Serotoninergic Modulation of Phototactic Variability Underpins a Bet-Hedging Strategy in Drosophila melanogaster

When organisms’ environmental conditions vary unpredictably in time, it can be advantageous for individuals to hedge their phenotypic bets. It has been shown that a bet-hedging strategy possibly underlies the high inter-individual diversity of phototactic choice in Drosophila melanogaster. This study shows that fruit flies from a population living in a boreal and relatively unpredictable climate have more variable variable phototactic biases than fruit flies from a more stable tropical climate, consistent with bet-hedging theory. We experimentally show that phototactic variability of D. melanogaster is regulated by the neurotransmitter serotonin (5-HT), which acts as a suppressor of the variability of phototactic choices. When fed 5-HT precursor, boreal flies exhibited lower variability, and they were insensitive to 5-HT inhibitor. The opposite pattern was seen in the tropical flies. Thus, the reduction of 5-HT in fruit flies’ brains may be the mechanistic basis of an adaptive bet-hedging strategy in a less predictable boreal climate.

Comparison of Productivity and Physiological Traits of Faba Bean (Vicia faba L.) Varieties under Conditions of Boreal Climatic Zone

This study aimed to evaluate and compare the physiological traits, productivity, and seed quality of nine faba bean varieties grown in a field trial under the Boreal climate conditions. A two-factor field experiment was laid out in a split-plot design: The seeds in the main plots were sown and treated with seed fungicide (SF) and untreated (without SF) (factor A). The sub-plots were assigned to nine varieties (factor B). The physiological traits of faba bean significantly varied among the varieties, and the behavior of faba bean varieties differed between the two growing seasons. The values of physiological traits for varieties Julia and Boxer significantly surpassed the trial mean under wet conditions, while the trait values for Fuego and Bioro were surpassed under conditions of a lack of moisture. Fungicidal seed treatment had a negligible effect on the physiological traits, while it had a significant negative influence on the leaf area index at the beginning of the flowering stage. SF had a noticeable effect on seed yield only for the varieties Nida DS and Fuego. The findings of the study revealed that Fuego and Isabell were the most suitable faba bean varieties for cultivation in the Boreal climate zone as they were distinguished from the other tested ones by the highest seed yields.

Soil microbiome of different-aged stages of self-restoration of ecosystems on the mining heaps of limestone quarry (Elizavetino, Leningrad region)

Soil microbiome plays an important role in soil forming process as well as soil functioning. This is especially relevant for initial stages of soil regeneration after strong anthropogenic impact (i.e., in quarrying complexes). The study of soil microbiome in such areas is crucial for both understanding the forces driving soil formation and optimization of the reclamation techniques. This study is aimed to investigate the soil microbiome of different ages of soil formation on the heaps of limestone mines in conditions of boreal climate of North-West of Russia. Soil microbiome analysis was performed using high-throughput sequencing. Soils of the investigated sites were predominantly Rhendzic Leptosols. The initial set (2 years) of OTUs in the entire period of soil formation remains unchanged, accumulating more than 98% of the total microbiome in each time point. Analysis of beta-diversity (weighted and unweighted) demonstrated a clear differentiation of microbiomes of all time points, which suggests that underlying taxonomic structure variations can be attributed to variation of the minor taxa set composition. The most significant differences occur in Proteobacteria, Chloroflexi, Acidobacteria, and Actinobacteria, but majority of these phyla have different sets of OTUs demonstrating opposite trends. Generally time positively correlate with microbiome of carbonate soils in all cases of benchmark and newly formed soils is familiar because of the uniform zonal environmental conditions in geochemically specific landscape of Izhora upland.

Oribatid mites (Acari: Oribatida) from the Sella massif (Dolomites, Trentino, Italy) with description of Trichoribates valeriae n. sp. (Ceratozetidae)

Results from collections of oribatid mites in the cushion plant belt of Sass Pordoi and Piz Boè in the Italian Dolomites (Prov. Trento) are presented. A total of 10 oribatid species belonging to seven families were found. Most have a wide general distribution, Anachipteria shtanchaevae is restricted to the Alps. Three species are frequently or mainly found in the montane to alpine zone (A. shtanchaevae, Camisia horrida, Oribatula interrupta). Remarkable findings are Camisia foveolata, hitherto only known from the boreal climate zone, which indicates a preglacial relict distribution, and Kunstidamaeus lengersdorfi as highest recorded altitude for this species. Trichoribates valeriae n. sp., found in large numbers on both mountains, is described and compared with other congeners, and its systematic position is discussed. This species is characterized by a lamellar structure with small ridges and widely separated cusps, rounded rostrum with nose-like protuberance, 10 pairs of medium long notogastral setae with short bristles, notogastral porose area A1 divided in two parts, porose areas present on all tibiae and tarsi. Additional morphological information on the presence of porose areas on tarsi of Trichoribates scilierensis Bayartogtokh and Schatz, 2008 is given.

Vegetated roofs in boreal climate support mobile open habitat arthropods, with differentiation between meadow and succulent roofs

Vegetated roofs are hoped to benefit urban wildlife, yet there are few empirical results regarding the conservation potential of such roofs. In this paper, we focus on arthropods on vegetated roofs. We vacuum sampled 17 succulent, meadow or succulent-meadow roofs, in Helsinki, Finland, and used order to species level information together with trait data to describe the communities. We evaluated the importance of biophysical roof characteristics on shaping arthropod assemblages to provide information concerning roof designs that promote rich arthropod fauna. Arthropod communities differed between the three roof types and the influence of roof variables varied between and within arthropod orders. The main local drivers of arthropod abundance across the individually analysed taxa were roof height and vegetation, with mainly positive effects of height (up to 11 m) and litter cover, and mainly negative effects of grass cover. Based on trait data from true bugs, spiders and ants, the roofs consisted mainly of common dispersive species that are generalist feeders and associated with dry open habitats or have wide habitat tolerance. We found one true bug species new to the country and assume that it arrived with imported vegetation. Based on these findings, vegetated roofs of varying height and size benefit common generalists and fauna of open dry habitats, but seem to lack rare native specialists and may introduce non-natives if imported plant material is used. Because the responses to vegetation characteristics are taxon-specific, high diversity of roof vegetation types would benefit arthropod conservation.

The effects of organic and inorganic phosphorus amendments on the biochemical attributes and active microbial population of agriculture podzols following silage corn cultivation in boreal climate

Phosphorus (P) is the second most important macronutrient that limits the plant growth, development and productivity. Inorganic P fertilization in podzol soils predominantly bound with aluminum and iron, thereby reducing its availability to crop plants. Dairy manure (DM) amendment to agricultural soils can improve physiochemical properties, nutrient cycling through enhanced enzyme and soil microbial activities leading to improved P bioavailability to crops. We hypothesized that DM amendment in podzol soil will improve biochemical attributes and microbial community and abundance in silage corn cropping system under boreal climate. We evaluated the effects of organic and inorganic P amendments on soil biochemical attributes and abundance in podzol soil under boreal climate. Additionally, biochemical attributes and microbial population and abundance under short-term silage corn monocropping system was also investigated. Experimental treatments were [P0 (control); P1: DM with high P2O5; P2: DM with low P2O5; P3: inorganic P and five silage-corn genotypes (Fusion RR, Yukon R, A4177G3RIB, DKC 23-17RIB and DKC 26-28RIB) were laid out in a randomized complete block design in factorial settings with three replications. Results showed that P1 treatment increased acid phosphatase (AP-ase) activity (29% and 44%), and soil available P (SAP) (60% and 39%) compared to control treatment, during 2016 and 2017, respectively. Additionally, P1 treatments significantly increased total bacterial phospholipids fatty acids (ΣB-PLFA), total phospholipids fatty acids (ΣPLFA), fungi, and eukaryotes compared to control and inorganic P. Yukon R and DKC 26-28RIB genotypes exhibited higher total bacterial PLFA, fungi, and total PLFA in their rhizospheres compared to the other genotypes. Redundancy analyses showed promising association between P1 and P2 amendment, biochemical attributes and active microbial population and Yukon R and DKC 26-28RIB genotypes. Pearson correlation also demonstrated significant and positive correlation between AP-ase, SAP and gram negative bacteria (G−), fungi, ΣB-PLFA, and total PLFA. Study results demonstrated that P1 treatment enhanced biochemical attributes, active microbial community composition and abundance and forage production of silage corn. Results further demonstrated higher active microbial population and abundance in rhizosphere of Yukon R and DKC 26-28RIB genotypes. Therefore, we argue that dairy manure amendment with high P2O5 in podzol soils could be a sustainable nutrient source to enhance soil quality, health and forage production of silage corn. Yukon R and DKC 26-28RIB genotypes showed superior agronomic performance, therefore, could be good fit under boreal climatic conditions.