Search

11 páginas, 5 figuras, 1 tabla, Many degraded ecosystems need active restoration to conserve biodiversity and re-establish ecosystem function, both highlighted targets of the UN Decade on Ecosystem Restoration and the proposed EU Nature restoration law. Soil translocation, where both plant propagules and their associated soil biota are co-introduced, has increasingly been proposed as a powerful restoration technique for terrestrial ecosystems. However, a synthesis of the effectiveness of this method across ecosystems is lacking. To address how soil translocation affects restoration success, we performed a meta-analysis synthesizing data from 46 field experiments and their respective reference ecosystems in 17 countries across four continents. In each experiment, vegetation composition was recorded in response to soil translocation treatments and the resultant vegetational changes (diversity and composition) were quantified. We found that soil translocation leads to plant community development further away from the control and more towards the reference plant communities compared with treatments where only plant propagules were introduced. However, the variability of effect sizes among experiments was large, suggesting strong dependence of restoration success on restoration context. We found that restoration success was more likely on loamy soils and when translocation treatments were implemented over larger spatial areas (>180 m2). Furthermore, we found that restoration success either consistently increased or decreased over time depending on the experiment. Not only is this congruent with positive feedbacks between plant and soil communities driving plant community development, but it also suggests that the composition of the translocated plant and soil communities, and initial starting conditions, are critical for long-term restoration success. Synthesis and applications. Our analysis highlights soil translocation can be a successful restoration method across a broad range of ecosystems. However, its implementation needs to depend on a thorough evaluation of local conditions and the potential added value. Further refinement of soil translocation techniques is needed to increase success rates.

SummaryEcological theory posits that temporal stability patterns in plant populations are associated with differences in species’ ecological strategies. However, empirical evidence is lacking about which traits, or trade-offs, underlie species stability, specially across different ecosystems.To address this, we compiled a global collection of long-term permanent vegetation records (>7000 plots from 78 datasets) from a wide range of habitats and combined this with existing trait databases. We tested whether the observed inter-annual variability in species abundance (coefficient of variation) was related to multiple individual traits and multivariate axes of trait variations (PCoA axes).We found that species with greater leaf dry matter content and seed mass were consistently more stable over time (lower variability in species abundance) although other leaf traits played a significant role as well, albeit weaker. Using multivariate axes did not improve predictions by specific traits.Our results confirm existing theory, providing compelling empirical evidence on the importance of specific traits, which point at ecological trade-offs in different resource use and dispersal strategies, on the stability of plant populations worldwide.

Growing anthropogenic impacts on natural and semi-natural ecosystems have created a network of degraded sites throughout the world. These disturbed ecosystems are often colonized by invasive plants such as Pteridium aquilinum, which is one of the most widespread plants worldwide. In northern Iran, P. aquilinum is often found invading newly-created habitats formed after anthropogenic disturbance. This study aimed to assess the relationship between P. aquilinum performance and a range of environmental factors (soils, climate, topography and land-use) in northern Iran. In fifteen sites dominated by P. aquilinum, that spanned the regional distribution of P. aquilinum, we measured its cover, density and biomass. Pteridium aquilinum was found to occur in a variety of land-uses including abandoned agricultural lands, degraded forests and upland rangelands. The performance of P. aquilinum varied significantly between the sites and it performed better in a moderate-Mediterranean climate. Variation partitioning confirmed the importance of climate followed by soil and land-use in explaining the performance of P. aquilinum. Topographic variables did not show any significant effect on P. aquilinum. Both temperature and rainfall affected P. aquilinum performance. Density was correlated positively with early-spring rainfall whereas biomass and cover were found to have positive correlation with temperature. There was also a gradient of soil texture/pH/N/P influencing P. aquilinum. Frond density and biomass were correlated positively with sand content, N and P, but negatively with pH, lime and bulk density. Thus, soil conditions alongside temperature in spring and early summer could explain P. aquilinum cover, but for density, rainfall in early spring was the most important factor, suggesting that in northern Iran P. aquilinum performance appears to be intermediate compared to responses reported for temperate (temperature-controlled) and tropical climates (rainfall-controlled).

Analysing temporal patterns in plant communities is extremely important to quantify the extent and the consequences of ecological changes, especially considering the current biodiversity crisis. Long-term data collected through the regular sampling of permanent plots represent the most accurate resource to study ecological succession, analyse the stability of a community over time and understand the mechanisms driving vegetation change. We hereby present the LOng-Term Vegetation Sampling (LOTVS) initiative, a global collection of vegetation time-series derived from the regular monitoring of plant species in permanent plots. With 79 data sets from five continents and 7,789 vegetation time-series monitored for at least 6 years and mostly on an annual basis, LOTVS possibly represents the largest collection of temporally fine-grained vegetation time-series derived from permanent plots and made accessible to the research community. As such, it has an outstanding potential to support innovative research in the fields of vegetation science, plant ecology and temporal ecology., The authors acknowledge institutional support as follows. Nicola J. Day: Te Apārangi Royal Society of New Zealand (Rutherford Postdoctoral Fellowship). Jiří Danihelka: Czech Science Foundation (project no. 19-28491X) and Czech Academy of Sciences (project no. RVO 67985939). Francesco de Bello: Spanish Plan Nacional de I+D+i (project PGC2018-099027-B-I00). Eric Garnier: La Fage INRA experimental station. Tomáš Herben: GAČR grant 20-02901S. Anke Jentsch: German Federal Ministry of Education and Research (grant 031B0516C - SUSALPS) and Oberfrankenstiftung (grant OFS FP00237). Norbert Juergens: German Federal Ministry of Education and Research (grant 01LG1201N - SASSCAL ABC). Frédérique Louault and Katja Klumpp: AnaEE-France (ANR-11-INBS-0001). Robin J. Pakeman: Strategic Research Programme of the Scottish Government's Rural and Environment Science and Analytical Services Division. Meelis Pärtel: Estonian Research Council (PRG609) and European Regional Development Fund (Centre of Excellence EcolChange). Josep Peñuelas: Spanish Government (grant PID2019-110521GB-I00), Fundación Ramon Areces (grant ELEMENTAL-CLIMATE), Catalan Government (grant SGR 2017-1005), and European Research Council (Synergy grant ERC-SyG-2013-610028, IMBALANCE-P). Ute Schmiedel: German Federal Ministry of Education and Research (Promotion numbers 01LC0024, 01LC0024A, 01LC0624A2, 01LG1201A, 01LG1201N). Hana Skálová: GAČR grant 20-02901S. Karsten Wesche: International Institute Zittau, Technische Universität Dresden. Susan K. Wiser: New Zealand Ministry for Business, Innovation and Employment’s Strategic Science Investment Fund. Ben A. Woodcock: NERC and BBSRC (NE/N018125/1 LTS-M ASSIST - Achieving Sustainable Agricultural Systems). Enrique Valencia: Program for attracting and retaining talent of Comunidad de Madrid (no. 2017-T2/AMB-5406) and Community of Madrid and Rey Juan Carlos University (Young Researchers R&D Project. Ref. M2165 – INTRANESTI). Truman P. Young: National Science Foundation (LTREB DEB 19-31224).

Aim\ud \ud Climate and land use are key determinants of biodiversity, with past and ongoing changes posing serious threats to global ecosystems. Unlike most other organism groups, plant species can possess dormant life‐history stages such as soil seed banks, which may help plant communities to resist or at least postpone the detrimental impact of global changes. This study investigates the potential for soil seed banks to achieve this.\ud \ud \ud \ud Location\ud \ud Europe.\ud \ud \ud \ud Time period\ud \ud 1978–2014.\ud \ud \ud \ud Major taxa studied\ud \ud Flowering plants.\ud \ud \ud \ud Methods\ud \ud Using a space‐for‐time/warming approach, we study plant species richness and composition in the herb layer and the soil seed bank in 2,796 community plots from 54 datasets in managed grasslands, forests and intermediate, successional habitats across a climate gradient.\ud \ud \ud \ud Results\ud \ud Soil seed banks held more species than the herb layer, being compositionally similar across habitats. Species richness was lower in forests and successional habitats compared to grasslands, with annual temperature range more important than mean annual temperature for determining richness. Climate and land‐use effects were generally less pronounced when plant community richness included seed bank species richness, while there was no clear effect of land use and climate on compositional similarity between the seed bank and the herb layer.\ud \ud \ud \ud Main conclusions\ud \ud High seed bank diversity and compositional similarity between the herb layer and seed bank plant communities may provide a potentially important functional buffer against the impact of ongoing environmental changes on plant communities. This capacity could, however, be threatened by climate warming. Dormant life‐history stages can therefore be important sources of diversity in changing environments, potentially underpinning already observed time‐lags in plant community responses to global change. However, as soil seed banks themselves appear, albeit less, vulnerable to the same changes, their potential to buffer change can only be temporary, and major community shifts may still be expected.

In recent decades, the biodiversity of freshwater environments has decreased sharply due to anthropogenic disturbances that damaged ecosystem structures and functions. Habitat restoration has emerged as an important method to mitigate the degradation of river ecosystems. Although in many cases a post-project monitoring has been promoted to access the restoration progress, it is still unclear how aquatic community changes following river habitat restoration in China. Macroinvertebrate communities intermediately positioned within ecosystem food webs play a key role in ecosystem processes within river ecosystem, driving energy flow and nutrient cycling. Here, benthic macroinvertebrates are used as bio-indicators to assess the ecosystem health of degraded urban rivers, restored urban rivers, and undisturbed rivers. This study aims to determine (i) how habitat restoration influences macroinvertebrates diversity and how this compared to degraded and reference conditions; (ii) how did macroinvertebrate community compositions differ in restored, degraded, and reference sites; and (iii) the environmental factors shaping macroinvertebrate communities. Habitat restoration significantly increased the diversity and richness of macroinvertebrate community and intolerant species and shifted the community composition towards reference status. Habitat characteristics and water chemistry, including substrate diversity, water velocity, and both nutrients (TN) and organic pollutants (TOC), appeared to shape the turnover of these communities. Habitat characteristics contributed to most of the variation of the entire macroinvertebrate community. Our research indicates that habitat restoration is an efficient approach to restore the aquatic community and hence improve river ecosystem health for freshwater conservation and sustainable management in Zhejiang province. This study strengthens our understanding of the changes of macroinvertebrate community after habitat restoration and important controlling variables that attribute to these changes, which provides an important guidance for future freshwater management.

Arbuscular mycorrhizal fungi (AMF) are the predominant type of mycorrhizal fungi in roots and rhizosphere soil of grass species worldwide. Grasslands are currently experiencing increasing grazing pressure, but it is not yet clear how grazing intensity and host plant grazing preference by large herbivores interact with soil- and root-associated AMF communities. Here, we tested whether the diversity and community composition of AMF in the roots and rhizosphere soil of two dominant perennial grasses, grazed differently by livestock, change in response to grazing intensity. We conducted a study in a long-term field experiment in which seven levels of field-manipulated grazing intensities were maintained for 13 years in a typical steppe grassland in northern China. We extracted DNA from the roots and rhizosphere soil of two dominant grasses, Leymus chinense (Trin.) Tzvel. and Stipa grandis P. Smirn, with contrasting grazing preference by sheep. AMF DNA from root and soil samples was then subjected to molecular analysis. Our results showed that AMF α-diversity (richness) at the virtual taxa (VT) level varied as a function of grazing intensity. Different VT showed completely different responses along the gradient, one increasing, one decreasing, and others showing no response. Glomeraceae was the most abundant AMF family along the grazing gradient, which fits well with the theory of disturbance tolerance of this group. In addition, sheep-grazing preference for host plants did not explain much of the variation in AMF α-diversity. However, the two grass species exhibited different AMF community composition in their roots and rhizosphere soils. Roots exhibited a lower α-diversity and higher β-diversity within the AMF community than soils. Overall, our results suggest that long-term grazing intensity might have changed the abundance of functionally diverse AMF taxa in favor of those with disturbance-tolerant traits. We suggest our results would be useful in informing the choice of mycorrhizal fungi indicator variables when assessing the impacts of grassland management choices on grassland ecosystem functioning.

Analysing temporal patterns in plant communities is extremely important to quantify the extent and the consequences of ecological changes, especially considering the current biodiversity crisis. Long-term data collected through the regular sampling of permanent plots represent the most accurate resource to study ecological succession, analyse the stability of a community over time and understand the mechanisms driving vegetation change. We hereby present the LOng-Term Vegetation Sampling (LOTVS) initiative, a global collection of vegetation time-series derived from the regular monitoring of vascular plants in permanent plots. With 79 datasets from five continents and 7789 vegetation time-series monitored for at least six years and mostly on an annual basis, LOTVS possibly represents the largest collection of temporally fine-grained vegetation time-series derived from permanent plots and made accessible to the research community. As such, it has an outstanding potential to support innovative research in the fields of vegetation science, plant ecology and temporal ecology.

The aim of this study was to understand the changes of floodplain vegetation following the disruption of lateral connectivity from streams by levee construction under the temperate monsoonal conditions of South Korea. We compared the plant community structure and selected environmental variables in paired floodplains, one connected to the stream inside a levee and the other isolated by a levee. Cluster analysis of the vegetation identified ten plant communities and their associated indicator species. There were clear differences in communities between the connected floodplains and isolated floodplains. Pioneer and early-successional communities, which are resistant to flood disturbance, were found only in the connected floodplains. In contrast, diverse aquatic-macrophytic communities, adapted to long flood duration, and late-successional communities sensitive to flooding disturbance were found mainly in the isolated floodplains. β-turnover was the main driver in species compositions in both types of floodplain. The isolated floodplains had a longer flood duration, and their soils had a finer texture, higher moisture content, and were more acidic compared to the connected floodplains. Flood duration and topological elevation were identified as the most important environmental variables with respect to plant community composition. Our results suggest that reinstatement of lateral connectivity is necessary to restore the fluvial native vegetation in the isolated floodplains of a region with a monsoonal climate.

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved. Our analysis of time series from 79 datasets across the world showed that stability was associated more strongly with the degree of synchrony among dominant species than with species richness. The relatively weak influence of species richness is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities. Land management, nutrient addition, and climate change treatments had relatively weak and varying effects on stability, modifying how species richness, synchrony, and stability interact. Our results demonstrate the prevalence of biotic drivers on ecosystem stability, with the potential for environmental drivers to alter the intricate relationship among richness, synchrony, and stability., We were supported by US NSF Grants DEB-8114302, DEB8811884, DEB-9411972, DEB-0080382, DEB-0620652, DEB-1234162, and DEB0618210; the Nutrient Network (https://nutnet.org/) experiment from NSF Research Coordination Network Grant NSF-DEB-1042132; the New Zealand National Vegetation Survey Databank; and Institute on the Environment Grant DG-0001-13. Data (Dataset 56, SI Appendix, Supplementary Text S4) owned by NERC Database Right/Copyright NERC. Further support was provided by the Jornada Basin Long-Term Ecological Research project, Cedar Creek Ecosystem Science Reserve, and the University of Minnesota. The Rothamsted Long-term Experiments National Capability is supported by UK Biotechnology and Biological Sciences Research Council Grant BBS/E/C/000J0300 and the Lawes Agricultural Trust. This research was funded by Czech Science Foundation Grant GACR16-15012S and Czech Academy of Sciences Grant RVO 67985939. E.V. was funded by 2017 Program for Attracting and Retaining Talent of Comunidad de Madrid Grant 2017-T2/AMB-5406.

Questions. Compensatory dynamics are described as one of the main mechanisms that increase community stability, e.g., where decreases of some species on a year‐to‐year basis are offset by an increase in others. Deviations from perfect synchrony between species (asynchrony) have therefore been advocated as an important mechanism underlying biodiversity effects on stability. However, it is unclear to what extent existing measures of synchrony actually capture the signal of year‐to‐year species fluctuations in the presence of long‐term directional trends in both species abundance and composition (species directional trends hereafter). Such directional trends may lead to a misinterpretation of indices commonly used to reflect year‐to‐year synchrony. Methods. An approach based on three‐term local quadrat variance (T3) which assesses population variability in a three‐year moving window, was used to overcome species directional trend effects. This “detrending” approach was applied to common indices of synchrony across a worldwide collection of 77 temporal plant community datasets comprising almost 7,800 individual plots sampled for at least six years. Plots included were either maintained under constant “control” conditions over time or were subjected to different management or disturbance treatments. Results. Accounting for directional trends increased the detection of year‐to‐year synchronous patterns in all synchrony indices considered. Specifically, synchrony values increased significantly in ~40% of the datasets with the T3 detrending approach while in ~10% synchrony decreased. For the 38 studies with both control and manipulated conditions, the increase in synchrony values was stronger for longer time series, particularly following experimental manipulation. Conclusions. Species’ long‐term directional trends can affect synchrony and stability measures potentially masking the ecological mechanism causing year‐to‐year fluctuations. As such, previous studies on community stability might have overemphasised the role of compensatory dynamics in real‐world ecosystems, and particularly in manipulative conditions, when not considering the possible overriding effects of long‐term directional trends., We thank multiple entities for the financial support necessary to obtain the different databases: the U.S. National Science Foundation under grant numbers DEB‐8114302, DEB‐8811884, DEB‐9411972, DEB‐0080382, DEB‐0620652, DEB‐1234162, DEB‐9707477, DEB‐0316402, DEB‐08‐16453, and DEB‐12‐56034, DEB‐0618210, the Nutrient Network (http://www.nutnet.org) experiment from the National Science Foundation Research Coordination Network (NSF‐DEB‐1042132), the New Zealand National Vegetation Survey Databank, the Spanish MINECO (Project CGL2014‐53789‐R), the Madrid Regional Government (Projects REMEDINAL‐3 and REMEDINAL‐TE), the European Research Council Synergy grant 610028 (IMBALANCE‐P), the Institute on the Environment (DG‐0001‐13), the SOERE‐ACBB financed through French National Agency for Research (ANAEE‐F, ANR‐11‐INBS‐0001), the Estonian Research Council (IUT 20‐28, IUT 20‐29), Czech Science Foundation (GAČR 17‐05506S and 19‐28491X), the European Regional Development Fund (Centre of Excellence EcolChange), the German Federal Environmental Foundation (DBU) for a grant to the NABU Hamburg (management experiment Calamagrostis epigejos), and the German Federal Ministry of Education and Research within the framework of the project BIOTA Southern Africa (promotion numbers 01LC0024, 01LC0024A and 01LC0624A2), Task 159 of SASSCAL (promotion number 01LG1201) and the Scottish Government's Rural and Environmental Science and Analytical Services division. Acknowledgement Data owned by NERC© Database Right/Copyright NERC. Further support was provided by the Jornada Basin Long‐Term Ecological Research (LTER) project, Cedar Creek Ecosystem Science Reserve and the University of Minnesota. We also thank the Lawes Agricultural Trust and Rothamsted Research for data from the e‐RA database. The Rothamsted Long‐term Experiments National Capability (LTE‐NCG) is supported by the UK Biotechnology and Biological Sciences Research Council (Grant BBS/E/C/000J0300) and the Lawes Agricultural Trust.

Despite existing evidence of pronounced seasonality in arbuscular mycorrhizal\ud (AM) fungal communities, little is known about the ecology of AM fungi in\ud response to grazing intensity in different seasons. Here, we assessed AM fungal\ud abundance, represented by soil hyphal length density (HLD), mycorrhizal root\ud colonization intensity (MI), and arbuscule intensity (AI) throughout three\ud seasons (spring, summer, autumn) in a farm-scale field experiment in typical,\ud grazed steppe vegetation in northern China. Seven levels of field-manipulated,\ud grazing intensities had been maintained for over 13 years within two\ud topographies, flat and slope. We also measured soil nutrients and carbon content \ud throughout the growing season to investigate whether seasonal variation in AM\ud fungal abundance was related to seasonal shifts in soil resource availability\ud along the grazing gradient. We further examined the association between AM fungal\ud metrics in the different grazing treatments through the growing season. Our\ud results showed a pronounced seasonal shift in HLD but there was no clear\ud seasonality in MI and AI. HLD was significantly negatively related to grazing\ud intensity over the course of the growing season from spring to autumn. However,\ud MI and AI were related negatively to grazing intensity only in spring. In\ud addition, differential responses of AM fungal abundance to grazing intensity at\ud the two topographical sites were detected. No strong evidence was found for\ud associations between AM fungal abundance and soil resource availability.\ud Moreover, AM fungal internal and external abundance were correlated positively\ud under the different grazing intensities throughout the growing season. Overall,\ud our study suggests that external AM fungal structures in soil were more\ud responsive to seasonal variation and grazing than internal structures in roots.\ud The findings also suggest that early grazing may be detrimental to AM fungal root\ud colonization of newly emerged plants.

Arbuscular mycorrhizal fungi (AMF), common symbiotic root-associated soil biota, play a key role in maintaining ecosystem function and stability. However, how AMF are affected by livestock grazing in grassland\ud ecosystem is variable, and this uncertainty in mycorrhizal responses to grazing is mainly due to the contextdependent nature of the AMF symbiosis association. The effects of grazing on AMF are through grazing-induced\ud changes in the environment experienced by the mycorrhizal fungi and this includes both plant and soil-related\ud factors. Here, we introduce a conceptual framework that highlights potential drivers and mechanistic pathways\ud through which long-term grazing impacts AMF. We focus on known drivers of AMF abundance and diversity that\ud are expected to be influenced by grazing including plant above-ground biomass and diversity, nutrient availability (soil available nitrogen and phosphorus) and edaphic properties (soil organic carbon, soil pH, soil bulk\ud density and soil moisture). Given that the identity and relative importance of each of these drivers may differ\ud across different ecosystems, the application of our framework of potential environmental drivers allows us to\ud generalize, organize and help formulate hypotheses for testing the impact of various grazing management approaches on AMF. We also argue the herbivory-AMF relationship can be moderated by climate, seasonality and\ud topography. We reviewed the current state of knowledge of livestock grazing impacts on AMF and discussed\ud some of the reasons behind conflicting results among empirical studies. We also provide suggestions for future\ud research aimed at improving experimental design to unravel underlying mechanisms determining the impacts of\ud grazing on AMF.

Rushes, such as soft rush (Juncus effusus L.), hard rush (Juncus inflexus L.) and compact rush (Juncus conglomeratus L.) have become problem species within upland grasslands across the UK and the coastal grasslands of western Norway. Indeed, being largely unpalatable to livestock and having a vigorous reproductive ecology means that they can rapidly come to dominate swards. However, rush dominance results in a reduction in grassland biodiversity and farm productivity. Anecdotal evidence from the UK suggests that rush cover within marginal upland grasslands has increased considerably in recent decades. Yet, there is currently no published evidence to support this observation. Here, we use recent and historical Google Earth imagery to measure changes in rush frequency over a 13-year period within four survey years: 2005, 2009, 2015 and 2018. During each survey year, we quantified rush presence or absence using a series of quadrats located within 300 upland grassland plots in the West Pennine Moors, UK. Data were analysed in two stages, first, by calculating mean rush frequencies per sample year using all the available plot-year combinations (the full dataset), and second by examining 25 differences in rush frequency using only the plots for which rush frequency data were available in every sample year (the continuous dataset). The full dataset indicated that rush frequency has increased by 82% between 2005 and 2018. Similarly, the continuous dataset suggested that rush frequency has increased by 174% over the same period, with the increases in frequency being statistically significant (P

Background Ecological communities tend to be spatially structured due to environmental gradients and/or spatially contagious processes such as growth, dispersion and species interactions. Data transformation followed by usage of algorithms such as Redundancy Analysis (RDA) is a fairly common approach in studies searching for spatial structure in ecological communities, despite recent suggestions advocating the use of Generalized Linear Models (GLMs). Here, we compared the performance of GLMs and RDA in describing spatial structure in ecological community composition data. We simulated realistic presence/absence data typical of many β-diversity studies. For model selection we used standard methods commonly used in most studies involving RDA and GLMs. Methods We simulated communities with known spatial structure, based on three real spatial community presence/absence datasets (one terrestrial, one marine and one freshwater). We used spatial eigenvectors as explanatory variables. We varied the number of non-zero coefficients of the spatial variables, and the spatial scales with which these coefficients were associated and then compared the performance of GLMs and RDA frameworks to correctly retrieve the spatial patterns contained in the simulated communities. We used two different methods for model selection, Forward Selection (FW) for RDA and the Akaike Information Criterion (AIC) for GLMs. The performance of each method was assessed by scoring overall accuracy as the proportion of variables whose inclusion/exclusion status was correct, and by distinguishing which kind of error was observed for each method. We also assessed whether errors in variable selection could affect the interpretation of spatial structure. Results Overall GLM with AIC-based model selection (GLM/AIC) performed better than RDA/FW in selecting spatial explanatory variables, although under some simulations the methods performed similarly. In general, RDA/FW performed unpredictably, often retaining too many explanatory variables and selecting variables associated with incorrect spatial scales. The spatial scale of the pattern had a negligible effect on GLM/AIC performance but consistently affected RDA’s error rates under almost all scenarios. Conclusion We encourage the use of GLM/AIC for studies searching for spatial drivers of species presence/absence patterns, since this framework outperformed RDA/FW in situations most likely to be found in natural communities. It is likely that such recommendations might extend to other types of explanatory variables.

Environmental and management pressures are considered a threat for preserving plant communities worldwide. Identification of long-term impacts of changing management practices on plant community composition must, therefore, be a major priority to ensure improvement in conservation value. Land abandonment/wilding is one topical area where there is little available information on long-term impacts. To address this, here, we describe plant species compositional change over relatively long-time scales in a range of four British upland communities (high-level grasslands, intermediate grasslands, blanket bogs and high-level bogs) and its relationships with a series of life-history and plant trait variables. Our aims were to determine whether the business-as-usual sheep grazing practice was maintaining these communities, and if grazing was to be removed as part of abandonment/wilding strategies, would there be a conservation benefit. We used a series of long-term experimental grazing-exclosure studies at twelve sites (>40 years) on the Moor House National Nature Reserve in northern England. Each site consisted of paired plots; i.e. sheep-grazed versus ungrazed. Our results showed that there was relatively little change in dominant plant species with most change occurring within sub-dominant species. Similarly, different temporal responses in plant species richness were detected between the experiments (richness was reduced in three experiments, only one increased). In any case, the vegetation temporal trajectories were moving in similar direction in grazed and ungrazed plots at most sites. Interestingly, blanket bog experiments showed a clear compositional convergence for both grazed and ungrazed plots, although, the between-site differences related to a combination of elevation and past burning testament. Finally, the bryophytes (especially liverworts) and lichens were the groups that contributed most to the reductions in species richness. Moreover, implementation of a no-stock grazing strategy under a land abandonment/wilding approach will not bring about much plant change in the short-term in the plant communities studied here.

Rewilding or wilding is a popularised means for enhancing the conservation value of marginal land. In the British uplands, it will involve a reduction, or complete removal, of livestock grazing (sheep), based on the belief that grazing has reduced plant species diversity, the ‘Wet Desert’ hypothesis. The hope is that if livestock is removed, diversity will recover. If true, we hypothesise that the species extirpated/reduced by grazing and then recover on its removal would more nutritious compared to those that persisted. We test this hypothesis at Moor House National Nature Reserve (North‐Pennines), where seven sets of paired plots were established between 1953 and 1967 to compare ungrazed/sheep‐grazed vegetation. Within these plot‐pairs, we compared leaf properties of seven focal species that occurred only, or were present in much greater abundance, in the absence of grazing to those of 10 common species that were common in both grazed and ungrazed vegetation. Each sample was analysed for macro‐nutrients, micro‐nutrients, digestibility, palatability and decomposability. We ranked the species with respect to 22 variables based on effect size derived from Generalised Linear Modelling (GLM) and compared species using a Principal Components Analysis. We also assessed changes in abundance of the focal species through time using GLMs. Our results support the ‘Wet Desert’ hypothesis, that is, that long‐term sheep grazing has selectively removed/reduced species like our focal ones and on recovery, they were more nutritious (macro‐nutrients, some micro‐nutrients) palatable, digestible and decomposable than common species. Measured changes in abundance of the focal species suggest that their recovery will take 10–20 years in blanket bog and 60 years in high‐altitude grasslands. Collectively, these results suggest that sheep grazing has brought about biotic homogenization, and its removal in (re)wilding schemes will reverse this process eventually! The ‘white woolly maggots’ have eaten at least part of the heart out of the highlands/uplands, and it will take some time for recovery.

Ecological restoration of freshwater ecosystems is now being implemented to mitigate anthropogenic disruption. Most emphasis is placed on assessing physico-chemical and hydromorphological properties to monitor restoration progress. However, less is known about the structural integrity and ecosystem health of aquatic ecosystems. In particular, little is known about how ecosystem function changes following river habitat restoration, especially in China. Leaf litter decomposition can be used as an indicator of stream ecosystem integrity. Therefore, the leaf breakdown rate was measured to assess the ecosystem function of restored rivers. By comparing leaf breakdown rates in urban rivers undergoing habitat restoration with that in degraded urban rivers and rivers in forested areas (i.e., reference conditions), we aimed to determine: (i) how habitat restoration affected leaf litter decomposition? (ii) the relationship between leaf litter decomposition to both environmental (habitat and physico-chemical variables) and biological factors (benthic communities), and (iii) identify the factors that contribute most to the variance in leaf litter breakdown rates. The results demonstrated a significant increase in leaf breakdown rate (120% in summer and 28% in winter) in the restored rivers compared to the degraded rivers. All environmental and biotic factors evaluated contributed synergistically to the differences in leaf litter decomposition among the three river types. The role of macroinvertebrates, mainly shredders, appeared to be particularly important, contributing 52% (summer) and 33% (winter) to the variance in decomposition, followed by habitat characteristics (e.g. substrate diversity, water velocity; 17% in summer, 29% in winter), physico-chemical variables (e.g. nutrient and organic pollutants; 11% in summer, 1% in winter) and biofilm bacteria (0% in summer, 15% in winter). Habitat restoration positively affected the structure and function of the previously degraded streams. Knowledge on controlling variables and their attribution to changes of ecosystem functioning provides guidance to assist the future planning of ecological restoration strategies.

We used the seedling emergent method using the soil sample to study the vegetation change and regeneration strategy after flooding in river ecosystem, and the effect of prescribed burning and grazing on wetland vegetation in Blanket Bog moorlands, UK, and the spread of alien invasive plants during road constructions. In the river ecosystem, above-ground vegetation and soil seed banks have a low similarity. However, there are species found only in soil seed banks without above-ground vegetation. Therefore, the soil seed banks are regarded to support biodiversity. In addition, the formation of soil seed banks and ground-level vegetation in the stream has been simplified after the flood, but it has been studied that the flood functions to maintain the native vegetation of the stream as the number of aquatic plants has increased. The Blanket Bog moorlands in the UK are well-developed peat layers that play an important role in controlling the global carbon concentration. In the second study, we proposed the appropriate intervals of prescribed burning to maintain Sphagnum species, the main species forming peat layers, and the Calluna vulgaris community, which provides essential ecosystem services. Finally, the dispersal trend of alien invasive plants along the road was studied using the hand sorting seed count method. The alien invasive plants are introduced during the road construction and they tend to spread according to the movement of the vehicle and the road conditions. We found that the unique ‘tubular’ structure of the road enables the long-distance dispersal in a relatively short time. As such, the study of seed banks in the soil can be applied in various ways, providing a clue to the solution of phenomena occurring in the ecosystem. There are considerations, such as the inability to identify all seeds in the soil samples and the fact that the dominant above-vegetation species may differ from the soil seed bank in an ecosystem. However, there are advantages, such as providing information for predicting potential vegetation, and it takes relatively short time with less than four months, in common, to evaluate.

Rewilding is currently being proposed as a means of enhancing the conservation value of marginal land in many parts of the world. This is especially true in the British uplands where rewilding will almost certainly involve either a reduction in livestock grazing, or its complete removal. The aim of reducing stock numbers would be to reverse the degradation of these ecosystems that has been caused by past over‐grazing. However, little is known about the likely outcomes, or the time‐scales over which such ecosystem recovery might occur. Here, we report preliminary results from a recent study of eight sites at Moor House NNR in the north‐Pennines, where permanent plots with‐ and without‐sheep grazing were established between 1954 and 1967 on a range of typical upland plant communities. Soils and vegetation were sampled, and their chemical properties analysed; for vegetation an assessment of the herbage quality for animal nutrition was also made. No significant differences in soil properties, above‐ground biomass and nutritional status of the vegetation was detected that could be attributed to sheep grazing removal. The only significant effect associated with grazing removal was a reduced digestibility of the vegetation (greater acid detergent fibre concentration) where sheep were removed. These results show that a rewilding strategy that relies only on reducing sheep numbers will have very little impact on ecosystem recovery in terms of soil or herbage chemistry over short‐ to medium‐term time‐scales. Rewilding policies, therefore, attempting to restore ecosystems degraded by over‐grazing must, therefore, be viewed as long‐term (>50 y).

The effect of prescribed burning for conservation management of plant communities is controversial for moorlands growing on peat. These ecosystems provide many services that may be damaged by fire, hence it is important to fully assess its impact on all aspects of ecosystem structure and function experimentally over relatively long time‐scales. This paper describes change in community composition, major plant species, and plant functional types on moorland on peat in upland Britain over 60 years subject to 3 burning treatments after an initial burn in 1954/1955: no further burn and burning at 10‐ and 20‐year intervals (all ± sheep grazing). Data were analysed using multivariate and univariate methods. Vegetation composition and individual species abundance reflected the degree of disturbance. The least disturbed was dominated by Calluna vulgaris and pleurocarpous mosses, whereas the most disturbed treatment (burned every 10 years) had greater Eriophorum vaginatum , Sphagnum spp., acrocarpous mosses, liverworts, and lichens. The 20‐year treatment was intermediate in response disturbance. Repeated burning increased species abundance‐weighted Ellenberg values for moisture, reaction, light through time, and fertility; the exception was the 10‐year rotation for fertility. These confirm that prescribed burning is not deleterious to peat‐forming species (Eriophorum spp. and Sphagnum spp.), indeed these species were found in greater abundance in frequently burned treatments. It also confirms that a no‐burn policy will lead to increasing dominance of C. vulgaris , a flammable, fire‐adapted shrub, which increases summer wildfire risk. These results inform conservation management policy for moorland vegetation growing on peat; for this site, a 20‐year prescribed burning rotation is recommended.

Restoring intensive agricultural fields to species-rich semi-natural grassland could have profound effects on biodiversity and ecosystem services. However, only a minority of European agri-environment scheme funding is currently devoted to such measures (

Ecological restoration of high-quality, semi-natural communities of conservation value on ex-arable soils with raised fertility has been a major problem in northern Europe. One suggested way of tackling this problem is to use Full-Inversion Tillage (FIT) where the fertile top-soil is moved below infertile sub-surface layers. This should provide infertile conditions at least in the short- to medium-term for the establishment of communities that require these conditions. Here, we pioneer a rigorous test of the efficacy of this approach. Our new method, using Principal Response Curves (PRCs), overcomes the difficulty in testing for change in soil physico-chemical properties down soil profiles with the inherent problem of autocorrelations between soil layers. Principal Response Curves (PRCs) is a multivariate technique, usually used to test for effects of treatment effects through time on a community matrix. We propose an extension of their use for the multivariate analysis of properties down a soil-depth profile. We tested the effects of FIT in two contrasting soils, before and after treatment. In a clay loam soil, FIT was effective in reducing the soil fertility in the surface 12 cm. Indeed the soil available P concentration, a key variable, was more than halved in the surface layers, and was below the lowest literature target threshold for the establishment of semi-natural grassland. In contrast, in the sandy soil, soil properties increased throughout the profile after FIT, primarily because of the pre-treatment nutrient distribution within the soil. Before FIT treatment, the maximum concentrations of most measured variables were at mid-depth and FIT redistributed these to the surface and bottom layers. Our results demonstrate the potential for FIT in ecological restoration, but indicate that its efficacy depends on soil type and the site history. We recommend that in future a pre-treatment assessment of soil properties with depth is undertaken before FIT is implemented, and that afterwards our PRC approach can be used to test efficacy immediately after treatment, and has the potential for measuring soil resilience to perturbation through time.

Plant growth in nitrogen (N)-limited, unfertilised terrestrial ecosystems should respond to additional N inputs from atmospheric deposition (Ndep). We investigated this for sites in Great Britain (GB) by compiling 796 estimates of net primary productivity (NPP) from measured biomass production over the period 1932–2014, although the great majority were for 1990 onwards. The sites were largely vegetated with shrubs, grass and bracken, and had a wide range of Ndep (0.5–3.3 gN m−2 a−1 in 2000). The measured NPP estimates were compared with calculated values from the biogeochemical ecosystem model N14CP, which predicts that NPP depends strongly upon Ndep. The measured and modelled average total NPP values (gC m−2 a−1) from all data were 387 (standard deviation, SD = 193) and 377 (SD = 72) respectively. Measured and modelled averages for vegetation classes followed the sequence: broadleaved trees ~ needle-leaved trees > herbs (rough grassland + bracken) ~ shrubs. After averaging measured values for sites in individual model grid cells (5 km × 5 km) with 10 or more replicates, the measured and modelled NPP values were correlated (n = 26, r2 = 0.22, p = 0.011), with a slope close to unity. Significant linear relationships were found between measured ln NPP and cumulative Ndep for both herbs (n = 298, p = 0.021) and shrubs (n = 473, p = 0.006), with slopes comparable to those predicted with the model. The results suggest that semi-natural NPP in GB depends positively upon Ndep, in a manner that agrees quantitatively with N14CP predictions. Calculations with the model, using modelled temporal variation in Ndep, indicate that fertilisation by Ndep caused average increases in semi-natural NPP over the period 1800 to 2010 of 30% for shrubs, 71% for herbs, and 91% for broadleaved trees. Combined with previous published results for forests, our findings suggest a general and widespread vegetation response to fertilisation by Ndep.

Across the world, there have been increasing attempts to restore good ecological condition to degraded rivers through habitat restoration. Microbial communities developing as biofilms play an important role in river ecosystem functioning by driving organic matter decomposition and ecosystem respiration. However, little is known about the structure and function of microbial communities in riverine systems and how these change when habitat restoration is implemented. Here, we compared the biofilm bacterial community composition using 16S rRNA genes targeted high-throughput Illumina Miseq sequencing in three river types, degraded urban rivers, urban rivers undergoing habitat restoration and forested rivers (our reference conditions). We aimed to determine: (i) the biofilm bacterial community composition affected by habitat restoration (ii) the difference in bacterial diversity in restored rivers, and (iii) correlations between environmental variables and bacterial community composition. The results showed that both water quality and biofilm bacterial community structure were changed by habitat restoration. In rivers where habitat had been restored, there was an increase in dissolved oxygen, a reduction in organic pollutants, a reduction in bacterial diversity and a related developing pattern of microbial communities, which is moving towards that of the reference conditions (forested rivers). River habitat management stimulated the processing of organic pollutants through the variation in microbial community composition, however, a big difference in bacterial structure still existed between the restored rivers and the reference forest rivers. Thus, habitat restoration is an efficient way of modifying the biofilm microbial community composition for sustainable freshwater management. It will, however, take a much longer time for degraded rivers to attain a similar ecosystem quality as the &ldquo, pristine&rdquo, forest sites than the seven years of restoration studied here.

Habitat restoration requires realistic goals. To naturally regenerate European lowland calcareous grassland, whose extent has severely declined, over a century may be required for vegetation to become indistinguishable from that of old calcareous grassland. Progress of natural regeneration can be characterized using member species of the reference vegetation as indicators of favourable site condition. Chronosequence studies have suggested that calcareous-grassland species differ predictably in their ability to colonize ex-arable land, with some usually colonizing early on, and others in later stages. If such patterns are affected by gradually-attenuating establishment limitation, this would have important implications for restoration practice and indication of progress. Particularly, late-colonizing species might be better indicators of favourable site conditions than early colonizers. To explore these aspects, we have reanalysed chronosequence data previously used to investigate causal mechanisms affecting calcareous-grassland restoration progress. We carried out an indicator species analysis to determine which species are indicative of particular stages of natural regeneration. Using correlation analyses, we tested whether species colonization patterns matched those found by previous chronosequence studies that were geographically more limited or relied on more informal approaches to determine species order of colonization. Correlation analyses were also used to test whether order of colonization could be explained by establishment limitation or by dispersal limitation, or by established plant strategies that underlie such limitations. We identified 30 species as indicative of particular stages of natural regeneration, including nine that specifically indicate old calcareous grassland. Correlation results confirmed high congruence with species order of colonization in previous chronosequence studies, and indicated that establishment limitation plays a role in shaping species order of colonization, potentially mediated through differential stress tolerance. We failed to demonstrate a role of dispersal limitation in shaping order of colonization. Based on our results, we derived three categories of indicator species for passively-restored calcareous grassland, mirroring the regeneration stage during which these species usually colonize. This includes a category labelled by us as ‘old-grassland indicators’ that achieve notable abundance only in old grassland. We conclude by discussing how such a categorization can benefit the measurement of restoration progress, the tentative identification of old grassland and its conservation, e.g. through linking agri-environment payments to the occurrence of old-grassland indicators, thus fostering positive change in farmer attitudes towards old grassland.

Background: The plant communities within reservoir drawdown zones are ecologically important as they provide a range of ecosystem services such as stabilizing the shoreline, improving water quality, enhancing biodiversity, and mitigating climate change. The aim of the study was therefore to identify the major environmental factors affecting these plant communities within the drawdown zone of the Soyangho Reservoir in South Korea, which experiences a monsoonal climate, and thereafter to (1) elucidate the plant species responses and (2) compare the soil seedbank composition along main environmental gradients. Results: Two main environmental gradients affecting the plant community structure were identified within the drawdown zone; these were a vertical and longitudinal gradient. On the vertical dimension, a hydrological gradient of flood/exposure, the annual-dominated plant community near the water edge changed to a perennial-dominated community at the highest elevation. On the longitudinal dimension from the dam to the upstream, plant species composition changed from an upland forest-edge community to a lowland riverine community, and this was correlated with slope degree, soil particle size, and soil moisture content. Simultaneously, the composition of the soil seedbank was separated along the vertical gradient of the drawdown zone, with mainly annuals near the water edge and some perennials at higher elevations. The species composition similarity between the seedbank and extant vegetation was greater in the annual communities at low elevation than in the perennial communities at higher elevation. Conclusions: The structures of plant community and soil seedbank in the drawdown zone of a monsoonal riverine reservoir were changed first along the vertical and secondly along the longitudinal gradients. The soil seedbank could play an important role on the vegetation regeneration after the disturbances of flood/exposure in the drawdown zone. These results indicate that it is important to understand the vertical and longitudinal environmental gradients affecting shoreline plant community structure and the role of soil seedbanks on the rapid vegetation regeneration for conserving and restoring the drawdown zone of a monsoonal reservoir. This work was supported by INHA UNIVERSITY Research Grant.

Keystone root symbiotic arbuscular mycorrhizal fungi play a major role in maintaining plant biodiversity, increasing plant productivity and enhancing storage of carbon in soil. AM fungi are ubiquitous and found in most ecosystems including grasslands currently experiencing increasing pressures form human activity. Grazing is known to impact AM fungi but very little is known about how AM fungi are affected by different levels of grazing intensity. Here we report on results from a long-term experimental site in a typical steppe in the north of China, containing seven levels of field-manipulated grazing intensities maintained for over 13 years. We assessed arbuscular mycorrhizal fungal abundance, represented by soil hyphal length density and mycorrhizal root colonization (mycorrhizal root frequency, intensity and arbuscule intensity) within the farm-scale field experiment. We also measured environmental variables to explain the responses of mycorrhizal fungi to grazing intensity. Our results showed that with an increase in grazing intensity, soil hyphal length density linearly decreased. There was, however, no significant trend for mycorrhizal root colonization variables in relation to grazing intensity. Mycorrhizal root frequency was negatively correlated with topographic-induced changes in soil nitrogen and phosphorus, while arbuscule intensity was marginally negatively correlated with soil available phosphorus. Further, we found a possible hump-shaped relationship between the ratio of external to internal AM fungal structures and grazing intensity. Our finding showed that external AM fungal structure was clearly impacted by grazing intensity but that this was not the case for internal mycorrhizal structures. This indicated that mycorrhizal functioning was impacted by the intensity of grazing as the mycorrhizal structures responded differently. Indeed the ratio of the foraging extra-radical mycorrhizal hyphae to intra-radical mycorrhizal structures was highest at moderate grazing intensity but strongly decreased by high grazing intensity. Our study suggests that the impacts of grazing intensity on the plant-AMF association could lead to further knock-on effects on the plant-soil system via the feedbacks that exist between plant and AMF communities.

Rare plants are vulnerable to environmental change but easy to over-look during survey. Methods are therefore needed that can provide early warnings of population change and identify potentially suitable vegetation that could support new or previously overlooked populations. We developed an indicator species approach based on quantifying the association between rare plants across their British ecological range and their suite of more common neighbours. We combined quadrat data, targeted on six example species selected from the Botanical Society of Britain and Ireland's Threatened Plant Project (TPP), with representative survey data from across Britain. Bayes Theorem was then used to calculate the probability that the rare species would occur given the presence of an associated species that occurred at least once with the rare species in the TPP quadrats. These values can be interpreted as indicators of habitat suitability rather than expectations of species presence. Probability values for each neighbour species are calculated separately and are therefore unaffected by biased recording of other species. The method can still be applied if only a subset of species is recorded, for example, where weaker botanists record a pre-selected subset of more easily identifiable neighbour species. Disadvantages are that the method is constrained by the availability of quadrats currently targeted on rare species and results are influenced by any recording biases associated with existing quadrat data.

The establishment of gypsicolous vegetation of high conservation value on land impacted by quarrying requires restoration measures to overcome constraints imposed by the new landforms created in the process. The aim of this study was to assess the suitability of three standard hydroseeding methods to restore gypsicolous vegetation on quarry spoil slopes under a dry Mediterranean climate. The treatments were as follows: paper cellulose mulch, paper cellulose mulch + organic blanket, and wood fibre mulch, compared against a control. These treatments were tested on two slopes (10–15% vs 60–65%) and two contrasting aspects (north vs south). We evaluated the cover of all plant species 2·8 years after treatment, assessing both target gypsicolous species and non-target species. Our results showed strong compositional and cover differences between hydroseeded and control plots. Control plots had a low cover of target species with a vegetation composed of early-successional species that had the potential to hinder target species establishment over time. All hydroseeding treatments improved target vegetation cover, with wood fibre performing best in most situations studied here, alternatives being the cheaper but less effective paper mulch on shallow slopes, or the more expensive paper mulch + blanket on steep slopes in case of high erosion risk. Shallow and southern-steep slopes were more suitable for the recovery of gypsum vegetation by hydroseeding, compared to northern-steep slopes where non-target species developed more readily outcompeting target species. These results will help to guide management decisions to restore gypsicolous vegetation by hydroseeding in disturbed gypsum habitats. Copyright © 2017 John Wiley & Sons, Ltd.

1. Reliable modelling of above-ground Net Primary Production (aNPP) at fine resolution is a significant challenge. A promising avenue for improving process models is to include response and effect trait relationships. However, uncertainties remain over which leaf traits are correlated most strongly with aNPP. 2. We compared abundance-weighted values of two of the most widely used traits from the Leaf Economics Spectrum (Specific Leaf Area and Leaf Dry Matter Content) with measured aNPP across a temperate ecosystem gradient. 3. We found that Leaf Dry Matter Content (LDMC) as opposed to Specific Leaf Area (SLA) was the superior predictor of aNPP (R2=0.55). 4. Directly measured in situ trait values for the dominant species improved estimation of aNPP significantly. Introducing intra-specific trait variation by including the effect of replicated trait values from published databases did not improve the estimation of aNPP. 5. Our results support the prospect of greater scientific understanding for less cost because LDMC is much easier to measure than SLA.

a b s t r a c t Flooding can have a major impact on riverside plant communities, and this is likely to be especially important in monsoonal climates, where large floods occur after heavy rain. In urban areas where ripar- ian vegetation remnants are the only vegetation of conservation interest remaining, understanding the impacts that floods have on these ecosystems is needed to inform their future conservation. Accordingly, we assessed the impact of a flood caused by Typhoon "Ewiniar" on the soil seed bank of five plant com- munities of the only remaining fragment of high-quality riverine habitat within the Seoul city stretch of the Han River (South Korea). We surveyed the seed bank composition of the five dominant plant com- munities before and after the flood. We also measured selected soil physico-chemical properties in each community. We used univariate and multivariate methods to examine the effect of the flood on both seed bank and soil physico-chemical properties. Flooding resulted in variable deposition of sediment within the plant communities; four communities varied from 14.6 to 18.8 cm but the fifth (dominated by Mis- canthus sacchariflorus) had much less sediment (4.8 cm). The physico-chemical properties of the surface soil also changed after the flood, with the sediment particle size being the most affected. The species richness and composition of the seed bank suffered significant changes after the flood. In both cases there was a homogenization process, with was also impinged on species with different life-forms (annuals and perennials). Our results suggest that an extreme flood can affect the riparian vegetation seed bank by removing wetland plant species and allowing common and ruderal species to establish. There may also be different interactions between the different plant communities in terms of sediment capture and this translates into altered soil conditions and seed banks. These results are of use to conservation policy- makers aiming to conserve a native flora within severely modified urban rivers, and these remnant areas can provide an important seed source of wetland plants to aid restoration of riparian ecosystems.

Compositional indicators (i.e. indices that focus on the identity of species, genes or phylogeny) have been widely used to estimate and monitor biodiversity, however, their use in combination with species and/or community functional characteristics remains limited. Using large-scale, spatio-temporal data, we use both compositional and functional indices to investigate land-use change impacts on the vegetation of a semi-natural grassland ecosystem (Machair) for fourteen regions in Scotland, UK. Our study aimed to identify national- and regional-scale temporal vegetation patterns, and through use of simple compositional and functional indices (e.g. Competitor, Stress, Ruderal and Ellenberg scores) link observed changes to agricultural intensification and/or land-use abandonment. Using linear-mixed modelling and non-metric multi-dimensional scaling, we showed significant national and regional-scale changes in species composition over time. Increases in diversity, particularly gains in Machair grassland, identified several regions that may have benefited from past government incentivised schemes to protect the Machair, but which may also be suffering from an extinction lag. Shifts in plant functional signatures (CSR & Ellenberg values) identified varying degrees of internal (competition) and external (land-use) factors, highlighting several regions where biodiversity change could be linked to reduced disturbance (i.e. lower grazing intensity) or greater disturbance (i.e. land-use intensification). Our results demonstrate the utility of simple compositional and functional indices for monitoring biodiversity of semi-natural grasslands and identifying land-use drivers of change across different spatial scales.

Temperate ecosystems, for example British heathlands and moorlands, are predicted to experience an increase in severe summer drought and wildfire frequency over the next few decades. The development of fire ignition probability models is fundamental for developing fire-danger rating systems and predicting wildfire outbreaks. This work assessed the flammability properties of the fuel complex of British moorlands as a function of their moisture content under laboratory conditions. Specifically, we aimed to develop: (1) models of the probability of fire ignition in peat/litter fuel-beds (litter of four different plant species, Sphagnum moss and peat); (2) flammability properties in terms of ignitability, sustainability, consumability and combustibility of these peat/litter fuel-beds; (3) the probability of ignition in a canopy-layer of Calluna vulgaris (the most dominant heath/moor species in Britain) as a function of its dead-fuel proportion and moisture content; (4) the efficacy of standardized smouldering and flaming ignition sources in developing sustained ignitions. For this, a series of laboratory experiments simulating the fuel structure of moor vegetation were performed. The flammability properties in peat/litter fuel-beds were influenced strongly by the fuel moisture content. There were small differences in moisture thresholds for experiencing initial flaming ignitions (35-59%), however, the threshold for sustained ignitions (i.e. spreading a fixed distance from the ignition point) varied across a much wider range (19-55%). Litter/peat fuel-beds were classified into three groups: fuel-beds with high ignitability and combustibility, fuel-beds with high levels of sustainability, and fuel-beds with low levels in all flammability descriptors. The probability of ignition in the upper Calluna-vegetation layer was influenced by both the proportion of dead fuels and their moisture content, ranging from 19% to 35% of moisture as dead fuel proportion increased. Smouldering sources were more efficient in igniting peat/litter fuel-beds but in the Calluna-vegetation layer flaming sources performed better. This work can assist in improving the predictions of fire-rating systems implemented in British moorlands, by providing better warnings based on critical moisture thresholds for various fuel types. Language: en

Question Are optimal intervention levels in ecological restoration linked to disturbance severity or spatial and temporal scales of restoration activities in the studies included in this special feature? Methods Comparison of ten studies of restoration in the context of disturbance severity, regional biodiversity, and predictability of succession trajectories. Results The ten studies largely represent restoration of grasslands in Europe but also include restoration following disturbances by mining, invasive species, and trampling by tourists. Maximal intervention levels were used in studies with high or low disturbance severity, low regional biodiversity, and high predictability of successional trajectories. The spatial and temporal scales of restoration activities had little effect on intervention levels. Conclusions General guidelines on how to optimize intervention levels in restoration activities can be sought by comparing success rates across gradients of disturbance severity.

Pteridium is a cosmopolitan genus that acts as an invasive species in many parts of the world. Most research on this genus has occurred in Europe, and there is a lack of data on it from South America, in spite of causing considerable conservation problems. We compared the biomass allocation of P. esculentum subsp. arachnoideum in two ecosystems in Brazil - Atlantic forest and Brazilian savanna. We measured the biomass of fronds, rhizomes and above-ground litter. We also compared the density, length and biomass of fronds from this Brazilian study with similar data of P. esculentumsubsp. arachnoideum derived from Venezuela and P. aquilinum from Europe. P. esculentum subsp. arachnoideum showed a wide response range. We found a negative relationship between frond and necromass, indicating a negative feedback effect, while a positive relationship was observed between frond and rhizome biomass. The continental comparison of relationships showed that Pteridium responds in a different way in both Brazil and Europe, and that in Brazil fronds tend to be longer and heavier, presumably as a result of the continuous growing season in South America while is shortened in Europe by frost. The paper shows the ability of Pteridium to adapt to different ecosystems. Pteridium é um gênero cosmopolita que inclui espécies invasoras em várias partes do mundo. Os estudos sobre o gênero têm ocorrido principalmente na Europa, e existem poucas informações para as espécies que ocorrem na América do Sul. Nesse estudo comparamos a alocação de biomassa de P. esculentum subsp. arachnoideum em dois ecossistemas brasileiros – Mata Atlântica e Cerrado - em cada um dos quais medimos a biomassa nos rametas, nos rizomas e na serapilheira. Comparamos, também, a densidade, comprimento e biomassa dos rametas com informações obtidas sobre P. esculentum subsp. arachnoideum na Venezuela e P. aquilinumna Europa. P. esculentum subsp. arachnoideumapresentou respostas distintas. Encontramos uma relação negativa entre a biomassa de rametas e da serapilheira, indicando uma retro-alimentação negativa, enquanto houve uma relação positiva entre a biomassa dos rametas e dos rizomas. A comparação das relações entre os continentes indicou que Pteridiumresponde diferentemente no Brazil e na Europa, e também que no Brasil os rametas são maiores e contêm mais biomassa, possivelmente devido à estação de crescimento contínua, enquanto na Europa o crescimento é limitado pelas baixas temperaturas. Esse estudo demonstra o sucesso adaptativo de Pteridium em diferentes ecossistemas.

In the version of this Article originally published, the authors neglected to include information on Competing Interests; this has now been included in all versions of the Article.

The invasion of native habitats by alien species has received considerable attention. However, in Britain high levels of dominance by a small number of aggressive native plant species may have an equal, or greater, impact on the richness of native woodlands. Here, we examine this hypothesis by modelling the realized niche of native-dominant species along the principal coenocline of British woodlands, and examined niche overlaps with 78 woodland specialist species and two alien species. Four native species had a much greater cover than all other field-layer species, and between them they entirely covered the response range of all other field-layer species, replacing one another along the coenocline. These findings, combined with autecological information suggest that Hedera helix, Mercurialis perennis, Pteridium aquilinum and Rubus fruticosus have the potential to become ‘over-dominant’ and perhaps may impinge on other field-layer species. Our results also identified which field-layer species are likely to be impacted by a change in abundance of each of these dominant-species, and as such, provide a novel quantitative method of risk assessment to aid conservation policy. Understanding how woodland communities remain diverse, even in the presence of aggressive native species, may provide insights into how the impact of exotic invasive species can be managed.

This study assessed the impact of prescribed burning on the peat properties of moorlands during the post-fire succession in a multi-site study within a major moorland region of Great Britain. Three replicate moorland sites were sampled; all were ombrotrophic bogs and had peat soils overlying similar geology and similar vegetation. A chronosequence approach was used to sample soils from a post-fire succession (3–52 years since burning) on each site and a number of chemical properties measured. The data on soil chemical properties were analysed using both linear-mixed-effects modelling and multivariate analysis. There were clear differences in some soil properties between moorland sites, but for most soil variables measured there was no change through the post-fire succession. Four variables (available P and Ca; total P and K) showed a significant interaction, i.e. different responses on each moorland site through time. These results suggest that there are complex interactions between nutrient inputs (rainfall and dry deposition which is affected by elevation), storage and cycling within the soil-peat system and losses that differ on the three moorland sites. The most interesting result was the additive response of the C:N ratio which differed between moorland sites; all sites showed the same negative slope with respect to elapsed time since burning, indicating an increased N saturation. This result suggests that the oldest stands sampled here may have either (i) responded to the large N inputs added from the atmosphere in the latter part of the twentieth century, or (ii) the younger ones have had some of this N removed during prescribed burning. This suggestion needs further investigation. Nevertheless, the impacts of prescribed burning on the peat properties during the post-fire succession were relatively small.

Plant functional response traits, which consistently respond to the environment, are useful for identifying drivers of vegetation change, particularly in response to disturbance gradients. Similarly, functional diversity indices have proven useful for investigating processes governing community assembly, particularly patterns of functional convergence/divergence. This study investigated the functional ecology of biodiverse, seminatural coastal grasslands (Scottish machair) at the national scale. We examined temporal shifts in functional response traits and functional diversity metrics using a series of null model, multivariate and regression analyses. The aim was to link temporal shifts in traits and diversity metrics to environmental variables in which to gauge the contribution of landuse change to plant functional composition and processes governing plant assembly. We observed significant shifts in the composition of 8 out of 12 functional response traits at the national scale, whereas at the regional scale all traits displayed at least one significant shift. Ordination of response traits found PC axis 1 (accounting for 39% of the variation) to be positively correlated to vegetation height and negatively correlated to specific leaf area, similar to that expected along a disturbance gradient. Significant changes in functional diversity indices were also observed at both national and regional scales, with varying convergence/divergence patterns observed across individual regions. We found functional richness (t = 4.87, p < 0.001) and divergence (t = 9.3, p < 0.001) to increase along PC axis 1, suggesting greater convergence and lower divergence along a disturbance gradient. This study demonstrates the potential for using functional diversity indices in combination with response traits as a sensitive method for detecting landuse change and its impacts on biodiversity. We conclude that landuse change, particularly management declines and intensification is a major driver governing change among the functional composition and functional diversity for machair grasslands, influencing convergence/divergence patterns, and subsequently community assembly processes.

Moorlands on blanket bog are high-priority ecosystems from a conservation viewpoint in the British Isles; they are often managed through using prescribed burning to increase their productivity for sheep and Red grouse. However, there is an increasing demand to conserve these moorlands for other environmental services, e.g. carbon sequestration and water supplies. There is, therefore, a need for experimental evidence on the role that fire and fire-rotation intervals have on these moorlands ecosystems for the development of ecologically-sound management plans. Here, the impact of prescribed burning on the propagule banks was evaluated at two contrasting geographical moorland locations differing in productivity, climate and past pollution history. Two different approaches were used; chronosequences of elapsed time since burning and a long-term replicated grazing and burning experiment (1954–2010) where different burning rotations were applied. The propagule banks in both moorlands were very species-poor and the species present were mainly common ones. The chronosequences showed that few species had significant effects with elapsed time since burning; the dominant Calluna vulgaris increased in the above-ground litter fraction which acted as a barrier to seed transfer to the underlying peat. Within the experiment, the seed bank of C. vulgaris and the frequency of occurrence of Sphagnum species increased as rotation-interval increased. It is suggested that prescribed burning rotations simultaneously at two temporal scales within a moorland landscape may be needed to conserve Sphagnum species, short-rotation burns (every 10-years) to enhance its abundance in the vegetation and long-rotations (>55 years) to maintain Sphagnum propagules in the surface peat.