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BACKGROUND: Immune-mediated necrotizing myopathy (IMNM) is an autoimmune myopathy characterised by proximal muscle weakness, high creatine kinase (CK) values, and autoantibodies recognizing 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) or the signal recognition particle (SRP). There are currently no approved therapies for IMNM and many patients experience active disease despite off-label treatment with intravenous immunoglobulin, glucocorticoids, and immunosuppressants. Detection of complement-activating anti-HMGCR and anti-SRP autoantibodies and the presence of complement deposition on the sarcolemma of non-necrotic myofibers led to the hypothesis that complement activation may be pathogenic in IMNM, therefore zilucoplan, a complement component 5 (C5) inhibitor, could be a potential therapy. METHODS: IMNM01, a phase 2, multicenter, randomised, double-blind, placebo-controlled study (NCT04025632) at 15 sites (four countries) evaluated efficacy, safety, and tolerability of zilucoplan in adult participants with anti-HMGCR or anti-SRP autoantibody-positive IMNM. Participants were randomised 1:1 to receive daily subcutaneous zilucoplan (0·3mg/kg) or placebo for eight weeks; with optional enrolment in the study open-label extension. Primary efficacy endpoint was percent change from baseline to Week 8 in CK levels. Secondary endpoints included safety. FINDINGS: Between 07 November 2019 and 07 January 2021, 27 participants (13 female and 14 male) received zilucoplan (n=12) or placebo (n=15) and completed the 8-week main study. At Week 8 there were no clinically relevant or statistically significant differences, despite target engagement based on mode of action, between treatment arms in mean percent change (standard deviation) of CK levels versus baseline (-9·86% [26·06] versus -20·72% [31·22] in zilucoplan [n=10] and placebo arms [n=14], p=0·46, respectively) and no clinically relevant improvement over time within the treatment arm. There were no unexpected adverse safety or tolerability findings. Treatment emergent adverse events (TEAEs) and serious TEAEs were reported in n=9 (75·0%) vs n=13 (86·7%) and n=0 (0%) and n=3 (20·0%) participants, respectively. The most frequent TEAEs were headache (n=4 in both groups [33·3% and 26·7%, respectively]) and nausea (n=3 in both groups [25·0% and 20·0%, respectively]). INTERPRETATION: C5 inhibition does not appear to be an effective treatment modality for IMNM. Rather than driving myofiber necrosis, complement activation may be secondary to muscle injury. FUNDING: Study funded by Ra Pharmaceuticals (now part of UCB Pharma).

Spatial arrangement of trees is determined by a complex suite of factors, including disturbance history, competition, and resource availability. These spatial patterns drive adaptive capacity by influencing arrangement of growing space, neighborhood competitive relationships, and disturbance response, with irregular patterns supporting higher adaptive capacity. While spatial structure in relation to disturbance and climate change resilience has been studied in dry conifer forests and old-growth temperate forests, it has never been explored in the context of climate adaptive management in mesic, second-growth forests. To address this gap, we analyzed tree spatial patterns in second-growth northern hardwood forests under four different climate adaptation management approaches: no action; resistance or resilience to impacts of climate change; and transition to future-adapted forest types. We used spatial point statistics approaches to describe how patterns differed among the four treatments. We found that the treatments focused on future adaptation led to patterns with variable tree spacing and clumping, while those focused on perpetuating current conditions resulted in less pattern variation. This indicates that adaptation strategies that include uneven-aged regeneration methods that restore and maintain tree spatial patterns historically generated by gap dynamics can be successful in altering resource availability patterns and adaptation space in forest stands. Key words: spatial pattern, forest adaptation, climate change resilience, structural complexity, silviculture, northern hardwood forest, Introduction Forest ecosystems and their ecological processes are defined by the presence and arrangement of tree species, sizes, and elements of stand structure, all of which can reflect a combination [...]

INTRODUCTION/AIMS: Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive muscular dystrophy without approved therapies. In this study we evaluated whether locally acting ACE-083 could safely increase muscle volume and improve functional outcomes in adults with FSHD. METHODS: Participants were at least 18 years old and had FSHD1/FSHD2. Part 1 was open label, ascending dose, assessing safety and tolerability (primary objective). Part 2 was randomized, double-blind for 6 months, evaluating ACE-083240 mg/muscle vs placebo injected bilaterally every 3 weeks in the biceps brachii (BB) or tibialis anterior (TA) muscles, followed by 6 months of open label. Magnetic resonance imaging measures included total muscle volume (TMV; primary objective), fat fraction (FF), and contractile muscle volume (CMV). Functional measures included 6-minute walk test, 10-meter walk/run, and 4-stair climb (TA group), and performance of upper limb midlevel/elbow score (BB group). Strength, patient-reported outcomes (PROs), and safety were also evaluated. RESULTS: Parts 1 and 2 enrolled 37 and 58 participants, respectively. Among 55 participants evaluable in Part 2, the least-squares mean (90% confidence interval, analysis of covariance) treatment difference for TMV was 16.4% (9.8%-23.0%) in the BB group (P

Several aspects of the forest carbon cycle have not been examined in detail, including sources of variation in carbon dioxide (C[O.sub.2]) emissions from coarse woody material (CWM). To address this knowledge gap, we examined C[O.sub.2] emissions from Acer saccharum Marshall logs within four harvesting treatments, using closed chambers fitted to the logs. We found that C[O.sub.2] emissions were highest for logs in small (31.8 [+ or -] 20.4 [micro]molC[O.sub.2][m.sup.- 3][s.sup.-1]) and large gaps (29.6 [+ or -] 24.4 [micro]molC[O.sub.2][m.sup.-3][s.sup.-1]) compared to those in control (13.9 [+ or -] 8.3 [micro]molC[O.sub.2][m.sup.-3][s.sup.-1]) and thinned matrix (13.6 [+ or -] 8.0 [micro]molC[O.sub.2][m.sup.-3] [s.sup.-1]) treatments. C[O.sub.2] flux rates did not differ between gap sizes, but they increased with temperature, which was higher in the small gap treatment. In addition, two individual logs fitted with multiple closed chambers revealed significant within-log variability in C[O.sub.2] emissions. On a subset of logs repeatedly sampled throughout the day, we found that log surface temperature generally peaked at midday and was positively correlated with C[O.sub.2] emissions, although this relationship was weak in one log. This study provides insight into sources of variation in C[O.sub.2] emissions from CWM while improving our understanding of the forest carbon cycle. Key words: carbon dioxide, carbon flux, forest carbon cycle, woody material, wood decomposition, Introduction Forests are important contributors to the global carbon cycle, both as a sink of carbon dioxide (C[O.sub.2]) through photosynthesis as well as an emitter of C[O.sub.2] as these carbon [...]

ObjectiveTo determine whether rituximab is safe and potentially beneficial, warranting further investigation in an efficacy trial for acetylcholine receptor antibody-positive generalized MG (AChR-Ab+ gMG).MethodsThe B-Cell Targeted Treatment in MG (BeatMG) study was a randomized, double-blind, placebo-controlled, multicenter phase-2 trial that utilized a futility design. Individuals 21-90 years of age, with AChR-Ab+ gMG (MG Foundation of America Class II-IV) and receiving prednisone ≥15 mg/day were eligible. The primary outcome was a measure of steroid-sparing effect, defined as the proportion achieving ≥75% reduction in mean daily prednisone dose in the 4-weeks prior to week 52 and with clinical improvement or no significant worsening as compared to the 4-week period prior to randomization. The co-primary outcome was safety. Secondary outcomes included MG-specific clinical assessments. Fifty-two individuals were randomized (1:1) to either a two-cycle rituximab/placebo regimen, with follow-up through 52-weeks.ResultsOf the 52 participants included, mean (±SD) age at enrollment was 55.1 (±17.1) years; 23 (44.2%) were female, and 31 (59.6%) were MGFA Class II. The mean (±SD) baseline prednisone dose was 22.1 (±9.7) mg/day. The primary steroid-sparing outcome was achieved in 60% of those on rituximab vs. 56% on placebo. The study reached its futility endpoint (p=0.03) suggesting that the pre-defined clinically meaningful improvement of 30% due to rituximab over placebo was unlikely to be achieved in a subsequent, larger trial. No safety issues identified.ConclusionsWhile rituximab was safe and well-tolerated, these results suggest that there is a low probability of observing the defined clinically meaningful steroid-sparing effect over a 12-month period in a phase-3 trial of mild-moderately symptomatic AChR-Ab+ gMG.Classification of evidenceThis study provides Class I evidence that for mild-to-moderate AChR-Ab+ gMG, compared with placebo, rituximab is safe but unlikely to reduce steroid use by an absolute difference of at least 30% at 1 year.Trial registrationClinicalTrials.gov Identifier: NCT02110706.

ObjectiveTo assess long-term (2 years) effects of bimagrumab in participants with sporadic inclusion body myositis (sIBM).MethodsParticipants (aged 36-85 years) who completed the core study (RESILIENT [Efficacy and Safety of Bimagrumab/BYM338 at 52 Weeks on Physical Function, Muscle Strength, Mobility in sIBM Patients]) were invited to join an extension study. Individuals continued on the same treatment as in the core study (10 mg/kg, 3 mg/kg, 1 mg/kg bimagrumab or matching placebo administered as IV infusions every 4 weeks). The co-primary outcome measures were 6-minute walk distance (6MWD) and safety.ResultsBetween November 2015 and February 2017, 211 participants entered double-blind placebo-controlled period of the extension study. Mean change in 6MWD from baseline was highly variable across treatment groups, but indicated progressive deterioration from weeks 24-104 in all treatment groups. Overall, 91.0% (n = 142) of participants in the pooled bimagrumab group and 89.1% (n = 49) in the placebo group had ≥1 treatment-emergent adverse event (AE). Falls were slightly higher in the bimagrumab 3 mg/kg group vs 10 mg/kg, 1 mg/kg, and placebo groups (69.2% [n = 36 of 52] vs 56.6% [n = 30 of 53], 58.8% [n = 30 of 51], and 61.8% [n = 34 of 55], respectively). The most frequently reported AEs in the pooled bimagrumab group were diarrhea 14.7% (n = 23), involuntary muscle contractions 9.6% (n = 15), and rash 5.1% (n = 8). Incidence of serious AEs was comparable between the pooled bimagrumab and the placebo group (18.6% [n = 29] vs 14.5% [n = 8], respectively).ConclusionExtended treatment with bimagrumab up to 2 years produced a good safety profile and was well-tolerated, but did not provide clinical benefits in terms of improvement in mobility. The extension study was terminated early due to core study not meeting its primary endpoint.Clinical trial registrationClinicaltrials.gov identifier NCT02573467.Classification of evidenceThis study provides Class IV evidence that for patients with sIBM, long-term treatment with bimagrumab was safe, well-tolerated, and did not provide meaningful functional benefit. The study is rated Class IV because of the open-label design of extension treatment period 2.

ObjectiveTo examine whether sustained minimal manifestation status (MMS) with complete withdrawal of prednisone is better achieved in thymectomized patients with myasthenia gravis (MG).MethodsThis study is a post hoc analysis of data from a randomized trial of thymectomy in MG (Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy [MGTX]). MGTX was a multicenter, randomized, rater-blinded 3-year trial that was followed by a voluntary 2-year extension for patients with acetylcholine receptor (AChR) antibody-positive MG without thymoma. Patients were randomized 1:1 to thymectomy plus prednisone vs prednisone alone. Participants were age 18-65 years at enrollment with disease duration less than 5 years. All patients received oral prednisone titrated up to 100 mg on alternate days until they achieved MMS, which prompted a standardized prednisone taper as long as MMS was maintained. The achievement rate of sustained MMS (no symptoms of MG for 6 months) with complete withdrawal of prednisone was compared between the thymectomy plus prednisone and prednisone alone groups.ResultsPatients with MG in the thymectomy plus prednisone group achieved sustained MMS with complete withdrawal of prednisone more frequently (64% vs 38%) and quickly compared to the prednisone alone group (median time 30 months vs no median time achieved, p < 0.001) over the 5-year study period. Prednisone-associated adverse symptoms were more frequent in the prednisone alone group and distress level increased with higher doses of prednisone.ConclusionsThymectomy benefits patients with MG by increasing the likelihood of achieving sustained MMS with complete withdrawal of prednisone.Clinicaltrialsgov identifierNCT00294658.Classification of evidenceThis study provides Class II evidence that for patients with generalized MG with AChR antibody, those receiving thymectomy plus prednisone are more likely to attain sustained MMS and complete prednisone withdrawal than those on prednisone alone.

IMPORTANCE: One major advantage of developing large, federally funded networks for clinical research in neurology is the ability to have a trial-ready network that can efficiently conduct scientifically rigorous projects to improve the health of people with neurologic disorders. OBSERVATIONS: National Institute of Neurological Disorders and Stroke Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) was established in 2011 and renewed in 2018 with the goal of being an efficient network to test between 5 and 7 promising new agents in phase II clinical trials. A clinical coordinating center, data coordinating center, and 25 sites were competitively chosen. Common infrastructure was developed to accelerate timelines for clinical trials, including central institutional review board (a first for the National Institute of Neurological Disorders and Stroke), master clinical trial agreements, the use of common data elements, and experienced research sites and coordination centers. During the first 7 years, the network exceeded the goal of conducting 5 to 7 studies, with 9 funded. High interest was evident by receipt of 148 initial applications for potential studies in various neurologic disorders. Across the first 8 studies (the ninth study was funded at end of initial funding period), the central institutional review board approved the initial protocol in a mean (SD) of 59 (21) days, and additional sites were added a mean (SD) of 22 (18) days after submission. The median time from central institutional review board approval to first site activation was 47.5 days (mean, 102.1; range, 1-282) and from first site activation to first participant consent was 27 days (mean, 37.5; range, 0-96). The median time for database readiness was 3.5 months (mean, 4.0; range, 0-8) from funding receipt. In the 4 completed studies, enrollment met or exceeded expectations with 96% overall data accuracy across all sites. Nine peer-reviewed manuscripts were published, and 22 oral presentations or posters and 9 invited presentations were given at regional, national, and international meetings. CONCLUSIONS AND RELEVANCE: NeuroNEXT initiated 8 studies, successfully enrolled participants at or ahead of schedule, collected high-quality data, published primary results in high-impact journals, and provided mentorship, expert statistical, and trial management support to several new investigators. Partnerships were successfully created between government, academia, industry, foundations, and patient advocacy groups. Clinical trial consortia can efficiently and successfully address a range of important neurologic research and therapeutic questions.

Black ash (Fraxinus nigra Marsh.) forests of north-central North America are currently threatened by the non- native emerald ash borer (Agrilus planipennis, EAB). Despite the wide distribution of F. nigra ecosystems, and the concern over EAB impact, little is known about their structure and natural stand dynamics. We sampled six old-growth F. nigra stands to assess structure, composition, tree recruitment, and past disturbance. Dendrochronological results revealed that disturbance rates fluctuated markedly over the past 200 years or more, but remained relatively low, suggesting small- to moderate-scale disturbances. Recruitment age structures revealed that (i) F. nigra is able to maintain long-term dominance through extended longevity as a canopy tree, and (ii) these systems have fairly continuous recruitment over time, with most sites showing F. nigra recruitment in every decade in the chronology. We speculate that recruitment is coupled with water table fluctuations, in addition to canopy disturbance, as these stands are subject to both frequent flooding and effective soil drought (given the shallow root systems). The low rates of past canopy disturbance and associated gap-phase replacement by F. nigra highlight the potential for dramatic shifts in these systems following emerald ash borer invasion and subsequent canopy tree mortality. Key words: black ash, dendroecology, emerald ash borer, gap dynamics, stand dynamics, moderate-severity disturbance Les forets de frenes noirs (Fraxinus nigra Marsh.) du centre-nord de l'Amerique du Nord sont actuellement menacees par l'agrile du frene (Agrilus planipennis, EAB), une espece non indigene. Malgre la large distribution des ecosystemes de F. nigra et l'inquietude concernant l'impact de l'agrile du frene, on sait peu de choses sur leur structure et la dynamique naturelle des peuplements. Nous avons echantillonne six peuplements anciens de F. nigra pour evaluer la structure, la composition, le recrutement des arbres et les perturbations passees. Les resultats dendrochronologiques ont revele que les taux de perturbation ont fluctue de facon marquee au cours des 200 dernieres annees ou plus, mais sont restes relativement faibles, ce qui suggere des perturbations a petite ou moyenne echelle. Les structures d'age du recrutement ont revele que (i) F. nigra est capable de maintenir une dominance a long terme grace a une longevite prolongee en tant qu'arbre de la canopee, et (ii) ces systemes ont un recrutement assez continu dans le temps, la plupart des sites montrant un recrutement de F. nigra dans chaque decennie de la chronologie. Nous supposons que le recrutement est couple aux fluctuations de la nappe phreatique, en plus de la perturbation de la canopee, car ces peuplements sont soumis a la fois a des inondations frequentes et a une secheresse effective du sol (etant donne la faible profondeur des systemes racinaires). Les faibles taux de perturbation de la canopee dans le passe et le remplacement par F. nigra qui y est associe soulignent le potentiel de changements dramatiques dans ces systemes apres l'invasion de l'agrile du frene et la mortalite subsequente des arbres de la canopee. [Traduit par la Redaction] Mots-cles : frene noir, dendroecologie, agrile du frene, dynamique des espaces, dynamique des peuplements, perturbation de gravite moderee, 1. Introduction Forest ecosystems can be dramatically altered when nonnative insects eliminate a foundational tree species, thereby causing shifts in food webs, energy flux, hydrology, and biodiversity (Ellison et al. [...]

BackgroundThe Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone (MGTX) showed that thymectomy combined with prednisone was superior to prednisone alone in improving clinical status as measured by the Quantitative Myasthenia Gravis (QMG) score in patients with generalised non-thymomatous myasthenia gravis at 3 years. We investigated the long-term effects of thymectomy up to 5 years on clinical status, medication requirements, and adverse events.MethodsWe did a rater-blinded 2-year extension study at 36 centres in 15 countries for all patients who completed the randomised controlled MGTX and were willing to participate. MGTX patients were aged 18 to 65 years at enrolment, had generalised non-thymomatous myasthenia gravis of less than 5 years' duration, had acetylcholine receptor antibody titres of 1·00 nmol/L or higher (or concentrations of 0·50-0·99 nmol/L if diagnosis was confirmed by positive edrophonium or abnormal repetitive nerve stimulation, or abnormal single fibre electromyography), had Myasthenia Gravis Foundation of America Clinical Classification Class II-IV disease, and were on optimal anticholinesterase therapy with or without oral corticosteroids. In MGTX, patients were randomly assigned (1:1) to either thymectomy plus prednisone or prednisone alone. All patients in both groups received oral prednisone at doses titrated up to 100 mg on alternate days until they achieved minimal manifestation status. The primary endpoints of the extension phase were the time-weighted means of the QMG score and alternate-day prednisone dose from month 0 to month 60. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00294658. It is closed to new participants, with follow-up completed.FindingsOf the 111 patients who completed the 3-year MGTX, 68 (61%) entered the extension study between Sept 1, 2009, and Aug 26, 2015 (33 in the prednisone alone group and 35 in the prednisone plus thymectomy group). 50 (74%) patients completed the 60-month assessment, 24 in the prednisone alone group and 26 in the prednisone plus thymectomy group. At 5 years, patients in the thymectomy plus prednisone group had significantly lower time-weighted mean QMG scores (5·47 [SD 3·87] vs 9·34 [5·08]; p=0·0007) and mean alternate-day prednisone doses (24 mg [SD 21] vs 48 mg [29]; p=0·0002) than did those in the prednisone alone group. 14 (42%) of 33 patients in the prednisone group, and 12 (34%) of 35 in the thymectomy plus prednisone group, had at least one adverse event by month 60. No treatment-related deaths were reported during the extension phase.InterpretationAt 5 years, thymectomy plus prednisone continues to confer benefits in patients with generalised non-thymomatous myasthenia gravis compared with prednisone alone. Although caution is appropriate when generalising our findings because of the small sample size of our study, they nevertheless provide further support for the benefits of thymectomy in patients with generalised non-thymomatous myasthenia gravis.FundingNational Institutes of Health, National Institute of Neurological Disorders and Stroke.

Threats to the future function of forested ecosystems and stability of ecosystem service provisioning due to global change have motivated climate-adaptive forest management strategies that include various forms of tree planting termed "adaptation plantings". Despite the emergence of these strategies, less is known as to how foresters and other natural resource managers perceive or are engaged with adaptation plantings like forest assisted migration (FAM). This knowledge gap is most pronounced in regions like New England and the North Central US (hereafter, the Northeastern US) where tree planting is less common but expected to be an important forest management tool for adaptation. To address this, we surveyed 33 natural resource managers in this region actively engaged in climate change adaptation (i.e., early adopters of the practice) to assess how tree planting for adaptation is currently being pursued against the perceived barriers, opportunities, and potential future engagement with the strategy. Survey respondents overwhelmingly (93.5%) forecast increases in the future use of adaptation plantings in their work in the region, attributed to increased awareness, acceptance, and interest in the practice. Respondents expressed notable interest in strategies related to diversification and most types of FAM (e.g., assisted population expansion and assisted range expansion), but hesitancy to engage with more contentious planting types like afforestation or FAM linked to the long-distance translocation of exotic species (e.g., assisted species migration). Although examples of local enrichment plantings (i.e., non-FAM) proliferate, nineteen of the top twenty most common tree genera planted contain at least one example of FAM in the study region. The most notable barriers reported were themed as 1) biotic and abiotic, 2) information and material, and 3) policy, social, and economic factors. While most respondents report difficulty obtaining adequate planting material from nurseries (i.e., seedlings), over 80% placed orders shortly before planting (< 1 year) which likely generates difficulty in sourcing seedlings suited for a specific site and future range of environmental conditions. Although this study is limited by focusing on subset of natural resource managers who are early adopters of climate change adaptation within the region, valuable inferences into the barriers and trends are possible from this population serving on the front lines of forest adaptation. Together, these results from early adopters suggest a potentially growing need for allocating resources that engage forest stewards in adaptation planning and serve to refine policy, financing, and management practices to support this adaptation strategy in this region and beyond. [ABSTRACT FROM AUTHOR]

The invasive shrub Scotch broom (Cytisus scoparius (L.) Link) is a pervasive threat to regenerating Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) stands in the Pacific Northwest, USA. Field observations indicate that the susceptibility of areas to Scotch broom invasion and dominance can vary by site. We selected 10 sites throughout the western Pacific Northwest that spanned a gradient of soil textures and other factors to test the site-specific susceptibility of Douglas-fir to overtopping by Scotch broom. We expected to find that the ability of Scotch broom to dominate a site was mediated by site-level factors, particularly those influencing soil water--the most limiting factor to growth in the region. We found Scotch broom and Douglas-fir were inversely affected by site-level factors. In general, Douglas-fir absolute height growth rates were more competitive with those of Scotch broom on fine-textured soils than on more coarsely textured soils. We also found Douglas-fir to have a more dramatic response to increasing down woody material than Scotch broom. Scotch broom height growth approached an asymptote at 3 m. Sites with fast-growing Douglas-fir were able to surpass this height 6-7 years after planting and appear likely to avoid suppression by Scotch broom. Key words: soil water content, depletion, absolute height growth rate, site-specific susceptibility, vegetation management. Le genet a balais (Cytisus scoparius (L.) Link) est un arbuste envahissant qui represente une menace omnipresente pour la regeneration des peuplements de douglas de Menzies (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) dans le Nord-Ouest du Pacifique, aux Etats-Unis. Des observations sur le terrain indiquent que la susceptibilite a l'invasion et a la dominance du genet a balais peut varier selon la station. Nous avons selectionne 10 stations dans la partie occidentale de la region du Nord-Ouest du Pacifique de facon a couvrir un gradient de textures du sol et d'autres facteurs pour identifier les facteurs stationnels qui influencent la susceptibilite du douglas de Menzies face a la dominance du genet a balais. Nous anticipions que la capacite du genet a balais a dominer une station etait influencee par des facteurs stationnels, en particulier ceux qui influencent l'eau du sol qui est le facteur qui limite le plus la croissance dans cette region. Nous avons trouve que le genet a balais et le douglas de Menzies etaient inversement influences par les facteurs stationnels. En general, le taux de croissance en hauteur absolu du douglas de Menzies etait plus eleve que celui du genet a balais sur les sols a texture fine, mais cette difference s'attenuait sur les sols a texture plus grossiere. Nous avons egalement constate que le douglas de Menzies reagit plus fortement a une augmentation de la quantite de debris ligneux au sol que le genet a balais. La croissance en hauteur du genet a balais approchait une valeur asymptotique a 3 m. Sur les stations ou il croit rapidement, le douglas de Menzies a pu depasser cette hauteur 6 a 7 ans apres la plantation et semble pouvoir eviter l'oppression exercee par le genet a balais. [Traduit par la Redaction] Mots-cles : teneur en eau du sol, epuisement, taux de croissance en hauteur absolu, susceptibilite specifique a la station, gestion de la vegetation., Introduction Evaluating the influence of site factors on the productivity of co-occurring species is important for predicting competitive outcomes across sites, particularly among native and nonnative species. Nonnative species invasion [...]

Epigeous fungal fruiting has important impacts on fungal reproduction and ecosystem function. Forest disturbances, such as timber harvest, impact moisture, host availability, and substrate availability, which in turn may drive changes in fungal fruiting patterns and community structure. We surveyed mushrooms in 0.4 ha patch cuts (18 months post-harvest) and adjacent intact hardwood forest in northern New Hampshire, USA, to document the effects of timber harvest on summer fruiting richness, biomass, diversity, and community structure of ectomycorrhizal, parasitic, and saprobic mushroom taxa. Fungal fruiting richness, diversity, and community heterogeneity were greater in intact forests than patch cuts. Among functional groups, ectomycorrhizal fruiting richness, diversity, and biomass were greater in unharvested areas than in the patch cuts, but parasitic and saprobic fruiting did not differ statistically between the two forest conditions. Our findings suggest that timber harvest simplifies fungal fruiting communities shortly after harvest, in particular triggering declines in ectomycorrhizal taxa which are important symbionts facilitating tree establishment and regeneration. Multi-aged silvicultural practices that maintain mature forest conditions adjacent to and throughout harvested areas through deliberate retention of overstory trees and downed woody material may promote fungal fruiting diversity in regenerating stands. Key words: ectomycorrhizal fungi, epigeous sporocarp, fungal fruiting body, forest disturbance, fungal diversity. La fructification des champignons epiges a des repercussions importantes sur la reproduction des champignons et la fonction de l'ecosysteme. Les perturbations de la foret, telles que la recolte de bois, ont un impact sur l'humidite ainsi que la disponibilite des hotes et du substrat, ce qui en retour peut amener des changements dans les patrons de fructification des champignons et la structure de la communaute. Nous avons inventorie les champignons dans des coupes par trouees de 0,4 ha (18 mois apres la recolte) et dans des forets feuillues adjacentes intactes dans le nord du New Hampshire, aux Etats-Unis, pour documenter les effets de la recolte de bois sur la diversite, la biomasse et la richesse des fructifications durant l'ete ainsi que sur la structure de la communaute des taxons de champignons ectomycorhiziens, parasites et saprobies. La richesse et la diversite des fructifications fongiques ainsi que l'heterogeneite des communautes etaient plus elevees dans les forets intactes que dans les coupes par trouees. Parmi les groupes fonctionnels, la richesse, la diversite et la biomasse des fructifications des champignons ectomycorhiziens etaient plus elevees dans les zones non recoltees que dans les coupes par trouees. Par contre, dans les deux situations la fructification des champignons parasites ou saprobies n'etait pas significativement differente. Nos resultats indiquent que la recolte de bois simplifie les fructifications des communautes fongiques peu de temps apres la recolte, surtout en provoquant le declin des taxons ectomycorhiziens, lesquels sont des symbiotes importants qui facilitent la regeneration et l'etablissement des arbres. Les pratiques sylvicoles inequiennes qui maintiennent les conditions de la foret mature adjacente aux zones recoltees et parmi ces zones par la retention deliberee d'arbres dominants et de materiel ligneux au sol, peuvent promouvoir la diversite des fructifications fongiques dans les peuplements en regeneration. [Traduit par la Redaction] Mots-cles : champignons ectomycorhiziens, sporocarpe epige, fructification fongique, perturbation de la foret, diversite fongique., Introduction Epigeous fungal sporocarps (mushrooms) play a critical role in fungal reproduction (Brown and Casselton 2001) and have secondary impacts on food webs (e.g., Orledge and Reynolds 2005), forest health [...]