Biotic Damage Research Articles

Impact of chilling injury on global trade in tropical products

Abstract International trade in fresh products is dominated by products capable of long-term refrigerated storage, allowing marketing flexibility. For tropical products, postharvest chilling injury (PCI) is a barrier to long-term storage that limits trade by exacerbating the already-challenging requirements to minimise physical or biotic damage to products. In this review, the practical consequences of PCI in terms of international trade are described. Options for choosing to grow more resistant varieties or to predict the chilling injury risk of batches of fresh products can reduce overall losses by allowing better-informed sequencing of product marketing. Recent advances in technologies that reduce PCI risk or predict its severity, some of which can be used before harvest, are reviewed. At a more fundamental level, there is a growing number of excellent reviews on the potential for gene editing to alleviate postharvest chilling injury in tropical fruits and vegetables. Most are focused on research into ways to alleviate the consequences of chilling injury: i.e. oxidative stress arising from membrane dysfunction. A few recent reports show that reducing membrane dysfunction itself is possible, for example by increasing desaturation of membrane lipids, but this approach comes with a new and predictable problem: increased preharvest susceptibility to heat stress. Refined suggestions for strategies that could produce durable improvements in product quality hold the potential for significant increases in global trade with resulting economic benefits, particularly for developing countries.

Eggs in faeces: defensive mechanisms and effects of faecal coating by a water scavenger beetle, Coelostoma stultum (Coleopterea: Hydrophilidae).

The egg stage in insect development is vulnerable to fluctuations in environmental conditions and attacks by natural enemies. Protective devices are effective means of avoiding both abiotic and biotic damage to eggs. Although some insects use their faeces as a protective device, few studies have focused on using faeces for egg protection, and studies that examined the mechanism are lacking. Females of a water scavenger beetle, Coelostoma stultum, typically lay eggs and coat them with cocoons and their faeces. The efficacy of a double defensive device, however, remains uncertain. Here, we conducted field observations and laboratory experiments to assess the protective effects of cocoons with faecal coating on eggs against predation and determine the duration and mechanisms of this defence. Our findings reveal that the faeces on the egg cocoon protected eggs from predation by the pill bugs, Armadillidium vulgare, and marsh slugs, Deroceras laeve. Laboratory experiments showed that the defensive effect of faecal coating was maintained for three days and decreased daily. The double protective traits with faecal coating on the egg cocoons protected the eggs from instense predation pressure in C. stultum. The behavioural patterns of the pill bugs and egg predation rates indicate that the faecal coating behaviour in C. stultum protects eggs with chemical compounds and textural camouflage in mud when the antennae of the pill bugs touch faeces. It is important to note that for this defence to be effective, the chemistry and texture of the faeces should be similar to that of the oviposition sites.

Forest managers’ perspectives on environmental changes in the biosphere reserve Mura-Drava-Danube

Riparian forests are particularly vulnerable to environmental change and anthropogenic influences because they are highly dynamic ecosystems, thus proper adaptation measures are crucial. The implementation of these measures, however, strongly depends on the actors’ perceptions of the specific problems occurring in such forests. For understanding the constraints of specific interest groups toward different adaptation activities, information in this field is essential. By conducting a questionnaire survey we explore how different types of forest managers, i.e., forestry professionals, forest owners, and conservation managers, perceive the effects of environmental change on forest management in the recently established Transboundary Biosphere Reserve Mura-Drava-Danube. We show that these forest managers are highly aware of ongoing environmental changes and appraise deteriorating forest conditions, especially after observing changes themselves. Abiotic damage is expected to increase the most, followed by biotic damage, the spread of non-native species, and tree dieback. Nearly 80% of the survey respondents expect further changes and almost all of them intend to adapt their management of forests to mitigate or prepare for these changes. Nevertheless, we show differences in sensitivity to change and willingness to initiate adaptation actions by assessing adaptation thresholds: conservation managers appear generally more tolerant to changes, which results in higher thresholds to initiate management adaptation than forestry professionals and forest owners. Respondents’ selection of target tree species depends on management goals and therefore, we found further differences between forestry professionals and conservation managers. These aspects need to be carefully considered to foster cooperation or develop sustainable management frameworks and adaptation strategies.

Monitoring Ash Dieback in Europe—An Unrevealed Perspective for Remote Sensing?

The ash dieback pandemic, caused by the invasive fungus Hymenoscyphus fraxineus, represents one of Europe’s biggest threats to preserving natural biodiversity. To ensure the suppression of forest damage caused by fungi, timely recognition of the symptoms of ash dieback and further continuous monitoring on an adequate spatial scale are essential. Visual crown damage assessment is currently the most common method used for identifying ash dieback, but it lacks the spatial and temporal coverage required for effective disease suppression. Remote sensing technologies, with the capabilities of fast and repetitive retrieval of information over a large spatial scale, could present efficient supplementary methods for ash damage detection and disease monitoring. In this study, we provided a synthesis of the existing remote sensing methods and applications that considers ash dieback disease, and we described the lifecycle of the disease using the major symptoms that remote sensing technologies can identify. Unfortunately, although effective methods of monitoring biotic damage through remote sensing have been developed, ash dieback has only been addressed in two research studies in the United Kingdom and Germany. These studies were based on single-date hyperspectral and very-high-resolution imagery in combination with machine learning, using previously specified ground-truth information regarding crown damage status. However, no study exists using high-resolution imagery such as Sentinel-2 or radar Sentinel-1, although some preliminary project results show that these coarser sources of information could be applicable for ash dieback detection and monitoring in cases of Fraxinus angustifolia, which forms pure, more homogenous stands in Southern Europe.

Microclimatic Monitoring—The Beginning of Saving Historical Sacral Buildings in Europe

A suitable indoor climate positively affects the lifespan of historical building structures. The path to an agreeable climate begins with monitoring current conditions. Considerable attention is given to monitoring the indoor climate of historical buildings. The motivation for monitoring air temperature and surface temperatures, relative air humidity or airflow can be, for example, the installation of heating, the occurrence of biotic damage, and others. Through the analysis of the most frequently used keywords, a strong connection was found, for example, between thermal comfort and the church. This review also summarises the various reasons for conducting microclimate monitoring studies in historical religious buildings on the European continent. It is supplemented with an evaluation of the monitoring methodology from the chosen period of the year point of view, the measured parameters, and the length of the interval between the recordings of quantities. It was found that in more than one-third of the cases, the recording time was less than or equal to 15 min, but mostly less than or equal to 1 h. Quite often, monitoring results are used to calibrate a simulation model describing the hydrothermal behaviour of a historical object under various operation alternatives (e.g., influence of ventilation, climate change, occupancy, etc.). This way, it is possible to test various intelligent systems in the virtual world without much risk before they are used in an actual building application.

THE INFLUENCE OF PRE-HARVEST TREATMENTS ON FRUITS QUALITY OF APPLE CULTIVARS (MALUS DOMESTICA BORKH.)

Apples fruit quality is mainly influenced by biotic and abiotic factors. Various possible pomological approaches are able to improve fruit quality and market value. Among these, techniques of fruit bagging and summer pruning have become an integral part of pomological practises in many countries, because it is a safe and eco-friendly technique to protect fruits from multiple stresses, preserving or improving the overall quality. The bagging consists essentially of enclosing a young fruit in a cardboard bag. Isolating the fruit from the external environment protects it during development from mechanical or biotic damage, especially in regions where fruits are prone to attacks by fungi, bacteria, insects and even birds. The expected increasing fruit skin color in comparison to non-bagged fruits can therefore correspond either to a reduction or an increase in color or even a greater homogeneity of the color itself.
 The aim of this research was to determine how the application of post-harvest aids affects the quality of fruits and storage capacity of three cultivars of late-ripening apples (Breaburn, Fuji and Pink Lady). Applying summer pruning and covering apple fruits with cardboard bags has a positive effect on increasing the surface of the complementary color on the skin of the fruit.In addition, the influence of these measures on the physical and chemical properties of the fruits after harvest and storage for a period of four months was examined. The experiment was set up in 2019 in a completely randomized design with five replications in the nine leaves old orchards of the Faculty of Agriculture in Belgrade. The used pre-harvest treatments influenced the increase in yield, fruit firmness, and chemical composition. The summer pruning of branches four weeks before harvesting significantly improve percentage of fruit skin color to all examined cultivars, while bagging of fruits only had increased of fruit skin to cultivar Breaburn. 

A spatio-temporal analysis of baboon damage using Sentinel-2 imagery and Extreme Gradient Boosting

The use of remote sensing for forest health monitoring has increased in popularity over the years, improving quality, spatial and spectral resolutions. However, revisit times of satellites is too slow for real-time detection. The need exists for high resolution monitoring, to quantify biotic damage, which is more difficult to detect due to the diversity of severity. Sentinel-2 MSI data, with 10 - 60 m spatial resolution and 443 - 2190 nm spectral range was used. Through strategical bands and derived vegetation indices, an accuracy of 89,34% with a Kappa of 0.85 using XGboost, was achieved. The study found: (1) Sentinel-2 identified baboon damage with high accuracy, with field measured data (2) different damage severities could be distinguished. SAVI and SIPI were most influential variables, due to good discrimination of structural variations in the canopy. The method provides an accurate and repeatable framework for rapid damage mapping at a sub-compartment scale.

About pests and diseases of some magnolia species in the Absheron conditions

The article examines the reproduction, frequency, distribution, density, preventive measures against pests of some Magnolia species on a scientific basis. Pests belonging to the species of this genus have been observed to be Icerya purchasi Mack, 1878, Ceroplastes sinensis Guer., Tetranychus urticae Koch., Helix pomatia Lin., 1758 and Pseudomonas syringae van Hall 1904. On the basis of phytosanitary monitoring, route observations and stationary examinations of magnolia plants grown in the experimental fields of the Institute of Dendrology in Absheron Peninsula (2020-2021), plant samples infected with pests and pathogens were collected and systematically analyzed. As a result of the monitoring of pests, magnolias were first discovered in Absheron: Icerya purchasi, Ceroplastes sinensis, Tetranychus urticae, Helix pomatia. Some bioecological features of the dangerous larvae of Icerya purchasi and Ceroplastes sinensis have been revealed. For the first time, a number of promising insecticides against their larvae have been selected. The data on the experimental work on the selection of drugs and their concentration as the most effective measure to control pest species are presented. The reason for the weakening of plants, and sometimes their death, is a complex of factors of negative impact: biotic harmful arthropods and damage by various diseases; abiotic unfavorable climatic conditions; anthropogenic violation of the soil cover and natural herbaceous vegetation, insufficient and untimely care of plants due to the limited funds allocated for this purpose.

Interactive effects of biotic stressors and provenance on chemical defence induction by holm oak (Quercus ilex)

Key MessageThe patterns of induced chemical defences in Quercus ilex leaves are specific to the biotic stress factor that causes them. Interactive effects between stressors depend on provenance.Quercus forests are suffering serious decline worldwide, closely linked to the consequences of climate change. The increase of biotic stressors threatens the survival of the holm oak (Quercus ilex), a dominant tree species in the Mediterranean Basin. A better understanding of its resistance mechanisms is urgently required to enable a better control of its decline. In this work, the ability of holm oaks from six Iberian provenances to respond to multiple biotic damage is studied through an analysis of their induced chemical defence patterns. Using 2016 seedlings established in a common garden trial (6 regions × 12 families/region × 7 seedlings/family × 4 treatments), biotic damage was induced at the root level (by infection with the widespread pathogen Phytophthora cinnamomi) and at the above-ground level (by mechanical defoliation). The levels of constitutive and induced total phenols, total tannins and condensed tannins were measured. Results showed that (1) the defensive chemical patterns present significant local and geographical variation, (2) survival to stress is more related to constitutive defences than induced ones, (3) the induced response is stressor-specific, and (4) there is an interactive effect amongst stressors whose sign (induction/inhibition) depends on the provenance. These findings on biotic stressor effects on the chemical defences and survival of holm oak can contribute to the development of genetic material selection programs in the integrated control of the widespread decline of Quercus.

LightCue: An Innovative Far-Red Light Emitter for Locally Modifying the Spectral Cue in Outdoor Conditions with Global Consequences on Plant Architecture.

Plasticity of plant architecture is a promising lever to increase crop resilience to biotic and abiotic damage. Among the main drivers of its regulation are the spectral signals which occur via photomorphogenesis processes. In particular, branching, one of the yield components, is responsive to photosynthetic photon flux density (PPFD) and to red to far-red ratio (R:FR), both signals whose effects are tricky to decorrelate in the field. Here, we developed a device consisting of far-red light emitting diode (LED) rings. It can reduce the R:FR ratio to 0.14 in the vicinity of an organ without changing the PPFD in outdoor high irradiance fluctuating conditions, which is a breakthrough as LEDs have been mostly used in non-fluctuant controlled conditions at low irradiance over short periods of time. Applied at the base of rapeseed stems during the whole bolting-reproductive phase, LightCue induced an expected significant inhibitory effect on two basal targeted axillary buds and a strong unexpected stimulatory effect on the overall plant aerial architecture. It increased shoot/root ratio while not modifying the carbon balance. LightCue therefore represents a promising device for progress in the understanding of light signal regulation in the field.

Abiotic and Biotic Damage of Microalgae Generate Different Volatile Organic Compounds (VOCs) for Early Diagnosis of Algal Cultures for Biofuel Production.

Open microalgal ponds used in industrial biomass production are susceptible to a number of biotic and abiotic environmental stressors (e.g., grazers, pathogens, pH, temperature, etc.) resulting in pond crashes with high economic costs. Identification of signature chemicals to aid in rapid, non-invasive, and accurate identification of the stressors would facilitate targeted and effective treatment to save the algal crop from a catastrophic crash. Specifically, we were interested in identifying volatile organic compounds (VOCs) that can be used to as an early diagnostic for algal crop damage. Cultures of Microchloropsis gaditana were subjected to two forms of algal crop damage: (1) active grazing by the marine rotifer, Brachionus plicatilis, or (2) repeated freeze–thaw cycles. VOCs emitted above the headspace of these algal cultures were collected using fieldable solid phase microextraction (SPME) fibers. An untargeted analysis and identification of VOCs was conducted using gas chromatography-mass spectrometry (GC-MS). Diagnostic VOCs unique to each algal crop damage mechanism were identified. Active rotifer grazing of M. gaditana was characterized by the appearance of carotenoid degradation products, including β-cyclocitral and various alkenes. Freeze–thaw algae produced a different set of VOCs, including palmitoleic acid. Both rotifer grazing and freeze–thawed algae produced β-ionone as a VOC, possibly suggesting a common stress-induced cellular mechanism. Importantly, these identified VOCs were all absent from healthy algal cultures of M. gaditana. Early detection of biotic or abiotic environmental stressors will facilitate early diagnosis and application of targeted treatments to prevent algal pond crashes. Thus, our work further supports the use of VOCs for monitoring the health of algal ponds to ultimately enhance algal crop yields for production of biofuel.

Impacts of Pervasive Climate Change and Extreme Events on Rocky Intertidal Communities: Evidence From Long-Term Data

Annual surveys of the abundance of intertidal invertebrates and macroalgae have been made at between 70 and 100 rocky intertidal time-series sites around the United Kingdom coastline since 2002 under the MarClim project. The data provide a unique opportunity to investigate the impacts of both pervasive climate change and their punctuation by extreme events on intertidal species. After the extreme storm events in the 2013/2014 winter season and the record heatwaves in the summers of 2018 and 2020, MarClim surveys recorded both physical and biological changes to rocky shore habitats. Subsequent surveys reassessed the effects on community structure via analysis of those species that resisted storm damage, those species that returned after the extreme storm events, and species that opportunistically occupied vacant habitat after storm-induced species loss. In addition, biannual storm damage surveys documenting communities recovery were carried out in the spring and winter of each year from 2014 to 2020 at three MarClim sites in north Cornwall (Crackington Haven, Trevone, and St. Ives), which experienced different types of abiotic and biotic damage resulting from these storms. Impacts of heatwaves and cold spells on the abundance of species were determined by regression on frequencies of event per year. Species of invertebrates and macroalgae generally declined in years of more frequent winter cold spells and summer heatwaves, while winter heatwaves and summer cold spells had similar numbers of positive and negative effects across species. Winter warm spells tended to have a more negative effect on cold-affinity species than on warm-affinity species. No abrupt shift was recorded after the 2013/2014 storms. Whilst a short-term change in some species was recorded in quantitative quadrat surveys, the biological communities returned to the long-term species composition and abundance within 2 years. The heatwave events caused sublethal heat damage in macroalgae, evidenced as dried areas of tissue on many individuals, with mortality-induced reductions in the abundance of only a few invertebrate species, recorded in Scotland and southwest England after the heatwave events in 2018 and 2020. MarClim and storm-damage surveys indicate that there have been no sustained impacts from either extreme thermal or storm events across the rocky intertidal communities, and biodiversity has not been significantly altered as a result. The abundance and biogeographical distributions of rocky intertidal species and communities around the United Kingdom are being driven by longer-term, large scale, pervasive change in environmental conditions, with a gradual shift towards dominance of Lusitanian species from the early 2000s in responses to warming of the marine climate.

MiRNA-based approaches for sustainable control of diseases

Abstract MicroRNAs (miRNAs) were envisioned, in recent years, as alternative, environmental friendly molecular tools to confer crop protection. This view was based on their ability to move across Kingdoms and to modulate gene expression at the post-transcriptional level, inhibiting pathogens or parasites’ invasive processes or promoting plant favorable microorganisms. Strategies based on miRNAs, complementing the already existing technologies or creating new unexplored ones, are expected to provide valuable tools to reduce crop biotic damage, increasing food production and safety. This review provides a brief overview of miRNA-based technologies applied so far for plant protection and reports some new approaches suggested by recent acquisitions on miRNA.

Large-scale spatial biostratinomic patterns along the Eastern Indian coasts: Identification of a generalized siliciclastic beach taphofacies applicable in analogues (paleo)environments

Studies on biostratinomy of modern molluscs are biogeographically (mostly from the Americas and Europe) and environmentally (mostly from subtropical and temperate carbonate settings) restricted, documenting local variation, while large-scale spatio-environmental patterns from the siliciclastic settings are less understood. Here, 8670 dead bivalve specimens were collected from several sandy, sandy-rock mixed, and sandy-clay mixed beach, and beaches associated with tidal flat and sea-grass habitat. Sampling stations were located along a stretch of about 2500 km covering several ecoregions along the eastern Indian coast, a large-scale, biogeographic pattern in biostratinomy is studied. Each shell was assigned seven grades based on shell damages intensities in reference to seven biostratinomic attributes (shell completeness, surface bioerosion, secondary rounding, abrasion, ligament loss, and external and internal wear); the summation of these values indicate the Total Taphonomic Grade (TTG) of individual specimens. Our results suggest, TTG values do not vary systematically with ecological factors (e.g., body size and shape, shell microstructure, etc.), although environmental (e.g., substrate and energy conditions) factors could play some role (e.g., high energy sandy beaches have higher TTG values); no large-scale biogeographic gradient is observed. Based on the characteristics of damage profiles, a siliciclastic beach taphofacies, common in all locations, is proposed: abrasion is the main damage type, whereas, shell fragmentation or biotic damages are negligible. Based on these, a biostratinomic pathway of shells is inferred: after death, shells are immediately locally transported to the beach, reducing exposure time for biotic damages; on beaches, constant swash and backwash cause external and internal abrasion. These taphofacies and biostratinomic pathway models can be used to identify the biostratinomic conditions of analogous modern and fossil assemblages.

Monitoring Bark Beetle Forest Damage in Central Europe. A Remote Sensing Approach Validated with Field Data

Over the last decades, climate change has triggered an increase in the frequency of spruce bark beetle (Ips typographus L.) in Central Europe. More than 50% of forests in the Czech Republic are seriously threatened by this pest, leading to high ecological and economic losses. The exponential increase of bark beetle infestation hinders the implementation of costly field campaigns to prevent and mitigate its effects. Remote sensing may help to overcome such limitations as it provides frequent and spatially continuous data on vegetation condition. Using Sentinel-2 images as main input, two models have been developed to test the ability of this data source to map bark beetle damage and severity. All models were based on a change detection approach, and required the generation of previous forest mask and dominant species maps. The first damage mapping model was developed for 2019 and 2020, and it was based on bi-temporal regressions in spruce areas to estimate forest vitality and bark beetle damage. A second model was developed for 2020 considering all forest area, but excluding clear-cuts and completely dead areas, in order to map only changes in stands dominated by alive trees. The three products were validated with in situ data. All the maps showed high accuracies (acc > 0.80). Accuracy was higher than 0.95 and F1-score was higher than 0.88 for areas with high severity, with omission errors under 0.09 in all cases. This confirmed the ability of all the models to detect bark beetle attack at the last phases. Areas with no damage or low severity showed more complex results. The no damage category yielded greater commission errors and relative bias (CEs = 0.30–0.42, relB = 0.42–0.51). The similar results obtained for 2020 leaving out clear-cuts and dead trees proved that the proposed methods could be used to help forest managers fight bark beetle pests. These biotic damage products based on Sentinel-2 can be set up for any location to derive regular forest vitality maps and inform of early damage.

Characterization of the Biogenic Volatile Organic Compounds (BVOCs) and Analysis of the PR1 Molecular Marker in Vitis vinifera L. Inoculated with the Nematode Xiphinema index.

Upon pathogen attack, plants very quickly undergo rather complex physico-chemical changes, such as the production of new chemicals or alterations in membrane and cell wall properties, to reduce disease damages. An underestimated threat is represented by root parasitic nematodes. In Vitis vinifera L., the nematode Xiphinema index is the unique vector of Grapevine fanleaf virus, responsible for fanleaf degeneration, one of the most widespread and economically damaging diseases worldwide. The aim of this study was to investigate changes in the emission of biogenic volatile organic compounds (BVOCs) in grapevines attacked by X. index. BVOCs play a role in plant defensive mechanisms and are synthetized in response to biotic damages. In our study, the BVOC profile was altered by the nematode feeding process. We found a decrease in β-ocimene and limonene monoterpene emissions, as well as an increase in α-farnesene and α-bergamotene sesquiterpene emissions in nematode-treated plants. Moreover, we evaluated the PR1 gene expression. The transcript level of PR1 gene was higher in the nematode-wounded roots, while in the leaf tissues it showed a lower expression compared to control grapevines.

Forest carbon stock in Left-bank Forest-Steppe of Ukraine according to intensive forest monitoring data

The issues of carbon stock and dynamic in different carbon pools in forest stands of Left-bank Forest-steppe of Ukraine are considered. The aim of the study was to evaluate carbon stocks and their changes in main pools: trees biomass and mortmass. Data of two repeated observations on 19 permanent intensive forest monitoring plots in Kharkiv and Sumy regions were used. Conversion method was used. 
 Study of increment and mortality dynamics at monitoring plots showed, that two processes impact carbon balance: biotic damage which leads to trees dieback, and partial removal of dead wood from stands.
 Oak stands have, on average, higher carbon stock in trees biomass and mortmass (102.9 t С ha-1) than the pine stands (98.7 t С ha-1), which is associated with a higher representation of mature and overmature oak stands. While comparison by age classes showed that pine stands, in general, have higher values of C in trees biomass, due to higher productivity. The increase in carbon stocks with age is observed. 
 The annual change of C stock in trees biomass is the highest in younger stands, and it decreases with age; while in mortmass it increases. Mature and overmature oak stands have negative trees biomass and positive dead wood growth.
 At age 81-100 years oak forest stands have higher carbon storage capacity than pine (total carbon stock in main pools (biomass, mortmass, litter and soils (30-cm layer)) is 191.7 t C ha-1 for oak and 175.4 t C ha-1 for pine stands). Trees biomass carbon prevails among other pools (50.3 % in oak forests, and 57.6% in pine), the next is soil carbon pool (45.9 and 29.0%, respectively). 
 National forest inventory will provide data for assessments of carbon stocks and dynamics in trees biomass and mortmass pools. However, forest soil monitoring is necessary to evaluate carbon pools in soils and litter.

Year-to-year crown condition poorly contributes to ring width variations of beech trees in French ICP level I network

Since the 1980-90′s episodes of decline in Central European Forests, forest condition has been surveyed thanks to the trans-national network the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). It has been traditionally accepted that leaf loss is directly related to impairment of physiological condition of the tree. A few studies tried to correlate crown condition and growth trends while others concentrated on linking annual growth with crown observation at one date clustered into fertility classes. However, none focussed on the high frequency synchronism between leaf loss from annual network observations and annual radial growth issued from dendrochronology. Therefore, we jointly studied annual leaf loss observations and tree-ring width measurements on 715 common beech (Fagus sylvatica L.) trees distributed in the French part of the ICP monitoring network. Detrended inter-annual variations of leaf loss and tree-ring width index were used as response variables in the machine-learning algorithm Random Forest to investigate a common response to abiotic (current and lagged) and biotic hazards, to test the extent to which leaf loss helped to predict inter-annual variations in radial growth. Using Random Forest was effective to identify a common sensitivity to soil water deficit at different time lags. Previous-year climatic variables tended to control leaf loss while radial growth was more sensitive to current-year soil water deficit. Late frost damages were observed on crown condition in mountainous regions but no impact was detected on radial growth. Few significant biotic damages were observed on growth or leaf loss. Leaf loss series did not show a clear common signal among trees from a plot as did radial growth and captured fewer pointer years. Radial growth index did not fall below normal until a 20% leaf loss was reached. However, this threshold is driven by a few extreme leaf loss events. As shown by our joint analysis of leaf loss and radial growth pointer years, no relationship occurred in cases of slight or moderate defoliation. Crown condition is a poorer descriptor of tree vitality than radial growth.

From a rare inhabitant into a potential pest – status of the nun moth in Finland based on pheromone trapping

Forests are affected by climate change in various ways. This includes abiotic factors such as droughts, but also biotic damage by pest insects. There are numerous examples from cases where pest insects have benefitted from longer growing seasons or from warmer summers. Similarly, new pest insects have been able to expand their range due to climatic conditions that have changed from hostile to tolerable. Such seems to be the case with the nun moth (), an important defoliator of coniferous trees in Europe. For centuries, the species has had massive outbreaks across Central-Europe, while it has been a rare inhabitant in Northern Europe. Recently, the nun moth population in Finland has not only expanded in range, but also grown more abundant. This research note describes the results from the first years (2018–2019) of a monitoring program that is being conducted with pheromone traps across central and southern Finland. So far, the northernmost individuals were trapped near the 64 N degrees. However, there were more southern locations where no moths were trapped. The species was present in every trapping site below the latitude of 62 N degrees. More importantly, at some sites the abundance of the nun moth suggested that local forest damage may already occur. Given the current climatic scenarios for Fennoscandia, it is likely that the nun moth populations will continue to grow, which is why systematic surveys on their abundance and range expansions will be topical.Lymantria monacha

Monitoring two REINFFORCE Network Arboreta: first result on site, climate and genetic interaction showing impact on phenology and biotic damages

Monitoring two REINFFORCE Network Arboreta: first result on site, climate and genetic interaction showing impact on phenology and biotic damages