On Bio-Deterioration of Solar Reflective Materials: An Innovative Experimental Procedure to Accelerate the Ageing Process of Surfaces

Solar reflective materials are one of the most efficient solution to the urban heat island effect, according to which temperatures, in urban areas are significantly higher than those in the surrounding rural areas. Solar reflective materials (SRM) are characterized by the ability to reflect solar radiation in the whole wavelength spectrum remaining cooler under the sun. The importance of radiative properties focused the attention more on SRM subjected to aging processes instead of the new products. According to this, several standards are, nowadays, available to investigate natural (ASTM G7, ANSI CRRC/S100) and accelerated (ASTM D7897) aging. Unfortunately, these standards do not take into account the presence and the growth of microorganisms such as algae and cyanobacteria, which can be responsible not only for the decrease of radiative properties against time, but also for the decay of physical and chemical properties of SRM themselves. This study outlines an experimental procedure to accelerate natural bio-deterioration of building materials through a laboratory test. Two types of SRM have been involved, studying their thermal properties before and after the bio-deterioration accelerated treatment. The methodology involves the use of a Temporary Immersion System (TIS bioreactor), which is based on the temporized soaking of materials samples with a liquid growth medium inoculated by selected species of algae or cyanobacteria. The system promotes a homogeneous contact between the materials surfaces and these microorganisms blowing sterilized air into the medium inside the bioreactor chamber. Within three weeks into TIS bioreactor, materials samples have shown large areas of biofilm deposition on themselves. The experimental procedure, hence, confirms the capability of the system to optimize environment conditions where the growth of microorganism and their interactions with materials results accelerated. Very high attention is given to the aim to make the procedure repeatable. For this proposal, all the variable factors are minimized, maintaining constant the environmental condition and working on sterility in order to do not contaminate or alter the growth inside the bioreactor

Effects of LED Lights and New Long-Term-Release Fertilizers on Lettuce Growth: A Contribution for Sustainable Horticulture

The horticulture sector has been directed by European guidelines to improve its practices related to environmental sustainability. Moreover, the practice of horticulture in urban areas is increasing since it provides fresh products that are locally produced. At the same time, horticulture needs to implement circular economy approaches and energy-efficient models. Therefore, to address these issues, this study investigated the effects of an integrated fertilizer-box-based cultivation system equipped with LED lights and coated porous inorganic materials (C-PIMs), which was applied as fertilizer, on Lactuca sativa L. growth. Two different types of lightweight aggregates were formulated considering agri-food and post-consumer waste, and they were enriched with potassium and phosphorus. Involving waste in the process was part of their valorization in the circular economy. Using PIMs as fertilizers enabled the controlled release of nutrients over time. The tests were carried out in controlled conditions using two LED lighting systems capable of changing their light spectrum according to the growth phases of the plants. The effects of two different lighting schemes on the growth of lettuce plants, in combination with different amounts of aggregates, were studied. The results showed that increasing the amount of C-PIMs statistically improved the lettuce growth in terms of dry biomass production (+60% and +34% for two different types of PIM application) when the plants were exposed to the first LED scheme (LED-1). Plant height and leaf areas significantly increased when exposed to the second LED scheme (LED-2), in combination with the presence of C-PIMs in the soil. The analysis of the heavy metal contents in the lettuce leaves and the soil at the end of the test revealed that these elements remained significantly below the legislated thresholds. The experimental achievements of this study identified a new approach to improve the environmental sustainability of horticulture, especially in an urban/domestic context

Review on the Influence of Biological Deterioration on the Surface Properties of Building Materials: Organisms, Materials, and Methods

A strong attention is recently paid to surface properties of building materials as these allows controlling solar gains of the building envelope and overheating of buildings and urban areas. In this regard, deterioration phenomena due to biological aggression can quickly damage solar-reflecting roof surfaces and thus increase sharply solar gains, discomfort, air-conditioning costs and waterproofing degradation. The same deterioration problem has deleterious effect on cultural heritage, ruining its huge historic and artistic value. This work is aimed at providing an overview on the different organisms that affect the surface of most used building materials, to support the design of new building materials with long-lasting surface properties and to find a way to preserve cultural heritage. Artificial ageing is the long-term aim of this investigation, in which what in nature happens after months or years is compressed in a very short time by forcing the growth of microorganisms through a strict control on the different conditioning factors. Both natural and artificial ageing are eventually outlined in the last part of this work to provide a comprehensive idea of what is necessary to study in a complete way biological ageing protocols on building materials. Several characterization techniques are also introduced to analyse the influence of microorganisms on the surface of different building materials

Suitability of Porous Inorganic Materials from Industrial Residues and Bioproducts for Use in Horticulture: A Multidisciplinary Approach

This study follows a circular economy approach through the preliminary implementation of a coated porous inorganic material (PIM), studied as sustainable controlled release fertilizer, and its application for lettuce Lactuca sativa L. cultivar Chiara growth. The PIM was made of pumice scraps that partially replaced clay as a natural raw material, spent coffee grounds as a porous agent, bovine bone ash and potassium carbonate to provide phosphorus (P) and potassium (K) nutrients, respectively. A coating made with defatted black soldier fly prepupae biomass was used as a nitrogen (N) source. Most of the ingredients used were industrial residues, with the aim of valorizing the raw waste materials present locally. The suitability of PIMs as a fertilizer was investigated with an interdisciplinary approach, which included the first chemical and physical characterization of the material, the evaluation of its antibacterial properties and of its use in horticulture through lettuce growth tests. As tests were carried out indoors, a specific LED lighting device was used to grow the lettuce. The release of nutrients into the soil was estimated by measuring the main elements in the fertilizers before and after their use in the soil. The first results from this characterization study support PIMs’ suitability for agronomic applications. The use of the PIMs suggested average higher dry weight (49%), fresh weight (112%), and leaf area (48%), compared to those with the use of a standard fertilizer soil, without the release of any dangerous element for the plant in the soil. These results are a promising beginning for the development of further studies already in progress on sustainable controlled-release fertilizers

Plant–environment interactions through a functional traits perspective: a review of Italian studies

Italy is among the European countries with the greatest plant diversity due to both a great environmental heterogeneity and a long history of man–environment interactions. Trait-based approaches to ecological studies have developed greatly over recent decades worldwide, although several issues concerning the relationships between plant functional traits and the environment still lack sufficient empirical evaluation. To draw insights on the association between plant functional traits and direct and indirect human and natural pressures on the environmental drivers, this article summarizes the existing knowledge on this topic by reviewing the results of studies performed in Italy adopting a functional trait approach on vascular plants, bryophytes and lichens. Although we recorded trait measurements for 1418 taxa, our review highlighted some major gaps in plant traits knowledge: Mediterranean ecosystems are poorly represented; traits related to belowground organs are still overlooked; traits measurements for bryophytes and lichens are lacking. Finally, intraspecific variation has been little studied at community level so far. We conclude by highlighting the need for approaches evaluating trait–environment relationship at large spatial and temporal scales and the need of a more effective contribution to online databases to tie more firmly Italian researchers to international scientific networks on plant traits

Propagazione in vitro di orchidee degli ambienti di risorgiva del medio Friuli.

Sono riportati i risultati relativi alla messa a punto di metodologie per la propagazione in vitro di orchidee di particolare interesse naturalistico. I semi utilizzati nella sperimentazione provengono da popolazioni naturali di orchidee di ambienti umidi e in particolare da paludi calcaree del medio Friuli

La germinazione in vitro delle orchidee: un approccio metodologico

La germinazione in vitro elle orchidee, in modo partiticolare di quelle terrestri, si presenta difficoltosa a causa dell'elevata dipendenza da funghi simbionti e delle diverse forme di dormienza dei semi. Sono illustrate le principali tecniche utilizzate per la germinazione in vitro e per la coltura delle plantule

Orchidee e insetti: una coevoluzione basata su ricompense e… inganni

I vantaggi derivanti dai perfetti adattamenti pianta-insetto sono il filo conduttore dell’opera di Darwin dedicata alle orchidee e i numerosi esempi riportati sono a delineare un quadro di straordinari rapporti che si sono stabiliti durante l’evoluzione tra le orchidee e i loro impollinatori. Vengono descritte alcune delle principali strategie di attrazione delle orchidee nei confronti dei pronubi.Il volume nel quale l'articolo è stato pubblicato è stato dedicato a Charles Darwin, socio onorario della Società dei Naturalisti e Matematici di Modena, in occasione del secondo centenario della sua nascita