Influence of site on dominant height : a comparison between Scots pine (Pinus sylvestris) and lodgepole pine (Pinus contorta)

En framtida befarad virkessvacka under 2000-talet gjorde att skogsbruket i Sverige började experimentera med främmande trädslag på 1960-talet. Målet var att öka produktionen med det snabbväxande trädslaget contortatall. Idag finns mer än 650 000 ha contortaskog på varierande marker i Norrland. Contortan och tallen är jämförbara trädslag men påverkas olika beroende på vilken miljö de lever i. I denna studie undersöks huruvida contorta och tall påverkas olika beroende på markfuktighet, översilning och jordtextur. Utifrån resultatet diskuteras det om contortan skulle vara mer lämpad på vissa typer av marker än den svenska tallen. Hypotesen var att trädslagens övre höjd påverkas olika beroende på grad av översilning, markfukt och typ av jordtextur. Mätdata från nio olika försökslokaler där contorta och tall planterats i liknande förhållanden användes till undersökningen. En variansanalys (ANOVA) gjordes för att jämföra ståndortsegenskaperna mot trädslagens övre höjd. Enligt modellen som skapades är det statistiskt bevisat att trädslag påverkar övre höjd och även att lokalen har ett samband med övre höjd. Modellen påvisar att översilning, markfuktighet och jordtextur inte påverkar övre höjd och inte heller att de påverkar de två trädslagen olika mycket. Om det finns en effekt från ståndortsegenskaperna är den effekten för liten för att upptäckas. Varje ståndortsegenskap är kopplad till den specifika lokalen träden växer på, vilket leder till att det är svårt att avgöra vilken variabel som påverkar resultatet.The fear of a future shortage of wood supply in the 21th century caused the Swedish forestry to start experimenting with exotic tree species during the 1960s. The goal was to increase the forest production with the new species lodgepole pine (Pinus contorta). Today there are over 650 000 hectares of lodgepole pine forests on different types of land in Norrland. Lodgepole pine and scots pine (Pinus sylvestris) are comparable tree species but will react differently to various habitats. This study examines whether the species react differently to ground moisture, lateral water and soil texture. Depending on the result, a discussion is made on how preferable the lodgepole pine is on different types of grounds compared to scots pine. The hypothesis was that lodgepole pines and scots pines upper height will have different reactions on the various ground properties. Data from nine different trials, where both tree species had been planted in similar habitats, were used for the analysis. An analysis of variance (ANOVA) was performed in order to compare the habitat's ground properties against the upper height of the two tree species. The result shows it is statistically significant that tree height depends on tree species and trial compartment. However, the model cannot prove that upper height is dependent on the three ground properties neither does the ground properties affect the tree species differently. If there is an effect from the ground properties it is probably too small to be found. Trial sites and ground properties are linked which makes a differentiation between them problematic

Material World: The Effects of Meditation Content on Materialistic Values

In the twenty-first century, Western cultures are highly materialistic and defined by consumeristic goals to garner as much “stuff” as possible (Berger, 2015). This constant pursuit has demonstrable adverse effects on personal and social well being (Bahl et al., 2016; Wang, et al., 2017), while overconsumption also has devastating impacts on the global environment. Previous studies found a negative relationship between levels of mindfulness and levels of materialism (Nagpaul & Pang, 2015; Watson, 2019), indicating the potential for mindfulness to combat otherwise materialistic behaviors. Furthermore, previous research demonstrated gratitude interventions led to lower scores on materialism (Chaplin, et al., 2018), indicating the significance of meditation content on one’s materialistic values. Following literature that meditation increased a person’s suggestibility (Gloede, et al., 2021), experiencing a ‘material abundance’ meditation may promote increased materialistic values. The purpose of this study was to explore the relationship between mindfulness meditation content and materialistic values through an experimental manipulation. We hypothesized participants who experienced a ‘material abundance’ meditation would show the highest materialistic values, followed by those who experienced a ‘body scan’ meditation, and lastly, those who experienced a ‘gratitude’ meditation would show the lowest materialistic values

Air Retention under Water by the Floating Fern Salvinia: The Crucial Role of a Trapped Air Layer as a Pneumatic Spring

The ability of floating ferns Salvinia to keep a permanent layer of air under water is of great interest, e.g., for drag‐reducing ship coatings. The air‐retaining hairs are superhydrophobic, but have hydrophilic tips at their ends, pinning the air–water interface. Here, experimental and theoretical approaches are used to examine the contribution of this pinning effect for air‐layer stability under pressure changes. By applying the capillary adhesion technique, the adhesion forces of individual hairs to the water surface is determined to be about 20 µN per hair. Using confocal microscopy and fluorescence labeling, it is found that the leaves maintain a stable air layer up to an underpressure of 65 mbar. Combining both results, overall pinning forces are obtained, which account for only about 1% of the total air‐retaining force. It is suggested that the restoring force of the entrapped air layer is responsible for the remaining 99%. This model of the entrapped air acting is verified as a pneumatic spring (“air‐spring”) by an experiment shortcircuiting the air layer, which results in immediate air loss. Thus, the plant enhances its air‐layer stability against pressure fluctuations by a factor of 100 by utilizing the entrapped air volume as an elastic spring

Template-controlled piezoactivity of ZnO thin films grown via a bioinspired approach

Biomaterials are used as model systems for the deposition of functional inorganic materials under mild reaction conditions where organic templates direct the deposition process. In this study, this principle was adapted for the formation of piezoelectric ZnO thin films. The influence of two different organic templates (namely, a carboxylate-terminated self-assembled monolayer and a sulfonate-terminated polyelectrolyte multilayer) on the deposition and therefore on the piezoelectric performance was investigated. While the low negative charge of the COOH-SAM is not able to support oriented attachment of the particles, the strongly negatively charged sulfonated polyelectrolyte leads to texturing of the ZnO film. This texture enables a piezoelectric performance of the material which was measured by piezoresponse force microscopy. This study shows that it is possible to tune the piezoelectric properties of ZnO by applying templates with different functionalities

Dry under water: air retaining properties of large-scale elastomer foils covered with mushroom-shaped surface microstructures

Superhydrophobic surfaces are well known for most different functions in plants, animals, and thus for biomimetic technical applications. Beside the Lotus Effect, one of their features with great technical, economic and ecologic potential is the Salvinia Effect, the capability to keep a stable air layer when submerged under water. Such air layers are of great importance, e.g., for drag reduction (passive air lubrication), antifouling, sensor applications or oil–water separation. Some biological models, e.g., the floating fern Salvinia or the backswimmer Notonecta, show long term stable air retention even under hydrodynamic conditions. Therefore, they are ideal models for the development of technical biomimetic air retaining surfaces. Up to now, several prototypes of such surfaces have been developed, but none provides both, stable air retention and cost effective large scale production. Meanwhile, a novel biomimetic surface is commercially available and produced on a large scale: an adhesive elastomeric film with mushroom-shaped surface microstructures that mimic the adhesion system of animals. In this study, we show that these films, which have been initially developed for a different purpose, due to their specific geometry at the microscale, are capable of stable air retention under water. We present first results concerning the capabilities of mushroom-shaped surface microstructures and show that this elastomer foil is able to stabilize a permanent air layer under water for more than two weeks. Further, the stability of the air layer under pressure was investigated and these results are compared with the predicted theoretical values for air retention of microstructured surfaces. Here, we could show that they fit to the theoretical predictions and that the biomimetic elastomer foil is a promising base for the development of an economically and efficient biomimetic air retaining surface for a broad range of technical applications