TRY plant trait database - enhanced coverage and open access.

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.

The effect of a multidisciplinary outpatient team approach on outcomes in diabetic foot care: a single center study.

BACKGROUND: Recent studies showed no reduction in major amputation rates after introduction of a multidisciplinary team (MDT) approach for the treatment of diabetic foot ulcer. The efficacy of MDTs in the current standard of care is being questioned. This retrospective single-center study evaluated the efficacy of an outpatient MDT approach on limb salvage and ulcer healing in treating diabetic foot ulcers. METHODS: Patients with a diabetic foot ulcer treated before (2015) and after (2017) implementation of an MDT in a single center were compared. The MDT met weekly and consisted of a vascular surgeon, physiatrist, internist, shoe technician, wound care nurse, nurse practitioner, cast technician, and podiatrist. The primary outcome was limb salvage at 1 year. Secondary outcomes were ulcer healing, amputation-free survival, freedom from any amputation, and overall survival. Multivariable Cox regression models were used to assess predictors for major amputation. RESULTS: A vascular surgeon treated 104 patients with 148 ulcers in 2015, and the multidisciplinary team treated 133 patients with 188 ulcers in 2017. Limb salvage (90.9% vs. 95.5%, P=0.050), freedom from any amputation (56.5% vs. 78.0%, P<0.001), and ulcer healing (48.3% vs. 69.2%, P<0.001) were significantly lower in the non-MDT group than in the MDT group. Amputation-free survival and overall survival did not differ significantly between the groups. Predictors for major amputation were University of Texas Wound Classification 3D (hazard ratio, 2.8; 95% confidence interval, 1.17-6.45) and being treated in the non-MDT group (hazard ratio, 3.7; 95% confidence interval, 1.25-11.08). CONCLUSIONS: This retrospective study found an MDT dedicated to diabetic foot care was highly effective in increasing limb salvage and ulcer healing. We advise that such an MDT is an integrated part of the patient's chain-based care.

Are we restoring functional fens? - The outcomes of restoration projects in fens re-analysed with plant functional traits.

In peatland restoration we often lack an information whether re-established ecosystems are functionally similar to non-degraded ones. We re-analysed the long-term outcomes of restoration on vegetation and plant functional traits in 38 European fens restored by rewetting (18 sites) and topsoil removal (20 sites). We used traits related to nutrient acquisition strategies, competitiveness, seed traits, and used single- and multi-trait metrics. A separate set of vegetation records from near-natural fens with diverse plant communities was used to generate reference values to aid the comparisons. We found that both restoration methods enhanced the similarity of species composition to non-degraded systems but trait analysis revealed differences between the two approaches. Traits linked to nutrient acquisition strategies indicated that topsoil removal was more effective than rewetting. After topsoil removal competitive species in plant communities had decreased, while stress-tolerant species had increased. A substantial reduction in nutrient availability ruled out the effect of initial disturbance. An ability to survive and grow in anoxic conditions was enhanced after restoration, but the reference values were not achieved. Rewetting was more effective than topsoil removal in restricting variation in traits values permitted in re-developing vegetation. We found no indication of a shift towards reference in seed traits, which suggested that dispersal constraint and colonization deficit can be a widespread phenomena. Two functional diversity indices: functional richness and functional dispersion showed response to restoration and shifted values towards reference mires and away from the degraded systems. We concluded that targeting only one type of environmental stressor does not lead to a recovery of fens, as it provides insufficient level of stress to restore a functional ecosystem. In general, restoration efforts do not ensure the re-establishment and long-term persistence of fens. Restoration efforts result in recovery of fen ecosystems, confirmed with our functional trait analysis, although more rigid actions are needed for restoring fully functional mires, by achieving high and constant levels of anoxia and nutrient stresses.

Top-down vs. bottom-up control on vegetation composition in a tidal marsh depends on scale.

The relative impact of top-down control by herbivores and bottom-up control by environmental conditions on vegetation is a subject of debate in ecology. In this study, we hypothesize that top-down control by goose foraging and bottom-up control by sediment accretion on vegetation composition within an ecosystem can co-occur but operate at different spatial and temporal scales. We used a highly dynamic marsh system with a large population of the Greylag goose (Anser anser) to investigate the potential importance of spatial and temporal scales on these processes. At the local scale, Greylag geese grub for below-ground storage organs of the vegetation, thereby creating bare patches of a few square metres within the marsh vegetation. In our study, such activities by Greylag geese allowed them to exert top-down control by setting back vegetation succession. However, we found that the patches reverted back to the initial vegetation type within 12 years. At large spatial (i.e. several square kilometres) and temporal scales (i.e. decades), high rates of sediment accretion surpassing the rate of local sea-level rise were found to drive long-term vegetation succession and increased cover of several climax vegetation types. In summary, we conclude that the vegetation composition within this tidal marsh was primarily controlled by the bottom-up factor of sediment accretion, which operates at large spatial as well as temporal scales. Top-down control exerted by herbivores was found to be a secondary process and operated at much smaller spatial and temporal scales.

Livestock as a potential biological control agent for an invasive wetland plant.

Invasive species threaten biodiversity and incur costs exceeding billions of US$. Eradication efforts, however, are nearly always unsuccessful. Throughout much of North America, land managers have used expensive, and ultimately ineffective, techniques to combat invasive Phragmites australis in marshes. Here, we reveal that Phragmites may potentially be controlled by employing an affordable measure from its native European range: livestock grazing. Experimental field tests demonstrate that rotational goat grazing (where goats have no choice but to graze Phragmites) can reduce Phragmites cover from 100 to 20% and that cows and horses also readily consume this plant. These results, combined with the fact that Europeans have suppressed Phragmites through seasonal livestock grazing for 6,000 years, suggest Phragmites management can shift to include more economical and effective top-down control strategies. More generally, these findings support an emerging paradigm shift in conservation from high-cost eradication to economically sustainable control of dominant invasive species.

An evolutionary perspective on leaf economics: phylogenetics of leaf mass per area in vascular plants.

In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This "worldwide leaf economics spectrum" consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf construction and light-interception borne by plants. We conducted a broad-scale analysis of the evolutionary history of LMA across a large dataset of 5401 vascular plant species. The phylogenetic signal in LMA displayed low but significant conservatism, that is, leaf economics tended to be more similar among close relatives than expected by chance alone. Models of trait evolution indicated that LMA evolved under weak stabilizing selection. Moreover, results suggest that different optimal phenotypes evolved among large clades within which extremes tended to be selected against. Conservatism in LMA was strongly related to growth form, as were selection intensity and phenotypic evolutionary rates: woody plants showed higher conservatism in relation to stronger stabilizing selection and lower evolutionary rates compared to herbaceous taxa. The evolutionary history of LMA thus paints different evolutionary trajectories of vascular plant species across clades, revealing the coordination of leaf trait evolution with growth forms in response to varying selection regimes.

Perceived usability and use of custom-made footwear in diabetic patients at high risk for foot ulceration.

OBJECTIVE: To assess the perceived usability and use of custom- made footwear in diabetic patients who are at high-risk for foot ulceration, and to elucidate the determinants of usability and use. DESIGN: Survey. SUBJECTS: A total of 153 patients with diabetes, peripheral neuropathy, prior plantar foot ulceration and newly prescribed custom-made footwear, recruited from 10 Dutch multidisciplinary foot clinics. METHODS: The Questionnaire of Usability Evaluation was used to assess the patients' perception of weight, appearance, comfort, durability, donning/doffing, stability, benefit and overall appreciation of their prescription footwear (all expressed as visual analogue scores). Data on priorities for usability and footwear use (in h/day) were obtained from patient reports. Multivariate logistic regression analysis was used to assess determinants of usability and use. RESULTS: Median (interquartile range) score for overall appreciation was 8.3 (7.1-9.1). Scores ranged from 6.5 (4.5-8.6) for weight to 9.6 (6.3-9.9) for donning/doffing. Footwear comfort was listed most often (33.3%) as the highest priority. Footwear use was <60% of daytime (where daytime was defined as 16 h out of bed) in 58% of patients. The only significant determinant of footwear use was the perceived benefit of the footwear (p = 0.045). CONCLUSION: Perceived usability of footwear was mostly positive, although individual scores and priorities varied considerably. Footwear use was low to moderate and dependent only on the perceived benefit of the footwear. Therefore, practitioners should focus on enhancing the patient's ap-preciation of the therapeutic benefit of custom-made footwear.

Herbivore trampling as an alternative pathway for explaining differences in nitrogen mineralization in moist grasslands.

Studies addressing the role of large herbivores on nitrogen cycling in grasslands have suggested that the direction of effects depends on soil fertility. Via selection for high quality plant species and input of dung and urine, large herbivores have been shown to speed up nitrogen cycling in fertile grassland soils while slowing down nitrogen cycling in unfertile soils. However, recent studies show that large herbivores can reduce nitrogen mineralization in some temperate fertile soils, but not in others. To explain this, we hypothesize that large herbivores can reduce nitrogen mineralization in loamy or clay soils through soil compaction, but not in sandy soils. Especially under wet conditions, strong compaction in clay soils can lead to periods of soil anoxia, which reduces decomposition of soil organic matter and, hence, N mineralization. In this study, we use a long-term (37-year) field experiment on a salt marsh to investigate the hypothesis that the effect of large herbivores on nitrogen mineralization depends on soil texture. Our results confirm that the presence of large herbivores decreased nitrogen mineralization rate in a clay soil, but not in a sandy soil. By comparing a hand-mown treatment with a herbivore-grazed treatment, we show that these differences can be attributed to herbivore-induced changes in soil physical properties rather than to above-ground biomass removal. On clay soil, we find that large herbivores increase the soil water-filled porosity, induce more negative soil redox potentials, reduce soil macrofauna abundance, and reduce decomposition activity. On sandy soil, we observe no changes in these variables in response to grazing. We conclude that effects of large herbivores on nitrogen mineralization cannot be understood without taking soil texture, soil moisture, and feedbacks through soil macrofauna into account.

Dispersal failure contributes to plant losses in NW Europe.

The ongoing decline of many plant species in Northwest Europe indicates that traditional conservation measures to improve the habitat quality, although useful, are not enough to halt diversity losses. Using recent databases, we show for the first time that differences between species in adaptations to various dispersal vectors, in combination with changes in the availability of these vectors, contribute significantly to explaining losses in plant diversity in Northwest Europe in the 20th century. Species with water- or fur-assisted dispersal are over-represented among declining species, while others (wind- or bird-assisted dispersal) are under-represented. Our analysis indicates that the 'colonization deficit' due to a degraded dispersal infrastructure is no less important in explaining plant diversity losses than the more commonly accepted effect of eutrophication and associated niche-based processes. Our findings call for measures that aim to restore the dispersal infrastructure across entire regions and that go beyond current conservation practices.

Self-organization and vegetation collapse in salt marsh ecosystems.

Complexity theory predicts that local feedback processes may strongly affect the organization of ecosystems on larger spatial scales. Whether complexity leads to increased resilience and stability or to increased vulnerability and criticality remains one of the dominant questions in ecology. We present a combined theoretical and empirical study of complex dynamics in mineralogenic salt marsh ecosystems that emerge from a positive feedback between clay accumulation and plant growth. Positive feedback induces self-organizing within the ecosystem, which buffers for the strong physical gradient that characterizes the marine-terrestrial boundary, and improves plant growth along the gradient. However, as a consequence of these self-organizing properties, salt marshes approach a critical state as the edge of the salt marsh and the adjacent intertidal flat becomes increasingly steep and vulnerable to wave attack. Disturbance caused, for instance, by a storm may induce a cascade of vegetation collapse and severe erosion on the cliff edge, leading to salt marsh destruction. Our study shows that on short timescales, self-organization improves the functioning of salt marsh ecosystems. On long timescales, however, self-organization may lead to destruction of salt marsh vegetation.

Predictive factors of cessation of ambulation in patients with Duchenne muscular dystrophy.

OBJECTIVES: To identify baseline patient and treatment characteristics that can predict wheelchair dependency within 2 yr. DESIGN: This prospective cohort study included 44 subjects who met study inclusion criteria. The same investigator examined them at 6-mo intervals. Ambulatory status, anthropometric data, muscle strength, range of motion of weight bearing joints, scoliosis, WeeFIM instrument, Functional Status II revised, and use of standing and walking aids. Cox proportional hazards regression analysis and the stepwise technique were used to search for prognostic factors of wheelchair dependency within 2 yr. RESULTS: Children with impaired hip extension and ankle dorsiflexion strength are 11.5 (95% confidence interval, 3.2-40.5) and 3.7 (95% confidence interval, 1.4-9.7) times, respectively, more likely to stop ambulating within 2 yr. CONCLUSIONS: This study confirms that strength loss, specifically in hip extension and ankle dorsiflexion, are the primary predictors of loss of ambulation in Duchenne muscular dystrophy. Further research is needed for medical interventions that can improve hip extension or ankle dorsiflexion and actually can improve ambulation.

The impact of herbivores on nitrogen mineralization rate: consequences for salt-marsh succession.

Soil net N-mineralization rate was measured along a successional gradient in salt-marsh sites that were grazed by vertebrate herbivores, and in 5-year-old exclosures from which the animals were excluded. Mineralization rate was significantly higher at ungrazed than at grazed sites. In the absence of grazing, mineralization rate increased over the course of succession, whereas it remained relatively low when sites were grazed. The largest differences in mineralization rate between grazed and ungrazed sites were found at late successional stages where grazing pressure was lowest. The amount of plant litter was significantly lower at grazed sites. In addition, the amount of litter and potential litter (non-woody, live shoots) was linearly related to net N-mineralization rate. This implies that herbivores reduced mineralization rate by preventing litter accumulation. Bulk density was higher at grazed salt-marsh sites than at ungrazed sites. This factor may also have contributed to the differences in net N-mineralization rate between grazed and ungrazed sites.