Cynipid galls on oak leaves are resilient to leaf vein disruption.

Oaks serve as host plants for numerous insects, including those forming galls. Galls induced on oaks are completely dependent on leaf resources. Many other folivores damage veins of leaves, which may result in cutting galls off from sources of assimilates, nutrients and water. We hypothesised that the disruption of the continuity of leaf vascular tissues stops gall development, leading to the death of the larva. Leaves of sessile oak (Quercus petraea) with Cynips quercusfolii galls in the initial stage of development were marked. The diameter of the galls was measured, and the vein on which the gall was present was cut. Four experimental treatments were established: control - with no cutting, cutting the vein distal to the gall relative to the petiole, cutting the vein basal to the gall and cutting both sides. The average survival rate (live galls at the end of the experiment including healthy larvae, pupae or imagines inside) - was 28.9%. The rate varied depending on the treatment and was 13.6% in the treatment with the vein cut on both sides and about 30% in the remaining treatments. However, this difference was not statistically significant. The growth dynamics of galls are highly dependent on the experimental treatment. The largest galls grew in the control treatment, and the smallest galls were in the treatments with the veins cut on both sides. Unexpectedly, even cutting veins on both sides did not result in the immediate dieback of the galls. The results suggest that the galls are very strong nutrient and water sinks. The functions of the cut vein are likely taken over by other lower-order veins, allowing nourishment of the gall to complete larva development.

Variability of Functional Groups of Rhizosphere Fungi of Norway Spruce (Picea abies (L.) H.Karst.) in the Boreal Range: The Wigry National Park, Poland.

Rhizosphere microbial communities can influence plant growth and development. Natural regeneration processes take place in the tree stands of protected areas, which makes it possible to observe the natural changes taking place in the rhizosphere along with the development of the plants. This study aimed to determine the diversity (taxonomic and functional) of the rhizosphere fungal communities of Norway spruce growing in one of four developmental stages. Our research was based on the ITS region using Illumina system sequencing. Saprotrophs dominated in the studied rhizospheres, but their percentage share decreased with the age of the development group (for 51.91 from 43.13%). However, in the case of mycorrhizal fungi, an opposite trend was observed (16.96-26.75%). The most numerous genera were: saprotrophic Aspergillus (2.54-3.83%), Penicillium (6.47-12.86%), Pyrenochaeta (1.39-11.78%), pathogenic Curvularia (0.53-4.39%), and mycorrhizal Cortinarius (1.80-5.46%), Pseudotomentella (2.94-5.64%) and Tomentella (4.54-15.94%). The species composition of rhizosphere fungal communities was favorable for the regeneration of natural spruce and the development of multi-generational Norway spruce stands. The ratio of the abundance of saprotrophic and mycorrhizal fungi to the abundance of pathogens was high and promising for the durability of the large proportion of spruce in the Wigry National Park and for forest ecosystems in general.

Accumulation of particulate matter, heavy metals, and polycyclic aromatic hydrocarbons on the leaves of Tilia cordata Mill. in five Polish cities with different levels of air pollution.

Urbanized areas are struggling with the problem of air pollution and as the number of people living in cities is increasing, the situation is likely to deteriorate. One of the most harmful pollutants is particulate matter (PM). Increased levels of PM in the atmosphere are likely to have a negative impact on human health. Phytoremediation technology could be a solution. It involves plants acting as bio-filters by accumulating particles on, and in the leaves, thus removing the particles from the atmosphere. This study investigates the accumulation of PM including heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs), on the foliage of small-leaved lime (Tilia cordata Mill.) in five Polish cities. There were significantly different PM amounts found in the trees between the cities which related to the different quantities of PM in the atmosphere at these cities. Significant differences were found between cities for the amounts of the different particulate size fractions, and the HMs and PAHs in leaves. Strong winds reduced the amount of PM on leaves, especially the smallest fractions, but no relationship with precipitation was found. The results suggest that T. cordata improves the air quality in cities and can be used as an effective bioindicator for PM air pollution.

Mobile samplers of particulate matter - Flying omnivorous insects in detection of industrial contamination.

Flying insects are potential mobile samplers of airborne particulate matter (PM). However, current knowledge on their susceptibility to PM is limited to pollinators. Insects' capacity for particle surface accumulation depends on the lifestyle, structure of the body integuments, and behavioral patterns. Here, we investigate how two species of flying omnivorous insects from the genus Vespula, possessing direct interactions with air, soil, plants, and herbivores, indicate industrial pollution by accumulating coarse (PM10) and fine (PM2.5) particles on their bodies. The internal accumulation of particles in wasps' gut tissues is assessed considering heavy metals exposure to reveal and discuss the potential magnitude of ecotoxicological risks. Female individuals of Vespula vulgaris and V. germanica were sampled with a hand-netting near to Harjavalta Cu-Ni smelter and in the control areas in southwestern Finland. They were analyzed with light microscopy (LM), electron microscopy (SEM, TEM), and energy-dispersive X-ray spectroscopy (EDX) methods. Near to the smelter, wasps trapped significantly more particles, which were of bigger size and their surface optical density was higher. Vespula vulgaris accumulated larger particles than V. germanica, but that wasn't associated with morphological characteristics such as body size or hairiness. In both areas, accumulated surface PM carried clays and silicates. Only in polluted environments PM consistently contained metallic and nonmetallic particles (from high to moderate weight %) of Fe, Ni, Cu, and S - major pollutants emitted from the smelter. Wasps from industrially polluted areas carried significantly more granules in the columnar epithelial midgut cells. TEM-EDX analyses identified those structures were associated with metal ions such as Cr, Cu, Ni, and Fe. As epithelial gut cells accumulated metal particles, midgut confirmed as a barrier for metal exposure in wasps. External PM contamination in wasps is suggested as a qualitative, yet a natural and simple descriptor of local industrial emissions.

Effects of nursery production methods on fungal community diversity within soil and roots of Abies alba Mill.

The aim of this study was to elucidate how different nursery production methods influence the composition of and relationship between soil and root community levels of Abies alba. In the Miedzylesie Forest District, we quantified the responses of samples of both community-level fine roots and surrounding soil to environmental changes evoked by various seedling production methods. Fungi levels were identified based on their ITS 1 region and 5.8 S rDNA component. Analysis was conducted using Illumina SBS technology, and the obtained sequences were compared with reference samples deposited in the UNITE. Chemical analysis of the soil was also performed. Different nursery production methods resulted in a strong decoupling in the responses of fungal community levels between soil and roots. Changes in growth conditions imposed by production methods were significant in determining species composition. We found differences in fungal communities among functional groups of samples. In the soil, the dominant species of mycorrhizal fungi were Tylospora asterophora, Amanita rubescens, and Russula ionochlora. Mycorrhizal fungi in roots included Tuber anniae, Thelephoraceae sp., and Acephala applanata. Specific soil substrate conditions significantly influenced fungal community composition, leading to an increase in abundance of mycorrhizal fungi, specifically T. anniae.

Adaptation of a simple method to determine the total terpenoid content in needles of coniferous trees.

In ecological research, quantitative methods are often used to measure the total content of metabolites groups (i.e., phenols, carbohydrates). Until recently, there has been no simple and effective method to determine the total terpenoid content with satisfactory repeatability and sensitivity. The procedure proposed by Ghorai et al. (2012) requires the use of fresh plant material. That may be problematic when experimental units are located far from a laboratory. Our goals were to optimize the procedure, and to find the threshold of misestimation using the procedure adjusted to work with dried material. Needles of Pinus sylvestris were used to test the effect of changes in drying, grinding, storage, and extraction on determined total terpenoid content. All applied changes in material storage and grinding decreased the quantity of the terpenoids in needles. Only air-dried and ball-milled material produced similar results to those obtained with fresh material - can be recommended if the fresh material unattainable. Air-dried material may be stored for up to three months, but it resulted in greater variation and then greater sample size is needed. Lower sample mass and solvent volume have no impact on accuracy. Shorter extraction time, oven-drying or microwaving leads to unreliability of measurements.

"Not just a hobby, but a lifestyle": Characteristics, preferences and self-perception of individuals with different levels of involvement in birdwatching.

Birdwatching is one of the most sustainable types of nature-based tourism and, at the same time, a form of recreation that is developing very dynamically. Birdwatching is attracting more and more people, not only professionals, but also amateurs from many countries. Birdwatching research is still relatively embryonic, especially when compared to nature tourism or wildlife tourism. Our main aim was to determine preferences and opinions of birdwatchers visiting the largest national park in Poland, in relation to their different levels of involvement. The data were collected in 2018 from a survey of a sample of 357 Polish and foreign birdwatchers. Results showed that birdwatcher respondents were predominantly male, middle-aged, and living in a large city. An important tool described in this article is a new scale that assesses the level of involvement of individual people engaged in birdwatching activity. This scale corresponds well with the individual characteristics of birdwatchers. Most birdwatchers defined their birdwatching activity as a permanent rather than a temporary hobby and therefore considered it to be more of a lifestyle than a hobby. Engagement in birdwatching activity increased with age and frequency of trips. The two most important reasons for birding were 'to be close to nature' and 'fascination with birds'. It has been proven that the development of birdwatching in the future will require a developed infrastructure enabling interaction with the objects of observation.

Survival and Recovery of the Pine-Tree Lappet Dendrolimus pini When Subjected to Simulated Starvation.

There are many reasons to study the survival and recovery of animals after starvation in simulated transport conditions or other passive dispersal methods. To do so, we chose Dendrolimus pini, an economically important pest of Scots pine with great potential in terms of passive dispersal outside its territory. In this work, we sought to answer the following questions: What is the maximum survival of different instar larvae after total starvation? Does access to dry tissues of the preferred host plant extend the lifespan of the larvae? Does the possibility of larvae recovery exist after starvation for various periods? We found that older larvae survived longer without food than younger larvae. Moreover, dry food did not extend the lifespan of the larvae. Our observations showed that insects were interested in food and tasted it at the beginning, but they did not feed on it for long. Furthermore, larvae recovery was indeed possible, and the time of starvation did not significantly affect this. We generally concluded that the D. pini larvae were characterized by the ability to survive without food for up to one month, which confirms that this species is able to survive long durations of transport to almost anywhere in the world.

Particulate matter on foliage of Betula pendula, Quercus robur, and Tilia cordata: deposition and ecophysiology.

Trees in urban and industrial areas significantly help to limit the amount of particulate matter (PM) suspended in the air, but PM has a negative impact on their life. The amount of PM gathered on leaves depends on quantity, size, and morphology of leaves and can also be increased by the presence of epicuticular waxes, in which PM can become stuck or immersed. In this study, we determined the ability of PM to accumulate on leaves in relation to the species of tree and PM source. We tested saplings of three common European tree species (Betula pendula, Quercus robur, and Tilia cordata) by experimentally polluting them with PM from different sources (cement, construction, and roadside PM), and then assessing the effects of PM on plant growth and ecophysiology. In all studied species, we have found two types of PM accumulation: a layer on the leaf surface and an in-wax layer. Results showed that the studied species accumulate PM on their leaf blade, reducing the efficiency of its photosynthetic apparatus, which in a broader sense can be considered a reduction in the plants' normal functioning. Saplings of Q. robur suffered the least, whereas B. pendula (especially photosynthetic rate and conductivity) and T. cordata (especially increase in leader shoot length) exhibited greater negative effects. The foliage of B. pendula collected the most PM, followed by Q. robur, and then T. cordata, regardless of the dust's source. All tested species showed a tendency for higher wax production when growing under PM pollution stress. We believe that, potentially, B. pendula best enhances the quality of the PM-contaminated environment; however, faster leaf fall, reduced productivity, and worse quality of wood should be considered in urban forest management.

The Effects of a Forest Therapy Programme on Mental Hospital Patients with Affective and Psychotic Disorders.

The positive effect of forest bathing on the mental health and wellbeing of those suffering from post-traumatic stress disorder or experiencing stress has been proven. It is not known, however, how 'forest therapy' affects the mental health of people who are treated in a psychiatric hospital for affective or psychotic disorders. Potentially, forest therapy could bring many benefits to these people. To test the potential effectiveness of this therapy, a quasi-experiment was carried out in a psychiatric hospital in Olsztyn (north Poland). In the summer and autumn of 2018, the patients of the psychiatric hospital in Olsztyn participated in forest therapy interventions. The proposed forest therapy consisted of participating in one hour and forty-five minutes walks under the supervision of a therapist. Subjects filled out the Profile of Mood States Questionnaire (POMS) and the State Trait Anxiety Inventory (STAI-S) before and after the study. In the case of a group of patients with affective disorders, forest therapy had a positive effect on nearly all POMS scale subscales, with the exception of the 'anger-hostility' subscale, which did not change its values significantly after the intervention. In these patients, the greatest impacts were noted in the subscales 'confusion' and 'depression-dejection'; the level of anxiety measured with the STAI-S scale also significantly decreased. In the case of patients with psychotic disorders, the values of the 'confusion' and 'vigour' subscales and the STAI-S scale exhibited the greatest changes. These changes were positive for the health of patients. Regarding the 'fatigue' subscale, no significant changes were observed in patients with psychotic disorders. The observed changes in psychological indicators in psychiatric hospital patients with both kinds of disorders indicate that the intervention of forest therapy can positively affect their mental health. The changes observed in psychological indicators were related to the characteristics of the given disorder.

Intensity of Stripping and Sugar Content in the Bark and the Bast of European Beech (Fagus Sylvatica).

The choice of particular trees for stripping by deer is puzzling because a preference is observed for trees of the highest social class. Trees ranked highest in the stand can produce more carbohydrates as a product of carbon assimilation. Among the many important nutrient and defense groups of metabolites in plants, high sugar content is postulated to be an attractant due to its impact on the sense of taste of different herbivores. Thus, we hypothesize that the carbohydrate content in the bast of the European beech is the most important factor by which deer make their choice. Our aim was to assess whether the sugar content in the bark and in the bast can be a factor which influences the intensity of bark stripping of particular trees in a beech thicket by red deer. A single episode connected with tree damaging pertained to 7% of the trees on the analyzed sampling plots. In total, 27% of the trees were damaged, including old damages. The mean size of damage to a given tree equaled 36% of the tree's circumference and 0.06 m2 of the trunk's surface. Analysis of the sugar content in the bast and in the bark jointly indicates that the trees subjected to bark stripping possessed a distinctly higher sugar content than the trees which were not damaged. The probability of bark stripping grows together with an increase in the sugar content of the bark and of the bast.

Changing Host Plants Causes Structural Differences in the Parasitoid Complex of the Monophagous Moth Yponomeuta evonymella, but Does Not Improve Survival Rate.

Recently in Poland, cases of host expansion have frequently been observed in the typically monophagous bird-cherry ermine moth (Yponomeuta evonymella), which has moved from its native host plant, bird cherry (Prunus padus), to a new, widely distributed plant that is invasive in Europe, black cherry (P. serotina). We attempted to verify the reasons behind this host change in the context of the enemy-free space hypothesis by focusing on parasitoids attacking larval Y. evonymella on one of three host plant variants: The primary host, P. padus; initially P. padus and later P. serotina (P. padus/P. serotina); or the new host, P. serotina. This experiment investigated if changing the host plant could be beneficial to Y. evonymella in terms of escaping from harmful parasitoids and improving survival rate. We identified nine species of parasitoids that attack larval Y. evonymella, and we found that the number of parasitoid species showed a downward trend from the primary host plant to the P. padus/P. serotina combination to the new host plant alone. We observed a significant difference among variants in relation to the percentage of cocoons killed by specific parasitoids, but no effects of non-specific parasitoids or other factors. Total mortality did not significantly differ (ca. 37%) among larval rearing variants. Changing the host plant caused differences in the structure of the parasitoid complex of Y. evonymella but did not improve its survival rate. This study does not indicate that the host expansion of Y. evonymella is associated with the enemy-free space hypothesis; we therefore discuss alternative scenarios that may be more likely.

Particulate matter on two Prunus spp. decreases survival and performance of the folivorous beetle Gonioctena quinquepunctata.

Woody plants growing along streets and construction sites play an important role in removing harmful particulate matter (PM). Researchers rarely consider the impact of different types and size fractions of PM deposited on the leaves on insect folivores. We determined differences in the accumulation of cement and roadside PM on the leaves of two Prunus species (P. padus and P. serotina) with different leaf surface structures. We also determined the effect of PM on the beetle Gonioctena quinquepunctata, the main pest of these plants. Saplings were artificially dusted in greenhouses and leaves were utilised for larval and adult insect stages feeding in laboratory conditions. Road PM accumulated in greater amounts than did cement PM, regardless of plant species. For both PM sources, P. padus accumulated twofold more than did P. serotina. Insect survival was negatively affected by PM pollution; however, neither Prunus species nor PM source variant significantly affected masses of larvae and pupae, duration of larval and pupal development or relative growth rates. The experiment showed strong negative influences of PM were noted only for adult insects, due to the grazing period being longer than that in larvae. The mass of adult insects and the efficiency of conversion of ingested food (ECI) were lower for insects exposed to PM than those for control insects. Insects compensated for lower ECI by eating a greater total amount of food (TFE). Adult insects gained significantly higher mass when fed with P. serotina than with P. padus. The effect of PM on analysed plant metabolites was insignificant. Only Prunus sp. and date of collection affected the level of condensed tannins and total phenols. Our results indicate that, when investigating the effect of the host plant on folivore performance, the accumulation of PM, as well as its type and quantity, should be taken into account.

Sex Ratio and Body Mass of Adult Herbivorous Beetles Depend on Time of Occurrence and Light Conditions.

Body mass and sex ratio (F/M) of folivorous insects are easily measured parameters that are commonly used to assess the effect of food quality, living conditions, and preferences on the selection of favourable sites for offspring. A study was conducted on the polyphagous beetle, Gonioctenaquinquepunctata (a pest of the native Prunus padus and alien P. serotina) and on the monophagous beetle, Alticabrevicollis coryletorum (a pest of Corylus avellana). Both species have a similar life cycle with emergence of current-year adults in summer, and reproduction of 1-year-old insects in spring. A. brevicollis coryletorum feeds primarily on sunlit shrubs, while G. quinquepunctata prefers shaded leaves. The present study assessed the effect of time of occurrence(insect age) on body mass in both sexes and on the sex ratio F/M, taking into account the influence of light conditions associated with their favoured food source (sunlit vs. shaded leaves). We hypothesized that a change in body mass in current-year insects would be determined by the amount of consumed food, while the sex ratio would be stable, when in 1-year-old insects females would die shortly after oviposition, while males would be active for a prolonged time. Results confirmed the hypothesis that changes in mass of current-year beetles was determined by the amount of food intake. We also found that in spring, unfertilized females coexist with fertilized ones and that the latter females live for some time after oviposition; resulting in fluctuations of the mean mass for females. In both species, 1-year-old beetles were heavier than current-year. The preference of A. brevicollis coryletorum for sunlit leaves results in a higher body weight than in G. quinquepunctata in both seasons. The data are consistent and indicate seasonal fluctuations in body mass and changes in the sex ratio in 1-year-old beetles, due to the entrance into their reproductive period.

Preferential feeding and occupation of sunlit leaves favors defense response and development in the flea beetle, Altica brevicollis coryletorum--a pest of Corylus avellana.

The monophagous beetle, Altica brevicollis coryletorum, is a major leaf pest of Corylus avellana (common hazel). In contrast to majority of the other studied species of shrubs, sunlit leaves are grazed to a much greater extent than shaded leaves. Since the observation of a link between leaf irradiance level and A. brevicollis feeding is unique, we hypothesized that feeding preference of this beetle species is related to the speed needed to escape threats i.e. faster jumping. We also hypothesized that sunlit leaves are more nutritious and easier to consume than the leaves of shaded shrubs. Results indicated that beetle mass was greater in beetles occupying sunlit leaves, which is consistent with our second hypothesis. The study also confirmed under laboratory conditions, that larvae, pupae and beetles that were fed full-light (100% of full light) leaves were significantly heavier than those fed with shaded leaves (15% of full light). In the high irradiance conditions (higher temperature) duration of larval development is also reduced. Further results indicated that neither the concentration of soluble phenols, leaf toughness, or the number of trichomes could explain the insect's preference for sunlit leaves. Notably, measurements of jump length of beetles of this species, both in the field and under laboratory conditions, indicated that the defense pattern related to jumping was associated with light conditions. The jump length of beetles in the sun was significantly higher than in the shade. Additionally, in laboratory tests, beetle defense (jumping) was more strongly affected by temperature (15, 25, or 35°C for 24 h) than by leaf type. The effect of sunlit, higher nutrient leaves (greater level of non-structural carbohydrates) on defense (jumping) appears to be indirect, having a positive effect on insect mass in all developmental stages.