Helena Santos

The influences of forest stand management on biotic and abiotic risks of damage

Abstract• This article synthesizes and reviews the available information on the effects of forestry practices on the occurrence of biotic and abiotic hazards, as well as on stand susceptibility to these damaging agents, concentrating on mammal herbivores, pest insects, pathogenic fungi, wind and fire.• The management operations examined are site selection, site preparation, stand composition, regeneration method, cleaning and weed control, thinning and pruning, and harvesting. For each of these operations we have examined how they influence the occurrence of biotic and abiotic damaging agents, the susceptibility of European forests, and describe the ecological processes that may explain these influences.• Overall, we find that the silvicultural operations that have the largest influence on both biotic and abiotic risks to European forest stands are closely related to species composition and the structure of the overstorey. Four main processes that drive the causal relationships between stand management and susceptibility have been identified: effect on local microclimate, provision of fuel and resources to biotic and abiotic hazards, enhancement of biological control by natural enemies and changes in individual tree physiology and development.• The review demonstrates an opportunity to develop silvicultural methods that achieve forest management objectives at the same time as minimising biotic and abiotic risks.Résumé• Cette revue bibliographique s’intéresse aux effets de la sylviculture sur la sensibilité des peuplements forestiers aux principaux agents de dégâts biotiques et abiotiques que sont les mammifères herbivores, les insectes ravageurs, les champignons pathogènes, le feu et les vents forts.• Les pratiques forestières analysées sont la sélection et la préparation des sites de reboisement, la définition de la composition en essences et le choix du matériel génétique, les méthodes de régénération et d’entretien, les modalités d’éclaircie et d’élagage, le mode de récolte finale. L’influence de chacune de ces opérations sur l’occurrence des agents de dégâts biotiques et abiotiques et sur la sensibilité des peuplements est examinée ainsi que les processus écologiques sous-jacents.• Les opérations sylvicoles qui se révèlent les plus déterminantes pour la sensibilité des forêts en Europe sont celles qui affectent la composition et la structure de la strate arborée. Quatre principaux processus écologiques semblent expliquer la relation entre sylviculture et sensibilité des peuplements : la modification du micro-climat, l’apport de ressources ou de combustible aux agents de dégâts, l’amélioration du contrôle biologique par les ennemis naturels et l’altération de la physiologie et du développement des arbres.• Cette revue permet donc d’envisager le développement de méthodes de gestion des peuplements forestiers qui permettent d’atteindre les objectifs de production tout en minimisant les risques de dégâts sanitaires.

Natural History of the Processionary Moths (Thaumetopoea spp.): New Insights in Relation to Climate Change

It is difficult to find a genus of Lepidoptera showing the high variability of life history traits observed in Thaumetopoea. There are typical summer feeding close to winter feeding species, and in one special case a recent switch has been detected even within one species, the pine processionary moth, indicating that the natural history traits are constantly evolving at a fast rate. There are species adapted to cold conditions of high mountains and high latitude close to truly Mediterranean and sub-desert region species. All species have gregarious behaviour as larva and are protected against vertebrate predators by urticating setae.

Phenotypic divergence in reproductive traits of a moth population experiencing a phenological shift

Allochrony that is reproductive isolation by time may further lead to divergence of reproductive adaptive traits in response to different environmental pressures over time. A unique “summer” population of the pine processionary moth Thaumetopoea pityocampa, reproductively isolated from the typical winter populations by allochronic differentiation, is here analyzed. This allochronically shifted population reproduces in the spring and develops in the summer, whereas “winter” populations reproduce in the late summer and have winter larval development. Both summer and winter populations coexist in the same pine stands, yet they face different climatic pressures as their active stages are present in different seasons. The occurrence of significant differences between the reproductive traits of the summer population and the typical winter populations (either sympatric or allopatric) is thus hypothesized. Female fecundity, egg size, egg covering, and egg parasitism were analyzed showing that the egg load was lower and that egg size was higher in the summer population than in all the studied winter populations. The scales that cover the egg batches of T. pityocampa differed significantly between populations in shape and color, resulting in a looser and darker covering in the summer population. The single specialist egg parasitoid species of this moth was almost missing in the summer population, and the overall parasitism rates were lower than in the winter population. Results suggest the occurrence of phenotypic differentiation between the summer population and the typical T. pityocampa winter populations for the life-history traits studied. This work provides an insight into how ecological divergence may follow the process of allochronic reproductive isolation.

Experimental evidence for heritable reproductive time in 2 allochronic populations of pine processionary moth

Phenology allows organisms to overcome seasonally variable conditions through life‐cycle adjustment. Changes in phenology can drastically modify the evolutionary trajectory of a population, while a shift in the reproductive time may cause allochronic differentiation. The hypothesis of heritable reproductive time was experimentally tested, by studying a unique population of the pine processionary moth Thaumetopoea pityocampa (Den. & Schiff.) which has a shifted phenology, and however co‐occurs with the typical population following the classical life cycle. When populations of both types were reared under controlled conditions, the reproductive time was maintained asynchronous, as observed in the field. The shifted population was manipulated in the laboratory to reproduce later than usual, yet the offspring emerged in the next year at the expected dates thus “coming back” to the usual cycle. Hybrids from crosses performed between the 2 populations showed an intermediate phenology. From the emergence times of parents and offspring, a high heritability of the reproductive time (h = 0.76) was observed. The offspring obtained from each type of cross was genetically characterized using microsatellite markers. Bayesian clustering analysis confirmed that hybrids can be successfully identified and separated from the parental genetic classes by genotyping. Findings support the hypothesis that, for this particular population, incipient allochronic speciation is due to a heritable shift in the reproductive time that further causes assortative mating and might eventually cause ecological adaptation/maladaptation in response to environmental changes.

Climate Warming and Past and Present Distribution of the Processionary Moths (Thaumetopoea spp.) in Europe, Asia Minor and North Africa

Pine processionary moth, Thaumetopea pityocampa, is a model insect indicator of global warming, the northwards and upwards range expansion of this Mediterranean species being directly associated with the recent warming up. The knowledge about the drivers of moth expansion is synthesized. A first standardized mapping of the northern expansion edge, from Western Europe to Turkey, is presented, then detailed for 20 countries of Europe, Asia Minor and North Africa, including future trends. Additional data about the responses of the other Thaumetopoea species are given. Finally, the chapter points out the importance of the man-mediated introductions in the expansion process.

Genetic Diversity and Structure at Different Spatial Scales in the Processionary Moths

This chapter presents the evolutionary history of Thaumetopoea species associated with pines, at different temporal and spatial scales. It corresponds to recent discoveries and ongoing works using sequencing technologies and population genetics. Most of the subchapters focus on the winter pine processionary moths T. pityocampa/T. wilkinsoni including a population with a shifted life cycle. Results concerning the summer pine processionary moth T. pinivora and the evolution of the whole genus are also presented. This chapter gives insights about the effects of Quaternary climate changes in different regions, and allow to study the contemporary changes due to the present climate warming.

Dysarthria in individuals with Parkinson's disease: a protocol for a binational, cross-sectional, case-controlled study in French and European Portuguese (FraLusoPark)

Introduction Individuals with Parkinsons disease (PD) have to deal with several aspects of voice and speech decline and thus alteration of communication ability during the course of the disease. Among these communication impairments, 3 major challenges include: (1) dysarthria, consisting of orofacial motor dysfunction and dysprosody, which is linked to the neurodegenerative processes; (2) effects of the pharmacological treatment, which vary according to the disease stage; and (3) particular speech modifications that may be language-specific, that is, dependent on the language spoken by the patients. The main objective of the FraLusoPark project is to provide a thorough evaluation of changes in PD speech as a result of pharmacological treatment and disease duration in 2 different languages (French vs European Portuguese). Methods and analysis Individuals with PD are enrolled in the study in France (N=60) and Portugal (N=60). Their global motor disability and orofacial motor functions is assessed with specific clinical rating scales, without (OFF) and with (ON) pharmacological treatment. 2 groups of 60 healthy age-matched volunteers provide the reference for between-group comparisons. Along with the clinical examinations, several speech tasks are recorded to obtain acoustic and perceptual measures. Patient-reported outcome measures are used to assess the psychosocial impact of dysarthria on quality of life. Ethics and dissemination The study has been approved by the local responsible committees on human experimentation and is conducted in accordance with the ethical standards. A valuable large-scale database of speech recordings and metadata from patients with PD in France and Portugal will be constructed. Results will be disseminated in several articles in peer-reviewed journals and in conference presentations. Recommendations on how to assess speech and voice disorders in individuals with PD to monitor the progression and management of symptoms will be provided. Trial registration number NCT02753192, Pre-results.

Overproduction, purification, crystallization and preliminary X-ray characterization of the family 46 carbohydrate-binding module (CBM46) of endo-β-1,4-glucanase B (CelB) from Bacillus halodurans

Plant cell-wall polysaccharides offer an abundant energy source utilized by many microorganisms, thus playing a central role in carbon recycling. Aerobic microorganisms secrete carbohydrate-active enzymes (CAZymes) that catabolize this composite structure, comprising cellulose, hemicellulose and lignin, into simple compounds such as glucose. Carbohydrate-binding modules (CBMs) enhance the efficacy of associated CAZYmes. They are organized into families based on primary-sequence homology. CBM family 46 contains more than 40 different members, but has yet to be fully characterized. Here, a recombinant derivative of the C-terminal family 46 CBM module (BhCBM46) of Bacillus halodurans endo-β-1,4-glucanase B (CelB) was overexpressed in Escherichia coli and purified by immobilized metal-ion affinity chromatography. Preliminary structural characterization was carried out on BhCBM46 crystallized in different conditions. The crystals of BhCBM46 belonged to the tetragonal space group I4₁22. Data were collected for the native form and a selenomethionine derivative to 2.46 and 2.3 Å resolution, respectively. The BhCBM46 structure was determined by a single-wavelength anomalous dispersion experiment using AutoSol from the PHENIX suite.

Insect – Tree Interactions in Thaumetopoea pityocampa

The pine processionary moth is, by far, the most important insect defoliator of pine forests in Southern Europe and North Africa, both in terms of its temporal occurrence, geographic range and socioeconomic impact. Monitoring and pest management actions are therefore required on a regular basis, to ensure the detection, evaluation and mitigation of potential risks to forest and public health. However, we still lack some of the basic knowledge required for relevant analyses of the risk posed by the pine processionary moth. Pest risk is defined as a combination of three components: (1) pest occurrence, which depends on the spatiotemporal dynamics of populations; (2) plant vulnerability to the pest, resulting in a certain amount of damage; and (3) the socioeconomic impact of damage, depending on the potential value of the plants damaged (Jactel et al. 2012). The population dynamics of the processionary moth has been extensively studied, in particular within the context of climate change (see Battisti et al. 2014, Chap. 2, this volume). Several studies have recently addressed the question of tree and forest vulnerability to pine processionary attacks but a comprehensive review of evidence was missing. This is the first objective of this chapter. In particular we were interested in a better understanding of the ecological mechanisms responsible for the host tree selection, at both the species and individual tree levels. In a second part we show that pine susceptibility to the pine processionary moth could be reduced by improving forest diversity at different spatial scales. In the last part of this chapter we provide quantitative estimate of the growth losses caused by defoliations of the pine processionary moth. Altogether this information paves the way for quantitative risk analyses on pine processionary moth infestations based on forest growth models.

Automatic Detection of Parkinson’s Disease: An Experimental Analysis of Common Speech Production Tasks Used for Diagnosis

Parkinson’s disease (PD) is the second most common neurodegenerative disorder of mid-to-late life after Alzheimer’s disease. During the progression of the disease, most individuals with PD report impairments in speech due to deficits in phonation, articulation, prosody, and fluency. In the literature, several studies perform the automatic classification of speech of people with PD considering various types of acoustic information extracted from different speech tasks. Nevertheless, it is unclear which tasks are more important for an automatic classification of the disease. In this work, we compare the discriminant capabilities of eight verbal tasks designed to capture the major symptoms affecting speech. To this end, we introduce a new database of Portuguese speakers consisting of 65 healthy control and 75 PD subjects. For each task, an automatic classifier is built using feature sets and modeling approaches in compliance with the current state of the art. Experimental results permit to identify reading aloud prosodic sentences and story-telling tasks as the most useful for the automatic detection of PD.