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Applications of growth retardants, daminozide and CCC (chlormequatchloride), were studied in order to determine their effects on morphology and post-planting growth of silver birch (Betula pendula Roth) container seedlings. Daminozide was sprayed once (on 28 June at concentrations of 1.0 – 6.0 g l–1) and CCC was sprayed twice (on 29 June and 27 July at concentrations of 0.5–3.0 gl–1). Height growth, morphology of seedlings at the end of the growing season, the shoot and root growth potential the following spring and field performance during the following seasons were measured. During the first summer in the nursery, both daminozide and CCC retarded height growth,but daminozide was more effective. The effects of compounds on stem diameter during the summer of application were small. Neither of the compounds affected the field performance of seedlings. The most suitable applications for retardation of height growth, without negative effects on other morphological variables, were 4 g l–1 (32 mg per seedling) for daminozide and 2 g l–1 (16 mg per seedling), sprayed in two applications, for CCC. 相似文献
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Projecting global and regional outlooks for planted forests under the shared socio-economic pathways
Korhonen Jaana Nepal Prakash Prestemon Jeffrey P. Cubbage Frederick W. 《New Forests》2021,52(2):197-216
New Forests - There is rising global interest in growing more trees in order to meet growing population, climate change, and wood energy needs. Using recently published data on planted forests by... 相似文献
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Bäck Jaana Turunen Minna Ferm Ari Huttunen Satu 《Water, air, and soil pollution》1997,100(1-2):119-132
Scots pine (Pinus sylvestris) needles from forest sites differing in distance from big fur farms emitting large amounts of ammonia and ammonium (=NHy) were examined by scanning and transmission electron microscopy. Specific features indicating an ammonium-nitrogen overload, such as an abundance of needle surface organisms and modifications in cellular and wax structures, were classified. Throughout the study area (up to 1000 m from the farms), mesophyll cells had thin cytoplasm and folding plasmalemma indicating frost damage. Phloem damage attributable to a possible nutrient imbalance was also observed. Chloroplast membranes were undulating and the occurrence of leaf surface organisms (e.g. aerophilic algae) was more abundant at the closest sites. The changes were related both to the direct effects of dry NHy deposition on the needles, and to the effects operating via soil acidification. The needle epicuticular waxes proved to be structurally rather inert against the influence of ammonium compounds, since no significant changes due to NHy were observed. 相似文献
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Suchodolski JS Morris EK Allenspach K Jergens AE Harmoinen JA Westermarck E Steiner JM 《Veterinary microbiology》2008,132(3-4):379-388
Limited information is available about the prevalence and phylogenetic classification of fungal organisms in the gastrointestinal tract of dogs. Also, the impact of fungal organisms on gastrointestinal health and disease is not well understood. The aim of this study was to evaluate the prevalence of fungal DNA in the small intestine of healthy dogs and dogs with chronic enteropathies. Small intestinal content was analyzed from 64 healthy and 71 diseased dogs from five different geographic locations in Europe and the USA. Fungal DNA was amplified with panfungal primers targeting the internal transcriber spacer (ITS) region. PCR amplicons were subjected to phylogenetic analysis. Fungal DNA was detected in 60.9% of healthy dogs and in 76.1% of dogs with chronic enteropathies. This prevalence was not significantly different between the two groups (p=0.065). Fungal DNA was significantly more prevalent in mucosal brush samples (82.8%) than in luminal samples (42.9%; p=0.002). Sequencing results revealed a total of 51 different phylotypes. All sequences belonged to two phyla and were classified as either Ascomycota (32 phylotypes) or Basidiomycota (19 phylotypes). Three major classes were identified: Saccharomycetes, Dothideomycetes, and Hymenomycetes. The most commonly observed sequences were classified as Pichia spp., Cryptococcus spp., Candida spp., and Trichosporon spp. Species believed to be clinically more important were more commonly observed in diseased dogs. These results indicate a high prevalence and diversity of fungal DNA in the small intestine of both healthy dogs and dogs with chronic enteropathies. The canine gastrointestinal tract of diseased dogs may harbor opportunistic fungal pathogens. 相似文献
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Mini-plug transplant seedlings of Norway spruce have been cultivated in closed growth systems, so-called plant factories, for few years. The aim of the experiment was to define a short-day treatment (SD) that harden seedlings to sustain 3 months of cold storage, but does not have adverse effects on growth, morphology, and vitality. The seedlings were subjected to one of the following treatments: (1) 12?h photoperiod + 3 weeks duration; (2) 8?h photoperiod + 3?wk duration; (3) 12?h photoperiod + 5?wk duration; and (4) 8?h photoperiod + 5?wk SD. All the SD treatments yielded healthy seedlings that grew well after the cold storage. The frost hardiness of the seedlings improved when the photoperiod was reduced from 12 to 8?h, and when the SD duration was increased from 3 weeks to 5 weeks, but reducing the photoperiod from 12?h to 8?h caused growth reductions. The root and shoot regrowth after cold storage was highest in seedlings that had received 12?h photoperiod and 5?wk duration. However, 12?h photoperiod and 3?wk duration may be an adequate practice for nurseries that treat multiple crops in their SD facilities. 相似文献
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Jaana Laurila Asko Hannukkala Johanna Nykyri Miia Pasanen Valérie Hélias Linda Garlant Minna Pirhonen 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(2):249-262
Biochemical characterisation of Dickeya strains isolated from potato plants and river water samples in Finland showed that the majority of the strains were biovar 3. They thus resembled the strains recently isolated from potato in the Netherlands, Poland and Israel and form a new clade within the Dickeya genus. About half of the Finnish isolates resembling strains within this new clade were virulent and caused wilting, necrotic lesions and rotting of leaves and stems. Similar symptoms were caused by D. dianthicola strains isolated from one potato sample and from several river water samples. Frequently, the rotting caused by the Dickeya strains was visible in the upper parts of the stem, while the stem base was necrotic from the pith but hard and green on the outside, resulting in symptoms quite different from the blackleg caused by Pectobacterium atrosepticum. The presence of Dickeya in the symptomatic plants in the field assay was verified with a conventional PCR and with a real-time PCR test developed for the purpose. The virulent Dickeya strains reduced the yield of individual plants by up to 50% and caused rotting of the daughter tubers in the field and in storage. Management of Dickeya spp. in the potato production chain requires awareness of the symptoms and extensive knowledge about the epidemiology of the disease. 相似文献
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Immigration in Finland has increased significantly in the last decades. The integration of immigrants and autochthonous Finns poses new challenges to the society. Nevertheless, the resulting cultural diversity creates opportunities for intercultural social development. According to previous studies, urban nature can benefit human well-being and it can also play a role in integration processes. However, the role urban nature can potentially play in integration is largely overlooked, and immigrants are rarely involved in the planning of urban nature. This paper presents the main results of a qualitative study carried out in Helsinki metropolitan area, Finland. The aim was to understand the role of urban nature in integration, and to address how the planning of urban nature can support integration and interculturalism. We found that using urban nature helps immigrants feel comfortable and enjoy their living environment. The interviewed immigrants were interested in getting information on urban planning, especially in their own neighbourhood, and many of them wanted to participate in planning, although they were unsure of their right to do so, and access to planning processes appeared problematic in many ways. To support integration and interculturalism, urban planning should take the opportunity to enhance intercultural understanding. Adhering to culturally sensitive processes, and developing trust with local residents by taking their views seriously, can do this. Nature has the potential to inspire people to connect with one another. 相似文献
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Westermarck E Skrzypczak T Harmoinen J Steiner JM Ruaux CG Williams DA Eerola E Sundbäck P Rinkinen M 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(2):177-186
Fourteen dogs had shown chronic or intermittent diarrhea for more than 1 year. Diarrhea had been successfully treated with tylosin for at least 6 months but recurred when treatment was withdrawn on at least 2 occasions. Tylosin-responsive diarrhea (TRD) affects typically middle-aged, large-breed dogs and clinical signs indicate that TRD affects both the small and large intestine. Treatment with tylosin eliminated diarrhea in all dogs within 3 days and in most dogs within 24 hours. Tylosin administration controlled diarrhea in all dogs, but after it was discontinued, diarrhea reappeared in 12 (85.7%) of 14 dogs within 30 days. Prednisone given for 3 days did not completely resolve diarrhea. Probiotic Lactobacillus rhamnosus GG did not prevent the relapse of diarrhea in any of 9 dogs so treated. The etiology of TRD, a likely form of antibiotic-responsive diarrhea (ARD) is unclear. The following reasons for chronic diarrhea were excluded or found to be unlikely: parasites, exocrine pancreatic insufficiency, inflammatory bowel disease, small intestinal bacterial overgrowth, enteropathogenic bacteria (Salmonella spp., Campylobacter spp., Yersinia spp., or Lawsoni intracellularis), and Clostridium perfringens enterotoxin and Clostridium difficile A toxin. A possible etiologic factor is a specific enteropathogenic organism that is a common resident in the canine gastrointestinal tract and is sensitive to tylosin but difficult to eradicate. Additional studies are required to identify the specific cause of TRD. 相似文献
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