Current Climate Change Research Articles

Sex-dependent resilience to extreme drought events: implications for climate change adaptation of a South American endangered tree species

BackgroundRecent changes in climatic trends are resulting in an increased frequency and intensity of extreme events, with unknown effect on ecosystem dynamics in the near future. Extreme drought episodes are recognized as disturbance factors capable of modifying forest dynamics and tree growth. Within this context, dioecious tree species may be impacted by climatic extremes, affecting male/female proportions and, consequently, reproductive processes and species persistence. Therefore, there is an urgent need for species-specific assessments of growth tolerance to extreme dry spells in dioecious tree species, to establish effective conservation strategies for these particular natural resources. Araucaria araucana (araucaria), an endangered dioecious Patagonian tree species, has recently undergone decay and mortality episodes in response to increasing dry climatic conditions. While sex-dependent tolerance to extreme drought episodes has been assessed in the species’ humid distribution range, there is still a lack of information on the gender-based resilience of trees growing in the drier environments of the species’ distribution.MethodsWe reconstructed, through dendrochronological methods, the sex-dependent response of 105 araucaria individuals (55 female and 50 male trees) to five regional extreme dry spells employing a set of different indices. Resistance, recovery period, and average growth reduction of standardized tree-ring growth were examined, analysing the effect of biotic (sex, pre-drought stem tree growth) and abiotic (local climatic conditions before, during, and after extreme climatic episodes) factors on tree resilience.ResultsSex influences only the species resistance to climatic disturbance, with male individuals showing lower tolerance to extreme drought events. Pre-drought radial growth rates and local meteorological conditions preceding, during, and following extreme dry spells strongly modulated araucaria radial growth resilience regardless of tree sex, influencing the species resistance, recovery period, and average growth reduction.ConclusionsWe provide novel and crucial information for the species conservation and management in the current climate change scenario, and contribute to the debate regarding the role of tree sex as a factor influencing woody species growth under particularly adverse climatic conditions. In the face of climate change, an increase in extreme drought events is expected in the easternmost araucaria xeric end distribution area, which will likely decrease the species resilience.

Grass cover and shallow tillage inter-row soil cultivation affecting CO2 and N2O emissions in a sloping vineyard in upland Balaton, Hungary

Greenhouse gas (GHG) emissions can accelerate the current climate change trend, resulting in higher soil temperatures and changes in soil water contents. The aim of the study was to investigate to what extent different cultivation methods and sampling positions on the slope (location along the slope) are affecting soil GHG emissions in vineyards. In the study, different inter-row soil cultivation methods were investigated including shallow soil tillage (ST) and grass cover (GC) inter-rows. Intact soil columns were collected and different soil water contents were applied under a laboratory environment to simulate different precipitation conditions. Our findings showed significant differences in the emitted CO2 and N2O between the cultivation methods, where the GC soil had 2.9 times higher average CO2 and 6.1 times higher N2O emissions compared to the bare, ST soil. The amount of initial and longer term soil water content significantly influenced soil-derived GHG emissions, with the highest averaged values observed for the continuously high water content soil samples (0.377 mgCO2 m−2 s−1 and 0.076 μgN2O m−2 s−1). For the GC inter-rows, we also observed significant differences in the GHG emissions among the different sampling positions of the investigated slopes. We found that besides the different soil water contents, the main causes for these differences could be the variances in the soil physical and chemical properties. The findings of this study can be used to better estimate soil GHG emissions at various water contents, for different inter-row soil management cultivation methods, and potentially mitigate some adverse effects of global warming by reducing the amount of GHG released into the atmosphere.

Wide climatic niche breadth and traits associated with climatic tolerance facilitate eucalypt occurrence in cities worldwide

AbstractAimEucalypts are important and popular urban tree species across cities worldwide. However, little is known about how their climatic niche breadth (CNB) and functional traits predict their success, and vulnerability, to current climate change in cities. We assessed the relationship between the CNB of eucalypts and key traits to understand their tolerance to climate change.LocationGlobal urban areas, 66 cities in 21 countries.Time period1981 to 2022.Major species studiedFifty ‘eucalypt’ species belonging to the genera Eucalyptus, Angophora and Corymbia.MethodsWe used the species' safety margin concept to determine cities where eucalypts were planted outside the limits of their CNB, as defined from the native range, considering two extreme variables, maximum temperature of the warmest month (MTWM) and precipitation of the driest month (PDM). We assessed correlations between functional traits (leaf δ13C, leaf dry mass, leaf length, leaf N per dry mass, wood density) and negative safety margins, indicative of tolerance to non‐native conditions.ResultsIn total, 42 species planted in 40 cities exceeded their safety margins for MTWM, while 43 species in 38 cities exceeded their safety margins for PDM. Within 24 cities, all species exceeded their native CNB for both MTWM and PDM. The cities of Atakpame (Togo), Chennai (India), Chongqing (China) and the US cities of Phoenix and Riverside had the highest richness of eucalypt species growing outside their native CNB. Broadly, species with wide CNB, small leaves, high δ13C, high leaf N per dry mass and high wood density were more likely to persist in cities where climatic conditions exceeded their native CNB.Main conclusionsEucalypts occupy many cities experiencing climatic conditions outside their native CNB. Species with traits characteristic of heat and drought tolerance are more often planted in cities where climatic conditions may exceed their CNB native limits.

Application of graph neural networks to forecast urban flood events: the case study of the 2013 flood of the Bow River, Calgary, Canada

ABSTRACT Mitigating the harmful effects of flooding is essential in the current climate change and urban growth scenario, where these natural phenomena are expected to occur more often. Addressing this problem, we present a novel graph-based forecasting model for predicting urban flooding and showcase its application in the Bow River in the City of Calgary, Alberta, Canada. The proposed model is based on graph theory and deep learning paradigms and was used to forecast flooding occurrences up to 24 h ahead. Our new approach developed the SAGE algorithm, a hybrid learning and planning approach that accurately predicted floodings for various analyzed forecasting horizons, increasing the forecasting performance by up to 44% compared to the persistence model. The SAGE model also returned superior or competitive results compared to other models in the literature. The superiority of the SAGE model was highlighted for longer forecast horizons of 24 h ahead, where it reached a maximum improvement of 79%, suggesting its superiority in capturing spatiotemporal information in the dataset. These results indicate that the SAGE approach is a cutting-edge tool for flooding forecasting, and it could be used to develop early flood warning systems to reduce potential flooding impacts.

The value of marsh restoration for flood risk reduction in an urban estuary

The use of nature-based solutions (NBS) for coastal climate adaptation has broad and growing interest, but NBS are rarely assessed with the same rigor as traditional engineering solutions or with respect to future climate change scenarios. These gaps pose challenges for the use of NBS for climate adaptation. Here, we value the flood protection benefits of stakeholder-identified marsh restoration under current and future climate change within San Francisco Bay, a densely urbanized estuary, and specifically on the shores of San Mateo County, the county most vulnerable to future flooding in California. Marsh restoration provides a present value of $21 million which increases to over $100 million with 0.5 m of sea level rise (SLR), and to about $500 million with 1 m of SLR. There are hotspots within the county where marsh restoration delivers very high benefits for adaptation, which reach $9 million/hectare with likely future sea level and storm conditions. Today’s investments in nature and community resilience can result in increasing payoffs as climate change progresses and risk increases.

Collaborative Monitoring of Plant Biodiversity and Research on Sweet Acorn Oaks within Paths of Knowledge and Sustainability Education

Numerous studies have shown the multiple benefits of plant biodiversity and the crucial role of residents’ awareness of conservation and land management. Plant biodiversity was investigated in an analytical monitoring report conducted jointly with the local population engaged in livestock activities and young residents who were shifting toward hospitality and tourism. The study area, covering over 800 km2 in Sardinia, is half forested and attracts interest in its landscape. During our research, genotypes of Quercus ilex L., with sweet acorns rich in polyphenols, as the oldest ecosystem services in these rural communities, were discovered. Collaborative monitoring focused attention on the benefits of plants in different habitats as follows: 53% were known to livestock farmers as food for local breeds of goats and pigs, 15% were official, and 13% were endemic. They had also been used for human nutrition within the Mediterranean diet and attracted interest for their use in landscapes and gardens. This study analyzes numerical data from critical and educational perspectives. These data serve as indicators of ecosystem health for the purpose of sustainable management policies and attest to collaborative monitoring as a tool for analyzing human activities and the necessary balance between profit and biodiversity conservation, given the current challenging climate change conditions.

Agroindustrial By-Products as a Source of Biostimulants Enhancing Responses to Abiotic Stress of Horticultural Crops.

Together with other abiotic stresses such as drought and high temperatures, salt stress is one of the most deleterious environmental factors affecting plant development and productivity, causing significant crop yield reductions. The progressive secondary salinisation of irrigated farmland is a problem as old as agriculture but is aggravated and accelerated in the current climate change scenario. Plant biostimulants, developed commercially during the last decade, are now recognised as innovative, sustainable agronomic tools for improving crop growth, yield, plant health and tolerance to abiotic stress factors such as water and soil salinity. Biostimulants are a disparate collection of biological extracts, natural and synthetic organic compounds or mixtures of compounds, inorganic molecules and microorganisms, defined by the positive effects of their application to crops. The growing interest in biostimulants is reflected in the increasing number of scientific reports published on this topic in recent years. However, the processes triggered by the biostimulants and, therefore, their mechanisms of action remain elusive and represent an exciting research field. In this review, we will mainly focus on one specific group of biostimulants, protein hydrolysates, generally produced from agricultural wastes and agroindustrial by-products-contributing, therefore, to more sustainable use of resources and circular economy-and primarily on the consequences of their application on the abiotic stress resistance of horticultural crops. We will summarise data in the scientific literature describing the biostimulants' effects on basic, conserved mechanisms activated in response to elevated salinity and other abiotic stress conditions, such as the control of ion transport and ion homeostasis, the accumulation of osmolytes for osmotic adjustment, or the activation of enzymatic and non-enzymatic antioxidant systems to counteract the induced secondary oxidative stress. The collected information confirms the positive effects of biostimulants on crop tolerance to abiotic stress by enhancing morphological, physiological and biochemical responses, but also highlights that more work is needed to further establish the molecular mechanisms underlying biostimulants' effects.

How much heat does non-photochemical quenching produce?

Non-photochemical quenching (NPQ) is a protective mechanism used by plants to safely dissipate excess absorbed light energy as heat, minimizing photo-oxidative damage. Although the importance of NPQ as a safety valve for photosynthesis is well-known, the physiological and environmental effects of the heat produced remain unclear because the amount of heat produced by NPQ is considered negligible, and its physiological effects have not been directly observed. Here, we calculated the heat produced by NPQ and evaluated its impact on the leaf and global warming based on simplified models. Our evaluation showed that the heat produced by NPQ in a given leaf area is 63.9 W m-2 under direct sunlight. Under the standard condition, NPQ warms up the leaf at less than 0.1°C, but it could be 1°C under particular conditions with low thermal conductance. We also estimated the thermal radiation of vegetation's NPQ to be 2.2 W m-2 par global averaged surface area. It is only 0.55% of the thermal radiation by the Earth's surface, but still significant in the current climate change response. We further discuss the possible function of NPQ to plant physiology besides the safety valve and provide strategies with artificial modification of the NPQ mechanism to increase food production and mitigate global warming.

Hydro-sediment responses to management options under current and future climate change scenarios in Maybar watershed, South Wollo Zone, Ethiopia

Climate change coupled with inappropriate land use management is a serious environmental challenge in the highland part of Ethiopia. The aim of this study was to investigate hydro-sediment responses to management options under current and future climate change scenarios in Maybar watershed, Northern Ethiopia. We employed soil and water assessment tool (ArcSWAT 2012.10_7.24) for hydrologic modeling and CORDEX-climate data under RCP 4.5 and RCP 8.5 emission scenarios for climate projections. Soil map was prepared by digitizing soil characterization map of the watershed generated by Weigel in 1986. DEM data with 2 m spatial resolution was obtained from water and land resource center and land use classification was done through digitization of google earth images. Better agreement between calibrated SWAT simulation and observed variables was achieved. Delta change bias correction method was employed to improve the climate simulation in reproducing the observed climate variables. We found a considerable increase in annual precipitation by 18.71 % and 22.33 % for RCP 4.5 and RCP 8.5, respectively compared with the current climate conditions. Climate change induced hydro-sediment results were observed to be consistent with predicted precipitation. Under the current climatic conditions, average sediment yield at the sub-basin scale varies from negligible (under terrace complementation) to approximately more than 50 t ha−1 yr−1 with a basin average of 32 t ha−1 yr−1 (under no-terrace conditions). The implementation of management alternatives gets the dry season's hydrological behavior of the catchment improved and climate change induced sediment yield reduction. Generally, the information could possibly support decision makers and planners to implement best-fitted management options and thereby reduce current and expected aggressive sediment loss situations.

Evaluating climate change scenarios on global pea aphid habitat suitability using species distribution models

The global threat of invasive alien species (IAS) being introduced into new habitats is concerning, particularly in agricultural crops as invasive insect species are continuing to expand their distribution through anthropogenic activities and climate changes. Pea aphids (Acyrthosiphon pisum Harris) are an economic threat to numerous legume crops as they can reproduce parthenogenetically, damage crops directly, and vector over 30 plant viruses as the insect's distribution continues to spread. There are no existing pea aphid-specific risk maps that identify the habitat suitability of pea aphids at either a regional or global scale. Here, we used Species Distribution Models (SDMs) to evaluate which climatic variables influence pea aphid distribution, identify regions of potential distribution, and analyze the global distribution of pea aphids under current and future climate change scenarios (SSP 126, 245, and 370) by utilizing presence-only SDMs based on Maximum Entropy (MaxEnt). The modeling results indicate suitable conditions are relevant for pea aphid establishment in six out of seven continents, with significant range expansion in western Canada, the United States of America, and across Europe. We identified human influence to be the most prominent predictor in determining the distribution of pea aphids, supporting the fact that invasive species distributions are heavily impacted by human activities.

A past and present perspective on the European summer vapor pressure deficit

Abstract. The response of evapotranspiration to anthropogenic warming is of critical importance for the water and carbon cycle. Contradictory conclusions about evapotranspiration changes are caused primarily by their brevity in time and sparsity in space, as well as the strong influence of internal variability. Here, we present the first gridded reconstruction of the summer (June, July, and August) vapor pressure deficit (VPD) for the past 4 centuries at the European level. This gridded reconstruction is based on 26 European tree ring oxygen isotope records and is obtained using a random forest approach. According to validation scores obtained with the Nash–Sutcliffe model efficiency, our reconstruction is robust over large parts of Europe since 1600, in particular for the westernmost and northernmost regions, where most tree ring records are located. Based on our reconstruction, we show that from the mid-1700s a trend towards higher summer VPD occurred in central Europe and the Mediterranean region that is related to a simultaneous increase in temperature and decrease in precipitation. This increasing summer VPD trend continues throughout the observational period and in recent times. Moreover, our summer VPD reconstruction helps to visualize the local and regional impacts of the current climate change, as well as to minimize statistical uncertainties of historical VPD variability. This paper provides also new insights into the relationship between summer VPD and large-scale atmospheric circulation, and we show that summer VPD has two preferred modes of variability, namely a NW–SE dipole-like mode and a N–S dipole-like mode. Furthermore, the interdisciplinary use of the data should be emphasized, as summer VPD is a crucial parameter for many climatological feedback processes in the Earth's surface system. The reconstructed summer VPD gridded data over the last 400 years are available at the following link: https://doi.org/10.5281/zenodo.5958836 (Balting et al., 2022).

Species distribution modeling combined with environmental DNA analysis to explore distribution of invasive alien mosquitofish (Gambusia affinis) in China.

China has become one of the most serious countries suffering from biological invasions in the world. In the context of global climate change, invasive alien species (IAS) are likely to invade a wider area, posing greater ecological and economic threats in China. Western mosquitofish (Gambusia affinis), which is known as one of the 100 most invasive alien species, has distributed widely in southern China and is gradually spreading to the north, causing serious ecological damage and economic losses. However, its distribution in China is still unclear. Hence, there is an urgent need for a more convenient way to detect and monitor the distribution of G. affinis to put forward specific management. Therefore, we detected the distribution of G. affinis in China under current and future climate change by combing Maxent modeling prediction and eDNA verification, which is a more time-saving and reliable method to estimate the distribution of species. The Maxent modeling showed that G. affinis has a broad habitat suitability in China (especially in southern China) and would continue to spread in the future with ongoing climate change. However, eDNA monitoring showed that occurrences can already be detected in regions that Maxent still categorized as unsuitable. Besides temperature, precipitation and human influence were the most important environmental factors affecting the distribution of G. affinis in China. In addition, by environmental DNA analysis, we verified the presence of G. affinis predicted by Maxent in the Qinling Mountains where the presence of G. affinis had not been previously recorded.

Strong differences in egg heat tolerance between closely related lowland and alpine butterfly species

Abstract Temperature variation is one of the best‐known and studied factor constraining life history along the altitudinal gradients. Ectotherms such as insects are sensitive to temperature across all life stages, resulting in a wide range of adaptations in populations and species living at different elevations. In butterflies, the egg stage is particularly sensitive to temperature variation as eggs cannot move and deploy behavioural responses to overheating. Using a gradient polymerase chain reaction thermocycler to finely control temperature treatments, we tested for differences in egg heat tolerance between five closely related Coenonympha (Nymphalidae: Satyrinae) species living at different elevations. We found strong differences in egg heat tolerance ranges between lowland species (C. arcania (Linnaeus) and C. pamphilus (Linnaeus)) and two high elevation alpine species (C. gardetta (Prunner) and C. cephalidarwiniana Verity). Surprisingly, the third alpine species (C. darwiniana Staudinger) showed a heat tolerance range closer to that of the lowland species than that of alpine species. The sensitivity of eggs to overheating matched the temperature regimes recorded in the microhabitats utilised for oviposition and may explain the oviposition site selection of females observed in the wild. The narrower egg heat tolerance of some of alpine species may partly explain the position of their lower elevational limit but also raises concern about the fate of these species in the face of current climate change. Our results highlight the need to study all life stages, as well as microclimate choice for oviposition, to understand species distribution and the threats to their persistence.

Evolution of trends in Sri Lankan mangrove research and future prospects

The trend of sporadic surveys and qualitative descriptions of Sri Lankan mangrove flora in the first half of the 20th century has gradually changed to include quantitative studies on floristics, nevertheless, studies on quantification of fauna associated closely with mangrove ecosystems are scarce. Microbial diversity, especially in soil, and its ‘contribution to the detritus cycle are the least studied. The tendency to engage in short-term research at convenient sites affects the quality and relevance of research output with some redundancy, resulting in a marginal contribution to the knowledge base on mangrove ecology. Studying mangrove ecosystem functions/ services demands long-term collection of data that would have made them less attractive research ventures. Research on trophic relationships, detritus and nutrient cycling, habitat and pollination functions too have had the same fate. The Indian Ocean tsunami in 2004 triggered a considerable interest in the coastal protection function of mangroves, as it was evident that mangroves and other coastal vegetation provided superior resistance to tsunami waves than hard engineering coastal protective structures. This has led to an unprecedented trend of mangrove afforestation for coastal defense, more than to research on planting techniques and maintenance to enhance the survival and growth of seedlings. This is still an under-researched aspect. Escalating recognition of blue carbon as a climate-smart solution and the development of market mechanisms for blue carbon trading have induced a considerable research interest in quantifying the mangrove blue carbon stocks, especially in the soil. Research on atmospheric carbon removal capacity/rates of mangrove plants/forests through photosynthesis however, lags behind for the reason that it requires data collection for a longer period that demands greater financial and labour investment. The urgency created by the current climate change crisis for effective solutions to reduce atmospheric greenhouse gases may provide a conducive environment for mangrove research.

Improving continental hydrological models for future climate conditions via multi-objective optimisation

Australian hydrological characteristics vary across the continent, encompassing diverse climate zones with wet and dry extremes. Moreover, Australia’s hydro-climate is projected to change in response to rising greenhouse gas emissions, where change is now evident from observations. Adaptation to these projected-to-be more intense impacts, requires nationally consistent hydro-climate projections along with an historical context.Calibrating a continental hydrological model against multiple objectives and varying hydroclimate conditions will enable a robust model configuration, thereby improving confidence in projections. We propose using a multi-objective optimisation approach to tune a continental model to represent stores and fluxes across the water cycle, current regional hydroclimes and possible future climate changes. By devising a set of experiments or scenarios which represent plausible projected futures and regional hydrological characteristics, trade-offs between different scenarios are assessed. We show that whilst no one parameter set “fits all” scenarios, this approach can provide a model configuration which “fits most”.

Shoals in troubled waters? The impact of rising temperatures on metabolism, foraging, and shoaling behavior in mixed-species shoals.

Rising water temperatures across aquatic habitats, in the current global climate change scenario, can directly affect metabolism and food intake in fish species. This can potentially alter their physiological, behavioral, and shoaling properties. In the current study, we examined the effects of high temperatures on metabolism, foraging, and shoaling in tropical fish. Mixed-species (comprising flying barbs, zebrafish, and gambusia) and single-species (flying barbs and zebrafish) shoals were conditioned for 45 days to three kinds of temperature regimes: the current temperature regime (CTR), in which shoals were maintained at water temperature of 24°C (i.e., the current mean temperature of their habitat), the predicted temperature regime (PTR) at 31°C (i.e., simulating conditions projected for their habitat in 2100), and the dynamic temperature regime (DTR), which experienced daily temperature fluctuations between 24 and 31°C (i.e., resembling rapid temperature changes expected in their natural environments). We found species-specific responses to these temperature regimes. Flying barbs exhibited significantly lower body weight at PTR but maintained consistent muscle glycogen content across all temperature regimes. In contrast, zebrafish and gambusia displayed significantly elevated muscle glycogen content at PTR, with similar body weights across all three temperature regimes. Cohesion within flying barb shoals and cohesion/polarization in mixed-species shoals decreased significantly at PTR. Shoals exposed to DTR exhibited intermediate characteristics between those conditioned to CTR and PTR, suggesting that shoals may be less impacted by dynamic temperatures compared to prolonged high temperatures. This study highlights species-specific metabolic responses to temperature changes and their potential implications for larger-scale shoal properties.

Determinants and their spatial heterogeneity of carbon emissions in resource-based cities, China

Global climate change associated with increased carbon emissions has become a global concern. Resource-based cities, by estimations, have emerged as major contributors to carbon emissions, accounting for approximately one-third of the national total. This underscores their pivotal role in the pursuit of carbon neutrality goals. Despite this, resource-based cities have long been neglected in current climate change mitigation policy discussions. Accordingly, using exploratory spatial data analysis and Geographical Weighted Regression method, this study investigates the determinants of carbon emissions and their spatial pattern in 113 resource-based cities in China. It can be concluded that: (1) The proportion of carbon emissions from resource-based cities in the national total has shown a marginal increase between 2003 and 2017, and the emissions from these cities have not yet reached their peak. (2) A relatively stable spatial pattern of “northeast high, southwest low” characterizes carbon emissions in resource-based cities, displaying significant spatial autocorrelation. (3) Population size, economic development level, carbon abatement technology, and the proportion of resource-based industries all contribute to the increase in carbon emissions in these cities, with carbon abatement technology playing a predominant role. (4) There is a spatial variation in the strength of the effects of the various influences.

Methyl Jasmonate Improves Antioxidants, Protecting Photosynthetic Apparatus in Blueberry Plants under Water Deficit

The plant water status is crucial for growth and production, but the current climate change scenario makes it challenging to match the water plant demand. Blueberries are an economically important crop and play an acknowledged role in human health due to their antioxidant compounds. This research aimed to determine whether the exogenous application of methyl jasmonate (MeJA) improves the antioxidant defense mechanisms for protecting the photosynthetic performance in the blueberry plant cultivar ‘Brigitta’ under the stress condition of a water deficit (WD). A greenhouse experiment was carried out under a 16-h light period, at 20 °C, and 60–80% relative humidity for two weeks before the application of MeJA to the blueberry plants (Vaccinium corymbosum, cultivar ‘Brigitta’). The following treatments were maintained for 7-days: (i) 80% field capacity (NoWD), (ii) 80% field capacity plus MeJA application (NoWD + MeJA), (iii) 20% field capacity (WD), and (iv) 20% field capacity plus MeJA application (WD + MeJA). The MeJA was sprayed as an aqueous solution of 10 µM MeJA over the plant’s foliar system. At the end of the assay, the blueberry leaves were analyzed for their relative water content, specific leaf area, lipid peroxidation, total antioxidant activity, total phenols, total anthocyanins, anthocyanidin compounds, and photosynthetic performance. The ‘Brigitta’ cultivar showed a significant decrease in the oxidative stress at leaf levels, with an increase in antioxidant activity, phenolic compounds, total anthocyanins, delphinidin, petunidin, antheraxanthin, zeaxanthin, and an improvement in photosynthetic performance parameters. The ‘Brigitta’ blueberry cultivar was shown to be susceptible to WD, which mainly decreased photosynthesis. However, the application of MeJA to the leaves induced metabolic changes through an increase of the antioxidant strategy within the plant to counteract the negative effects of WD and protect the photosynthetic apparatus, which allowed the ‘Brigitta’ cultivar to withstand the period of a WD.

A Comparison of the Chronologies of Introduced versus Native Coniferous Tree Species Growing in Northwestern Poland during the Period of Global Warming

The ongoing climatic changes are causing the extinction of numerous species or their withdrawal from previously occupied areas. The environmental and economic significance of introduced species may increase. The aim of the present study was to examine the rate of growth of coniferous species growing in northwestern Poland and to analyze the tree ring width–climate relationships. Six tree species were selected for this study. Two of these species have natural occurrences in Poland: Pinus sylvestris and Larix decidua. The remaining four species were introduced from North America: Chamaecyparis lawsoniana, Thuja plicata, Pseudotsuga menziesii, and Pinus strobus. Samples were collected from 131 trees using a Pressler borer at 1.3 m above ground. Tree ring widths were measured down to 0.01 mm. Climatic data were retrieved from a weather station located 23 km from the study plot. The average tree ring width reaches the lowest value for the P. sylvestris chronology (1.62 mm/year) and for P. strobus (1.69 mm/year), and the highest value is reached for T. plicata (2.80 mm/year) and P. menziesii (2.56 mm/year). The analysis of weather conditions in the designated pointer years and the response function analysis indicate that winter and early spring air temperature is the factor responsible for the formation of wide tree rings in the following species studied: P. sylvestris, C. lawsoniana, P. menziesii, and T. plicata. For L. decidua and P. strobus, the climate–growth relationships are different: weather conditions in the previous growth year are important, and it is the weather in the late spring and summer months. Two of the investigated introduced species (T. plicata and P. menziesii) are characterized by very good acclimatization and are best adapted to the new habitat during the current climate changes. These tree species can constitute a basis for replacing native species, which, due to increasingly severe droughts and higher temperatures, are doing less and less well in their current habitats. Foresters wanting to conduct sustainable forest management will look for replacement species that are well adapted to new habitat conditions in order to maintain the continuity of forest cover.

Nanoparticle applications in agriculture: overview and response of plant-associated microorganisms.

Globally, food security has become a critical concern due to the rise in human population and the current climate change crisis. Usage of conventional agrochemicals to maximize crop yields has resulted in the degradation of fertile soil, environmental pollution as well as human and agroecosystem health risks. Nanotechnology in agriculture is a fast-emerging and new area of research explored to improve crop productivity and nutrient-use efficiency using nano-sized agrochemicals at lower doses than conventional agrochemicals. Nanoparticles in agriculture are applied as nanofertilizers and/or nanopesticides. Positive results have been observed in terms of plant growth when using nano-based agricultural amendments. However, their continuous application may have adverse effects on plant-associated rhizospheric and endospheric microorganisms which often play a crucial role in plant growth, nutrient uptake, and disease prevention. While research shows that the application of nanoparticles has the potential to improve plant growth and yield, their effect on the diversity and function of plant-associated microorganisms remains under-explored. This review provides an overview of plant-associated microorganisms and their functions. Additionally, it highlights the response of plant-associated microorganisms to nanoparticle application and provides insight into areas of research required to promote sustainable and precision agricultural practices that incorporate nanofertilizers and nanopesticides.