Analysis of non-target beetle species collected on pheromone-baited adhesive panels in two mixed oak forest stands infested with <i>Lymantria dispar</i> (Lepidoptera: Erebidae) in southern Romania

Occurrence of severe dieback, decline, and mortality in oak (Quercus spp.) stands have been reported frequently during the last 20 years in various parts of the world. As a result, numerous research activities have been initiated. 'Recent Problems in Oak Decline' was also the topic of a meeting of the International Union of Forestry Research Organizations (IUFRO) units Sl.06.00, S2.06.00 and S2.07.00 at the IUFRO XX World Congress held in Tampere, Finland during August 1995. A selection of five papers presented during this meeting is published in this issue in which symptoms of oak damage are characterized and potential causal factors as well as factor combinations (insects and fungi, climatic factors, site-related aspects, genetics) are described. DONAUBAUER, Austria, summarizes the macroscopic symptoms of oak decline and reports on the regional role of parasites as predisposing and as contributing factors. S!WECKI and UFNALSKI, Poland, give a review of oak stand decline in Poland with special reference to the role of climatic factors. They found that climatic conditions had a decisive influence on the vigour of Quercus robur. Increased frequency of dry years resulted in the complex phenomenon of oak decline. STEINER, USA, observes oak decline in the context of genetic management. In order to minimi ze susceptibility to oak decline he suggests forest practices which favour the maintenance of high levels of genetic variation and the use of local provenances in artificial regeneration and large seedling populations. Prediction models for estimating mortality of oak due to gypsy moth (Lymantria dispar), based on a new analysis using defoliation intensity classes as a variable along with species, crown position, and crown condition, are presented by GOTTSCHALK et al. USA. STANDOVAR and SOMOGYI, Hungary, stress the importance of site characteristics and tree growth. Oaks seem more susceptible to decline outside of their natural range. Most presentations stressed the necessity for further investigations because the results are still preliminary and there is a wide variation in responses . The various methodological approaches used in these papers are of special interest. We hope that this collection of papers contributes to the progress on the long path to a better understanding of oak ecosystems and of improving the health of the world's oak forests.

Динамика популяции непарного шелкопряда в лесостепных дубравах Европейской России

Effects of Sea-Level Rise and Anthropogenic Development on Priority Bird Species Habitats in Coastal Georgia, USA

Pheromone traps were used to monitor the following tortricid moths, i.e. Adoxophyes orana, Archips podanus, A. rosanus, Hedya nubiferana, Pandemis heparana, Spilonota ocellana, Cydia pomonella, Cydia funebrana and Cydia molesta in the localities Brno-Tuřany (Brno-město), Nebovidy (Brno-venkov) and Prakšice (Uherské Hradiště). Other Lepidoptera non-target species were present in these target-species pheromone traps, i.e. Adoxophyes orana, Agrotis segetum, Amphipoea oculaea, Archips rosanus, Celypha striana, Cydia coronillana, Enarmonia formosana, Epiblema scutulanum, Epinotia huebneriana, Eucosma fervidana, Euxoa tritici, Hedya pruniana, H. nubiferana, Lymantria dispar, Noctua pronuba, Notocelia rosaecolana, N. roborana, Pammene albuginana, P. suspectana, Pandemis cerasana, Pyrausta rectefascialis, P. aurata, Spilonota ocellana, Yponomeuta malinellus and Zygaena purpuralis.

Here we consider the morphotypes and changing species composition of naked amoebae in soils of forest areas in Zhytomyr region (Ukraine). The species composition and morphotypes of amoebae are influenced by the microclimate of soil and litter. Complexes of naked amoebae in the study area constitute two clusters: one of broadleaf (oak) and mixed forests, another of coniferous forests. The most similar species compositions were found in soils of oak and mixed forests (64 % similarity). The least similar were amoebae complexes of coniferous forests and oak forests, and coniferous forests and mixed forests. Non-parametric multidimensional scaling (MDS) showed that species complex of amoebae of mixed forests and oak forests had moister and more acidic soils compared to coniferous forests.

ABSTRACT. Numbers of gypsy moth larvae feeding on each of 922 randomly sampled trees in a Quercus—Acer—Fraxinus forest in southwestern Quebec, Canada were counted in 1979 and in 1980 to quantify the larval feeding preferences as observed in the field for eighteen deciduous and one coniferous tree species at the northern range limit of the gypsy moth. Both the diameter at breast height (dbh) and the estimated foliage biomass of the sampled trees were used to calculate the relative proportions of foliage represented by each of the nineteen tree species in the forest canopy. With these data on availability and utilization of the tree species by the gypsy moth larvae an Ivlev‐type electivity index was used to quantify the larval feeding preferences. These preferences observed in the field define the susceptibility of a tree species to attack by the gypsy moth. The feeding preferences calculated using estimated foliage biomass were comparable to the simpler calculation based on dbh (Spearman's rho = 0.79; P= 0.0001). The dbh‐based feeding preferences remained almost unchanged in 1979 and 1980 (Spearman's rho = 0.83; P= 0.0001). The composite 1979—80, dbh‐based feeding preferences show Quercus rubra, Populus grandidentata, Ostrya virginiana, Amelanchier spp. and Acer saccharum were preferentially attacked by gypsy moth. Prunus serotina, Betula lutea, Acer rubrum, A. pensylvanicum, Fraxinus americana, Ulmus rubra, P. pensylvanicum and B. papyrifera were avoided. All nineteen tree species were, however, utilized to at least some degree by gypsy moth larvae. These results quantitatively affirm and clarify earlier reports of gypsy moth feeding preferences in North America and Eurasia. The advantages and limitations of using an electivity index to estimate the susceptibility of different tree species to attack by folivores like the gypsy moth are discussed.

Stress factors associated with forest decline in xeric oak forests of south-central United States

The Cleveland Metroparks Brecksville Reservation initiated an oak forest restoration in 1990, using thinning and burning to encourage regeneration of oak forest species. In 96 quadrats (81 treatment and 15 control), understory woody species were inventoried from 1992 to 2002, and canopy opening was quantified. Six years into the study, the entire reservation became heavily populated with white-tailed deer (Odocoileus virginianus) and gypsy moths (Lymantria dispar), complicating the restoration efforts. During data analysis, understory woody species were classified into oak forest type and nonoak forest type, and three distinct phases became evident (phase 1: 1992–1994 treatment effects only, phase 2: 1995–1999 period of invasion by deer and gypsy moths, and phase 3: 2000–2002 post-invasion period). Both oak forest and nonoak forest species increased in the treatment area over the control area. During phase 1, burning encouraged oak seedlings, and thinning reduced competition from nonoak species, suggesting a temporarily successful restoration attempt. The intense gypsy moth browse in phase 2 reduced the number of oak seedlings, creating conditions favorable to nonoak species. The quantity and diversity of seedlings increased as gypsy moths opened the canopy. Deer browsed most species, oak and nonoak, even when deer populations decreased and more species were available. Original treatment effects may have been continuing in phase 3; however, additional years of study are needed.

Gypsy moths and powdery mildew play a significant role in oak decline processes. However, information is lacking on the effects on the gypsy moth of impaired tree vitality caused by defoliation or parasite infection. We assessed how pedunculate oak leaves collected from vigorous, declining, and infected trees influenced gypsy moth preference and performance (growth and nutritional indices). We found a negative effect of powdery mildew-infected leaves on gypsy moth performance, while declining trees had positive effects on gypsy moth performance and preference. All examined parameters of larvae fed declining oak leaves were higher than those of larvae fed vigorous oak leaves. Increased growth on declining oak leaves was caused by both higher consumption and more efficient food utilization. The results of this research could help us to better understand multitrophic interactions in complex communities such as oak forests.

This chapter focuses on the methods used in the even-aged silviculture of oak (Quercus) forests. The traditional objective of even-aged management is to regulate a forest by managing the stands within it as a mosaic of different age classes. Stands under even-aged management are either regenerated naturally (through one of three silvicultural methods, viz., clear felling, shelterwood or seed tree methods) or artificially (afforestation and enrichment planting). The most serious and widespread threats to oak forests such as the gypsy moth (Lymantria dispar), oak decline, oak wilt and sudden oak death caused by Phytophthora ramorum are also covered.

Oak forests are an important part of temperate European ecosystems, where they are actively improving biodiversity, carbon storage, and ecological stability. However, current concerns such as climatic changes, and especially rising temperatures and changing precipitation patterns, are impacting their resilience. In this context, our study intends to evaluate the impact of climatic variability on temperate oak forests, focusing on the influence of temperature and precipitation. This covers different sites that have different environmental conditions. By using both a bibliometric approach and a systematic analysis of publications that have studied the influence of climate change on oak forests, our study has identified specific species and site responses to climate stressors. Furthermore, we have also evaluated trends in drought sensitivity. All these aspects have allowed us to understand and suggest improvements for the impact of climate change on the resilience and productivity of oak ecosystems. We have analyzed a total number of 346 publications that target the impact of climate change on oak forests. The articles were published between 1976 and 2024, with the majority originating from the USA, Spain, Germany, and France. These studies were published in leading journals from Forestry, Environmental Sciences, and Plant Sciences, among which the most cited journals were Forest Ecology and Management, the Journal of Biogeography, and Global Change Biology. As for the keywords, the most frequent ones were climate change, drought, growth, forest, and oak. However, we have observed a trend towards drought sensitivity, which indicates the intensification of climate changes on oak ecosystems. Moreover, this trend was more present in central and southern regions, which further highlights the impact of regional conditions. As such, certain local factors (soil properties, microclimate) were also taken into account in our study. Our literature review focused on the following aspects: Oak species affected by climate change; Impact of drought on oak forests; Influence of climate change on mixed forests containing oaks; Effects of climate change on other components of oak ecosystems; Radial growth of oaks in response to climate change; Decline of oak forests due to climate change. Our results indicate that oak forests decline in a process caused by multiple factors, with climate change being both a stressor and a catalyst. Across the globe, increasing temperatures and declining precipitation affect these ecosystems in their growth, functions, and resistance to pathogens. This can only lead to an increased forest decline. As such, our results indicate the need to implement forest management plans that take into account local conditions, species, and climate sensitivity. This approach is crucial in improving the adaptivity of oak forests and mitigating the impact of future climate extremes.

Gypsy moth defoliation of oak trees has been shown to lead to increased tannin levels, which, in turn, lead to reduced gypsy moth growth and fecundity. In laboratory experiments, increased tannin levels can interfere with the transmission of a virus that is consumed by larvae on oak foliage, and high mortality rates of larvae in the field are sometimes associated with low levels of defoliation. These latter results have led to the suggestion that gypsy moth defoliation may cause reduced mortality attributable to the virus by elevating oak tannin levels. In a series of field experiments, we directly tested the hypothesis that gypsy moth defoliation of oaks leads to reduced virus transmission rates. In each of three study years, in oak forests with almost no naturally occurring gypsy moths or virus, we measured virus transmission rates in gypsy moths feeding on oaks, with and without experimental defoliation. By carefully synchronizing our experiments with the phenology of natural gypsy moth populations, we mimicked natural virus transmission processes during that part of the gypsy moth life cycle when virus transmission occurs. In our experiments, there was no effect of gypsy moth defoliation on tannin levels; consequently, virus transmission in both the field and the lab was unaffected by defoliation. Although we did observe increased tannin levels on more severely defoliated oak trees in one of two naturally defoliated oak stands late in the season, virus transmission had virtually ceased by that time. Our results suggest that gypsy moth defoliation does not affect tannin levels early enough in the larval season to have a measurable effect on the interaction between the gypsy moth and its nuclear polyhedrosis virus.

The existence of large databases is fundamental to improve ecological and phytogeographical information to build a ‘natural’ syntaxonomic scheme. In different parts of Europe, deciduous forests have already been well studied and their phytosociological meaning interpreted at regional level, nevertheless a broader scale approach is often missing. To define the thermophilic and mesophilic oak deciduous forests of Southern Europe there are several syntaxonomical proposals at higher ranks, that show differences in their ecological significance. Several Authors use the Querco-Fagetea class by which the differences between oak, mixed and beech forests are expressed at the level of order and alliance. Despite the clear link between the Italian and Balkan Peninsula, the Apennines maintain strong links with the forest vegetation of Central Europe, interpretable only within the QuercoFagetea class. In Italy phytosociological studies focused on deciduous oak forests have a relative recent tradition compared with other countries. In particular there are a great number of local contributions, while there are only few contributions that tackle syntaxonomical issues at a broader, peninsular level. For these reasons the aim of this database is to collect releves of oak forests belonging to the Quercetalia pubescenti-petraeae and Fagetalia sylvaticae orders to perform numerical analyses and classification. Thermophilous and thermo-mesophilous oak forests are dominated by various species such as Quercus cerris, Q. pubescens, Q. frainetto, Carpinus betulus, Carpinus orientalis, Ostrya carpinifolia, Fraxinus ornus and Acer opalus obtusatum. The present project is based on selected published (and unpublished) releves recorded according to the Braun-Blanquet approach and stored in a TURBOVEG database. At present 1,600 releves of oak forests vegetation surveyed in Peninsular Italy are stored in the Deciduous Oak Forests Database of the Italian Peninsula (GIVD ID EU-IT-006). The future goals are to determine whether the variation in species composition follows a geographical pattern, to test the real ecological characteristics of the associations recognised by phytosociological studies and to identify which diagnostic species can be used for different types.

The future of the Mediterranean oak forests is under threat from the dangerous effects of global climate change, such as increasing droughts and heatwaves. The combined or individual action of certain climatic and environmental factors can lead to oak decline in various oak forest types. A study was conducted between 2015 and 2022 in southern Italy, encompassing thirty oak forest stands dominated by various Quercus species, including Q. cerris, Q. frainetto, Q. ilex, Q. pubescens, and affected by oak decline. The study employed field sampling, NDVI data, and remote sensing techniques. The distribution of the forest stands encompassed both the Temperate and Mediterranean bioclimatic regions. A total of 18 quantitative and 4 qualitative variables were recorded and subsequently compared with a damage severity scale based on field observations. The values of the variables were analyzed using both descriptive and multivariate statistics to ascertain their role in triggering oak decline episodes. It was found that eight variables were the most significant in explaining the occurrence of oak decline. These were the first-semester average rainfall (PL), average maximum summer temperature, Rainfall anomaly index, Downward shortwave radiation, Root zone soil moisture, and three indicators concerning the number, amplitude, and duration of heatwaves. Quercus pubescens forests were found to be the most affected by oak decline. The years 2017 and 2022 were characterized by high levels of stress, with the combined effect of groups of diagnostic variables in exceeding the critical thresholds proving decisive in triggering episodes of oak decline. A vulnerability map was finally created reporting three vulnerability classes for oak decline: low, medium, and high. The analysis revealed that approximately 97% (116,700 hectares) of forest plots classified as vulnerable (31.7% of the total forest area in the study region) were categorized as medium or high vulnerability.

Both biotic and abiotic factors are raising concerns about Mediterranean oak forests resilience to climate change, particularly Holm oak (Quercus ilex L.) forests. In the last decade, many drought events impacted this species in several Mediterranean countries, and a widespread decline of holm oak forests has been observed due to a combination of drought and the soil pathogen Phytophthora cinnamoni. In addition, climate change has induced a rise in mean winter temperatures, a seasonal shift of precipitation from summer to wintertime, and a tendency towards heavy rain and prolonged droughts, which are triggering factors for the current decline of holm oak in Mediterranean regions. The resulting reduction in holm oak forest vitality and productivity can ultimately lead to profound changes in ecosystem processes and functions. Previous studies based on tree-ring δ13C and SSR genotyping showed that different holm oak populations can differ in their water use efficiency, resulting in different drought tolerance. This study highlighted the potential of this analysis for the selection of seed-bearing genotypes aimed to preserve Mediterranean holm oak ecosystem and improving its forest management. In this context, LIFE RECLOAK project aims to restore and improve the conservation status of threatened forests by holm oak dieback using genotypes characterized by high level of drought tolerance and pathogen resistance. A step-by-step approach will allow the achievement of this ambitious goal over the five years of the project. In the first instance, drought-tolerant and pathogen-resistant genotypes will be selected through a genetic screening based on SSR genotyping and the identification of genetic markers associated with stress tolerance. A mesocosm trial will be carried out to confirm the drought tolerance and the pathogen resistance of the holm oak genotypes. Then, the selected seedlings will be planted in four pilot sites areas located in Mediterranean holm oak forests included in Natura 2000 network and affected by widespread dieback: Monti dell’Uccellina in Parco della Maremma (Tuscany, Italy); Parco della Maddalena (Sardinia, Italy); Muela de Cortes y el Caroche (Valencia province, Spain), Raso del Conejo Forest (Sierra Morena, Andalucia, Spain) and Wied il-Mielaħ u l-Inħawi tal-Madwar (Malta). After that, seasonal and multi-year monitoring for three years after the plantation will begin at each pilot site. The monitoring of pilot sites will be done by visual assessment and through the measurement of plant physiological performances by integrating gas exchange measurements with proximal sensing measures. The effects of reforestation on ecosystem functioning and climate mitigation will be investigated by measuring soil moisture, respiration, and microbial communities’ composition, as well as monitoring understory and overstory vegetation cover and biomass accumulation. Overall, this project will provide a reliable demonstration of restoring forest structure, thereby promoting forestry with conservation objectives and opening the possibility of restoring other Mediterranean areas affected by holm oak dieback.