@phdthesis{Stollberg2024, author = {Stollberg, Maren}, title = {Vertical planting design: The suitability and microclimatic effect of perennials in a textile living wall system.}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-924}, school = {Hochschule Geisenheim University}, pages = {I -- 211}, year = {2024}, abstract = {Urban green infrastructure has gained significant attention in the context of adaptation to climate change because of its positive effects. One approach to enhancing urban green infrastructure is through the use of Living walls (LW), also known as vertical greenery systems. While considerable knowledge and studies on traditional green facades already exist, there is limited information available on LW. Both green facades and LW are associated with numerous well-documented benefits (e.g., biodiversity and clean air), but these benefits depend on the functionality and vitality of the plants. Our knowledge of plants suitable for LW is limited to only a few climate zones and empirical values that lack confirmed validity. To address this gap, we conducted a three-year experiment using a novel, modular LW system on experimental walls exposed with different exposures. The aim of the research was to develop a textile-based, substrate-free Living Wall, which displays a perennial, attractive and diverse plant image and contributes to cooling. In this experiment, we documented the development of the plants, assessed their suitability, and measured the effect of the plants on the ambient temperature. The experiment took place over three years (2017-2019) in Geisenheim, Germany, which has a temperate oceanic climate and falls under the winter hardiness Zone 8a. For the LW system, we utilized a textile-based mat without soil (1 m²) and selected plants from wet/fresh habitats to enhance evaporative cooling. We maintained frequent irrigation with a nutrient solution, resulting in the mat being consistently overwatered. Based on common designs used in landscape architecture and on the conditions of wet habitats, we created three variants: one which was seeded: "Meadow" and two plant modules: "Cascade" and "Ground Cover". Together these modules consisted of 34 perennials and geophytes. Additionally, we sowed seed mixtures of over 30 species on the textile mat (Meadow/Seeding). We also included a Control group without plants, in which moss and weeds developed and were partially removed. After a pre-growing period on horizontal greenhouse tables, we placed the green mats vertically on experimental walls facing north, south, east, and west. Four replicates of each variant were randomly installed. We assessed plant development using various methods, including visual evaluation of aesthetics and growth form, height measurements, photographs, analysis of species coverage and visibility, canopy analysis, winter survival rate, biomass measurement, root position, and leaf area. Additionally, we employed temperature sensors and an infrared (IR) camera to measure the temperature effects of the plants on and of the ambient temperature under different setups. Through the experiment, we gained valuable insights into the techniques, cultivation, and maintenance of LW. Overall, we observed differences in plant development depending on the exposure, season, plant variant, and spontaneous vegetation. The tested plants exhibited a special vertical growth form and height. We noticed delayed growth on the north exposure, with complete coverage achieved in the third year. The south exposure showed particularly high growth, while the east and west exhibited similar but slightly lower growth compared to the south. The perennials retained their visual appearance throughout the year, with almost all variants looking attractive from May to September. Until the onset of winter, all variants had an appealing appearance. Unexpectedly, we observed the establishment of moss. Most plants survived the mild winters (2018/2019), although a cold winter (2017/1018) with a late frost resulted in damage and mortality for many plants. We conducted a detailed analysis of the different plant variants, as follows: The Ground cover variant exhibited an attractive appearance and foliage decoration throughout the year. At the east, west, and north exposures, the plants showed an attractive appearance shortly after winter, while on the south wall, it took until May for the species to start regrowing. In particular, Waldsteinia ternata displayed a nice leaf texture and, together with Pachysandra terminalis, was the most visually appealing. Ajuga tenorii 'Mauro', Alchemilla caucasica, Glechoma hederacea, and Geum coccineum 'Carlskaer' demonstrated beautiful ornamental effects and flowered during the summer. The Cascade variant showcased its attractiveness during the summer season, as most of the plants became less prominent during the winter. We observed that Tellima grandiflora 'Rubra' and Heuchera Hybrid 'Purple Petticoats' were the most visually appealing in this variant. Hosta sieboldii 'Harry van Trier' exhibited a pleasing ornamental effect and flowered during the summer. The ferns exhibited delayed growth but gradually developed a nice leaf texture. Self-settled moss complemented the planting, covering the entire mat. In the Meadow / Seeding variant, we observed increasing growth in height and vegetation coverage that extended from April to October. Initially, we sowed 32 different plant species, but only 10 were able to establish and become visible. These included Galium (album and palustre), Lycopus europaeus s. str., Stachys palustris, Anthoxanthum odoratum s. str., Festuca spp., and Poa spp. It is important to follow maintenance steps for the Meadow-LW. We noticed that the vegetation recovered within a few weeks after cutting. We recommend one complete cut during the summer and the removal of dead plant material after the frost period ends in spring. To examine the temperature effects of the plants on the ambient temperature and the climatic conditions to which they were exposed, we measured the temperature in different setups. The vegetation temperature depends on factors such as air temperature, measurement position, planting variant, and plant species. We observed a cooling effect only at a short distance from the LW, indicating a microclimatic impact. In conclusion, it is possible to effectively green a textile-based, soilless LW system. However, an automated irrigation system and regular monitoring and maintenance are essential. We identified suitable perennial species for each exposure and compiled a list of plants suitable for LW, along with their specific requirements. Seeded meadow-LW can easily be established. Furthermore, we recommend continuing our methodological approaches to obtain temperature measurements in LW in future studies.}, language = {mul} } @phdthesis{Doerr2020, author = {D{\"o}rr, Oliver Sebastian}, title = {Influence of artificial sunlight from a microwave plasma lamp on morphology and secondary metabolism of horticultural plants}, volume = {2020}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-122}, school = {Hochschule Geisenheim University}, pages = {158}, year = {2020}, abstract = {Light is one of the most important abiotic factors for plant physiological processes. In addition to light intensity, the spectral quality of light can also influence the plant morphology and the content of secondary metabolites. In the horticultural industry, artificial light is used in to enable year-round production of herbs, ornamental plants and vegetables in winter terms. Until today, discharge lamps like high-pressure sodium (HPS) lamps, emitting predominantly orange and red light and high amounts of infrared radiation, are the most common lamp systems in greenhouses. In the last decades, light-emitting diodes (LEDs) emerged as an efficient alternative light source. LEDs have the advantage of distinct adjustments to the light spectrum. For a usage in horticultural industry LEDs are often too expensive. Furthermore, reduced plant growth can occur due to incorrectly adjusted light spectra and lower leaf temperatures caused by the lack of infrared radiation. In a research project (LOEWE, funding no. 487/15-29) funded by the Hessen State Ministry of Higher Education, Research and Arts, Microwave plasma lamps (MPL) were tested as new light sources for horticultural industry and plant research. The electrodeless lamp systems emit light in similar properties like sun light. The aim of the study was to determine the influence of artificial sunlight of the MPL on the accumulation of secondary metabolites, plant architecture and plant physiology of three different species (coleus, basil and potted roses). The MPL was compared with other light systems such as commercial HPS lamps, LEDs or ceramic metal halide lamps (CDM). In addition to morphological parameters such as plant height, internode length or fresh and dry weight, the phenolic content of leaves grown under the respective light sources were examined. Overall an increased far-red light content in the emission spectra of the MPL showed high influence on the plant architecture which was observed in all three plant species. Artificial sunlight from MPL induced stem elongation in coleus and basil plants, compared to the other tested light sources. In potted roses a reduced branching degree was observed under MPL light compared to HPS grown plants. In addition to the impact of far-red light also the blue light content of the emission spectra was found to be a strong influencing factor for plant physiological processes. A positive correlation between blue light content and leaf thickness was determined in coleus cultivated under MPL, LED, HPS and CDM lamps. Low blue light content in HPS emission spectra resulted in shade-adapted leaves with low photosynthetic capacity and susceptibility to high irradiances. Blue light was assumed to increase phenolic metabolites in basil and rose leaves. Furthermore, the different light treatments resulted in an alteration of the composition of essential oils of basil. Experiments with coleus plants demonstrated that besides light color also the infrared radiation, had an influence on secondary metabolites by causing different leaf temperatures. Coleus plants grown with MPL showed the lowest content of phenolic compounds such as rosmarinic acid per dry weight. Infrared radiation resulted in a faster plant development indicated by increased biomass production and higher leaf formation rate as observed in coleus and basil plants. The results obtained in this study show that the influence of leaf temperature should always be considered when comparing different lamp systems. Especially when LEDs are compared to discharge lamps an overestimation of light color can be a consequence since also infrared radiation influences the content of phenolic compounds and plant growth.}, language = {en} }