Photoreceptors' gene expression of Arabidopsis thaliana grown with biophilic LEDsourced lighting systems

Using specific photoreceptors, plants can sense light signals fundamental to their growth and development under changing light conditions. Phytochromes sense red and far-red light, cryptochromes and phototropins sense UV-A and blue light, while the UVR8 gene senses UV-B signals. The study of the molecular mechanisms used by plants to respond to artificial biophilic lighting is of pivotal importance for the implementation of biophilic approaches in indoor environments. CoeLux® is a new lighting system that reproduces the effect of natural sunlight entering through an opening in the ceiling, with a realistic sun perceived at an infinite distance surrounded by a clear blue sky. We used the model plant Arabidopsis thaliana to assess the gene expression of the main plant photoreceptors at different light intensities and at different times after exposure to the CoeLux® light type, using highpressure sodium (HPS) lamps as control light type. Genes belonging to different families of photoreceptors showed a similar expression pattern, suggesting the existence of a common upstream regulation of mRNA transcription. In particular, PHYA, PHYC, PHYD, CRY1, CRY2, PHOT1, and UVR8, showed a common expression pattern with marked differences between the two light types applied; under the HPS light type, the expression levels are raising with the decrease of light intensity, while under the CoeLux® light type, the expression levels remain nearly constant at a high fold. Moreover, we showed that under biophilic illumination the light spectrum plays a crucial role in the response of plants to light intensity, both at the molecular and morphological levels

Effect of tree density on root distribution in Fagus sylvatica stands: a semi-automatic digitising device approach to trench wall method

5Knowledge of root profiles is essential for measuring and predicting ecosystem dynamics and function. In the present study, the effects of management practices on root (0.5 <= ø < 20 mm) spatial distribution were examined in a 40-year-old coppice stand (CpS 1968) and other two stands converted from coppice to thinned high forest in 1994 (CvS 1994) and 2004 (CvS 2004), respectively. The use of a semi-automatic digitising device approach was compared with a conventional root mapping method in order to estimate the time per person required from fieldwork to the final digital map. In July 2009, six trench walls per stand were established according to tree density, i.e. as equidistant as possible from all surrounding trees. Findings highlighted differences between the stands with CvS 1994 showing a lower number of small roots (2 <= ø < 5 mm), a higher mean cross-sectional area (CSA) of coarse roots (5 <= ø < 20 mm) and different root depth distribution as compared to CpS 1968 and CvS 2004 whose values were close to each other. The three diameter classes selected in this study showed significant relationships in terms of number of roots, scaling down from coarse- to small- and fine-roots. Forest management practices significantly affected only the number of small roots. The number of fine roots (0.5 <= ø < 2 mm) was isometrically related to their root length density (RLD, cm cm-3). No relationship occurred with RLD of very fine roots (ø < 0.5 mm). In conclusion, forest management practices in terms of conversion thinnings significantly affected belowground biomass distribution of beech forest in space and time. In particular, frequency of coarse roots was related to the stand tree density, frequency of small roots was related to the cutting age. Size of coarse roots was related to tree density but only several years after felling. The allometric relationship occurring between fineand small-roots highlighted how fine root number and RLD were only indirectly affected by forest management practices. These findings suggest that future investigations on the effect of forest thinning practices on fine-root traits like number, length and biomass several years after felling cannot ignore those on small roots.openDi Iorio, A.; Montagnoli, A.; Terzaghi, M.; Scippa, G.S.; Chiatante, D.DI IORIO, Antonino; Montagnoli, A.; Terzaghi, M.; Scippa, G. S.; Chiatante, Donat

Indicators of biodiversity in an intensively cultivated and heavily human modified landscape

Nowadays, the loss of biodiversity in agroecosystems due to the intensification of farming practices is happening very fast, and therefore, stopping or slowing it down should be a priority for conservation. To detect changes in these environmental contexts, one approach contemplates focusing on a limited set of indicator species that can alert us to ongoing changes in progress. In this research, we aimed to measure the biodiversity of vertebrates using a multi-taxa approach in an intensively cultivated and highly inhabited area located in northern Italy. We investigated the relationships between biodiversity and environmental characteristics and we identified the taxonomic groups that can be used as indicators of biodiversity. Data collection was carried out in 2016 with different methods depending on the taxonomic group, in 131 sampling units chosen using a Tessellation Stratified Sampling. Then we calculated for each sampling unit a standardized Biodiversity Index, which was related to environmental variables concerning the land use and the landscape configuration using Multiple Linear Regression Analysis and Information-Theoretic approach. We used correlation analyses and the Indicator Species Analysis (IndVal) to identify the taxonomic groups and species that can be used as indicators of biodiversity. Biodiversity was positively related to the number of patches of natural vegetation, whereas it was negatively affected by the number of patches of artificial surfaces and by habitat diversity. Our findings agree with those obtained by many other researchers, which pointed out that agroecosystems provide adequate shelters, suitable foraging habitats and nesting sites. The negative effect of habitat diversity was explained by the area-heterogeneity trade-off. Therefore, sites with high heterogeneity will not contain enough cover of residual natural vegetation, essential to maintain high biodiversity, because increasing compositional heterogeneity within a fixed area simultaneously reduces the surface of each cover type. The analyses showed that birds and reptiles might be used as biodiversity indicators of vertebrates. Eurasian Magpie and Green Whip Snake, both generalist species, were associated with sites of low biodiversity, whereas seven birds, both generalists and farmland specialists, were associated with sites of medium biodiversity. In high biodiversity sites there were not indicator species. To conclude, in less natural environments, such as urban and agricultural landscapes, a combination of specialist and generalist indicator species seems adequate to monitor biodiversity changes. Our findings increase the knowledge of these very dynamic ecosystems, being important both to plan strategies for biodiversity conservation and to guarantee ecosystems services useful for humans

Asymmetrical copper root pruning may improve root traits for reforesting steep and/or windy sites

Our research demonstrates that plant material can be produced in the nursery with asymmetrical root systems, which may have utility for reforestation of difficult planting sites characterized by steep slopes and/or windy conditions. Such a root system can be generated using chemical root pruning by applying cupric carbonate (Cu) that can arrest the development of, or cause mortality to, root apical meristems resulting in the formation of new lateral roots with an overall increase in the biomass, length, and volume of the root system. Our objective was to investigate the effect of chemical root pruning on the morphological and architectural traits of adventitious roots produced by poplar cuttings (Populus nigra L.) grown in containers coated with Cu in various symmetrical (Side, Bottom, Side + Bottom) and asymmetrical (half side + half bottom) patterns. After six weeks, roots of the cuttings were extracted from different container depths (Top, Middle, and Bottom) and portions (non-coated, Cu-coated), and analyzed. The root systems reacted to all coating patterns by increasing length, biomass, volume, and average diameters, but magnitude of increase was further affected by depth. In particular, root growth was unaffected at the Top of the container, and length was the highest at the Bottom depth. The Middle depth had a significant increment in both biomass and volume. Also, the root population increased in diameter as a possible response to Cu exposure. Interestingly, in the asymmetrically coated containers this depth response in the non-coated portions was of higher magnitude than in the Cu-coated portions

Fine-root seasonal pattern, production and turnover rate of European beech (Fagus sylvatica L.) stands in Italy Prealps: Possible implications of coppice conversion to high forest

The aim of this study was to investigate the possible effects of coppice conversion to high forest on the beech fine-root systems. We compared the seasonal pattern of live and dead fine-root mass (d<2 mm), production and turnover in three beech stands that differed in management practices. Tree density was higher in the 40-year-old coppice stand than in the stands that were converted from coppice to high forest in 1994 and 2004, respectively. We found that a reduction in tree density reduced the total fine-root biomass (Coppice stand, 353.8 g m-2; Conversion 1994 stand, 203.6 g m-2; Conversion 2004 stand, 176.2 g m-2) which continued to be characterised by a bimodal pattern with two major peaks, one in spring and one in early fall. Conversion to high forest may also affect the fine-root soil depth distribution. Both fine-root production and turnover rate were sensitive to management practices. They were lower in the Coppice stand (production 131.5 g m-2 year-1; turnover rate 0.41 year-1) than in the converted stands (1994 Conversion stand: production 232 g m-2 year-1, turnover rate 1.06 year-1; 2004 Conversion stand: production 164.2 g m-2 year-1, turnover rate 0.79 year-1)

Meristematic connectome: A cellular coordinator of plant responses to environmental signals?

Mechanical stress in tree roots induces the production of reaction wood (RW) and the formation of new branch roots, both functioning to avoid anchorage failure and limb damage. The vascular cambium (VC) is the factor responsible for the onset of these responses as shown by their occurrence when all primary tissues and the root tips are removed. The data presented confirm that the VC is able to evaluate both the direction and magnitude of the mechanical forces experienced before coordinating the most fitting responses along the root axis whenever and wherever these are necessary. The coordination of these responses requires intense crosstalk between meristematic cells of the VC which may be very distant from the place where the mechanical stress is first detected. Signaling could be facilitated through plasmodesmata between meristematic cells. The mechanism of RW production also seems to be well conserved in the stem and this fact suggests that the VC could behave as a single structure spread along the plant body axis as a means to control the relationship between the plant and its environment. The observation that there are numerous morphological and functional similarities between different meristems and that some important regulatory mechanisms of meristem activity, such as homeostasis, are common to several meristems, supports the hypothesis that not only the VC but all apical, primary and secondary meristems present in the plant body behave as a single interconnected structure. We propose to name this structure \u201cmeristematic connectome\u201d given the possibility that the sequence of meristems from root apex to shoot apex could represent a pluricellular network that facilitates long-distance signaling in the plant body. The possibility that the \u201cmeristematic connectome\u201d could act as a single structure active in adjusting the plant body to its surrounding environment throughout the life of a plant is now proposed

Biochar Enhances Plant Growth, Fruit Yield, and Antioxidant Content of Cherry Tomato (Solanum lycopersicum L.) in a Soilless Substrate

Biochar soil amendment can improve growing medium water and nutrient status and crop productivity. A pot experiment was conducted using Solanum lycopersicum var. cerasiforme plants to investigate the effects of biochar amendment (20% application rate) on a soilless substrate, as well as on plant growth, fruit yield, and quality. During the experiment, substrate characteristics, plant morphological traits, and root and leaf C/N content were analyzed at three sampling points defined as early stage (36 days after germination), vegetative stage (84 days a. g.), and fruit stage (140 days a. g.). Fruit morphological traits, titratable acidity, lycopene, and solid soluble content were measured at the end of the experiment. Biochar ameliorated substrate characteristics (Nav increase of 17% and Ctot increase of 13% at the beginning of the study), resulting in a promotion effect on plant root, shoot, and leaf morphology mainly at the vegetative and fruit stages. Indeed, at these two sampling points, the biochar-treated plants had a greater number of leaves (38 and 68 at the vegetative and fruit stages, respectively) than the untreated plants (32 and 49, respectively). The biochar also increased leaf area with a rise of 26% and 36% compared with the values measured in the untreated plants. Moreover, the amendment increased twofold root length, root surface area, and root, stem, and leaf biomasses in comparison with untreated plants. Regarding plant productivity, although fruit morphology remained unchanged, biochar increased flower and fruit numbers (six times and two times, respectively), acidity (75%), lycopene (28%), and solid soluble content (16%). By unveiling promoting changes in morphological traits, fruit number, and antioxidant content occurring in cherry tomato plants growing in a biochar-treated soilless substrate, it could be possible to highlight the importance of biochar for future applications in the field for enhancing plant production and fruit quality in a sustainable agriculture framework

Density of woodpeckers in a fragmented lowland landscape of Northern Italy

Habitat fragmentation is a major threat to biodiversity. Understanding how to enhance connectivity in highly fragmented landscape is crucial for wild fauna conservation. Here we investigate the habitat value of unmanaged forest patches, agro-forestry plantations and tree rows for two woodland species (Great Spotted Woodpecker and Green Woodpecker) in the fragmented lowland landscape of province of Pavia (Northern Italy). Distance sampling method was used to calculate densities of woodpeckers. Areas with high density of rows and unmanaged forest areas showed higher density of Great Spotted Woodpeckers. Density of Green Woodpeckers was similar in agro-forestry and unmanaged forest areas

Woodpeckers as Focal Species for an Ecological Network Design in the Po Plain (Northern Italy)

Habitat fragmentation is a major threat to biodiversity. Thus the improvement of connectivity in highly fragmented landscape is a crucial issue for animal conservation. In this study we designed an ecological network for woodland birds in the agricultural landscape of the Po Plain (Northern Italy) using woodpeckers (great spotted woodpeckers Dendrocopos major, lesser spotted woodpeckers Dendrocopos minor and green woodpeckers Picus viridis) as focal species. Habitat suitability for woodpeckers was evaluated by generalized linear models and multimodel inference handling data on land use, landscape metrics and surrounding context. Circuit theory was used to define the best corridors network, subsequently compared with the distribution of other woodland birds. Wooded riversides, extended agro-forestry plantations and scattered natural forest stands appeared as the best components of a corridor design for woodland birds. The fact that other species threatened by forest fragmentation (e.g. Eurasian nuthatches Sitta europaea and marsh tits Poecile palustris) mainly occurred in the corridors network defined in the present study emphasized these results