Can continental bogs with stand the pressure due to climate change?

Not all peatlands are alike. Theoretical and process based models suggest that ombrogenic, oligotrophic peatlands can withstand the pressures due to climate change because of the feedbacks among ecosystem production, decomposition and water storage. Although there have been many inductive explanations inferring from paleo-records, there is a lack of deductive empirical tests of the models predictions of these systems’ stability and there are few records of the changes in the net ecosystem carbon balance (NECB) of peatlands that are long enough to examine the dynamics of the NECB in relation to climate variability. Continuous measurements of all the components of the NECB and the associated general climatic and environmental conditions have been made at the Mer Bleue (MB) peatland, a large, 28 km2, 5 m deep, raised ombro-oligotrophic, shrub and Sphagnum covered bog, near Ottawa, Canada from May 1, 1998 until the present. The sixteen-year daily CO2, CH4, and DOC flux and NECB covers a wide range of variability in peatland water storage from very dry to very wet growing seasons. We used the MB data to test the extent of MB peatland’s stability and the strength of the underlying key feedback between the NECB and changes in water storage projected by the models. In 2007 we published a six-year (1999-2004) net ecosystem carbon balance (NECB) for MB of ∼22 ± 40 g C m-2 yr-1, but we have since recalculated the 1998-2004 NECB to be 32 ± 40 g C m-2 yr-1 based on a reanalyzed average NEP of 51 ± 41 g C m-2 yr-1. Over the same period the net loss of C via the CH4 and DOC fluxes were -4 ± 1 and -15 ± 3 g C m-2 yr-1. The 1998-2004 six-year MB average NECB is similar to the long-term C accumulation rate, estimated from MB peat cores, for the last 3,000 years. The post 2004 MB NEP has increased to an average of ∼96 ± 32 g C m-2 yr-1 largely to there being generally wetter growing seasons. The losses of C via DOC (18 ± 1 g C m-2 yr-1) and CH4 (7 ± 4 g C m-2 yr-1) while showing considerable year-to-year variability are not significantly different post 2004. Hence, the proportional loss of C as DOC and CH4 in the MB NECB is slightly less post-2004 than it was before 2004 though the cumulative errors preclude statistically differences. As a result the MB NECB has increased to 79 ± 29 g C m-2 yr-1 post 2004 yielding a 14 year contemporary NECB of 56 ± 36 g C m-2 yr-1, which is double the long-term accumulation rate of C. The variability in the annual NECB and growing season mean NEP for the MB bog can be explained (r2 = 0.35, p \u3c 0.01) by the variability in growing season water table depth. These results suggest the carbon balance – water table feedback is sufficient enough to create stability in continental bogs so they will withstand a considerable amount of climate change

Factors associated with screening or treatment initiation among male United States veterans at risk for osteoporosis fracture

Male osteoporosis continues to be under-recognized and undertreated in men. An understanding of which factors cue clinicians about osteoporosis risk in men, and which do not, is needed to identify areas for improvement. This study sought to measure the association of a provider\u27s recognition of osteoporosis with patient information constructs that are available at the time of each encounter. Using clinical and administrative data from the Veterans Health Administration system, we used a stepwise procedure to construct prognostic models for a combined outcome of osteoporosis diagnosis, treatment, or a bone mineral density (BMD) test order using time-varying covariates and Cox regression. We ran separate models for patients with at least one primary care visit and patients with only secondary care visits in the pre-index period. Some of the strongest predictors of clinical osteoporosis identification were history of gonadotropin-releasing hormone (GnRH) agonist exposure, fragility fractures, and diagnosis of rheumatoid arthritis. Other characteristics associated with a higher likelihood of having osteoporosis risk recognized were underweight or normal body mass index, cancer, fall history, and thyroid disease. Medication exposures associated with osteoporosis risk recognition included opioids, glucocorticoids, and antidepressants. Several known clinical risk factors for fracture were not correlated with osteoporosis risk including smoking and alcohol abuse. Results suggest that clinicians are relying on some, but not all, clinical risk factors when assessing osteoporosis risk

Rabies in primates: are aggressive pet lemurs a risk to humans?

Non-human primates harbor zoonotic pathogens including the rabies virus (Rabies lyssavirus). Though the chances of rabies transmission from primates is low, guidelines currently recommend a post-exposure prophylaxis for unvaccinated persons. In Madagascar, lemurs have been described as carriers of the rabies virus, but a discussion about the risk of rabies transmission to humans from lemurs, particularly in the context of in-country ownership of lemurs, has not been studied. We use qualitative and quantitative data collected from household surveys (n = 271 interviewees who had seen a pet lemur across 1 2 urban towns), web-based surveys (n = 229), and the literature (publications using data collected by the Institute Pasteur of Madagascar over the last century) to examine the context in which the rabies virus could be transmitted from lemurs to humans. Though only a few wild and pet lemurs in Madagascar have tested positive for rabies, post-exposure treatment is sometimes also sought out following aggressive incidents with lemurs. Many interviewees (22 ± 6%, mean ± 95% confidence interval CI) across 1 2 towns indicated that pet lemurs they had seen, had a history of aggression. Some lemur owners appear to be aware that their pets could transmit the rabies virus and seek veterinary care to prevent this. The public health burden of rabies is relatively low in Madagascar and despite some anecdotes in the literature, it appears that lemurs are rarely the source of rabies when humans become infected. However, this case study highlights the lack of data and publications regarding the public health implications of human-lemur contact in Madagascar. RÉSUMÉLes primates non-humains hébergent des pathogènes zoonotiques incluant le virus de la rage (Rabies lyssavirus). Bien que les risques de transmission de la rage par les primates soient faibles, les lignes directrices recommandent actuellement une prophylaxie post-exposition pour les personnes non vaccinées. À Madagascar, les lémuriens ont été décrits comme porteurs du virus de la rage, mais une discussion sur le risque de transmission de la rage à l'Homme par les lémuriens, en particulier dans le contexte de la propriété locale des lémuriens, n'a pas été étudiée. Nous utilisons des données qualitatives et quantitatives collectées à partir d'enquêtes auprès des foyers (n = 271 interviewés ayant vu un lémurien dans 1 2 villes), des enquêtes en ligne (n = 229) et de la littérature (publications utilisant des données collectées par l' Institut Pasteur de Madagascar au cours du siècle dernier) pour examiner le contexte dans lequel le virus de la rage pourrait être transmis par les lémuriens aux humains. Bien que seuls quelques lémuriens sauvages et animaux de compagnie à Madagascar aient été testés positifs à la rage, un traitement post-exposition est parfois également recherché suite à des agressions par des lémuriens. De nombreuses personnes interrogées (22 ± 6%, moyenne ± Intervalle de confiance IC à 95%) dans 1 2 villes ont indiqué que les animaux de compagnie qu' ils avaient vus avaient des antécédents d'agression. Quelques propriétaires de lémuriens semblent être conscients que leurs animaux de compagnie peuvent transmettre le virus de la rage et demander des soins vétérinaires pour éviter cela. La rage constitue une charge relativement faible pour la santé publique à Madagascar et malgré quelques anecdotes dans la littérature, il semble que les lémuriens soient rarement la source de la rage lorsque les humains sont infectés. Cependant, cette étude de cas souligne le manque de données et de publications concernant les implications / conséquences du contact entre humains et lémuriens sur la santé publique à Madagascar

An individual reproduction model sensitive to milk yield and body condition in Holstein dairy cows

To simulate the consequences of management in dairy herds, the use of individual-based herd models is very useful and has become common. Reproduction is a key driver of milk production and herd dynamics, whose influence has been magnified by the decrease in reproductive performance over the last decades. Moreover, feeding management influences milk yield (MY) and body reserves, which in turn influence reproductive performance. Therefore, our objective was to build an up-to-date animal reproduction model sensitive to both MY and body condition score (BCS). A dynamic and stochastic individual reproduction model was built mainly from data of a single recent long-term experiment. This model covers the whole reproductive process and is composed of a succession of discrete stochastic events, mainly calving, ovulations, conception and embryonic loss. Each reproductive step is sensitive to MY or BCS levels or changes. The model takes into account recent evolutions of reproductive performance, particularly concerning calving-to-first ovulation interval, cyclicity (normal cycle length, prevalence of prolonged luteal phase), oestrus expression and pregnancy (conception, early and late embryonic loss). A sensitivity analysis of the model to MY and BCS at calving was performed. The simulated performance was compared with observed data from the database used to build the model and from the bibliography to validate the model. Despite comprising a whole series of reproductive steps, the model made it possible to simulate realistic global reproduction outputs. It was able to well simulate the overall reproductive performance observed in farms in terms of both success rate (recalving rate) and reproduction delays (calving interval). This model has the purpose to be integrated in herd simulation models to usefully test the impact of management strategies on herd reproductive performance, and thus on calving patterns and culling rate

Trade of parrots in urban areas of Madagascar

The live capture of parrots is causing increasing concern across Africa. In Madagascar, home to three species of parrot (Coracopsis nigra, C. vasa, Agapornis canus), no study has examined how these species are being extracted from the wild and traded. In this study, we examined the procurement, length of ownership, and the end of ownership of pet parrots. Data were collected via household surveys (n = 440 interviews in 9 towns), market visits (nd = 1 7 markets in 6 towns), and opportunistic data collection methods in urban, Malagasy towns. Most Coracopsis spp. are purchased (59%) or captured directly by the owner from the wild (22%), although we were unable to determine how A. canus was procured. Survey respondents reported purchasing Coracopsis spp. for the price of USD 5.36 ± 3.20. The average Coracopsis spp. was kept in captivity for 3.1 7 ± 2.51 years. No survey respondents provided information on the purchase price or length of ownership for A. canus. Ownership ended primarily when Coracopsis spp. escaped/flew away (36%) or died of unknown causes (21%). A. canus also flew away, although this was only reported in one instance. In-country demand appears to be met by a trade network of both informal and formal actors. It is unclear whether current protections for Madagascar’s parrots, as far as the domestic market is concerned, are sufficient to ensure sustainable extraction of live individuals

Ecosystem CO2 and CH4 exchange in a mixed tundra and a fen within a hydrologically diverse Arctic landscape: 1. Modeling versus measurements

CO2 and CH4 exchange are strongly affected by hydrology in landscapes underlain by permafrost. Hypotheses for these effects in the model ecosys were tested by comparing modeled CO2 and CH4 exchange with CO2 fluxes measured by eddy covariance from 2006 to 2009, and with CH4 fluxes measured with surface chambers in 2008, along a topographic gradient at Daring Lake, NWT. In an upland tundra, rises in net CO2 uptake in warmer years were constrained by declines in CO2 influxes when vapor pressure deficits (D) exceeded 1.5kPa and by rises in CO2 effluxes with greater active layer depth. Consequently, net CO2 uptake rose little with warming. In a lowland fen, CO2 influxes declined less with D and CO2 effluxes rose less with warming, so that rises in net CO2 uptake were greater than those in the tundra. Greater declines in CO2 influxes with warming in the tundra were modeled from greater soil-plant-atmosphere water potential gradients that developed under higher D in drained upland soil, and smaller rises in CO2 effluxes with warming in the fen were modeled from O2 constraints to heterotrophic and belowground autotrophic respiration from a shallow water table in poorly drained lowland soil. CH4 exchange modeled during July and August indicated very small influxes in the tundra and larger effluxes characterized by afternoon emission events caused by degassing of warming soil in the fen. Emissions of CH4 modeled from degassing during soil freezing in October-November contributed about one third of the annual total

McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments

We developed the McGill Wetland Model (MWM) based on the general structure of the Peatland Carbon Simulator (PCARS) and the Canadian Terrestrial Ecosystem Model. Three major changes were made to PCARS: (1) the light use efficiency model of photosynthesis was replaced with a biogeochemical description of photosynthesis; (2) the description of autotrophic respiration was changed to be consistent with the formulation of photosynthesis; and (3) the cohort, multilayer soil respiration model was changed to a simple one box peat decomposition model divided into an oxic and anoxic zones by an effective water table, and a one-year residence time litter pool. MWM was then evaluated by comparing its output to the estimates of net ecosystem production (NEP), gross primary production (GPP) and ecosystem respiration (ER) from 8 years of continuous measurements at the Mer Bleue peatland, a raised ombrotrophic bog located in southern Ontario, Canada (index of agreement [dimensionless]: NEP = 0.80, GPP = 0.97, ER = 0.97; systematic RMSE [g C m<sup>−2</sup> d<sup>−1</sup>]: NEP = 0.12, GPP = 0.07, ER = 0.14; unsystematic RMSE: NEP = 0.15, GPP = 0.27, ER = 0.23). Simulated moss NPP approximates what would be expected for a bog peatland, but shrub NPP appears to be underestimated. Sensitivity analysis revealed that the model output did not change greatly due to variations in water table because of offsetting responses in production and respiration, but that even a modest temperature increase could lead to converting the bog from a sink to a source of CO<sub>2</sub>. General weaknesses and further developments of MWM are discussed

Natural Disturbance-Based Forest Management: Moving Beyond Retention and Continuous-Cover Forestry

Global forest area is declining rapidly, along with degradation of the ecological condition of remaining forests. Hence it is necessary to adopt forest management approaches that can achieve a balance between (1) human management designs based on homogenization of forest structure to efficiently deliver economic values and (2) naturally emerging self-organized ecosystem dynamics that foster heterogeneity, biodiversity, resilience and adaptive capacity. Natural disturbance-based management is suggested to provide such an approach. It is grounded on the premise that disturbance is a key process maintaining diversity of ecosystem structures, species and functions, and adaptive and evolutionary potential, which functionally link to sustainability of ecosystem services supporting human well-being. We review the development, ecological and evolutionary foundations and applications of natural disturbance-based forest management. With emphasis on boreal forests, we compare this approach with two mainstream approaches to sustainable forest management, retention and continuous-cover forestry. Compared with these approaches, natural disturbance-based management provides a more comprehensive framework, which is compatible with current understanding of multiple-scale ecological processes and structures, which underlie biodiversity, resilience and adaptive potential of forest ecosystems. We conclude that natural disturbance-based management provides a comprehensive ecosystem-based framework for managing forests for human needs of commodity production and immaterial values, while maintaining forest health in the rapidly changing global environment.Peer reviewe