10 research outputs found
Cellulose biosaccharification by Irpex lacteus wood decay fungus
Enzymatic hydrolysis is an environmentally friendly technology to produce sugars from pretreated biomass. Here, we show that the new Il-11 Irpex lacteus strain can synthesize cellulases in a high quantity. The peptone and filter paper contained in the medium significantly enhanced activity of endo-1,4-β-D-glucanases (app. 50 IU/mL) and total cellulases (app. 9 IU/mL), whereas the medium with peptone and sodium carboxymethyl cellulose stimulated activity of exo-1,4-β-D-glucanases (33 IU/mL). The expression of cellulases reached its maximum within 96–144 hours, and the optimum pH is 3,7. Thermal treatment at 30 °C for 60 minutes activated endo-1,4-β-D-glucanases and total cellulases, while exo-1,4-β-D-glucanases activity was enhanced following 40 °C treatment. In total, the cellulases complex (300 IU/g) saccharified untreated cellulose by 38 % in 48 hours. Concentrate with filter paper activity 100 IU/g is the more balanced enzyme-substrate ratio (2 %), which allows prolonging the saccharification process that will have a positive effect on the cost of the final product
River Regulation Causes Rapid Changes in Relationships Between Floodplain Oak Growth and Environmental Variables
The radial growth of pedunculate oak (Quercus robur), a species often ecologically dominating European deciduous forests, is closely tied up with local environmental variables. The oak tree-ring series usually contain a climatic and hydrologic signal that allows assessing the main drivers of tree growth in various ecosystems. Understanding the climate-growth relationship patterns in floodplains is important for providing insights into the species persistence and longevity in vulnerable riverine ecosystems experiencing human-induced hydrology alteration. Here, we use 139 years long instrumental records of local temperature, precipitation, and water levels in the Dnipro River in Kyiv to demonstrate that the implementation of river regulation has decoupled the established relationship between the radial growth of floodplain oak and local hydro-climatic conditions. Before the river flow has been altered by engineering modifications of 1965–1977, the water level in the Dnipro River was the key driver of oak radial growth, as reflected in the tree-ring width and earlywood width. The construction of two dams has altered the seasonal distribution of water level diminishing the positive effect of high water on oak growth and subsequently reversing this trend to negative, resulting from a seasonal ground water surplus. The decrease in the correlation between oak growth indices and the river’s water level in April–June was unprecedentedly rapid and clearly distinguishable among other changes in the growth-to-climate relationship. Our findings further demonstrate that trees growing in areas exposed to urban development are the most susceptible to downside effects of river regulation
Morphological and phenological shifts in the Plantago lanceolata L. species as linked to climate change over the past 100 years
Herbarium collections have proven to be irreplaceable information base in recent studies directed towards revealing shifts in plants phenology and morphology caused by climate change. We examined eight parameters of morphological traits in the perennial herb species Plantago lanceolata L. collected in the wild between 1905 and 2019 and stored at the KW-herbarium (Kyiv, Ukraine) to find out if there were changes in plants’ organ sizes during the last 114 years. For this period, we also calculated 13 climatic parameters obtained from meteorological records from the State archive that gave us the opportunity to check if there are any relations between the climate change in Kyiv region and shifts in morphological parameters of plants. Our results have shown Plantago lanceolata leaf blades, petioles and spikes had become significantly longer with time, increasing 3.0 cm, 2.1 cm and 0.6 cm respectively. The Co-inertia analysis revealed that 34% of the morphological changes was attributed to climate change. The analysis also demonstrated that leaf length correlated more with raised temperatures when plants were in flower, while spike length depended on the temperatures during bud development. Received knowledge can be used to reveal rapid evolutionary processes of the Plantago species and predicting their further course for the construction of historical climate models based on the leaves traits
The climate to growth relationships of pedunculate oak in steppe
Pedunculate oak (Quercus robur L.) is a long-lived species that dominates the extra–zonal natural forests in the steppe landscape of southeastern Ukraine. Although Q. robur is considered to be one of the most important species in European dendrochronology, it has received little attention in the steppe zone because of its scarcity in the often-degraded steppe forests. Nevertheless, a small and unique patch of old-growth oak exists within the boundary of Donetsk, a large industrial center in Eastern Europe. This forest is a remnant of an ancient wood and includes several dozen old-age trees that can contribute to filling some of the spatial gaps in pedunculate oak dendrochronology in Eastern Europe. In this study, we aim to determine the effect of climatic variables on pedunculate oak growth in the steppe zone, and to estimate the longevity of this species in the heterogeneous conditions of an urban forest. A total of 20 trees were cored for this study, varying in age from 55 to 254. The resulting tree-ring chronology correlates strongly with local precipitation in spring and summer, and with local temperature in April, June and July. Moving correlation analysis indicates a shift over the last 80 years in the relationship between oak growth and late winter and early spring temperatures, as well as between oak growth and precipitation in February and August. These findings imply that warming has caused both an advance in oak phenology and changes in the climatic conditions in early spring
Фенотипічна мінливість структури епідермісу та кремнієві включення у листках Quercus robur у парку “Феофанія”
The micromorphology of the leaf epidermis, localization, and silicon content in the epidermal cells of Quercus robur leaves growing in the shade and under direct sunlight in the Feofaniya Park (Kyiv, Ukraine) were studied using scanning electron microscopy and laser confocal microscopy. Silicon inclusions were found in the anticlinal and periclinal walls of adaxial epidermal cells, trichomes, guard cells of stomata, and walls of regular epidermal cells on the abaxial leaf surface, the amount of which varied according to the conditions of growth. Natural shading and the intensity of solar irradiation were found affecting the size of leaf blades, the ultrastructure of the leaf epidermis, and changes in the silicon content of oak leaves. Studies have shown that the anticlinal walls of the adaxial epidermis and the trichomes and stomata of the abaxial epidermis of leaves are the main silicon accumulators. The findings suggest that changes in leaf microstructure and silicon content contribute to maintaining optimal water balance in plants and can be regarded as signs of phenotypic plasticity in plants and an adaptive marker depending on the sunlight conditions of oak growth.За допомогою скануючої електронної мікроскопії та лазерної конфокальної мікроскопії досліджено мікроморфологію листкового епідермісу, а також локалізацію та вміст кремнію в епідермальних клітинах листків дерев Quercus robur, що зростали у затінку та під прямим сонячним світлом у парку “Феофанія” (Київ, Україна). В антиклінальних і периклінальних стінках клітин адаксіального епідермісу, у трихомах, замикаючих клітинах продихів і стінках звичайних клітин епідермісу абаксіальної поверхні виявлено кремнієві включення, кількість яких варіювала залежно від умов зростання. Виявлено, що природне затінення та інтенсивність сонячного опромінення впливають на розмір листкових пластинок, ультраструктуру епідермісу листків та вміст кремнію в листках дубу. Дослідження показали, що антиклінальні стінки адаксіального епідермісу, а також трихоми і продихи абаксіального епідермісу листків є основними накопичувачами кремнію. Отримані дані дозволяють припустити, що зміни мікроструктури листків та вмісту кремнію сприяють підтримці оптимального водного балансу рослин і можуть розглядатися як ознаки фенотипової пластичності, а також як адаптивний маркер залежно від умов сонячного освітлення дуба звичайного
Is there Chornobyl nuclear accident signature in Scots pine radial growth and its climate sensitivity?
The extensive radioactive fallout resulting from the 1986 Chornobyl accident caused tree death near the nuclear power plant and perturbed trees communities throughout the whole Chornobyl exclusion zone. Thirty years into the post-accident period, the radiation continues to exert its fatal effects on the surviving trees. However, to what extent the continuous multi-decadal radiation exposure has affected the radial tree growth and its sensitivity to climate variation remains unascertained. In this comparative study, we measure the Scots pine radial growth and quantify its response to climate at two sites along the western track of the nuclear fallout that received significantly different doses of radiation in 1986. The common features of the two sites allow us to disentangle and intercompare the effects of sub-lethal and moderate radiation doses on the pine's growth and climatic sensitivity. We extend the response function analysis by making the first use of the Full-Duration at Half-Maximum FDHM method in dendrochronology and apply the double-moving window approach to detect the main patterns of the growth-to-climate relationships and their temporal evolution. The stand exposed to sub-lethal radiation shows a significant radial growth reduction in 1986 with a deflection period of one year. The stand exposed to moderate radiation, in contrast, demonstrates no significant decrease in growth either in 1986 or in the following years. Beyond the radiation effects, the moving response function and FDHM enabled us to detect several mutual patterns in the growth-to-climate relationships, which are seemingly unrelated to the nuclear accident. To advance our predictive understanding of the response of forest ecosystems to a massive radioactive contamination, future studies should include quantitative wood anatomy techniques.Impact de la gestion forestière et du changement climatique sur le microclimat en sous-boisImpact de la gestion forestière et du changement climatique sur le microclimat en sous-boi
Acquisition of invasive traits in ant, Crematogaster subdentata mayr (Hymenoptera: Formicidae) in urban environments
The native (primary) range of Crematogaster subdentata Mayr lies in Central Asia. Within the
secondary range in Ukraine and Russia, it is invasive. The 1st objective of this work was to
study the evolution of the biological and ecological features (habitats, queen number, colony
structure, behavior, worker’s activity on foraging trails) of C. subdentata in the urban
environments (Tashkent) and secondary ranges (Crimea, Rostov-On-Don region). Whilst, the
2nd objective was to compared these parameters in the natural habitats in the native
(Uzbekistan) range. Result showed that in the territory of the primary range in Kyzylkum,
colonies of C. subdentata are strictly monogynous; in Zarafshan’s oasis (riparian forests) they
were polygynous (5.0±1.2 queens), but in cities of Uzbekistan C. subdentata forms
supercolonies with hundreds of nests, and in total with hundreds of queens (on average 17.7±4.4
queens per one nest in supercolony). In the secondary range, C. subdentata forms even larger
supercolonies with thousands of nests, containing 53.0±8.7 queens per nest. C. subdentata
avoids contacts with another invasive ant species, Lasius neglectus, in the foraging territories
both in the primary and secondary ranges, but other ant species avoid C. subdentata. Workers
of C. subdentata are aggressive toward conspecific ones from other nests in the natural habitats,
but are tolerance to those in both the secondary range and in the cities in the primary range. In
conclusion, our results show that some ants may acquire invasive species traits in the urban
habitats in the primary range
Nuptial flight in ants (Hymenoptera: Formicidae)
Based on the collected data set (758 observations for the period 2007-2021) on the dates of the
nuptial flight for 73 species of ants, an analysis of possible time shifts due to global climate
changes has been carried out. It was found that for Eastern Europe and Asia, for most species
of ants, the dates of nuptial flight were shifted by at least two weeks earlier in comparison with
the data for Western Europe. In a cold climate, there are significant changes, towards earlier
dates, in the phenology of nuptial flight for two species: Lasius flavus (P<0.05) and Polyergus
rufescens (P<0.01). The corresponding rates of change are 3.9 and 6.25 days per year. In other
types of climate, no significant changes in the phenology of the nuptial flight were found.
Taking into account the boundaries of future climatic zones in temperate and arid zones, such
changes were recorded for several species. Solenopsis fugax in temperate climates shows a
tendency to delay flight at a rate of 6 days per year (P<0.05). Within the predicted boundaries
of the arid climate, the flight phenology delay was recorded for Lasius niger (5.8 days per year;
P<0.01) and Messor sp. (4.4 days per year; P<0.05). At the same time, for Polyergus rufescens,
there is a tendency to an earlier flight at a rate of eight days per year (P<0.05). No connection
was found between the date of nuptial flight and the geographic distance between populations
(or locations)
Local site conditions reduce interspecific differences in climate sensitivity between native and non-native pines
Two European pine species, Pinus sylvestris and Pinus nigra, are experiencing dieback as a result of the increasing frequency and intensity of extreme climatic events. Recent species distribution models predicted shrinkage of ecological niches in the near future and shifted their habitat range towards the northeast. Consequently, P. sylvestris may contract its range and P. nigra may expand in Central Europe. To test whether native pine species have an advantage over introduced pine species in acclimation to a novel climate in Central Europe, we investigated the climate sensitivity and vitality of P. sylvestris, P. nigra and P. rigida. We sampled mature stands of each pine species at three sites in Central Europe, for which we determined climate–growth relationships: temporal stability of temperature and precipitation correlations with tree-ring width and resilience indices. Based on remote sensing data, we assessed differences in surface reflectance and photosynthetic activity obtained from the normalised difference vegetation index (NDVI). Our analyses revealed that the climate sensitivity and surface reflectance of pines are not due to their nativeness in Central Europe but better explained by local site conditions. The specificity and variability of drought events may determine both the homogeneous and diverse susceptibility of species to a negative water balance. Therefore, the character of future climatic extremes seems to be the key to understanding the acclimation of native and non-native pine species in Central Europe. Because our study do not provide evidence of the superiority of non-native pine species over P. sylvestris, and the potential impacts of introduced species on local habitats seem poorly understood in the face of climate change, we urge particular caution in introducing species with unrecognized invasive potential