Natural Turfs Research Articles

Phylogenetic analyses of Macaronesian turf-forming species reveal cryptic diversity and resolve Stichothamnion in the Vertebrata clade (Rhodomelaceae, Rhodophyta)

ABSTRACT Algal turfs are ecosystem engineers receiving steadily growing attention in recent years in relation to their expansion on temperate reefs due to global change. However, their species diversity and taxonomy are still poorly understood, mostly based solely on morphological information. Algal turfs are the dominant type of assemblage in Macaronesia, but molecular diversity surveys have barely been applied in this region. We aim to show how molecular tools can assist us to improve our understanding of the diversity and taxonomy of natural algal turfs by studying the turf-forming rhodomelacean genus Stichothamnion which has only one recognized species in Macaronesia, the generitype S. cymatophilum. Stichothamnion resembles other members of the tribe Streblocladieae, but it has unbranched trichoblasts, an unusual character in the family. Here, we show using phylogenetic analyses of the rbcL gene that specimens collected in the Canary Islands and the Azores identifiable morphologically as S. cymatophilum exhibit cryptic diversity, and these analyses position Stichothamnion in the Vertebrata clade with full support. We place Stichothamnion in synonymy with Vertebrata, transfer the existing species, and describe a newly discovered cryptic species as V. barbarae Muñoz-Luque & Díaz-Tapia, sp. nov., found exclusively in the Azores. The new species was morphologically indistinguishable from V. cymatophila but diverged by 2.1–2.3% in the rbcL gene. This study illustrates the work required to better understand the extraordinary species diversity in algal turfs such as those in Macaronesia which remain taxonomically under-studied.

Artificial-turf surfaces for sport and recreational activities: microbiota analysis and 16S sequencing signature of synthetic vs natural soccer fields

Synthetic fibres are used in place of the natural grass worldwide, for realizing playgrounds, soccer fields and even domestic gardens or recreational structures. An intensive use of artificial turf is currently observed in sports facilities, due to lower costs, higher sustainability in recycling of materials, and advantages related to athletic practice and performance. However, even if chemical and physical risks were studied, the microbiological component was not fully addressed, especially considering a comprehensive evaluation of the microbiota in synthetic vs natural playground surfaces. Here, we investigated the microbial community present on soccer fields, using Next Generation Sequencing and a 16S amplicon sequencing approach. Artificial and natural turfs show own ecosystems with different microbial profiles and a mean Shannon's diversity value of 2.176 and 2.475, respectively. The bacterial community is significantly different between facilities (ANOSIM: R = 0.179; p < 0.001) and surface materials (ANOSIM: R = 0.172; p < 0.005). The relative abundance of potentially pathogenic bacterial OTUs was higher in synthetic than in natural samples (ANOVA, F = 2.2). Soccer fields are characterized by their own microbiota, showing a different 16S amplicon sequencing signature between natural and artificial turfs.

Comparison of high-impact load-absorbing property of natural turf for professional use with various types of natural and artificial turfs in football

The present study aimed to illustrate load stress-strain properties of various types of natural and artificial turfs. A modified high-loading test rig was used to measure shock absorbency and concurrent deformation of these surfaces in situ to calculate quasi stress-strain curves. A natural turf professionally maintained for top professional league soccer matches (N-stadium) was used as the reference surface. Other surfaces included two natural turfs without professional maintenance (one with and one without polyethylene pile reinforcement), four new artificial turfs (sand infill only, rubber infill only, both sand and rubber, and thermoplastic elastomer infill), and one aged artificial turf (8 years old with sand/rubber infill). All artificial turfs failed to mimic two properties of N-stadium, plastic deformation, and hysteresis profile, suggesting N-stadium has more energy absorbable properties than those of artificial turfs. The aged artificial turf with conventional infill was substantially stiffer than the new artificial turf with the same infill, indicating age affects the stiffness of these surfaces. Also, distinctive differences were detected between N-stadium and other natural turfs, suggesting factors such as daily maintenance work are very influential on their quasi stress-strain properties. Interestingly, no difference in the quasi stress-strain curve existed between the natural turf with and without polyethylene pile reinforcement. While artificial surfaces are improving, there is still a difference in properties between these surfaces and natural turf pitches.

Sustainable Harvesting of the Ecosystem Engineer Corallina officinalis for Biomaterials

Macroalgae are of increasing interest for high-value biotechnological applications, but some seaweeds, such as coralline red algae, cannot be grown in cultivation cost-effectively. Wild harvesting of seaweeds, particularly of those that are ecosystem engineers, must be demonstrably sustainable: here we address the topic of resource sustainability in the context of harvesting Corallina officinalis in Ireland for bioceramics. C. officinalis provides habitat for a diverse macrofaunal community and the effects of harvesting C. officinalis on the associated fauna must be included in any assessment of harvesting sustainability. Corallina intertidal turfs subject to experimental harvesting were confirmed, using DNA barcoding with cox1, to comprise only C. officinalis and not the pseudocryptic species C. caespitosa, despite the wide range of morphologies, and they had high genetic diversity. Harvesting of C. officinalis was carried out at experimental sites by two techniques (hand cutting and pulling) to test the recovery of the primary resource and the associated macroinvertebrate assemblage. Harvesting the alga by both methods encouraged regrowth: cut and pulled plots had a much higher growth rate than unharvested turfs, regaining their original length within 4-6 months of harvesting, suggesting that turfs of this species may grow to a predetermined length. The structure, richness and evenness of the invertebrate assemblage were not significantly affected by harvesting C. officinalis by cutting or pulling, though some organisms within the community showed a response to harvesting. The pattern of recovery of the sediment, an important component of the C. officinalis habitat, was consistent with the shorter (harvested) turf trapping more sediment than longer natural turfs. As many of the organisms associated with the habitat use the sediment for food or building materials, this may have ameliorated the effects of harvesting on the community. A period of a year between harvests is recommended to allow the C. officinalis biomass to return to baseline levels and unharvested fallow areas should be included in a harvesting plan to allow macroinvertebrates to re-colonise the harvested turf.

The Effects of Natural Grass Turf on Some Motoric Characteristics of Young Soccer Players

The aim of this study is to examine the effect of soccer training on natural turfs on strength, speed, power and balance characteristics in prepubertal children. Twenty-two male athletes chosen from the 12-13 age group who play soccer in the youth team of an amateur soccer club from Istanbul, Turkey volunteered to participate in our study. In the study, 30 m sprint, Y-balance, standing long jump and vertical jump tests were done as pre- and post-tests. The same training program was assigned to the players, who were separated into two groups. One group was trained on synthetic grass turf (SG) while the other group was trained on natural grass turf (NG) for eight weeks. As a result of the statistical analyses, significant improvements were observed in all parameters between pre-and post-test measurements of both SG and NG groups (p&lt;0.05). When the developmental differences of the groups were examined, statistical improvement was found in the standing long jump parameter in favor of the group that trained on Natural Grass turf (p=0.037). In conclusion, depending on the characteristics of the soccer game, enhancements were observed on both surfaces. However, the challenge effect of natural grass turf was more effective than that of synthetic grass turf on leg strength improvement. It is considered that as a result of continuing their soccer trainings on natural grass turfs, young players can improve their performance and can avoid possible injuries.

Novel field equipment for assessing the stability of natural and hybrid turfs

Natural turf pitches are used for many outdoor sports. Turf is a complex network of interacting organic material, soil textures and water content. Turf is susceptible to damage under large surface forces, caused by intensive player movements in rugby union and football. To assess and monitor surface stability, there needs to be a reliable test method for ground staff and other stakeholders. At present, no turf stability mechanical test method exists that represents player–surface interaction, especially to represent a linear movement across the surface such as in a rugby scrummage. This paper describes the development of a novel device for assessing turf stability. Verification was undertaken in the laboratory on a variety of controlled soil samples, and during a field study. The device measurements were shown to be sensitive to the shear strength of a high clay content soil at varying water content and to the density and type of sandy soils. A programme of field data on high quality pitches suggested a large effect of the turf root reinforcement. A conceptual model of soil failure induced by the device was developed to identify the key soil variables and support experimental data interpretation.

Solar–terrestrial radiant-energy regimes and temperature anomalies of natural and artificial turfs

Artificial turf can develop unusually high surface temperature on hot sunny days. Solar and terrestrial radiant energy regimes as key determinants of thermal performance deserve detailed investigation. This study evaluated six components of the radiant-energy environment of a natural turf (NT) and a contiguous artificial turf (AT) sports fields in Hong Kong: direct solar, reflected solar, net solar, sky thermal, ground thermal, and net thermal. Temperature was monitored at five positions: air at 150cm, 50cm and 15cm height, turf surface, and substrate. The experiment included four replications, namely two summer sunny days, and two duplicated instrument sets at each turf site. The two sites reacted very differently to the same intense daily sum of solar radiation input of 23.70MWm−2 with 9h of bright sunshine (>120Wm−2), and daily sum of sky thermal radiation input of 38.59MWm−2. The maximum direct solar radiation reached 976.1Wm−2 at 1245h. NT albedo of 0.23 vis-à-vis AT of merely 0.073, and higher moisture content and specific heat of NT materials, presented critical differences. The hydrophobic and generally dry plastic (polyethylene) pile-fibers and black rubber-granule infill materials have low specific heat. Intense incoming shortwave and longwave radiation absorbed readily by AT materials raised turf surface temperature to 70.2°C and substrate 69.3°C, in comparison with <40°C at NT. A cascading warming effect was triggered, beginning with low albedo, high net solar irradiance and low material specific heat, leading to heated AT materials, high ground-thermal radiation, and heat flux to near-ground air by conduction and convection. The ephemeral rainfall cooling confirmed ineffective cooling by irrigation. Athletes are immersed in an anomalously intense and omnidirectional radiant-energy and sensible-heat ambience. The heat-stress health implications of AT for athletes in hot summer afternoon call for preventive–precautionary measures and re-assessment of NT-to-AT decisions.

A kinematic analysis of the spine during rugby scrummaging on natural and synthetic turfs

ABSTRACTArtificial surfaces are now an established alternative to grass (natural) surfaces in rugby union. Little is known, however, about their potential to reduce injury. This study characterises the spinal kinematics of rugby union hookers during scrummaging on third-generation synthetic (3G) and natural pitches. The spine was sectioned into five segments, with inertial sensors providing three-dimensional kinematic data sampled at 40 Hz/sensor. Twenty-two adult, male community club and university-level hookers were recruited. An equal number were analysed whilst scrummaging on natural or synthetic turf. Players scrummaging on synthetic turf demonstrated less angular velocity in the lower thoracic spine for right and left lateral bending and right rotation. The general reduction in the range of motion and velocities, extrapolated over a prolonged playing career, may mean that the synthetic turf could result in fewer degenerative injuries. It should be noted, however, that this conclusion considers only the scrummaging scenario.

Does soccer cleat design influence the rotational interaction with the playing surface?

Non-contact injuries in soccer players may be related to the interplay between cleat type and playing surface, and bladed shoes were often blamed for non-contact injuries with no research support. The aim of this study was to compare the rotational resistance (stiffness and peak sustainable torque) among three types of soccer cleats (metal studs, molded rubber studs, and bladed) in a controlled laboratory environment. The shoes were tested on both natural and artificial turfs under a compressive preload of 1000 N and with internal and external rotations. The three shoe models showed comparable performances with a good repeatability for each individual test on both playing surfaces. A less stiff behavior was observed for the natural turf. A tendency toward highest peak torque was observed in the studded model on natural surface. The bladed cleats provided peak torque and rotational stiffness comparable to the other models. Studded and bladed cleats did not significantly differ in their interaction with the playing surface. Therefore, soccer shoes with bladed cleats should not be banned in the context of presumed higher risk for non-contact injuries.

Evaluation of genetic diversity among some genotypes of Kentucky bluegrass by RAPD molecular markers

Genetic improvement of plants need a high genetic diversity and molecular markers offer a powerful tool for its assessment. Poa pratensis has extensive divergence in natural old turfs and pastures in temperate zones of Iran, being useful for breeding programs. In this research, RAPD markers were used to study the genetic diversity of 19 turfgrass genotypes (including 16 genotypes of Poa pratensis along with one genotype from each of Lolium perenne, Cynodon dactylon and Festuca arundinacea species). After screening 100 random 10-mer RAPD primers, 17 primers were selected based on the clarity of their amplified fragments in PCR and the high reproducibility for scoring. From the 284 produced bands, 281 were polymorphic. Cluster analysis of RAPD data was performed using the UPGMA method based on Jaccard’s similarity coefficients. Dendrogram at a similarity of 0.24 gave 5 main clusters. The correlation coefficient between the data matrix and the cophenetic matrix of cluster data was high (r = 0.99), indicating that the clustering dendrogram being highly fitted to similarity matrix. A relatively high genetic similarity was observed between some commercial cultivars and Iranian local genotypes. In addition, this research showed the high genetic diversity among studied genotypes as well as the high efficiency of RAPD markers for evaluation of genetic diversity among turfgrasses.

A Review of Football Injuries on Third and Fourth Generation Artificial Turfs Compared with Natural Turf

Football codes (rugby union, soccer, American football) train and play matches on natural and artificial turfs. A review of injuries on different turfs was needed to inform practitioners and sporting bodies on turf-related injury mechanisms and risk factors. Therefore, the aim of this review was to compare the incidence, nature and mechanisms of injuries sustained on newer generation artificial turfs and natural turfs. Electronic databases were searched using the keywords 'artificial turf', 'natural turf', 'grass' and 'inj*'. Delimitation of 120 articles sourced to those addressing injuries in football codes and those using third and fourth generation artificial turfs or natural turfs resulted in 11 experimental papers. These 11 papers provided 20 cohorts that could be assessed using magnitude-based inferences for injury incidence rate ratio calculations pertaining to differences between surfaces. Analysis showed that 16 of the 20 cohorts showed trivial effects for overall incidence rate ratios between surfaces. There was increased risk of ankle injury playing on artificial turf in eight cohorts, with incidence rate ratios from 0.7 to 5.2. Evidence concerning risk of knee injuries on the two surfaces was inconsistent, with incidence rate ratios from 0.4 to 2.8. Two cohorts showed beneficial inferences over the 90% likelihood value for effects of artificial surface on muscle injuries for soccer players; however, there were also two harmful, four unclear and five trivial inferences across the three football codes. Inferences relating to injury severity were inconsistent, with the exception that artificial turf was very likely to have harmful effects for minor injuries in rugby union training and severe injuries in young female soccer players. No clear differences between surfaces were evident in relation to training versus match injuries. Potential mechanisms for differing injury patterns on artificial turf compared with natural turf include increased peak torque and rotational stiffness properties of shoe-surface interfaces, decreased impact attenuation properties of surfaces, differing foot loading patterns and detrimental physiological responses. Changing between surfaces may be a precursor for injury in soccer. In conclusion, studies have provided strong evidence for comparable rates of injury between new generation artificial turfs and natural turfs. An exception is the likely increased risk of ankle injury on third and fourth generation artificial turfs. Therefore, ankle injury prevention strategies must be a priority for athletes who play on artificial turf regularly. Clarification of effects of artificial surfaces on muscle and knee injuries are required given inconsistencies in incidence rate ratios depending on the football code, athlete, gender or match versus training.

Football Helmet Drop Tests on Different Fields Using an Instrumented Hybrid III Head

An instrumented Hybrid III head was placed in a Schutt ION 4D football helmet and dropped on different turfs to study field types and temperature on head responses. The head was dropped 0.91 and 1.83 m giving impacts of 4.2 and 6.0 m/s on nine different football fields (natural, Astroplay, Fieldturf, or Gameday turfs) at turf temperatures of -2.7 to 23.9 °C. Six repeat tests were conducted for each surface at 0.3 m (1') intervals. The Hybrid III was instrumented with triaxial accelerometers to determine head responses for the different playing surfaces. For the 0.91-m drops, peak head acceleration varied from 63.3 to 117.1 g and HIC(15) from 195 to 478 with the different playing surfaces. The lowest response was with Astroplay, followed by the engineered natural turf. Gameday and Fieldturf involved higher responses. The differences between surfaces decreased in the 1.83 m tests. The cold weather testing involved higher accelerations, HIC(15) and delta V for each surface. The helmet drop test used in this study provides a simple and convenient means of evaluating the compliance and energy absorption of football playing surfaces. The type and temperature of the playing surface influence head responses.

Incidence of Injury Among Adolescent Soccer Players: A Comparative Study of Artificial and Natural Grass Turfs

To investigate the incidence of acute injuries and soccer-related chronic pain from long-term training and during matches in adolescent players using natural grass turfs (NT) and artificial turfs (AT). Case-controlled prospective study. Institutional-level Fédération Internationale de Football Association Medical Centre of Excellence. Youth soccer players (12-17 years of age) from 6 teams, with a predominant tendency to train on either NT or AT, were included. Of 332 players enrolled in this study, 301 remained to completion. Medically diagnosed acute injuries and chronic pain were recorded daily by team health care staff throughout 2005, and reports were provided monthly to the authors. Noninvasive prospective study. Age and turf type. Acute injuries per 1000 player hours on each surface and chronic complaints per 1000 player hours were evaluated according to frequency of surface used > or = 80% of the time. Incidence rate ratio (IRR) of acute injuries and chronic complaints during play on NT and AT was calculated. There was no significant difference in the incidence of acute injuries between the 2 surfaces during training and competition. However, the AT group showed a significantly higher incidence of low back pain during training (IRR, 1.62; 95% confidence interval, 1.06-2.48). Early adolescence and prolonged training hours were factors associated with an increased incidence of chronic pain in the AT group. Adolescent players routinely training on AT for prolonged periods should be carefully monitored, even on AT conforming to new standards.

Direct uptake of soil nitrogen by mosses

Mosses are one of the most diverse and widespread groups of plants and often form the dominant vegetation in montane, boreal and arctic ecosystems. However, unlike higher plants, mosses lack developed root and vascular systems, which is thought to limit their access to soil nutrients. Here, we test the ability of two physiologically and taxonomically distinct moss species to take up soil- and wet deposition-derived nitrogen (N) in natural intact turfs using stable isotopic techniques (15N). Both species exhibited increased concentrations of shoot 15N when exposed to either soil- or wet deposition-derived 15N, demonstrating conclusively and for the first time, that mosses derive N from the soil. Given the broad physiological and taxonomic differences between these moss species, we suggest soil N uptake may be common among mosses, although further studies are required to test this prediction. Soil N uptake by moss species may allow them to compete for soil N in a wide range of ecosystems. Moreover, since many terrestrial ecosystems are N limited, soil N uptake by mosses may have implications for plant community structure and nutrient cycling. Finally, soil N uptake may place some moss species at greater risk from N pollution than previously appreciated.

Role of colonization in spatio-temporal patchiness of microgastropods in coralline turf habitat

The ability of benthic macrofauna to disperse and colonize new habitats throughout their life may contribute substantially to small-scale patchiness in abundances in different habitats. Microgastropods in coralline turf on rocky shores in Australia are very patchy in abundance at different spatio-temporal scales. They therefore represent an ideal assemblage for testing hypotheses about processes of colonization. Patterns and rates of colonization of 10 species of microgastropods were investigated in one intertidal habitat (coralline turf) in Botany Bay, New South Wales, Australia, using artificial substrata, which are considered to be a good mimic of natural coralline turfs. The experiment was designed to test the hypotheses that (1) patterns (abundance of colonizing individuals) and mode (juveniles vs. adults) of colonization depends on the proximity of a patch to a potential source of dispersing colonists (i.e. patch of natural coralline turf), (2) different species show different rates of colonization, and (3) patterns of succession are not repeatable among different patches of natural algae. Seven different plots (natural patches of coralline turf) were randomly chosen in the area of study. Artificial units (called patches) were placed at different distances around each plot (within the plot and 0, 50 or 100 cm away from the edge). Samples were collected 6, 13, and 27 days after the experiment started. Colonization was rapid (i.e. within 6 days) for most species. Pattern (number of individuals) and mode of colonization (adults vs. juveniles) varied among algal plots. Most species responded differently across patches causing no consistent patterns of colonization. Furthermore, patterns of colonization of artificial units were not always synchronous with, or in the same direction as, changes in abundances in the nearest algal plots, which themselves showed no consistent spatio-temporal pattern.

Influence of natural turfs and sods of single crop plants on mycelial development of three basidiomycetous ground fungi, preferentially associated with grassland

Mycelia of three basidiomycetous ground fungi, preferentially associated with grassland ecosystems, were inserted in the untreated soil of 2-1 glass jars. Natural turf pieces and artificial single-plant sods were brought into direct or indirect contact with the inoculated soil substrate to simulate the conditions of the edaphosphere of herbaceous plants to the fungal mycelia. With the exception of certain leguminous crops whose rhizosphere is highly stimulatory, all kinds of sods grafted on the edaphosphere soil served predominantly as a cover that limits the outflow of inhibitory volatiles, produced in the soil itself. With some exceptions, mycelial development was neither stimulated by the possibility of profiting exudates of the plant rhizosphere nor by volatile exhalations released from the sods. It is concluded that mycelial growth in edaphosphere soils is inhibited by restricted exchange of gaseous metabolites, arising from the soil itself, and by volatiles from the plant population and its decaying residues, among which carbon dioxide and substances, released from dead plant material, appear to be most effective. In addition, the fairy-ring fungus, Lepista nuda, proved to be a facultative necrotrophe to climatically weakened herbs with a poor utilization of the subjacent soil, whereas Agaricus porphyrizon and Agrocybe praecox utilized the subjacent soil with a certain preference to dead plant residues. Their pretended association with herbs is caused in the stimulation of fruiting, but not in mycelial growth, by the crop plants accompanied. Die Myzelien von drei bodenbewohnenden Basidiomyceten, die vorzugsweise mit Grasland assoziiert sind, wurden in die unbehandelte Erde von 2-1 Glasgefäßen eingesetzt. Natürliche Rasenstücke und angesäte Rasen mit einer einzelnen Pflanzenart dienten, in direktem oder indirektem Kontakt mit dem beimpften Erdsubstrat, der Simulation der Edaphosphärebedingungen grüner Pflanzen für das Pilzmyzel. Abgesehen von einigen Leguminosen mit hochgradig stimulierendem Rhizosphäreneffekt erwiesen sich alle Rasenarten nach dem Aufsetzen auf das Erdsubstrat vor allem als Hindernis für den Abtransport der flüchtigen Hemmstoffe, die in dem Erdsubstrat selbst produziert werden. Die Myzelentwicklung wurde, mit einigen Ausnahmen, weder von nicht flüchtigen noch von gasförmigen Ausscheidungen der Wurzelballen stimuliert. Es wird gefolgert, daß die Myzelentwicklung im Erdsubstrat der Edaphosphäre sowohl durch die eingeschränkte Abgabe von gasförmigen Metaboliten aus der Erde selbst wie auch von Exhalationen der lebenden Pflanzenpopulation und der verrottenden Pflanzenteile gehemmt ist. Als besonders effektiv erscheinen CO2 und Substanzen aus verrottendem pflanzlichen Material. Des weiteren erwies sich der Hexenringpilz Lepista nuda als fakultativ nekrotropher Parasit gegenüber klimatisch geschwächten grünen Pflanzen bei einer geringen Ausnutzung der Unterrasenerde. Im Gegensatz dazu verwerteten Agaricus porphyrizon und Agrocybe praecox in erster Linie das Erdsubstrat mit einer gewissen Einbeziehung von pflanzlichen Resten. Ihre scheinbare Bindung an grüne Pflanzen beruht auf der Förderung der Fruchtbildung, nicht aber des Myzelwachstums, im pflanzlichen Ökosystem.

Artificial substrates as a means of monitoring rocky shore cryptofauna

Two types of artificial substrate (nylon pan-scourers) have been shown to be highly efficient collectors of cryptofauna on rocky shores. The communities which develop in them are closely similar to those which develop in naturally occurring red algal turfs in Bantry Bay. The physical structure of the red algae appears to be the prime factor in determining the development of populations of most of the cryptofaunal species studied. In monitoring protocols artificial substrates of the types described here can be substituted for naturally occurring red algae in studies on shore cryptofauna obviating the necessity for destructive sampling of algae and facilitating statistical analysis by providing a standard ‘unit’ of substrate for comparative purposes. Furthermore, recruitment intensity of two species of gastropod has been shown to be similar in the artificial substrates to that in natural turfs