Sampling strategies for budgeting two Swedish lakes: Morphometry, seasons and other factors

• Main Author: Bergsjö, Mattias
• Format: Bachelor Thesis
• Language: English
• Published: UmeÃ¥ universitet, Institutionen för ekologi, miljö och geovetenskap 2017
• Subjects: Natural Sciences; Naturvetenskap; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-130316

Two lakes in northern Sweden were sampled for carbon dioxide (CO2), dissolved inorganic carbon (DIC), total organic carbon (TOC), total nitrogen (TN), oxygen (O2) and temperature in April and in May 2016. This to calculate budgets for the lakes as well as make comparisons and find what makes them differ. Morphometry, seasons and trophic levels were explored and found to potentially have different degrees of effect on concentrations. Morphometry showed noticeable spatial variance within and between lakes, meaning that more complex lakes will have different concentration throughout the lake compared to a simple morphometry which will not show this spatial spread. Different seasons showed variance in total concentrations rather than spatial variance. Levels of humic substances showed a small potential variance in total concentrations between the two lakes. The variances found were then used to determine whether one of two sampling methods were more valid than another. One strategy entailed sampling the deepest point only and let it represent the whole lake. The other used points spread out over the lake’s area, taking the morphometry of the lake into account. Initial results pointed to the second strategy being more accurate because of morphometry etc. however when considering things such as time and cost, the reasonableness of this strategy may not be favorable depending on the aim of an eventual study.