each macro plot contained four 1-m² mesoplots in which the species composition was recorded in 2000 and 2001.Univariate statistical tests were applied to reveal change in vegetation cover between macroplots within 1 year and between years 2000 and 2001. Furthermore, statistical tests were used to reveal the change in single-species frequencies between the study years.Two years after deposition of topsoils, the vegetation cover was generally satisfactory from an aesthetical point of view. However, the variation in vegetation cover and species composition was considerable on different topsoils, reflecting both the local variation of the indigenous vegetation and the soil quality. A total of 121 species of vascular plants were recorded in all 10 macroplots, although not more than 59 species were found in one macroplot. Species composition and single-species frequencies changed considerably from the first year to the second. Among the 61 species that were recorded in more than five mesoplots, the frequency of 16 species increased and the frequency of 10 species decreased significantly (P<0.05). Most of the decreasing species can be considered as weed species and are not represented in the present indigenous vegetation, while most of the increasing species are. The vegetation change from 2000 to 2001 apparently represents the first steps in a succession towards an ecosystem dominated by species of the indigenous vegetation.     

Coagulase-negative, novobiocin-resistant staphylococci on the skin of animals and man, on meat and in milk.

The occurrence of coagulase-negative, novobiocin-resistant staphylococci, i.e. Staphylococcus cohnii, Staphylococcus saprophyticus, Staphylococcus sciuri and Staphylococcus xylosus, on the skin of animals and man has been studied. On cultures from cats, cows, dogs, guinea pigs, mice, rabbits and sheep studied, such organisms were predominant among the coagulase-negative staphylococci. From the skin of the hands of 21 of 38 persons whose professions brought them into contact with animals, e.g. inséminât ors, slaughterhouse workers and veterinarians, coagulase-negative, novobiocin-resistant staphylococci were isolated. This finding contrasted with that regarding 50 persons lacking such contacts, of whom only 1 harboured such bacteria. S. saprophyticus was isolated only from those slaughterers presenting with wounds on their hands. Coagulase-negative, novobiocin-resistant staphylococci were also isolated from every second specimen collected from the surface of meat at a slaughterhouse. No difference in the culture results could be demonstrated from specimens collected before and after cutting-up of the carcasses. Of 26 strains of coagulase-negative, DNase-negative staphylococci isolated from milk with pathological CMT, all but 5 were novobiocin-resistant. Fifteen were classified as S. xylosus, 4 as S. sciuri and 1 as S. cohnii. Of another 15 DNase-positive strains, 3 were resistant to novobiocin. Finally, clinical infections with coagulase-negative, novobiocin-resistant staphylococci in man, e.g. urinary tract infections caused by S. saprophyticus, are considered in relation to possible contagious reservoirs and modes of spread.     

Mixtures of crushed rock, forest soils, and sewage sludge used as soils for grassed green areas

In two container experiments, we evaluated mixtures of crushed rock, forest soil, and sewage sludge for use as growth media in green areas. We applied two types of crushed rock (0–2 mm fraction), two forest soils (sandy loam), and limed sewage sludge (pH 10), and studied the growth of ryegrass (Lolium multiflorum var. westervoldicum) during one growing season.Including ≥0.2 m³ m⁻³ sewage sludge in the soil mixtures initially inhibited growth, presumably due to toxic levels of ammonium-N. Up to 0.25 m³ m⁻³ sludge increased the total yield of ryegrass, but at a level as low as 0.1 m³ m⁻³, more nutrients were available than could be taken up by the crop. At present, up to 0.3 m³ m⁻³ sewage sludge is allowed in soil mixtures used in green areas in Norway, although that level should probably be lowered due to the risk of abnormal (enhanced or inhibited) plant growth, and leaching of nutrients. We recommend a maximum of 0.1 m³ m⁻³ when applying the kind of sludge used in our experiments.All mixtures containing acid forest soil gave better results than those comprising slightly alkaline forest soil. The best mixture for ryegrass was crushed rock and acid forest soil at a ratio of 1:2. Compared to pure acid forest soil ryegrass grew equally well or better on mixtures containing ≥0.50 m³ m⁻³ acid forest soil. The differences in growth between the various soil mixtures were due to texture and physical properties, and to dissimilarities in the effects of sewage sludge on mineralisation of nitrogen in the mixtures comprising acid and slightly alkaline forest soil.     

Gill amoebae from freshwater rainbow trout (Oncorhynchus mykiss): In vitro evaluation of antiparasitic compounds against Vannella sp.

Gill parasitic infections challenge farming of rainbow trout (Oncorhynchus mykiss, Walbaum) in freshwater facilities. Apart from flagellates (Ichthyobodo, (Pinto) and ciliates (Ichthyophthirius (Fouquet), Ambiphrya (Raabe), Apiosoma (Blanchard), Trichodinella (Sramek-Husek) and Trichodina (Ehrenberg)), we have shown that amoebae are prevalent in Danish trout farms. Gills were isolated from farmed rainbow trout in six fish farms (conventional and organic earth pond and recirculated systems) and placed on non-nutrient agar (NNA) moistened with modified Neff's amoeba saline (AS) (15°C). Gill amoebae from all examined fish colonized the agar and were identified based on morphological criteria showing species within the genera Trinema (Dujardin) (family Trinematidae), Vannella (Bovee) (family Vannellidae). In addition, hartmannellid amoebae were recorded. We established a monoculture of Vannella sp., confirmed the genus identity by PCR and sequencing and performed an in vitro determination of antiparasitic effects (dose–response studies) of various compounds including sodium chloride (NaCl), hydrogen peroxide, peracetic acid, formalin, aqueous garlic and oregano extracts and a Pseudomonas H6 surfactant. All amoebae were killed in concentrations of 16.90 mg/ml (garlic), 17.90 mg/ml (oregano), NaCl (7.5 mg/ml), hydrogen peroxide (100 µg/ml), peracetic acid (0.03 µg/ml), formaldehyde (25 µg/ml) and the Pseudomonas H6 surfactant (250 µg/ml).     

Testing the yield of a pilot‐scale bubble column photobioreactor for cultivation of the microalga Rhodomonas salina as feed for intensive calanoid copepod cultures

A dual column photobioreactor (PBR) (2 × 47 L) with mixed CO₂/air bubbling was tested for cultivation of the microalga Rhodomonas salina as food for live feed copepods. In the continuous growth phase, the cell density was relatively stable at 2.40 ± 0.13 × 10⁶ cells/ml at an average dilution rate of 0.46 ± 0.02 per day throughout the 30‐day experiment. The produced algae had a high content of both total fatty acids (TFA) and free amino acids (FAA). Especially, the harvested algae contained a high proportion of poly‐unsaturated fatty acids that made up 80% of the TFA and of essential amino acids (35% of all FAA), implicating desirable components as feed for copepods. The current PBR was sufficient to feed a culture of the calanoid copepod Acartia tonsa at a density of 2,500 adult/L in ca. 500 L culture with a daily yield of approximately 17 × 10⁶ eggs. To be able to sustain the integrated copepods production, the suggested volume of the algae cultures should be ca. 20% of the copepod culture volume.     

Rapid and non-destructive evaluation of seed quality of Chinese fir by near infrared spectroscopy and multivariate discriminant analysis

New Forests - Chinese fir (Cunninghamia lanceolata (Lamb) Hook) is a promising timber species for planting in the sub-tropical ecosystem. However, the germination rate of Chinese fir seed lots is...     

光温条件对新热带干旱树种种子萌发和苗木建成的影响

测定了香红椿（Cedrela odorata）、神圣愈疮木（Guaiacum sanctum）和柠檬树（Calycophyllum candidissimum）种子萌发所需要的条件、并对光强对在尼加拉瓜开阔地、半开阔地和干旱森林林冠下所营造的香红椿和神圣愈疮木的苗存活率和生长的影响进行了研究。结果表明,在20-35℃常温条件下,柠檬树在有光照条件下种子萌发率显著高于黑暗条件的种子萌发率;香红椿和神圣愈疮木的种子在光照和黑暗条件下都有一定程度的萌发,最适萌发温度均为20-25℃。研究还表明,变温条件培养并没有提高3个树种的种子萌发率。在林冠层下和开阔地上神圣愈疮木苗木的存活率分别为70％和80％,两种条件下的周径相对生长速率分别为1．42mm／月和1．88mm／月。总的来说,在3个树种中,香红椿幼苗存活率较低,特别是在冠层内生长的幼苗。以上结果说明：柠檬树种子萌发需要光照;而香红椿和神圣愈疮木种子萌发对温度条件较为敏感。神圣愈疮木幼苗在裸地条件下存活率较高,可以作为退化土地造林备选树种。图2表2参43。     

Looking at computer-visualized interior wood: A qualitative assessment using focus groups

The objective of this study was to explore and gather human reactions and perceptions on computer visualizations of interior wood. The subjective qualities of such products are important because they infl uence the most critical of consumer decisions: to buy or not. To learn more about a phenomenon than quantitative data can provide, qualitative methods are needed. Here, grounded theory was used with focus groups to form a map of 14 people’s experiences of wood. Six computer-generated pictures with visible wood were varied into 18 pictures, such that two-by-two comparison resulted in 3500 words. These were combined into a map that was generated earlier, which had found 2000 words. The main dimensions found were light, color, unity, and authenticity. Light is more than brightness; shadows and lighting seemed more important for the wood feeling, and color and contrast gave life and warmth to the material on the screen. Respondents wanted wood that was more “woody” and “warmer” than wood actually is, that is, a hyper-realistic picture. Perhaps smart modification rather than photorealism should be the goal. Distribution of the earlier found activity and harmony was important for most respondents. In addition, many subjects discussed the composition and/or the context or purpose of the pictures. The impact of wood is not just related to the wood itself; it is also intertwined with its surroundings.     

Temporal distribution of porcine circovirus 2 genogroups recovered from postweaning multisystemic wasting syndrome affected and nonaffected farms in Ireland and Northern Ireland.

Porcine circovirus type 2 (PCV2) is now recognized as the essential infectious component of porcine postweaning multisystemic wasting syndrome (PMWS). PMWS was first recognized in high-status, specific pathogen-free pigs in Canada in 1991 and is now an economically important disease that affects the swine industry around the world. Recently, reports of genomic studies on PCV2 viruses indicated that 2 distinctive genogroups of PCV2 exist.4,10 This report involves the results of a study on the distribution of predominant PCV2 genogroups recovered from samples taken from PMWS-affected and PMWS-nonaffected farms on the island of Ireland over a 9-year period and the results of a study on PCV2 genogroup recovery from fecal samples taken from a farm in Northern Ireland from 2003 to 2005 that was first diagnosed as PMWS positive in August 2005. The results indicate that, although at least 2 distinct genogroups of PCV2 have been circulating on pig farms on the island of Ireland, there does not appear to be a direct relationship between infection with these different genogroups of PCV2 and the development of PMWS.     

Landscape ecology as a theoretical basis for nature conservation

Conservation of representative biotopes, single species populations or biodiversity usually embraces two or more biotopes, and is often affected by surrounding croplands. The conclusions from landscape ecological studies can, therefore, offer important contributions to conservation, especially at early levels of landscape change or habitat fragmentation. Indicator and keystone species are useful for monitoring and managing fragmented biotopes, respectively. Communities as well as single species are affected by the juxtaposition of successional and climax biotopes, which influence climatic equability, seasonality, productivity and dispersal. Low levels of fragmentation may result in ill-functioning communities, and greater fragmentation may result in species losses and ultimately in the loss of whole communities. Fragmented habitats retain species with high reproductive and dispersal rates and generalized habitat selection. New combinations of interacting species will lead to trivialization of earlier habitat-specific interactions. Validation of these concepts was made with data from a Swedish research program on fragmented biotopes in production landscapes. General reserve selection and methods of management for preserving climax communities, single specialized species and high biodiversity are suggested.