Design and topographic evaluation of a canine humeral anatomic plating system (CHAPS) for humeral condylar fracture repair in spaniels.

OBJECTIVE: To design a precontoured plating system for humeral condylar fracture repair in spaniels with humeral intracondylar fissure (HIF) and quantify accuracy of fit of the system on 3D printed bone models. STUDY DESIGN: Experimental on 3D printed models. METHODS: The plating system was based on morphometric data obtained from CT. Plates were applied to models and impression material was measured under the plates at points of interest to define plate bone gap (PBG). Data on locking screw interference on plate application were also obtained. RESULTS: Eleven elbows models were plated. Statistical analysis to assess for any difference in PBG measurements between left and right humuri revealed two loci (3 and 17) under the lateral plate and two loci (3 and 17) under the medial plate. On cumulate portion analysis, 67% of lateral plate loci and 80% of medial plate loci had a PBG of ≤2 mm respectively. An incidence of 2.1% (3/143) screw interference occurred. CONCLUSION: Design of a contoured plating system for application to humeral models from spaniels with HIF and its application with objective measurement of PBG is described. The majority of the loci measured under both lateral and medial plates had a BPG of ≤2 mm and the incidence of locking screw interference on plate application was low. CLINICAL SIGNIFICANCE: This novel system may have application for the stabilization of humeral condylar fractures in spaniels avoiding the need for plate contouring and minimizing the incidence of locking screw interference.

Phenological sensitivity to climate across taxa and trophic levels.

Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate Sensitivity Profile approach to 10,003 terrestrial and aquatic phenological data sets, spatially matched to temperature and precipitation data, to quantify variation in climate sensitivity. The direction, magnitude and timing of climate sensitivity varied markedly among organisms within taxonomic and trophic groups. Despite this variability, we detected systematic variation in the direction and magnitude of phenological climate sensitivity. Secondary consumers showed consistently lower climate sensitivity than other groups. We used mid-century climate change projections to estimate that the timing of phenological events could change more for primary consumers than for species in other trophic levels (6.2 versus 2.5-2.9 days earlier on average), with substantial taxonomic variation (1.1-14.8 days earlier on average).

Inhibitory effects of climate change on the growth and extracellular enzyme activities of a widespread Antarctic soil fungus.

Temperatures approaching or exceeding 20°C have been measured during summer in polar regions at the surfaces of barren fellfield soils under cloudless skies around solar noon. However, despite the upper temperature limit for the growth of cold-adapted microbes-which are abundant in polar soils and have pivotal roles in nutrient cycling-typically being close to this temperature, previous studies have not addressed the consequences of climate change for the metabolism of these organisms in the natural environment. Here in a 5-year field experiment on Alexander Island in the southern maritime Antarctic, we show that the abundance of Pseudogymnoascus roseus, the most widespread decomposer fungus in maritime Antarctic fellfield soils, is reduced by 1-2 orders of magnitude when irrigated and nutrient-amended soils are warmed to >20°C during summer. Laboratory experiments under conditions mimicking those during midsummer in the natural environment indicated that the hyphal extension rates of P. roseus isolates and the activities of five extracellular enzymes are reduced by 54%-96% at high water availability after exposure to temperatures cycling daily from 2 to 21°C and 2 to 24°C, relative to temperatures cycling from 2 to 18°C. Given that the temperatures of surface soils at the study site already reach 19°C during midsummer, the observations reported here suggest that, at predicted rates of warming arising from moderate greenhouse gas emissions, inhibitory effects of climate change on the metabolism of P. roseus could manifest themselves within the next few decades. Furthermore, with peak temperatures at the surfaces of fellfield soils at other maritime Antarctic locations and in High Arctic and alpine regions already exceeding 20°C during summer, the observations suggest that climate warming has the potential to inhibit the growth of other cold-adapted microbes, with negative effects on soils as the Earth's climate continues to warm.

Long-term effect of temperature on honey yield and honeybee phenology.

There is growing concern about declines in pollinator species, and more recently reservations have been expressed about mismatch in plant-pollinator synchrony as a consequence of phenological change caused by rising temperatures. Long-term changes in honeybee Apis mellifera phenology may have major consequences for agriculture, especially the pollinator market, as well as for honey production. To date, these aspects have received only modest attention. In the current study, we examine honeybee and beekeeping activity in southern Poland for the period 1965-2010, supplemented by hive yields from a beekeeper in southern UK in the same period. We show that despite negative reports on honeybee condition, and documented climate change, the studied apiary managed to show a marked increase in honey production over the 46 year study period, as did that from the UK. The proportion of the annual yield originating from the first harvest decreased during the study period and was associated with rising temperatures in summer. Honeybee spring phenology showed strong negative relationships with temperature but no overall change through time because temperatures of key early spring months had not increased significantly. In contrast, increasing yields and an increased number of harvests (and hence a later final harvest and longer season) were detected and were related to rising temperatures in late spring and in summer.

Differences between urban and rural hedges in England revealed by a citizen science project.

BACKGROUND: Hedges are both ecologically and culturally important and are a distinctive feature of the British landscape. However the overall length of hedges across Great Britain is decreasing. Current challenges in studying hedges relate to the dominance of research on rural, as opposed to urban, hedges, and their variability and geographical breadth. To help address these challenges and to educate the public on the importance of hedge habitats for wildlife, in 2010 the Open Air Laboratories (OPAL) programme coordinated a hedge-focused citizen science survey. RESULTS: Results from 2891 surveys were analysed. Woody plant species differed significantly between urban and rural areas. Beech, Holly, Ivy, Laurel, Privet and Yew were more commonly recorded in urban hedges whereas Blackthorn, Bramble, Dog Rose, Elder and Hawthorn were recorded more often in rural hedges. Urban and rural differences were shown for some groups of invertebrates. Ants, earwigs and shieldbugs were recorded more frequently in urban hedges whereas blowflies, caterpillars, harvestmen, other beetles, spiders and weevils were recorded more frequently in rural hedges. Spiders were the most frequently recorded invertebrate across all surveys. The presence of hard surfaces adjacent to the hedge was influential on hedge structure, number and diversity of plant species, amount of food available for wildlife and invertebrate number and diversity. In urban hedges with one adjacent hard surface, the food available for wildlife was significantly reduced and in rural hedges, one adjacent hard surface affected the diversity of invertebrates. CONCLUSIONS: This research highlights that urban hedges may be important habitats for wildlife and that hard surfaces may have an impact on both the number and diversity of plant species and the number and diversity of invertebrates. This study demonstrates that citizen science programmes that focus on hedge surveillance can work and have the added benefit of educating the public on the importance of hedgerow habitats.

Can we detect a nonlinear response to temperature in European plant phenology?

Over a large temperature range, the statistical association between spring phenology and temperature is often regarded and treated as a linear function. There are suggestions that a sigmoidal relationship with definite upper and lower limits to leaf unfolding and flowering onset dates might be more realistic. We utilised European plant phenological records provided by the European phenology database PEP725 and gridded monthly mean temperature data for 1951-2012 calculated from the ENSEMBLES data set E-OBS (version 7.0). We analysed 568,456 observations of ten spring flowering or leafing phenophases derived from 3657 stations in 22 European countries in order to detect possible nonlinear responses to temperature. Linear response rates averaged for all stations ranged between -7.7 (flowering of hazel) and -2.7 days °C-1 (leaf unfolding of beech and oak). A lower sensitivity at the cooler end of the temperature range was detected for most phenophases. However, a similar lower sensitivity at the warmer end was not that evident. For only ∼14 % of the station time series (where a comparison between linear and nonlinear model was possible), nonlinear models described the relationship significantly better than linear models. Although in most cases simple linear models might be still sufficient to predict future changes, this linear relationship between phenology and temperature might not be appropriate when incorporating phenological data of very cold (and possibly very warm) environments. For these cases, extrapolations on the basis of linear models would introduce uncertainty in expected ecosystem changes.

The phenology of winter rye in Poland: an analysis of long-term experimental data.

The study of the phenology of crops, although quite popular, has limitations, mainly because of frequent changes to crop varieties and management practices. Here, we present data on the phenology and yield of winter rye in western Poland collected between 1957 and 2012 from a long-term field experiment. Data were examined for trends through time and compared to climatological factors using regression analysis. Both annual air temperature and precipitation increased during the study period, equivalent to 2 °C and 186 mm, respectively, over the 52-year period for which met data were available. We detected significant delays in sowing date and recently in emergence, but significant advances were apparent in full flowering date equivalent to 4 days/decade. Yield and plant density experienced a step like change in 1986; yield increasing by ca. 70 % and plant density increasing by ca. 50 %, almost coinciding with a similar change in annual mean temperature, but most likely caused by a changed seed rate and use of herbicides. Future climate change is expected to have a greater impact on this crop, but farmers may be able to adapt to these changes by modifying water regimes, using new machinery and sowing new rye varieties.

Climate sensitivity and variation in first flowering of 26 Narcissus cultivars.

The first flowering dates of 26 Narcissus cultivars were recorded over a 27-year period on the island of Guernsey, within the English Channel. We analysed flowering trends over time and relationships with climate variables. The study revealed that earlier flowering cultivars advanced most and were more variable than later flowering Narcissus. We furthermore discovered a strong relationship between flowering and climate variables, with temperature appearing to be the main driver. Whilst the first flowering date averaged over all cultivars did show a significant advance, this was significant for only one of the individual cultivars. This is likely because temperatures from December to March had not significantly increased in Guernsey during the study period (1985 to 2011).

Links between plant species' spatial and temporal responses to a warming climate.

To generate realistic projections of species' responses to climate change, we need to understand the factors that limit their ability to respond. Although climatic niche conservatism, the maintenance of a species's climatic niche over time, is a critical assumption in niche-based species distribution models, little is known about how universal it is and how it operates. In particular, few studies have tested the role of climatic niche conservatism via phenological changes in explaining the reported wide variance in the extent of range shifts among species. Using historical records of the phenology and spatial distribution of British plants under a warming climate, we revealed that: (i) perennial species, as well as those with weaker or lagged phenological responses to temperature, experienced a greater increase in temperature during flowering (i.e. failed to maintain climatic niche via phenological changes); (ii) species that failed to maintain climatic niche via phenological changes showed greater northward range shifts; and (iii) there was a complementary relationship between the levels of climatic niche conservatism via phenological changes and range shifts. These results indicate that even species with high climatic niche conservatism might not show range shifts as instead they track warming temperatures during flowering by advancing their phenology.

Changes in first flowering dates and flowering duration of 232 plant species on the island of Guernsey.

Climate change has affected plant phenology; increasing temperatures are associated with advancing first flowering dates. The impact on flowering duration, however, has rarely been studied. In this study, we analysed first flowering dates and flowering durations from a 27 year dataset of weekly flower observations on 232 plant species from the island of Guernsey in the English Channel. The aim of this study was to explore variation in trends and relationships between first flowering dates, flowering duration and temperature. We specifically looked for evidence that traits, such as life forms and phylogenetic groups, explained variation in sensitivity of first flowering and flowering duration among species. Overall trends revealed significantly earlier flowering over time, by an average of 5.2 days decade(-1) since 1985. A highly significant shortening of flowering duration was observed by an average of 10 days decade(-1) . Correlations between first flowering, flowering duration and year varied between different species, traits and flowering periods. Significant differences among traits were observed for first flowering and to a lesser degree for flowering duration. Overall, in comparison to first flowering, more species had significant trends in flowering duration. Temperature relationships revealed large differences in strength and direction of response. 55% of the species revealed a significant negative relationship of first flowering dates and temperature. In contrast, only 19% of flowering durations had a significant negative temperature relationship. The advance in first flowering date together with a shortening of flowering duration suggests potentially serious impacts on pollinators, which might pose a major threat to biodiversity, agriculture and horticulture. Human health, in terms of pollen allergies, however, might benefit from a shortening of specific plant pollen seasons.

Chilling outweighs photoperiod in preventing precocious spring development.

It is well known that increased spring temperatures cause earlier onset dates of leaf unfolding and flowering. However, a temperature increase in winter may be associated with delayed development when species' chilling requirements are not fulfilled. Furthermore, photosensitivity is supposed to interfere with temperature triggers. To date, neither the relative importance nor possible interactions of these three factors have been elucidated. In this study, we present a multispecies climate chamber experiment to test the effects of chilling and photoperiod on the spring phenology of 36 woody species. Several hypotheses regarding their variation with species traits (successional strategy, floristic status, climate of their native range) were tested. Long photoperiods advanced budburst for one-third of the studied species, but magnitudes of these effects were generally minor. In contrast to prior hypotheses, photosensitive responses were not restricted to climax or oceanic species. Increased chilling length advanced budburst for almost all species; its effect greatly exceeding that of photoperiod. Moreover, we suggest that photosensitivity and chilling effects have to be rigorously disentangled, as the response to photoperiod was restricted to individuals that had not been fully chilled. The results indicate that temperature requirements and successional strategy are linked, with climax species having higher chilling and forcing requirements than pioneer species. Temperature requirements of invasive species closely matched those of native species, suggesting that high phenological concordance is a prerequisite for successful establishment. Lack of chilling not only led to a considerable delay in budburst but also caused substantial changes in the chronological order of species' budburst. The results reveal that increased winter temperatures might impact forest ecosystems more than formerly assumed. Species with lower chilling requirements, such as pioneer or invasive species, might profit from warming winters, if late spring frost events would in parallel occur earlier.

Computed Tomography Topographical Analysis of Incomplete Humeral Intracondylar Fissures in English Springer Spaniel Dogs.

OBJECTIVE: The aim of this study was to use computed tomography (CT) images obtained from English springer spaniels (ESS) with different sizes of humeral intracondylar fissure (HIF) to describe the typical shape, origin and a possible propagation pattern of HIF in this breed. STUDY DESIGN: It is a retrospective analysis of 32 elbow CT from 27 ESS with incomplete HIF. Measurements included HIF articular surface length, centre of HIF at articular surface relative to the caudal edge of the supratrochlear foramen (CHIF), HIF depth and sagittal area of fissure. Measurement of isthmus area and diameter was obtained for each elbow. Humeral intracondylar fissure measurements were analysed as proportions of the isthmus. For parts of analysis, elbows were grouped by HIF area as a percentage of isthmus area (%HIF) into less than 20% (n = 10), 20 to less than 40% (n = 8), 40 to less than 60% (n = 9) and 60 to less than 90% (n = 5). RESULTS: The mean isthmus diameter was 12.31 mm (range: 10.96-13.69 mm). Mean CHIF for %HIF groups less than 20%, 20 to less than 40%, 40 to less than 60% and 60 to less than 90% were 57, 74, 86 and 96 degrees, respectively. The less than 20% group was significantly lower than 20 to less than 40% group (p = 0.035) and 40 to less than 60% and 60 to less than 90% groups (p < 0.001); the 20 to less than 40% group was significantly lower than the 60 to less than 90% group (p = 0.015). Humeral intracondylar fissure articular surface length increased in a sigmoidal fashion relative to %HIF, corresponding to segmental enlargement of the fissure as %HIF increases. CONCLUSION: In ESS, HIF typically originates approximately 57 degrees caudal to the supratrochlear foramen in the sagittal plane and may propagate in a segmental fashion with lesser propagation through the proximal intracondylar region.

Changes in the timing of hay cutting in Germany do not keep pace with climate warming.

A unique long-term phenological data set of over 110 000 records of 1st cutting dates for haymaking across Germany, spanning the years 1951-2011 was examined. In addition, we analyzed a long-term data set in the beginning of flowering of meadow foxtail (Alopecurus pratensis) covering the last 20 years. We tested whether hay-cutting dates (based on a human decision when to cut) showed trends, temperature relationships and spatial distribution similar to the development of this grassland species, and if these trends could be related to climate change. The timing of 1st hay cut was strongly influenced (P < 0.001) by altitude, latitude and longitude, revealing in particular an east-west gradient. Over the past 60 years, there have been changes in the timing of hay cutting, with the majority of German federal states having significant (P < 0.05) advances of approximately 1 day per decade. Overall, the response to mean March-May temperature was highly significant (-2.87 days °C(-1); P < 0.001). However, in the last 20 years, no federal state experienced a significant advance and two were even significantly delayed. The temperature response in this post-1991 period became less or non-significant for most of the federal states. We suggest that differences in agricultural land use and unequal uptakes of Agri-Environment Schemes (AES, which encourage later cutting) were likely to be responsible for the regional differences, while the general increase in AES appears to have confounded the overall trend in hay cutting in the last 20 years. Trends over time and responses to temperature were small relative to those associated with the phenology of meadow foxtail. The advance in phenology of this species is greater than the advance in hay cutting, implying that hay cutting may not be keeping pace with a changing climate, which may have a positive effect on grassland ecology.

Synchrony in the phenology of a culturally iconic spring flower.

We examine the flowering phenology of the cultural iconic Spring Snowflake Leucojum vernum, a considerable tourist attraction, recorded from two sites in western Poland. Flowering dates at the two sites were closely correlated but about 6 days later at the more natural area. The end of flowering was associated with the start of canopy leafing. Early flowering was related to a longer flowering season which may benefit ecotourism under future climate warming.

The influence of altitude and urbanisation on trends and mean dates in phenology (1980-2009).

Long-term studies on urban phenology using network data are commonly limited by the small number of observation sites within city centres. Moreover, cities are often located on major rivers and consequently at lower altitudes than their rural surroundings. For these reasons, it is important (1) to go beyond a plain urban-rural comparison by taking the degree of urbanisation into account, and (2) to evaluate urbanisation and altitudinal effects simultaneously. Temporal phenological trends (1980-2009) for nine phenological spring events centred on the German cities of Frankfurt, Cologne and Munich were analysed. Trends of phenological onset dates were negative (i.e. earlier onset in phenology) for 96% of the 808 time series and significantly negative for 56% of the total number. Mean trends for the nine phenological events ranged between -0.23 days year(-1) for beech and -0.50 days year(-1) for hazel. The dependence of these trends and of mean dates on altitude and on the degree of urbanisation was explored. For mean dates, we demonstrated an earlier phenological onset at lower altitude and with a higher degree of urbanisation: altitude effects were highly significant and ranged between 1.34 days (100 m)(-1) (beech) and 4.27 days (100 m)(-1) (hazel). Coefficients for the log-transformed urban index were statistically significant for five events and varied greatly between events (coefficients from -1.74 for spruce to -5.08 for hazel). For trends in phenology, altitude was only significant for Norway maple, and no urban effects were significant. Hence, trends in phenology did not change significantly with higher altitudes or urbanised areas.

Efficacy of autologous mesenchymal stromal cell treatment for chronic degenerative musculoskeletal conditions in dogs: A retrospective study.

Introduction: The objective of this study was to retrospectively analyze clinical data from a referral regenerative medicine practice, to investigate the efficacy of autologous mesenchymal stromal cells (MSC) in 245 dogs deemed unresponsive to conventional treatment by their referring vet. Methods: Diagnostic imaging [radiology and musculoskeletal ultrasound (MSK-US)] identified musculoskeletal pathology holistically. MSCs, produced according to current guidelines, were initially administered with PRP by targeted injection to joints and/or tendons, with a second MSC monotherapy administered 12 weeks later to dogs with severe pathology and/or previous elbow arthroscopic interventions. Dogs with lumbosacral disease received epidural MSCs with additional intravenous MSCs administered to dogs with spondylosis of the cervical, thoracic and lumbar spine. All dogs received laser therapy at 10 J/cm2 at the time of treatment and for 5 sessions thereafter. Objective outcome measures (stance analysis, range of joint motion, pressure algometry) and validated subjective outcome measures (owner reported VetMetrica HRQL™ and veterinary pain and quality of life impact scores) were used to investigate short and long-term (6-104 weeks) efficacy. Outcome data were collected at predetermined time windows (0-6, 7-12, 13-18, 19-24, 25-48, 49-78, 79-104) weeks after initial treatment. Results: There were statistically significant improvements in post compared with pre-treatment measures at all time windows in stance analysis, shoulder and hip range of motion, lumbosacral pressure algometry, and to 49-78 weeks in carpus and elbow range of motion. Improvements in 4 domains of quality of life as measured by VetMetricaTM were statistically significant, as were scores in vet-assessed pain and quality of life impact. In dogs receiving one initial treatment the mean time before a second treatment was required to maintain improvements in objective measures was 451 days. Diagnostic imaging confirmed the regenerative effects of MSCs in tendinopathies by demonstrating resolution of abnormal mineralization and restoration of normal fiber patterns. Discussion: This represents the first study using "real-world" data to show that cell-based therapies, injected into multiple areas of musculoskeletal pathology in a targeted holistic approach, resulted in rapid and profound positive effects on the patient's pain state and quality of life which was maintained with repeat treatment for up to 2 years.

Phenological changes and reduced seasonal synchrony in western Poland.

Botanical gardens offer continuity for phenological recording in observers, protocols and plant specimens that may not be achievable from other sources. Here, we examine phenological change and synchrony from one such garden in western Poland. We analysed 66 botanical phenophases and 18 interphase intervals recorded between 1977 and 2007 from the Poznan Botanical Garden. These were examined for trends through time and responsiveness to temperature. Furthermore, we derived measures of synchrony for start of spring and end of autumn events to assess if these had changed over time. All 39 events with a mean date before mid-July demonstrated a significant negative relationship with temperature. Where autumn events were significantly related to temperature, they indicated a positive relationship. Typically, spring events showed an advance over time and autumn events a delay. Interphase intervals tended to lengthen over the study period. The measures of synchrony changed significantly over time suggesting less synchrony among spring events and also among autumn events. In combination, these results suggest increases in growing season length. However, responses to a changing climate were species-specific. Thus, the transitions from winter into spring and from autumn into winter are becoming less clearly defined.

Long-term woodland restoration on lowland farmland through passive rewilding.

Natural succession of vegetation on abandoned farmland provides opportunities for passive rewilding to re-establish native woodlands, but in Western Europe the patterns and outcomes of vegetation colonisation are poorly known. We combine time series of field surveys and remote sensing (lidar and photogrammetry) to study woodland development on two farmland fields in England over 24 and 59 years respectively: the New Wilderness (2.1 ha) abandoned in 1996, and the Old Wilderness (3.9 ha) abandoned in 1961, both adjacent to ancient woodland. Woody vegetation colonisation of the New Wilderness was rapid, with 86% vegetation cover averaging 2.9 m tall after 23 years post-abandonment. The Old Wilderness had 100% woody cover averaging 13.1 m tall after 53 years, with an overstorey tree-canopy (≥ 8 m tall) covering 91%. By this stage, the structural characteristics of the Old Wilderness were approaching those of neighbouring ancient woodlands. The woody species composition of both Wildernesses differed from ancient woodland, being dominated by animal-dispersed pedunculate oak Quercus robur and berry-bearing shrubs. Tree colonisation was spatially clustered, with wind-dispersed common ash Fraxinus excelsior mostly occurring near seed sources in adjacent woodland and hedgerows, and clusters of oaks probably resulting from acorn hoarding by birds and rodents. After 24 years the density of live trees in the New Wilderness was 132/ha (57% oak), with 390/ha (52% oak) in the Old Wilderness after 59 years; deadwood accounted for 8% of tree stems in the former and 14% in the latter. Passive rewilding of these 'Wilderness' sites shows that closed-canopy woodland readily re-established on abandoned farmland close to existing woodland, it was resilient to the presence of herbivores and variable weather, and approached the height structure of older woods within approximately 50 years. This study provides valuable long-term reference data in temperate Europe, helping to inform predictions of the potential outcomes of widespread abandonment of agricultural land in this region.

A 250-year index of first flowering dates and its response to temperature changes.

Widespread concerns about global biodiversity loss have led to a growing demand for indices of biodiversity status. Today, climate change is among the most serious threats to global biodiversity. Although many studies have revealed phenological responses to climate change, no long-term community-level indices have been developed. We derived a 250-year index of first flowering dates for 405 plant species in the UK for assessing the impact of climate change on plant communities. The estimated community-level index in the most recent 25 years was 2.2-12.7 days earlier than any other consecutive 25-year period since 1760. The index was closely correlated with February-April mean Central England Temperature, with flowering 5.0 days earlier for every 1 degrees C increase in temperature. The index was relatively sensitive to the number of species, not records per species, included in the model. Our results demonstrate how multi-species, multiple-site phenological events can be integrated to obtain indices showing trends for each species and across species. This index should play an important role in monitoring the impact of climate change on biodiversity. Furthermore, this approach can be extended to incorporate data from other taxa and countries for evaluating cross-taxa and cross-country phenological responses to climate change.

Climate change and spring-fruiting fungi.

Most macrofungi produce ephemeral fruit bodies during autumn but some have adapted to spring fruiting. In this study, temporal changes in the time of spring fruiting in Norway and the UK during 1960-2007 have been investigated by statistical analyses of about 6000 herbarium and field records, covering 34 species. Nearly 30 per cent of the temporal variation in fruiting could be ascribed to spatial and species-specific effects. Correcting for these effects, linear trends towards progressively earlier fruiting were detected during the entire period in both Norway and the UK, with a change in average fruiting day of 18 days over the study period. Early fruiting was correlated with high winter temperatures in both countries, indicating that the observed phenological changes are likely due to earlier onset of spring. There were also significant correlations between climatic conditions in one year and timing of fruiting the following year, indicating that below-ground mycelia are influenced by climatic conditions over a longer time period before fruiting. Fruiting dates were, however, not strictly related to changes in vernal accumulated thermal time. Our results indicate that global warming has lead to progressively earlier fruiting of spring fungi in northwest Europe during the last half century.