Vegetation Season Research Articles

Vertical Columns with Sustainable Green Cover: Meadow Plants in Urban Design.

Unique vertical column structures were constructed for the greening of a structure at the Botanical Garden of Vilnius University, in which a plant cover was formed using the turf rolls of semi-natural meadows that were wrapped on 197 columns, with each column consisting of three equal segments. By evaluating the species composition and the abundance of vegetation in the segments of the columns, we studied how this natural cover changes and what its survival potential is. During the five years of observation, 97 plant species were determined in total. Over time, the initial plant species of fertile soils were mostly replaced by ruderal, nitrophilous, and pioneer plants. Out of the 58 original species, 18 disappeared, while 39 new ones emerged. In the vegetation cover on the north exposition of the building, the original species composition declined faster. The most persistent species were ruderal short-lived Conyza canadensis, Melilotus albus, and Urtica dioica, and long-lived Elytrigia repens. As for vegetation classes, the initial plant communities of the Molinio-Arrhenatheretea elatioris vegetation class were partially replaced by the plant communities of the Koelerio-Corynephoretea canescentis and Artemisietea vulgaris classes; however, unformed plant communities finally became prevalent. All directions, including the north, east, south and west, were equally dominated by semi-shade- and semi-light-loving plant species, together with a less abundant representation of light-loving species. Meanwhile, an unexpected establishment of the light-loving annual Arabidopsis arenosa was observed on the least illuminated north exposition. Likewise, the perennial Festuca pratensis, which is particularly resistant to wintering, emerged and spread on all expositions. The vegetation in the vertical columns was dynamic, and the initial plant species significantly diminished in the five years; however, as new species took place, the columns remained sufficiently covered with a green carpet of plants. This study reveals the benefits of using semi-natural meadow turfs in vertical greening of buildings in the harsh climate of a 5b hardiness zone, which is accompanied by distressing climatic fluctuations during the vegetation season.

Climate trends of a typical apple growing mid- hill district of Himachal Pradesh.

For four sample decades, the study examined the long-term climate trends along with the area and production changes in Chamba district of Himachal Pradesh. A database was collected for maximum temperature (Tmax ), minimum temperature (Tmin), and rainfall, and for the area and production of apple for the four representative decades of Chamba region of Himachal Pradesh. It has been observed that trends indicated that temperature in this district showed an increasing trend and precipitation (rainfall) showed decreasing trend. Temperature, rainfall was the main parameters collected along with other meteorological parameters. The minimum and maximum temperature & rainfall data were collected from the records of government departments for the period of at-least 25-30 years. Long term trends were generated to check the change detection. The minimum temperature in Chamba district has shown an increase of 0.36°C and maximum temperature increase by 0.3°C and annual rainfall decreased by 117.95 mm in 36 years. It has also been observed that many farmers are now opting for industrial crops like mushroom, flowers, off season vegetables because of climate change. Due to an increase in temperature, apple crop is getting less chilling hours, which is somehow affecting the quality of fruit. More long term research efforts are required to be conducted in Free Air Temperature Enrichment (FATE) which can enhance this study. This study also indicates that there is an increase in area and production in Chamba district but fluctuation is seen in productivity. Shifting to higher elevation might be temporary solution to meet the chilling requirement but a proper measures need to be taken. The area under apple cultivation has increased substantially from a mere 400 hectares in 1950s to 11. 4 lakhs hectares in 2020s but fluctuation is observed in the productivity of the crop. Considering the vital role that apple has in the economy of Himachal Pradesh, there is a need to study the production and productivity of the apple crop

Microclimatic gradients cause phenological variations within temperate tree canopies in autumn but not in spring

Tree crowns experience strong vertical microclimatic gradients, particularly in light availability. Surprisingly, little is known about whether these gradients cause within-crown variation in leaf phenology and whether such variations represent different light-use strategies of sun- and shade leaves.In a temperate mixed forest at the Swiss Canopy Crane II site in Switzerland, we measured over three years the annual leaf phenology in the upper and lower crowns of mature trees from six broadleaved and three conifer species. We further recorded the microclimate (temperature, humidity, light) continuously in various positions within the canopy.We found microclimatic canopy gradients to be strongest during summer, but negligible in winter and spring, indicating that any phenological gradients in autumn, but not in spring, might be driven by microclimatic differences. Budbreak timing did not differ within the crowns of any of the broadleaved trees. However, in the three species with deeper crowns, leaf unfolding was up to 10 days faster in the lower crown but showed no difference in the more shallow-crowned species. Surprisingly, only the evergreen conifers Abies alba and Picea abies showed earlier bud break in the lower crowns. In autumn, senescence in all broadleaved species progressed from the upper crown downwards, resulting in up to two weeks longer vegetation seasons in the lower crown.With this first broad assessment of within-tree phenology, we show how microclimatic gradients and different light-use strategies lead to a considerable variability of within-crown phenological gradients. We interpret the faster leaf unfolding in the lower crown of three broadleaved species as a shade avoidance strategy, allowing shade branches to improve their C balance early in the season. In contrast, longer retention of lower leaves in autumn is unlikely to significantly improve the C balance, and more likely caused by higher summer temperature and irradiance in the upper leaves.

The SWADE model for landslide dating in time series of optical satellite imagery

Landslides are destructive natural hazards that cause substantial loss of life and impact on natural and built environments. Landslide frequencies are important inputs for hazard assessments. However, dating landslides in remote areas is often challenging. We propose a novel landslide dating technique based on Segmented WAvelet-DEnoising and stepwise linear fitting (SWADE), using the Landsat archive (1985–2017). SWADE employs the principle that vegetation is often removed by landsliding in vegetated areas, causing a temporal decrease in normalized difference vegetation index (NDVI). The applicability of SWADE and two previously published methods for landslide dating, harmonic modelling and LandTrendr, are evaluated using 66 known landslides in the Buckinghorse River area, northeastern British Columbia, Canada. SWADE identifies sudden changes of NDVI values in the time series and this may result in one or more probable landslide occurrence dates. The most-probable date range identified by SWADE detects 52% of the landslides within a maximum error of 1 year, and 62% of the landslides within a maximum error of 2 years. Comparatively, these numbers increase to 68% and 80% when including the two most-probable landslide date ranges, respectively. Harmonic modelling detects 79% of the landslides with a maximum error of 1 year, and 82% of the landslides with a maximum error of 2 years, but requires expert judgement and a well-developed seasonal vegetation cycle in contrast to SWADE. LandTrendr, originally developed for mapping deforestation, only detects 42% of landslides within a maximum error of 2 years. SWADE provides a promising fully automatic method for landslide dating, which can contribute to constructing landslide frequency-magnitude distributions in remote areas.

The Brazilian peppertree biological control agent Pseudophilothrips ichini (Thysanoptera: Phlaeothripidae) displays a flexible feeding strategy between foliage and reproductive tissues

The biological control agent, Pseudophilothrips ichini, is being released for control of Brazilian peppertree, Schinus terebinthifolia (Anacardiaceae), an invasive weed of natural and agricultural areas of California, Florida, Hawaii, and Texas (USA). The thrips larvae and adults feed on flushed leaves and stems that are produced during the vegetative season of the host. However, during the reproductive season from September to December in Florida, few flushing leaves are available as resources are shunted to plant reproduction. As field releases were being implemented, thrips were found feeding and damaging immature fruits and flowers of their host. We hypothesized that the thrips used volatile organic compounds produced by reproductive tissues to locate and feed on these tissues. When examined under laboratory choice tests, individual thrips or groups of either 20 adults or larvae, chose flushing leaves over all reproductive tissues, female flowers, male flowers, and immature fruit. However, to simulate seasons when few flushing leaves were available, additional choice tests were conducted where flushing leaves were omitted, and only reproductive tissues and a filter paper control were included. Individual thrips or groups of either 20 adults or larvae selected all reproductive tissues over controls. When presented with a choice between immature and mature fruit, thrips chose immature fruit. Thrips caused significant damage to live female flowers, male flowers, and immature fruit, and thrips survival rates were similar when fed flush leaves, female flowers, or male flowers. The thrips responses could be tied to VOC production, which significantly varied among tissue types. Volatile blends from flush leaves that include DMNT, Terpinolene, and δ-Elemene may attract P. ichini whereas those that repel them include α-Thujene, α-Pinene, β-Pinene, Camphene, and β-Phellandrene. These results suggest P. ichini has a flexible feeding strategy and exploits Brazilian peppertree reproductive tissues when few flushing tips were available. Further they suggest thrips feeding will have direct impacts on Brazilian peppertree reproduction.

Latitudes and land use: Global biome shifts in vegetation persistence across three decades

Introduction: The dynamics of terrestrial vegetation are shifting globally due to environmental changes, with potential repercussions for the proper functioning of the Earth system. However, the response of global vegetation, and the variability of the responses to their changing environment, is highly variable. In addition, the study of such changes and the methods used to monitor them, have in of themselves, been found to significantly impact the findings.Methods: This research builds on a recently developed vegetation persistence metric, which is simple to use, is user‐controlled to assess levels of statistical significance, and is readily reproducible, all designed to avoid these potential pitfalls. This study uses this vegetation persistence metric to present a global exploration of vegetation responses to climatic, latitudinal, and land‐use changes at a biomes level across three decades (1982–2010) of seasonal vegetation activity via the Normalized Difference Vegetation Index (NDVI).Results: Results demonstrated that positive vegetation persistence was found to be greater in June, July, August (JJA), and September, October, November (SON), with an increasing vegetation persistence found in the Northern Hemisphere (NH) over the Southern Hemisphere (SH). While vegetation showed positive persistence overall, this was not constant across all studied biomes. Overall forested biomes along with mangroves showed positive responses towards enhanced vegetation persistence in both the northern hemisphere and southern hemisphere. Contrastingly, desert, xeric shrubs, and savannas exhibited no significant persistence patterns, but the grassland biomes showed more negative persistence patterns and much higher variability over seasons, compared to the other biomes. The main drivers of changes appear to relate to climate, with tropical biomes linking to the availability of seasonal moisture, whereas the northern hemisphere forested biomes are driven more by temperature. Grasslands respond to moisture also, with high precipitation seasonality driving the persistence patterns. Land-use change also affected biomes and their responses, with many biomes having been significantly impacted by humans such that the vegetation response matched land use and not biome type.Discussion: The use here of a novel statistical time series analysis of NDVI at a pixel level, and looking historically back in time, highlights the utility and power of such techniques within global change studies. Overall, the findings match greening trends of other research but within a finer scale both temporally and spatially which is a critical new development in understanding global vegetation shifts.

Free and underfit-scavenger river dynamics dominate the large Amazonian Pacaya-Samiria wetland structure

The Peruvian Amazon is known for harboring the greatest biodiversity on the planet, with a world record for biodiversity per unit area. Previous studies suggested that the high ecological value depends on correlations between ecosystem functionality and seasonal inundation control vegetation patches. However, the knowledge on how river morphodynamics and its complex erosion-depositional processes influence the aquatic mosaic and fishing activity in the region is still incipient. This study examines the hydrogeomorphology of the Peruvian tropical wetland of Pacaya Samiria, located in Western Amazonia, and its role in the distribution of aquatic habitats. By using remote sensing techniques, the hydrogeomorphological connectivity that bounds the Pacaya Samiria National Reserve is characterized by ancient to modern river processes. Additionally, river signatures developed by the Ucayali, Marañon, Huallaga, Pacaya, and Samiria Rivers overlap with fish extraction and dominant vegetation to describe how geomorphology is associated with the spatial distribution of fishing zones. Results indicated that paleochannels regulate wetland drainage within the Ucamara Depression, supporting stational water stagnation, vegetation cover, and formation of carbon rich detritus, relevant aspects to understand fish traits. Moreover, the Ucayali River dominates river dynamics in the Pacaya Samiria wetland, thus playing a pivotal role in shaping the complexity of streams and lakes. Furthermore, underfit-scavenger meandering rivers are observed in areas where paleochannels from large rivers are found. A geomorphological characterization of drainage patterns in freshwater environments, such as Amazonian wetlands, is crucial to develop sound management strategies. This methodological approach is expected to support decision-making in conservation actions in Amazonian environments based on understanding wetland connectivity and hydrogeomorphological behavior and their influence on commercial fisheries.

Impact of climatic factors on the duration of species fl owering in the Karadag Nature Reserve

The phenological responses of plants to changing weather conditions are very strong and can serve as an indicator of global climate change. If we understand how individual species respond to changing conditions, we can represent how ecosystems will change. The aim of this study was to analyze the exposure of climatic factors (air temperature and precipitation) on the fl owering duration of the wild vascular plants species in the Karadag Nature Reserve (Crimea). In general, 152 species were taken into account with a number of phenological observations from 5 to 8 years. Correlation analysis between the fl owering duration and the climatic parameters revealed a signifi cant response in 89 (58.6%) species. Moreover, the climatic factors of the current vegetative season impacted 71 species fl owering, previous vegetative season impacted 4 species fl owering, and both vegetative seasons impacted 14 species fl owering. Air temperature and precipitation equally impacted the fl owering duration: air temperature impacted 35 (41.2%) species fl owering; precipitation impacted 32 (37.7%) species fl owering; both factors impacted 18 (21.1%) species flowering. The flowering duration mostly was negatively correlated with air temperature values and positively with precipitation amount. Mesophytes and the forest community species were the most sensitive to the climatic factors; euxerophytes and the steppe community species were the least sensitive to the climatic factors.

Monitoring of protected fungi species by methods of modern information technologies

Monitoring of protected fungi species by methods of modern information technologies

Diversity of Agro-Biological Traits and Development of Diseases in Alfalfa Cultivars during the Contrasting Vegetation Seasons

Alfalfa exhibits high adaptability to a range of environmental conditions. The aim of this study was to evaluate the agro-biological traits of alfalfa and select its most promising cultivars under different contrasting vegetation seasons. The field experiment was carried out at the Institute of Agriculture of Lithuanian Research Centre for Agriculture and Forestry. In 2016 and 2018, eleven alfalfa cultivars of different origin were established in the Endocalcari Epigleyic Cambisol. In the seasons of 2017–2018 and 2019–2020, the agro-biological traits of alfalfa cultivars were evaluated during winter; at the height of spring regrowth; before flowering at the three cuts; and during the fresh and dry matter yields; we also examined the development of diseases at the three cuts. The cultivar Birutė from Lithuania was distinguished by its wintering, its plant height at spring regrowth, its height before flowering, and its fresh and dry matter yields. The cultivar Timbale from France was distinguished by its wintering, spring regrowth, and its height before flowering. The cultivar Magnat from Romania was distinguished by its height before flowering and the fact that it was less damaged by downy mildew. The cultivars Jõgeva 118, Juurlu, and Karlu from Estonia were distinguished by their wintering and the fact that they were less damaged by diseases. The cultivar Eugenia from Italy was distinguished by the fresh and dry matter yields and the height before flowering.

Performance study of an innovative concept of hybrid constructed wetland-extensive green roof with growing media amended with recycled materials

Implementation of green roofs requires a large amount of primary material, especially for constructing the growing media layer. In addition, irrigation of green roofs with potable water is uneconomical and unsustainable. The novel hybrid green roof system proposed in this paper is in line with the principles of circular economy as it incorporates recycled materials into green roof growing media and greywater for irrigation. Two experimental beds were built to evaluate the concept of treating greywater in a constructed wetland prior to using it to irrigate a dual-layer extensive green roof. The growing media in both two extensive green roof beds contained ca. 37.5% by volume of recycled crushed building rubble containing a large proportion of brick. One of the two beds additionally contained 9.5% by volume of sewage sludge-based biochar. The concept of the hybrid roof and novel growing media was evaluated based on laboratory analysis of the growing media and on onsite measurements of hydraulic and thermal performance. The growing media amended with recycled materials developed in this study had hydrophysical properties comparable to commercially available growing media without recycled materials. Observations made during one vegetation season from June to October and a ten day-intensive water quality monitoring campaign during September 2020 showed that the constructed wetland significantly reduced total nitrogen and orthophosphate concentrations in pre-treated greywater. Due to the irrigation method employed, in which water flowed predominantly through drainage mats below the growing media, nutrient-leaching by the irrigation water was avoided. Concentrations of nutrients in the effluent were observed to increase only in response to precipitation. The temperature peak of the bottom green roof layer was shifted by almost 9 h from the peak in air temperature, and temperature fluctuations were significantly reduced. Vegetation on the bed amended with biochar demonstrated more vigorous growth due to available nutrients in the biochar which increased the rate of temperature-reducing evapotranspiration. More water evapotranspirated more water, which provided more water retention capacity confirmed by a lower runoff coefficient. Simple storage routing hydraulic modeling of hybrid green roof runoff using a nonlinear reservoir was performed.

Fire Hazard: Undesirable Ecosystem Function of Orchard Vegetation

Fires will become an increasingly frequent perturbation even under the conditions of the mild climate zone and will interfere with the agricultural landscape. Fire is a natural phenomenon, and depending on ecosystems, vegetation may develop and contribute to the occurrence and spread of fire. Vegetation of the sour cherry orchard located in the climatically dry conditions of the South Moravian Region, Czech Republic (CR), was evaluated. Vegetation assessment was performed using phytocenological relevé. In each variant, 10 relevé were recorded. Coverage of the found species was estimated directly in percentages. Moreover, the maximum height in the stand was measured for each type of plant. Biomass of individual plant species was calculated, using the biomass index (IB) equation. The IB values of individual plant species in the treatments were processed by employing a multidimensional analysis of the ecological data. Different vegetation management practices in an orchard change the species diversity of the vegetation and thus the fire hazards in the orchard conditions. Grassy interrow has the most grass biomass during the entire vegetation season, and therefore represents the greatest hazard and spread of fire. The most important grasses include Arrhenatherum elatius, Dactylis glomerata, Festuca pratensis, Lolium perenne, and Poa pratensis. On the contrary, bare soil conditions in the interrow are most suitable for annual species, and this is the place with the highest changes in the number of species during the growing season. Biomass of the orchard vegetation combined with dry and warm weather increases the fire hazard. Annual and perennial grasses have very good potential for the production of biomass, which increases the hazard of fire. The nature of the vegetation in the orchards has the potential for the actual start of a fire and its subsequent spread, however, under other environmental conditions. During hot and dry weather, dead biomass may accumulate resulting in increasing the hazard of large wildfires. Varied orchard management practices lead to a higher diversity of vegetation and make orchards, islands of biodiversity in the agricultural landscape.

Characteristics of Soil Erosion and Nitrogen Loss in Vegetable Field Under Natural Rainfall

The effects of vegetable planting on soil loss and nutrient loss, runoff, soil erosion, and nitrogen (ammonium nitrogen and nitrate nitrogen) losses under individual rainfalls of fruit- and leaf-vegetable fields between April to October in 2021 were observed using in-situ observation testing. The results showed that: ① the runoff, erosion, and nitrogen loss of the fruit-vegetable pattern (eggplant-chili) were 1.27-2.00 times those under the leaf-vegetable pattern (leaf lettuce-sweet potato leaves), especially under the second season vegetable period. Those losses under the second season vegetable accounted for 50.86%-68.83% of the total losses under different vegetable patterns, which were approximately 1.03-2.04 times those under the first season vegetable. The runoff, erosion, and nutrient loss of vegetable fields under different treatments were both concentrated in June and July, and the nitrogen loss was mainly in the form of nitrate nitrogen with surface runoff. ② The runoff, erosion, and nutrient losses under individual rainfalls of vegetable fields under different treatments fluctuated among the vegetable growing season, and the losses were mainly concentrated in several typical rainfall events. On the whole, the loss and concentration of nitrate and ammonium nitrogen in runoff and erosion sediment of vegetables in the first season were lower than those in the second season. The runoff, erosion, and loss of ammonium nitrogen and nitrate nitrogen of fruit-vegetable were higher than those of leaf-vegetable. ③ Both rainfall amount and maximum 30 min rainfall intensity had significantly positive effects on runoff, soil loss, and nitrogen loss. Runoff, erosion, and nutrient losses under different vegetable patterns were mainly generated by moderate rain, heavy rain, and heavy rainstorms, which accounted for 29.58%-46.68%, 24.54%-36.79%, and 24.01%-39.13% of the total losses, respectively. The results also showed that soil erosion and nutrient losses generated by different rainfall grades were obviously different for the fruit- and leaf-vegetable treatments. The results indicated that the vegetable pattern had significant impacts on soil loss and nutrient loss, and the leaf-vegetable pattern could reduce soil erosion and nutrient loss compared with the fruit-vegetable pattern. Furthermore, for different vegetable patterns and vegetable growing seasons, the effects of rainfall on soil loss and nutrient loss were quite different. The results of this study were helpful in clarifying the soil erosion and nutrient loss characteristics of vegetable fields in South China.

Assessment of Climatic Impact on Vegetation Spring Phenology in Northern China

Spring phenology is often considered the start of season (SOS) for vegetation, which can affect ecosystem photosynthesis, respiration, and evapotranspiration. However, the long-run variation of SOS remains unclear at the regional scale. In this research, the long-term variation of SOS in northern China was explored by using the updated normalized difference vegetation index and monthly climatic data during 1982–2014. Furthermore, the relative importance of climatic factors on SOS was analyzed through partial correlation and multivariate regression methods. The main results were as follows: (1) average SOS largely ranged between day 120 and 165 of the year and varied widely for different vegetation types; (2) SOS during 1982–2014 showed an advancing trend, but it appeared to be reversed after 1998; (3) preseason minimum temperature was a dominant factor controlling SOS in most pixels in northern China, followed by maximum temperature (Tmx). However, impacts of radiation and precipitation on the trend of SOS primarily depended on vegetation types; (4) impacts of climatic factors on SOS declined in the period after 1998, especially for Tmx. These findings provide important support for modeling vegetation phenology and growth in northern China.

Plant phenology drives seasonal changes in shear stress partitioning in a semi-arid rangeland

Accurate representation of surface roughness in predictive models of aeolian sediment transport and dust emission is required for model accuracy and for models to inform wind erosion management. While past wind tunnel and field studies have examined roughness effects on drag partitioning, the spatial and temporal variability of surface shear velocity and the shear stress ratio remain poorly described. Here, we use a four-month dataset of total shear velocity (u*) and soil surface shear velocity (us*) measurements to examine the spatiotemporal variability of the shear stress ratio (R) before, during, and after vegetation green-up at a honey mesquite (Prosopis glandulosa Torr.) shrub-invaded grassland in the Chihuahuan Desert, New Mexico, USA. Results show that vegetation green-up, the emergence of leaves, led to increased drag and surface aerodynamic sheltering and a reduction in us* and R magnitude and variability. We found that us* decreased from 20% to 5% of u* as the vegetation form drag and its sheltering effect increased. Similarly, the spatiotemporal variability of R was found to be linked directly to plant phenological phases. We conclude that drag partition schemes should incorporate seasonal vegetation change, via dynamic drag coefficients and/or R, to accurately predict the timing and magnitude of seasonal aeolian sediment fluxes. The drag partition response to mesquite phenological phases also provided insight to potential mesquite herbicide treatment effects which, if successful, could increase wind erosivity and the onsite and downwind impacts of wind erosion unless protection by herbaceous plants is maintained.

On the Choice of the Most Suitable Period to Map Hill Lakes via Spectral Separability and Object-Based Image Analyses

Technological advances in Earth observation made images characterized by high spatial and temporal resolutions available, nevertheless bringing with them the radiometric heterogeneity of small geographical entities, often also changing in time. Among small geographical entities, hill lakes exhibit a widespread distribution, and their census is sometimes partial or shows unreliable data. High resolution and heterogeneity have boosted the development of geographic object-based image analysis algorithms. This research analyzes which is the most suitable period for acquiring satellite images to identify and delimitate hill lakes. This is achieved by analyzing the spectral separability of the surface reflectance of hill lakes from surrounding bare or vegetated soils and by implementing a semiautomatic procedure to enhance the segmentation phase of a GEOBIA algorithm. The proposed procedure was applied to high spatial resolution satellite images acquired in two different climate periods (arid and temperate), corresponding to dry and vegetative seasons. The segmentation parameters were tuned by minimizing an under- and oversegmentation metric on surfaces and perimeters of hill lakes selected as the reference. The separability of hill lakes from their surrounding was evaluated using Euclidean and divergence metrics both in the arid and temperate periods. The classification accuracy was evaluated by calculating the error matrix and normalized error matrix. Classes’ reflectances in the image acquired in the arid period show the highest average separability (3–4 higher than in the temperate one). The segmentation based on the reference areas performs more than that based on the reference perimeters (metric ≈ 20% lower). Both separability metrics and classification accuracies indicate that images acquired in the arid period are more suitable than temperate ones to map hill lakes.

Silver fir tree-ring fluctuations decrease from north to south latitude—total solar irradiance and NAO are indicated as the main influencing factors

Silver fir (Abies alba Mill.) is a flexible European tree species, mainly vegetating within the mountainous regions of Europe, but its growth responses across its latitudinal and longitudinal range have not yet been satisfactorily verified under changing environmental conditions. This study describes the tree-ring increment of silver fir in research plots across a latitudinal gradient from the northern range in Czechia (CZ), through Croatia (HR) to the southernmost range in Italy (IT). The research aims to analyze in detail the dynamics and cyclicity of the ring-width index (RWI) and how it relates to climatic factors (temperature and precipitation), the North Atlantic Oscillation (NAO), and total solar irradiance (TSI), including the determination of latitude. The results show that the main drivers affecting fir growth are the seasonal NAO index and TSI. Monthly temperatures affect RWI early in the vegetation season, while lack of precipitation during the summer is a limiting factor for fir growth, especially in July. Seasonal temperatures and temperatures in June and July negatively impact, while seasonal precipitation totals in the same months positively influence the RWI in all research plots across meridian. The longest growth cycles in fir RWI were recorded in the northernmost studied plots in CZ. These cyclical fluctuations recede approaching the south. The cyclic increase in RWI is related to the TSI, which decreases its effect from north to south. The TSI's effects vary, positively impacting CZ but negatively influencing HR while remaining relatively neutral in IT. On the other hand, seasonal NAO tends to negatively affect silver fir growth in HR and CZ but has a mildly positive effect in IT. In conclusion, the TSI and the influence of the seasonal NAO index are prevalent in the fir RWI and are accompanied by a greater cyclicity of RWI in Central Europe (temperature optimum) than in the Italian Mediterranean region, where this tree species is limited by climatic conditions, especially lack of precipitation.

Seasonal Dynamics of Vegetation in the Wetlands of the Lower Dniester NNP Based on Remote Data from the Landsat-8 Satellite

Over the season of 2020, the vegetation dynamics of the wetlands in the Lower Dniester National Nature Park were examined using the indices <i>NDVI </i>(Normalized Difference Vegetation Index) and <i>VCI</i> (Vegetation Condition Index) on the basis of Landsat-8 satellite remote sensing data. The results demonstrated that distribution of values throughout the vegetation season did not correspond to normal distribution, indicating variety of their habitat conditions. The vegetation development in spring was negatively affected by the pyrogenic factor, which formed some areas without vegetation and with poorly developed vegetation. Sharp increase in <i>NDVI</i> values in early summer occurred due to development of wetland ecosystems' edifier <i>Phragmites australis</i>, whose stems emerged from the pickle stage and developed a leaf lamina. In this period, the well-developed vegetation prevailed, its total area exceeded 97%. In autumn, the areas of the developed vegetation gradually decrease, whereas areas of the poorly developed increased. The results of the research showed effectiveness of remote sensing of wetland areas using <i>NDVI </i>and <i>VCI</i> to assess vegetation state; it also can be used for the purposes of the conservation, restoration and sustainable use of wetland ecosystems of the north-west Black Sea coastal area under increasing anthropogenic pressure and global climate change.

Airborne pollen and fungi indoors: Evidence from primary schools in Lithuania

The number of children suffering from respiratory allergies and asthma has been increasing worldwide and, hence, it is crucial to understand the burden of inhalant biological particles present in school facilities, where children spend one third of their life. From the perspective of indoor air quality, while there are numerous studies on outdoor bioaerosol exposure, there are still uncertainties regarding the diversity and deposition of airborne pollen and fungi indoors. When it comes to schools, there is limited research as to the potential bioaerosol exposure. Here we studied the indoor environment of public schools aiming to reveal whether primary schools of different sizes and at localities of different levels of urbanization may exhibit a variability in the biodiversity and abundance of particles of biological origin, which could pose a risk to child health. To achieve this, 11 schools were selected, located in a variety of environments, from downtown, to city centre-periphery, and to the suburbs. Fungal and pollen samples were collected from various surfaces in school classrooms and corridors, using passive air sampling and swab sampling. We demonstrated that fungi and pollen are detected in school premises during and after the vegetation season. The highest diversity of bioaerosols was found on the top of cabinets and windowsills, with Penicillium, Cladosporium and Acremonium being the most abundant indoors. The levels of fungi were higher in schools with more students. The diversity and amount of pollen in the spring were significantly higher than in samples collected in autumn. Our findings complemented existing evidence that bioaerosol measurements in schools (including kindergartens or informal education facilities) are vital. Hence, we here suggest that, in addition to monitoring air quality and bacterial levels indoors, fungi and pollen measurements have to be integrated in the existing regular biomonitoring campaigns so as to prevent exposure, increase awareness and manage efficiently allergic symptomatology.

Analysis of the Influence of Abiotic Factors on the Development of Microalgae in the Hyperhaline Kuyalnyk Estuary (Ukraine, the Black Sea Northwestern Coast)

Investigations were carried out in the ecosystem of the Kuyalnyk estuary during high water period in 2004-2007. Relationships between the species diversity of microalgae and their quantitative characteristics (cell numbers and biomass) and abiotic factors, including hydrophysical (water temperature, transparency, and suspended matter content), meteorological (precipitation sum), and hydrochemical (water salinity, the content of nitrogen, phosphorus, and silicon inorganic compounds, dissolved oxygen, readily oxidized organic matter, and pH) ones, were analyzed in different seasons. It has been shown that the biomass of microalgae in the Kuyalnyk estuary during vegetation season from April until October 2004-2007 correlated well with water level (<i>r</i> = -0.69) and water salinity (<i>r</i> = 0.71), and also with the content of mineral phosphorus (<i>r</i> = 0.77). The correlation with other abiotic factors was not so significant and depended on season.