Browsing by Subject "soil"

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  • Westman, Carl Johan; Starr, Michael; Laine, Jukka (Suomen metsätieteellinen seura, 1985)
  • Kuusipalo, Jussi (Suomen metsätieteellinen seura, 1985)
    The vegetation and some physical and chemical soil properties were studied in 410 sample plots in a random sample of stands by two-way indicator species analysis, discriminant analysis and analysis of variance. Understorey vegetation was dependent on site fertility and on the tree stand (especially species composition). Although the forest vegetation was distributed in a rather continuous way along a soil fertility gradient, relatively unambiguous site classification was possible based on the appearance of indicator species and species groups.
  • Ahonen, Irja; Porkka, H. Osmo; Paasio, Ilmari; Luotola, V. L. (Vanamo, 1931)
    Annales Societatis zoologicae-botanicae Fennicae Vanamo tom. 15
  • Lindholm, Tapio; Nummelin, Matti (Suomen metsätieteellinen seura, 1983)
  • Greiser, Caroline; Hylander, Kristoffer; Meineri, Eric; Luoto, Miska; Ehrlen, Johan (2020)
    The role of climate in determining range margins is often studied using species distribution models (SDMs), which are easily applied but have well-known limitations, e.g. due to their correlative nature and colonization and extinction time lags. Transplant experiments can give more direct information on environmental effects, but often cover small spatial and temporal scales. We simultaneously applied a SDM using high-resolution spatial predictors and an integral projection (demographic) model based on a transplant experiment at 58 sites to examine the effects of microclimate, light and soil conditions on the distribution and performance of a forest herb, Lathyrus vernus, at its cold range margin in central Sweden. In the SDM, occurrences were strongly associated with warmer climates. In contrast, only weak effects of climate were detected in the transplant experiment, whereas effects of soil conditions and light dominated. The higher contribution of climate in the SDM is likely a result from its correlation with soil quality, forest type and potentially historic land use, which were unaccounted for in the model. Predicted habitat suitability and population growth rate, yielded by the two approaches, were not correlated across the transplant sites. We argue that the ranking of site habitat suitability is probably more reliable in the transplant experiment than in the SDM because predictors in the former better describe understory conditions, but that ranking might vary among years, e.g. due to differences in climate. Our results suggest that L. vernus is limited by soil and light rather than directly by climate at its northern range edge, where conifers dominate forests and create suboptimal conditions of soil and canopy-penetrating light. A general implication of our study is that to better understand how climate change influences range dynamics, we should not only strive to improve existing approaches but also to use multiple approaches in concert.
  • Sarvela, Konsta (Helsingin yliopisto, 2020)
    The purpose of this thesis was to design, build and test a system, which is capable of measuring in real time simple quantities influencing on tire-soil contact of agricultural tractors mobility. The measuring equipment is based on acceleration and distance sensors connected to the Arduino Uno microcontroller. The tractor’s CAN bus was logged and the data was saved using a CAN bus card connected to a Raspberry Pi minicomputer. The sensors were calibrated, and their sensitivity checked before performing the experiments while driving in the field. Accelerometers were placed on top of the rear axle of the tractor at both ends in housings printed for them and distance sensors were mounted behind the rear axle. All sensors were logged by using Raspberry's Raspbian operating system with a python program. The Raspberry was chosen as a computer because of its demanding low space, low cost, and versatility of interfaces. The properties of the field were monitored by monthly penetrometer measurements as well as SoilScout sensors embedded in the ground, which indicated the moisture and temperature of the ground at that depth in real time. The purpose of this was to find out the changes in the field during the growing season, which would also affect the tractor's mobility. The measurement were carried out successfully and the result were considered to be reliable and provide many other opportunities for the future. The results clearly indicated the factors influencing the tractor’s mobility and the different stages of the tillage could be recognized. Future challenges remain the filtering of large amounts of data and the application of measuring equipment in further research. The measurement equipment developed in the work is well suited for its purpose in terms of measurement accuracy and economical affordability. In the future, better accuracy could be achieved with more accurate measuring devices as well as data obtained from this work.
  • Kuusipalo, Jussi (Suomen metsätieteellinen seura, 1984)
  • Allen, John A.; Setälä, Heikki; Kotze, David Johan (2020)
    Urban residents and their pets utilize urban greenspaces daily. As urban dog ownership rates increase globally, urban greenspaces are under mounting pressure even as the benefits and services they provide become more important. The urine of dogs is high in nitrogen (N) and may represent a significant portion of the annual urban N load. We examined the spatial distribution and impact of N deposition from dog urine on soils in three urban greenspace typologies in Finland: Parks, Tree Alleys, and Remnant Forests. We analyzed soil from around trees, lampposts and lawn areas near walking paths, and compared these to soils from lawn areas 8 m away from pathways. Soil nitrate, ammonium, total N concentrations, and electrical conductivity were significantly higher and soil pH significantly lower near path-side trees and poles relative to the 8 m lawn plots. Also, stable isotope analysis indicates that the primary source of path-side N are distinct from those of the 8 m lawn plots, supporting our hypothesis that dogs are a significant source of N in urban greenspaces, but that this deposition occurs in a restricted zone associated with walking paths. Additionally, we found that Remnant Forests were the least impacted of the three typologies analyzed. We recommend that landscape planners acknowledge this impact, and design parks to reduce or isolate this source of N from the wider environment.
  • Lipas, Erkki (Suomen metsätieteellinen seura, 1983)
  • Mälkönen, Eino (Suomen metsätieteellinen seura, 1976)
  • Rimhanen, Karoliina; Ketoja, Elise; Yli-Halla, Markku; Kahiluoto, Helena (2016)
    More than half of the cultivation-induced carbon loss from agricultural soils could be restored through improved management. To incentivise carbon sequestration, the potential of improved practices needs to be verified. To date, there is sparse empirical evidence of carbon sequestration through improved practices in East-Africa. Here, we show that agroforestry and restrained grazing had a greater stock of soil carbon than their bordering pair-matched controls, but the difference was less obvious with terracing. The controls were treeless cultivated fields for agroforestry, on slopes not terraced for terracing, and permanent pasture for restrained grazing, representing traditionally managed agricultural practices dominant in the case regions. The gain by the improved management depended on the carbon stocks in the control plots. Agroforestry for 6-20 years led to 11.4 Mg ha(-1) and restrained grazing for 6-17 years to 9.6 Mg ha(-1) greater median soil carbon stock compared with the traditional management. The empirical estimates are higher than previous process-model-based estimates and indicate that Ethiopian agriculture has greater potential to sequester carbon in soil than previously estimated.
  • Selonen, Salla; Dolar, Andraž; Jemec Kokalj, Anita; Sackey, Lyndon N.A.; Skalar, Tina; Cruz Fernandes, Virgínia; Rede, Diana; Hurley, Rachel; Nizzetto, Luca; van Gestel, Cornelis A.M. (Elsevier, 2021)
    Environmental Research 201: 111495
    Abrasion of tire wear is one of the largest sources of microplastics to the environment. Although most tire particles settle into soils, studies on their ecotoxicological impacts on the terrestrial environment are scarce. Here, the effects of tire particles (<180 μm) on three ecologically relevant soil invertebrate species, the enchytraeid worm Enchytraeus crypticus, the springtail Folsomia candida and the woodlouse Porcellio scaber, were studied. These species were exposed to tire particles spiked in soil or in food at concentrations of 0.02%, 0.06%, 0.17%, 0.5% and 1.5% (w/w). Tire particles contained a variety of potentially harmful substances. Zinc (21 900 mg kg−1) was the dominant trace element, whilst the highest concentrations of the measured organic compounds were detected for benzothiazole (89.2 mg kg−1), pyrene (4.85 mg kg−1), chlorpyrifos (0.351 mg kg−1), HCB (0.134 mg kg−1), methoxychlor (0.116 mg kg−1) and BDE 28 (0.100 mg kg−1). At the highest test concentration in soil (1.5%), the tire particles decreased F. candida reproduction by 38% and survival by 24%, and acetylcholinesterase (AChE) activity of P. scaber by 65%, whilst the slight decrease in the reproduction of E. crypticus was not dose-dependent. In food, the highest test concentration of tire particles reduced F. candida survival by 38%. These results suggest that micro-sized tire particles can affect soil invertebrates at concentrations found at roadsides, whilst short-term impacts at concentrations found further from the roadsides are unlikely.
  • Hakala, Kati P. (2020)
    Fungal disease late blight (Phytophthora infestans) causes considerable damage to potato crops worldwide. Fluazinam is a widely used pesticide employed against the late blight in potato cultivation. It ends up into soil during spraying and at the end of the growing season when potato foliage is incorporated into the soil. Nevertheless, there is very little literature about behaviour of fluazinam in soil, especially in the conditions that exist in Finland. Therefore, in the preparation of user guidelines, studies made elsewhere are used. From the environmental risks point of view, behaviour of fluazinam in Finnish conditions should be known better. Soils in the boreal zone are characterised by low pH and low temperatures that delay microbiological decomposition and they are typically high in organic matter and saturated by water for long periods in autumn, winter and spring. A prerequisite for assessing the environmental risk of fluazinam is knowledge of its sorption and desorption tendency as well as its degradation rate in boreal conditions. This information is needed, because more aggressive strains of Phytophthora infestans have spread to northern latitudes, increasing the need to use fungicides. In this study, a specific and repeatable high-performance liquid chromatography method utilizing a diode array detector was developed to determine the presence of fluazinam in soil. This method differs from most of the methods found in the literature, which used gas chromatography or gas chromatography-mass spectrometry as an instrument for analysing fluazinam. The method consists of acetonitrile extraction, clean-up with solid-phase extraction and separation using a mobile phase consisting of 70% acetonitrile and 30% water (v v-1), including 0.02% acetic acid. The method was successfully applied to various laboratory experiments and to soil samples collected from potato fields in which fluazinam had been used. In the systematic experiments carried out in controlled conditions, performed with both the fluazinam standard and the commercial product Shirlan®, the effect of soil organic matter on the fluazinam degradation was tested, as well as the persistence of fluazinam in the boreal zone soils for a maximum of one year. The major outcomes of the laboratory experiments were that fluazinam degradation was enhanced by the presence of soil organic matter and even after one year of incubation, more than half of the added fluazinam was recovered. Additionally, soil samples were collected from intensively cultivated potato fields. Over half of these field samples contained varying concentrations of fluazinam, but no substantial accumulation of fluazinam was detected.
  • Marley, Laura (Helsingfors universitet, 2009)
    The black truffle (Tuber melanosporum) is an inscrutable mushroom. It is widely believed that the physico-chemical properties of a soil are of great importance for it. Its cultivation in the Auvergne region in France is fraught with impediments. Gérard Chevalier (Institut National de la Recherche Agronomique) postulates that soils with higher than 40% clay content would be inauspicious, unless moderated by a compensating effect from increased rock fragments content. The work undertaken should substantiate this hypothesis, and furthermore take inventory of the mycorrhizal status of the 25 truffle orchards, some of which are thirty years old. The results show that 50% of the plantations still house Tuber melanosporum mycorrhizae. Statistical analysis of the collected information vis-à-vis soil analyses and interpretations of soil profiles in relation to production, shows that a high clay content diminishes the chances of success. The results attained are not sufficient to assert the compensatory effect of soil stoniness. This study moreover highlights the significant roles of total carbonate, active carbonate, phosphorus and potassium contents. These results should be considered with caution, since the small size sample consists of “instances” with heterogeneous characteristics, and the soil analysis methodology does not take into account various environmental factors, whose impact could well be significant (for example light conditions in the orchards). Despite these limitations, this study conveys a dual adage, both scientific and technical. For researchers, it brings some additional insights. For those who wish to produce Tuber melanosporum, it confirms an existing potential in Auvergne. By and large, it illuminates the murky manifest countenance of the black truffle.
  • Eriksson, J.; Bergholm, J.; Kvist, K. (Suomen metsätieteellinen seura, 1981)
  • Kubin, Eero (Suomen metsätieteellinen seura, 1990)
  • Valin, Marjo (Helsingfors universitet, 2014)
    Suomenlinna is a sea fortress that consists of eight islands and it is a very popular tourist attraction in Helsinki. The vegetation of Suomenlinna has been influenced by its location in the outer archipelago and by the previous military use. The primary aim of this study was to explore the composition and abundance of plant species in soil seed banks of dry meadows at Kustaanmiekka. The established vegetation of the dry meadows was studied in 2009. Soil seed samples were collected in April 2011 from ten dry meadows located around Kustaanmiekka. The samples were taken from two different soil layers: 0-4,5 cm and 4,5-9 cm. Seedling emergence method was chosen to study the seed banks. It was carried out from May to October 2011 in the Viikki campus greenhouse at the University of Helsinki. A total of 5887 seeds from 83 taxa germinated from the soil seed bank samples. The most common species were Berteroa incana (L.) DC., Festuca rubra L. and Potentilla argentea var. argentea. The seed banks contained a few polemochorous species (Berteroa incana, Epilobium hirsutum L. and Silene latifolia Poir. ssp. alba (Mill.) Greuter & Burdet which were brought in Finland with military troops. Noteworthy species found only in the seed bank were Descurainia sophia (L.) Webb ex Prantl and Matricaria recutita L.. The seed density varied from 5030 to17600 seeds/m2. Compared to the short-lived species, the amount of perennial species and their seeds was greater in the seed banks. The number of species and seeds differed between the dry meadows. A 2 luonnonalue had the highest number of species while Makeavesialtaiden luonnonalue and Kustaanmiekan sisäosan hiekkataso had the highest number of seeds. The total number of species and the average number of seeds didn´t correlate with the content of the main nutrients or humus in the soil, nor with soil pH or soil type. The soil seed banks could be utilized in the maintenance of the dry meadows in Kustaanmiekka by uncovering and breaking the soil. Rare meadow species that reproduce from seeds and that are still present in the vegetation would also benefit from this. More research is needed to determine the best method to utilize the soil seed banks when seeking to recruit as many species from the seed bank as possible.
  • Crosier, Brittni Joette (Helsingin yliopisto, 2020)
    Biogeography is a crucial aspect to ecological studies, as an ecosystem is comprised of the physical habitat, the organisms living there, and the interactions of these components. Community structure, and therefore functioning, are inherently of a spatial nature. Spatial structure of populations is often crucial basic knowledge for understanding the evolutionary history, dispersal patterns, and resilience of any given species. One aspect of spatial structure, and the topic covered in this study, is community distance decay, or the rate at which community similarity decreases with physical distance. More of the landscape is constantly being altered by humans on a large scale, so it is increasingly important to understand the effects that these anthroprogenic changes to the environment has on local populations. Studying community distance decay helps form understanding of dispersal and establishment limitations for different organisms, which is necessary for mitigating biodiversity loss. Many studies show that habitat fragmentation and loss has greatly impacted the structure of plant and animal communities, but there has been much less focus on fungal communities. There’s no certainty that fungi is impacted in the same ways, given the different lifestyles and dispersal methods, so the aim of this study is to contribute to the much needed research on fungal community structure at various scales. This aim is addressed by examining fungal community distance decay from small scale of a couple kilometers or less to a fairly large scale encompassing a landscape of primarily urban, forest, and agricultural areas. The five main localities of sampling were in middle and southern Finland: Helsinki, Lahti, Tampere, Jyväskylä, and Joensuu. Sampling locations and plot design were chosen to allow the comparison of communities separated by a mosaic, as well as along a short rural to urban gradient, to assess the effects of habitat type. From each location, six plots were decided, two in urban core, one in urban edge, two in natural core, and one in natural edge. The role of dispersal ability and functional traits in distance decay is also studied by comparing results from two different methods of fungi sampling, which were collecting spores from the air using cyclone samplers, and taking soil cores to gather fungal biomass. All samples were DNA analysed with high-throughput sequencing and the results from the DNA barcoding were used to create OTU clusters, by which the 30 plots could be compared through relative abundances of OTU’s. I determined the similarity of fungal communities using an analysis of similarity (ANOSIM) test in R, where all possible variables (site, habitat type, sample type) were used as a grouping in individual tests, thereby indicating which variable is associated with highest community difference. I also determined the differences in functional groups and major taxonomic levels among locations and sampling method using interactive taxanomic (KRONA) charts. Results showed that there are differences in fungal community structure among habitat type and sampling type. However there was greater difference at the level of plots than site locations, so clear patterns of strong community distance decay with physical distance was not measured in this study. The results suggest that fungal communities can be fairly impacted by human caused habitat change, and individual characteristics, such as dispersal methods or lifestyle, effect the rate of community distance-decay. This provides a valuable early insight into fungal community patterns, which need deeper study to understand the complexities and mechanisms behind them.