Evolution of organic matter indicators in response to major environmental changes: the case of a formerly cutover peatbog (Le Russey, Jura Mountains, France).

To assess whether the biochemical characteristics of peat can provide clues for past ecosystem changes or not, a study was carried out combining elemental analysis, micro-morphological counts and neutral monosaccharide determination of peat organic matter (OM) and the dominant living plants from a formerly cut-over peat bog in the Jura Mountains. Peat profiles (up to 50 cm depth) from two distinctive zones (bare peat, FRA and a regenerating stage, FRC) were compared with the reference profile (FRD) taken from an unexploited area of the bog. The results show contrasting OM composition along the profiles. In the upper sections of the FRD and FRC profiles, high C/N ratios and sugar contents (in the same range as in the source plants) and the large predominance of well preserved plant tissues indicate good preservation of primary biological inputs. In contrast, in peat from the FRA profile and deeper levels of the FRC profile, lower C/N ratios, lower amounts of sugars and a predominance of amorphous OM and mucilage suggest more extensive OM degradation. These features delineate a clear threshold between an uppermost "new" regenerating peat section and an "old" catotelm peat below. Nevertheless, even in the latter, the sugar contents remain relatively high (>80 mg/g) compared with other organic and mineral soils. Analysis of typical peat-forming plants and of bulk peat and fine grained fractions allowed identification of the following source indicators: xylose and arabinose for Cyperaceae; rhamnose, galactose and mannose for mosses; and ribose (and to a lesser extent, hemicellulosic glucose) possibly for microbial synthesis

Micromorphological and (bio)chemical organic matter changes in a formerly cutover peat bog : Le Russey, Jura Mountains, France.

Peatlands have been exploited since the Middle Ages for diverse uses, including fuel, animal bedding and growth substrate in horticulture and agriculture. In many countries, these traditional peatland uses are now redundant, but the sites are being reappraised for their specific biodiversity and suitability for long-term carbon storage

Crowdsourcing Without a Crowd: Reliable Online Species Identification Using Bayesian Models to Minimize Crowd Size

We present an incremental Bayesian model that resolves key issues of crowd size and data quality for consensus labeling. We evaluate our method using data collected from a real-world citizen science program, BeeWatch, which invites members of the public in the United Kingdom to classify (label) photographs of bumblebees as one of 22 possible species. The biological recording domain poses two key and hitherto unaddressed challenges for consensus models of crowdsourcing: (1) the large number of potential species makes classification difficult, and (2) this is compounded by limited crowd availability, stemming from both the inherent difficulty of the task and the lack of relevant skills among the general public. We demonstrate that consensus labels can be reliably found in such circumstances with very small crowd sizes of around three to five users (i.e., through group sourcing). Our incremental Bayesian model, which minimizes crowd size by re-evaluating the quality of the consensus label following each species identification solicited from the crowd, is competitive with a Bayesian approach that uses a larger but fixed crowd size and outperforms majority voting. These results have important ecological applicability: biological recording programs such as BeeWatch can sustain themselves when resources such as taxonomic experts to confirm identifications by photo submitters are scarce (as is typically the case), and feedback can be provided to submitters in a timely fashion. More generally, our model provides benefits to any crowdsourced consensus labeling task where there is a cost (financial or otherwise) associated with soliciting a label

How to assess cutover Peatland regeneration with combined organic matter indicators ?

International audienceWhen restored, cutover peatlands can favour biodiversity and carbon (C) sequestration. Within the EU program RECIPE, we aimed to identify combinations of site physico-chemical conditions, vegetation composition and below-ground microbiological characteristics that are beneficial to the long-term biodiversity and C sink function regeneration. To unreveal these characteristics, we assessed the bioindicator value of peat organic matter (OM) physico-chemistry from cutover peatlands at various stages of regeneration. Although OM continues to reflect disturbances in the catotelm deep peat, we show that along the chronosequence the regenerated peat tends to be biochemically and physically similar to the one from the non exploited area of the same site. The combination of several indicators provides an efficient assessment of ecological conditions and makes valuable for the management of cutover peatlands

Cut-over peatland regeneration assessment using organic matter and microbial indicators (bacteria and testate amoebae).

International audience1. Cutover peatlands are valuable as habitat for rare species and as carbon sinks. However, assessing peat accumulation is complicated. Approaches such as using biological and physico-chemical indicators may represent an alternative for managers. 2. In order to assess the potential of biological and physico-chemical parameters as restoration indicators, we studied the organic matter (OM), testate amoebae and bacteria in peat profiles from a cutover bog. We selected four regeneration stages and an unexploited area of the same peatland. Living Sphagnum was analysed for testate amoebae. Physico-chemical parameters were analysed on near-surface peat profiles. 3. Contrasting micromorphological and biochemical signatures of peat OM were observed along the profiles. Regenerating and natural peat profiles differ with respect to C/N ratio and OM degradation. 4. The OM composition of the newly regenerated peat also differed along the regeneration sequence. Peats from the recent regenerated sites were dominated by Sphagnum-derived tissues and were characterised by lesser carbohydrate preservation and a high bacterial biomass in comparison to the peat from older regenerating sites which showed a heterogeneous botanical composition and lower bacterial biomass. 5. Moss OM inputs are characterised by hemicellulosic mannose and galactose, while sedge inputs are characterised by hemicellulosic xylose and arabinose. Additional indicators of OM alteration included the differential biodegradation of cellulose and hemicellulose. 6. Testate amoeba communities changed from the early to the advanced stages of regeneration suggesting a shift from wet and mesotrophic conditions to drier and more acidic conditions. Species richness and diversity increased but density declined from the early to the late regeneration stage and the unexploited site. Biomass and the average size of species declined over the regeneration sequence but were higher in the unexploited site. 7. The spontaneous secondary succession in the studied cutover bog leads to an ecosystem similar to that of the intact reference site in terms of community structure while OM characteristics and testate amoebae continue to reflect disturbances associated with peat harvesting. This combination of biological and physico-chemical indicators provides a complete assessment of the present and recent past ecological conditions. Such an approach has practical applications for the management of cutover peatlands

Evaluating Promotional Approaches for Citizen Science Biological Recording: Bumblebees as a Group Versus Harmonia axyridis as a Flagship for Ladybirds

Over the past decade, the number of biological records submitted by members of the public have increased dramatically. However, this may result in reduced record quality, depending on how species are promoted in the media. Here we examined the two main promotional approaches for citizen science recording schemes: flagship-species, using one charismatic species as an umbrella for the entire group (here, Harmonia axyridis (Pallas) for Coleoptera: Coccinellidae), and general-group, where the group is promoted as a whole and no particular prominence is given to any one species (here, bumblebees, genus Bombus (Hymenoptera: Apidae)). Of the two approaches, the general-group approach produced data that was not biased towards any one species, but far fewer records per year overall. In contrast, the flagship-species approach generated a much larger annual dataset, but heavily biased towards the flagship itself. Therefore, we recommend that the approach for species promotion is fitted to the result desired

Evaluating the ability of citizen scientists to identify bumblebee (Bombus) species

Citizen science is an increasingly popular way of engaging volunteers in the collection of scientific data. Despite this, data quality remains a concern and there is little published evidence about the accuracy of records generated by citizen scientists. Here we compare data generated by two British citizen science projects, Blooms for Bees and BeeWatch, to determine the ability of volunteer recorders to identify bumblebee (Bombus) species. We assessed recorders' identification ability in two ways-as recorder accuracy (the proportion of expert-verified records correctly identified by recorders) and recorder success (the proportion of recorder-submitted identifications confirmed correct by verifiers). Recorder identification ability was low (<50% accuracy; <60% success), despite access to project specific bumblebee identification materials. Identification ability varied significantly depending on bumblebee species, with recorders most able to correctly identify species with distinct appearances. Blooms for Bees recorders (largely recruited from the gardening community) were markedly less able to identify bumblebees than BeeWatch recorders (largely individuals with a more specific interest in bumblebees). Within both projects, recorders demonstrated an improvement in identification ability over time. Here we demonstrate and quantify the essential role of expert verification within citizen science projects, and highlight where resources could be strengthened to improve recorder ability

FTIR spectroscopy can predict organic matter quality in regenerating cutover peatlands.

International audienceVegetational changes during the restoration of cutover peatlands leave a legacy in terms of the organic matter quality of the newly formed peat. Current efforts to restore peatlands at a large scale therefore require low cost, and high throughout, techniques to monitor the evolution of organic matter. In this study, we assessed the Fourier Transform Infrared (FTIR) spectra of the organic matter in peat samples at various stages of peatland regeneration from five European countries. Using predictive partial least squares analyses, we were able to reconstruct both peat C:N ratio and carbohydrate signatures, but not the micromorphological composit ion of vegetation remains, from the FTIR datasets. Despite utilising different size fractions, both carbohydrate (< 200 μm fraction) and FTIR (bulk soil) analyses report on the composition of plant cell wall constituents in the peat and therefore essentially reveal the composition of the parent vegetational material. This suggests that FTIR analysis of peat may be used successfully for evaluation of the present and future organic matter composition of peat in monitoring of restoration efforts

Ten years of invasion: Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Britain

1. Harmonia axyridis was first recorded in Britain in 2004. Two subsequent earlier records were received from 2003. 2. The UK Ladybird Survey, a citizen science initiative involving online recording, was launched in 2005 to encourage people across Britain to track the spread of H. axyridis. Tens of thousands of people have provided records of H. axyridis and other species of ladybirds, creating an invaluable dataset for large-scale and long-term research. Declines in the distribution of seven (of eight assessed) native species of ladybird have been demonstrated, and correlated with the arrival of H. axyridis, using the records collated through the UK Ladybird Survey. 3. Experimental research and field surveys have also contributed to our understanding of the ecology of H. axyridis and particularly the process of invasion. Harmonia axyridis arrived in Britain through dispersal and introduction events from regions in which it was deliberately released as a biological control agent. The rapid spread of this species has been attributed to its high natural dispersal capability by means of both flight and anthropogenic transport. A number of factors have contributed to the successful establishment and indeed dominance of this polymorphic species within aphidophagous guilds, including high reproductive capacity, intra-guild predation, eurytopic nature, high resistance to natural enemies within the invaded range, and potentially phenotypic plasticity. 4. The global invasion by H. axyridis and subsequent research on this species has contributed to the general understanding of biological invasions