Impact of water scarcity on spruce and beech forests

One of the greatest threats posed by ongoing climate change may be regarded the drought caused by changes in precipitation distribution. The aim of presented study was to characterize reactions to dry conditions and conditions without drought stress on gross primary production (GPP) and net ecosystem production (NEP) of spruce and beech forests, as these two species dominate within the European continent. Daily courses of GPP and NEP of these two species were evaluated in relation to an expected decrease in CO2 uptake during dry days. The occurrence of CO2 uptake hysteresis in daily production was also investigated. Our study was performed at Bily Kriz(spruce) and Stitna(beech) mountain forest sites during 2010–2012 period. We applied eddy covariance technique for the estimation of carbon fluxes, vapor pressure deficit and precipitation characteristics together with the SoilClim model for the determination of drought conditions, and the inverse of the Penman–Monteith equation to compute canopy conductance. Significant differences were found in response to reduced water supply for both species. Spruce reacts by closing its stomata before noon and maintaining a reduced photosynthetic activity for the rest of the day, while beech keeps its stomata open as long as possible and slightly reduces photosynthetic activity evenly throughout the entire day. In the spruce forest, we found substantial hysteresis in the light response curve of GPP. In the beech forest, the shape of this curve was different: evening values exceeded morning values.     

Selective method for cyanobacterial bloom removal: hydraulic jet cavitation experience

The aim of this study was to investigate the suitability of hydraulic jet cavitation as a method for cyanobacterial water-bloom management. Effects of cavitation were studied on laboratory culture of the cyanobacterium Microcystis aeruginosa, on a culture of a green alga Chlorella kessleri (as a non-target species) as well as on a real cyanobacterial biomass with Microcystis sp. as a dominant species. Our results suggested that the cavitation treatment of cyanobacteria is capable of causing the disintegration of their gas vesicles. Using this treatment, up to 99 % removal efficiency of cyanobacteria was achieved. Moreover, no effect on cyanobacterial membrane integrity or metabolic activity was detected by flow cytometry; thus, hydraulic cavitation seems to be harmless from the viewpoint of possible release of cyanotoxins into the water column. The green algae (here C. kessleri) were not affected negatively by the cavitation, and thus, they may still act as the natural nutrient competitors of cyanobacteria in lakes, ponds or reservoirs treated by cavitation.     

Adaptation of wheat rusts to the wheat cultivars in former Czechoslovakia

Summary In former Czechoslovakia virulence of rusts attacking wheat was studied since the sixties. Since the same time genes for resistance in the registered cultivars were identified. The role of Berberis and Thalictrum as alternate hosts for stem rust and leaf rust, respectively, was investigated as well. Determined changes of virulence in rust populations could only partially be ascribed to changes of resistance genes in the grown cultivars. Unnecessary genes for virulence had no negative effect on the fitness of the pathogen. All tested samples of aeciospores from barberries attacked rye, not wheat. None of Thalictrum species occurring in the Czech and Slovak Republics was found to host wheat leaf rust. However, the sexual stage of wheat stem rust and wheat leaf rust could be induced on Berberis vulgaris and Thalictrum speciosissimum, respectively. General epidemiological conclusions are drawn from the results and experience of the last 35 years.     

The effects of timber harvest in a South Carolina blackwater bottomland

This study was initiated on the South Fork Edisto River in South Carolina to investigate and compare the impacts of two different harvest methods (helicopter and rubber-tired skidder) on the ecological structure and function of a blackwater forested wetland. The two harvest treatments were chosen to represent a broad spectrum of potential impacts and were compared to an undisturbed site. Following harvest in 1991, functional responses in vegetative productivity, herpetofaunal populations, and soil and water quality were evaluated in 1992 and 1993. Herbaceous biomass was greater on the helicopter and skidder treatments than on the undisturbed control. In general, the biomass measured on the skidder treatment was not significantly different from the biomass measured on the helicopter treatment. Higher decomposition rates were noted in the harvested areas as compared to the control. This was mainly attributed to higher soil temperatures, which accelerated microbial activity. Increased decomposition rates may have been responsible for elevated levels of ammonium and organic carbon observed in ground water samples. A total of 29 species of herpetofauna (10 amphibians and 19 reptiles) were observed during the study. Salamanders were found more often in the undisturbed control. Reptiles were observed more frequently in the harvested area. Although herpetofaunal species composition was different between harvest and control, indices of diversity were similar.     

Effects of different crating periods on selected biochemical indices in broiler chickens

Effects of different crating periods on selected biochemical indices were monitored in a group of unsexed ROSS 308 broiler chickens aged 42 days. 120 randomly selected chickens were weighted and placed in 15 heavy duty plastic crates with reduction in floor space approx. 160 cm2/kg of body weight of broilers (average body weight was 2.75 kg). Five crates were kept for 4 hours (Group 4h), another five crates for 8 hours (Group 8 h) and another five crates for 12 hours (Group 12h). After tested periods of crating the broilers were released and blood samples were withdrawn from Vena bosilico in 24 randomly selected birds from each group (Groups 4 h, 8 h, 12 h respectively) and also in other 24 randomly selected non-crated control birds. The results of our experiment proved that duration of crating significantly influenced the stress response in broiler chickens. The duration of crating period was positively correlated with the plasma corticosterone level and negatively correlated with the lactate dehydrogenase, cholesterol, triglycerides, glucose and lactate levels in the blood of broiler chickens.     

POSITRON EMISSION TOMOGRAPHY OF THE EQUINE DISTAL LIMB: EXPLORATORY STUDY

Positron emission tomography (PET) is a highly sensitive, noninvasive imaging technique for quantifying biological functions of tissues. However, at the time of this study, PET imaging applications had not been reported in the horse. The aim of this exploratory study was to determine whether a portable high‐resolution PET scanner could be used to image the equine distal limb. Images of the front feet and fetlocks of three research horses, with known lesions localized to the distal front limbs, were acquired under general anesthesia after administration of ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG), with doses ranging from 1.5 to 2.9 MBq/kg. The radiation exposure measured during imaging was slightly higher than ^99mTechnetium scintigraphy. However, the use of general anesthesia allowed the proximity and the contact time with the patient to be minimized for the staff involved. ¹⁸F‐FDG uptake was evident throughout the soft tissues, with the highest uptake in the coronary band and the lowest uptake in the tendons. Anatomic structures could be discriminated due to the high contrast between soft tissue and bone. Detected lesions included lysis of the flexor cortex of the navicular bone, lesions of flexor tendons and suspensory ligament, and abnormal uptake through the lamina of a laminitic subject. Findings indicated that tomographic molecular imaging is feasible in the equine distal limb and could be useful as a future diagnostic technique for clinical and research studies, especially those involving tendinopathy/desmopathy and laminitis.     

Circle of life: the common hamster (Cricetus cricetus) adaptations to the urban environment

Traditionally, urbanization has been seen as a negative phenomenon for biota. However, changes in the environmental parameters induced by urbanization might be favorable for some species. Over the past half‐century, the common hamster has actively populated cities, establishing populations in some European, Russian and Kazakhstan cities. Based on integrative methods, we investigated free‐range common hamsters inhabiting Simferopol from 2015 to 2018 to reveal possible adaptations to the urbanized environment across several parameters, including lifespan, hibernation period, reproductive activity and body mass. Results show that in urban areas, the common hamster demonstrates an extremely short hibernation period compared to other localities, possibly due to enhanced food resources from urban forestry (walnuts, locus and hazelnut), allowing the species to start breeding very early (February) and finish as late as October. We present the first evidence of polyandry for this species: mating of receptive females with several males and subsequent confirmation of multiple paternity. Despite high reproductive potential, the lifespan of the common hamster in urban conditions is generally very short (less than 1 year). We speculate that in the process of synurbization, the common hamster's innate plasticity across many life history traits permits it to successfully colonize throughout a wide range of habitats, with the ability to form novel adaptations to urban environments.     

Detecting the non-breeding region and migration route of Whimbrels(Numenius phaeopus rogachevae)in the East Asian-Australasian Flyway

Determining the migration routes and connections of migratory birds at the population level helps clarify intraspecific differences in migration.Five subspecies...     

Chalcone synthase expression and pigments deposition in wheat with purple and blue colored caryopsis

Red and white caryopses are typical in common wheat. Genotypes with purple and blue caryopses are also described. This coloring is caused by anthocyanins which deposit in the pericarp (purple) or aleurone layer (blue). The anthocyanins biosynthetic pathway is well described. The key enzyme is chalcone synthase (CHS). It catalyzes the first step. We observed the deposition of anthocyanins in the pericarp and aleurone layer, the expression of a chalcone synthase gene and the amount of two anthocyanins - cyanidin-3-glycoside (pericarp of purple caryopses), and delphinidin-3-glycoside (aleurone layer of blue caryopses) during caryopsis development. Purple pigment deposition was not homogeneous and/or uniform. At first, small isolated spots of purple color were formed and thereafter they expanded. In blue caryopses, however, the coloring process was more homogeneous. The expression of chalcone synthase mRNA occurred five days before pigment deposition and finished earlier than expected. Amounts of cyanidin-3-glycoside and delphinidin-3-glycoside increased in a similar manner. Amounts of these fell at the end of caryopses development probably due to formation of more complex substances.