Mowing Frequency Research Articles

Salivary Cortisol, Equine Characteristics, and Management Factors Associated With Strongyle-Type Egg Shedding of Ohio Horses

Identification of factors associated with parasite infestation in horses could reduce frequency of anthelmintic administration and slow development of anthelmintic resistance. The study aim was to evaluate management factors, equine characteristics, and equine salivary cortisol concentrations for association with strongyle-type egg shedding levels. As immunocompromised horses appear to be more susceptible to parasite infestation, it was hypothesized that salivary cortisol concentration could be associated with parasite egg shedding. Saliva and fecal samples were collected from 200 horses across the state of Ohio. Equine management questionnaires were administered to barn managers. Fecal egg counts were performed with a modified Stoll method, and saliva samples were analyzed for salivary cortisol with an enzyme-linked immunosorbent assay (ELISA). A total of 24 variables were tested for association with fecal egg count results (dichotomized with 50 eggs per gram as a cutoff) using chi-square test of independence, Fisher's exact test, independent t-test, or Mann Whitney U test. The sample of horses was partitioned into tertiles based on salivary cortisol concentrations (i.e., low <0.052 µg/dL, medium 0.052–0.0712 µg/dL, and high >0.0712 µg/dL). Variables with P < .30 were analyzed for association with fecal egg count with multiple logistic regression. The final logistic regression model (P< .05) included horse age, horse salivary cortisol concentration, and pasture mowing frequency. Older horses had higher adjusted odds of having <50 EPG. Pasture mowing frequency of at least once per week increased the adjusted odds of <50 EPG. Horses with cortisol concentrations in the highest tertile had increased adjusted odds of having <50 EPG.

Influence of brush type and brushing frequency on putting green ball roll distance and turfgrass quality

AbstractGolf course managers manipulate cultural practices in preparation for golf tournaments to increase ball roll distance (BRD) for short periods of time. Brushing putting greens, thought to be a relatively minimally disruptive cultural practice using brush attachments mounted to mower units to vertically orient leaf blades prior to mowing, is growing in popularity despite little research validating purported benefits. The objectives of this study were to evaluate the impact of brush types (rotary, stiff push, and soft push brush) and brushing frequency (no brushing, once, or twice) combined with mowing on BRD and turfgrass quality on a creeping bentgrass (Agrostis stolonifera L.) putting green over a 2‐wk period. All brush types produced a &gt;20‐cm BRD reduction compared with no brushing by the end of the 14‐d trial in 2016 and 2017. Additionally, all brush types significantly lowered turfgrass quality, with the stiff brush resulting in unacceptable quality. Brushing and mowing once reduced BRD and turf quality compared with not brushing with daily mowing. Double brushing and mowing increased BRD equivalent to a single mowing without brushing, but turfgrass quality declined below acceptable thresholds. The results of this study indicate that brushing incorporated into a daily mowing regimen over a short 14‐d period decreases creeping bentgrass putting green BRD and quality. Increasing mowing frequency may eliminate BRD reductions from brushing, but golf course managers should practice caution when implementing brushing, especially over shorter periods of time when BRD and turfgrass quality expectations are increased.

Effects of mowing regimes on forage yield and crude protein of Leymus chinensis (Trin.) Tzvel in Songnen grassland

AbstractForage dry matter (DM) yield and its nutrient content are important in livestock nutrition; however, they have distinct, even opposite responses to mowing regimes. To optimize forage resources, two independent field experiments were conducted to determine effects of initial mowing time (15‐day intervals from May 15 to September 1) and mowing frequency (one to five times per year) on DM yield and nutritive value of Leymus chinensis (Trin.) Tzvel. The greatest cumulative DM yield (cDMY), pre‐mowing crude protein yield (pCPY) and cumulative crude protein yield (cCPY) were attained when initial mowing occurred from July 15 to August 15. The crude protein (CP) concentration of pDMY was higher, whereas fiber concentrations were lower, when initial mowing was from May 15 to June 15, with opposite results when the initial mowing was delayed (July 1 to September 30). When mowing three times annually, cDMY and cCPY of L. chinensis were higher (p &lt; .05) than with less frequent mowing. With more than three mowings, accumulated CP yield of L. chinensis was not significantly affected. With four or five yearly mowings, accumulated DM yield of L. chinensis decreased significantly compared to mowing one to three times. In conclusion, based on DM yield and nutritive value, the optimal initial mowing date ranged from July 15 to August 15, whereas optimal mowing frequency was three times yearly.

Influence of mowing height of cut and frequency for golf tournament preparation on putting green ball roll distance and turfgrass quality

AbstractIn preparation for golf course tournaments, turfgrass managers often seek increased ball roll distances on putting greens. The objective of this study was to determine the effect mowing height and frequency had on ball roll distance during simulated tournament conditions. Two 14‐d field experiments were conducted in 2015 and 2016 at the Joseph Valentine Turfgrass Research Center located in University Park, PA. Each study was conducted on a ‘Penn A‐4’ creeping bentgrass (Agrostis stolonifera L.; CBG) and annual bluegrass (Poa annua L.; ABG) putting green. Plots measured 1.5 m by 3.0 m and were arranged in a randomized complete block design with a 3 × 3 factorial treatment structure. For the main effect of height of cut (HOC), mowers were set to a bench height of 2.1 mm, 2.5 mm, and 2.9 mm. For mowing frequency (MF), plots were mowed once, twice, or four times per day. Single cut (SC) and double cut (DC) treatments were performed in the morning whereas double‐double cut (DD) treatments consisted of a DC in the morning and again in the afternoon. Ball roll distance (BRD) and turfgrass quality were assessed. Although a few interactions were present in the ABG study, the main effects of HOC and MF were significant on 79% and 82% rating dates, respectively. On CBG, the main effect of HOC and MF were significant on 89% and 86% of rating dates. For both species, turfgrass quality was reduced during the trial as HOC was reduced and MF was increased.

Carbon dioxide dynamics in a residential lawn of a tropical city

Turfgrass is an important component of the urban landscape frequently considered as an alternative land cover to offset anthropogenic CO2 emissions. However, quantitative information of the potential to directly remove CO2 from the atmosphere by turfgrass systems is lacking, especially in the tropics. Most assessments have considered the carbon accumulated by grass shoots and soil, but not the release of CO2 to the atmosphere by soil respiration (i.e., soil CO2 efflux). Here, we measured at high-temporal resolution (30-min) soil CO2 efflux, production, and storage rate for nearly three years in a residential lawn of Singapore. Furthermore, we quantified the carbon capture related to biomass production and CO2 emissions from fossil fuel consumption associated with maintenance activities (e.g., mowing equipment). Warm and humid conditions resulted in relatively constant rates of soil CO2 efflux, CO2 storage in soil, and aboveground biomass production (3370, 652, 1671 Mg CO2 km−2 yr−1; respectively), while the systematic use of mowing machinery emitted 27 Mg CO2 km−2 yr−1. Soil CO2 efflux and CO2 mowing emissions represent carbon losses to the atmosphere, while CO2 storage in soil and biomass productivity represent gains of carbon into the ecosystem. Under a steady state in which soil CO2 losses are only compensated by atmospheric CO2 uptake by photosynthesis, an ideal clipping waste disposal management, in which no CO2 molecule returns to the atmosphere (i.e., clippings are not burnt), and a 3-week mowing regime, this site can act as a sink of 2296 Mg CO2 km−2 yr−1. In the scenario of incinerating all clippings, the lawn acts as an emission source of 1046 Mg CO2 km−2 yr−1. Thus, management practices that reduce mowing frequency together with clipping disposal practices that minimize greenhouse gas emissions are needed to make urban lawns a potential natural solution to mitigate global environmental change.

Vacant lot soil degradation and mowing frequency shape communities of belowground invertebrates and urban spontaneous vegetation

Vacant land in legacy cities is increasingly recognized as a resource to support biodiversity and improve the quality of life for residents. However, the capacity for vacant lot parcels to provide these benefits is influenced by current management practices and landscape legacies of urbanization, which typically results in degraded soil quality. The role of soil quality in supporting urban biodiversity and ecosystem functions is often overlooked when developing sustainable urban planning initiatives. This study investigated how soil physical and chemical properties influenced the community of urban spontaneous vegetation and soil invertebrates found within vacant lots mowed monthly or annually in Cleveland, Ohio, USA. We found that soil chemical and physical properties were strong predictors of soil-dwelling invertebrates, as vacant lots highly contaminated with heavy metals had simplified communities. Moreover, increased mowing frequency resulted in greater biomass and blooms of urban spontaneous forbs. Importantly, vacant lots dominated by urban spontaneous forbs and high bloom abundances also were contaminated with heavy metals, with implications for herbivores and pollinators using these resources. Our findings indicate that conservation initiatives must consider landscape legacies from industrial activity and local habitat management practices in order to support above and belowground habitat quality of greenspaces in urban ecosystems. Understanding how soil degradation impacts habitat quality and the delivery of ecosystem services from vacant land is essential for legacy cities to maximize their environmental benefits.

Analysis of a radiation-induced dwarf mutant of a warm-season turf grass reveals potential mechanisms involved in the dwarfing mutant

Zoysia matrella [L.] Merr. is a widely cultivated warm-season turf grass in subtropical and tropical areas. Dwarf varieties of Z. matrella are attractive to growers because they often reduce lawn mowing frequencies. In this study, we describe a dwarf mutant of Z. matrella induced from the 60Co-γ-irradiated calluses. We conducted morphological test and physiological, biochemical and transcriptional analyses to reveal the dwarfing mechanism in the mutant. Phenotypically, the dwarf mutant showed shorter stems, wider leaves, lower canopy height, and a darker green color than the wild type (WT) control under the greenhouse conditions. Physiologically, we found that the phenotypic changes of the dwarf mutant were associated with the physiological responses in catalase, guaiacol peroxidase, superoxide dismutase, soluble protein, lignin, chlorophyll, and electric conductivity. Of the four endogenous hormones measured in leaves, both indole-3-acetic acid and abscisic acid contents were decreased in the mutant, whereas the contents of gibberellin and brassinosteroid showed no difference between the mutant and the WT control. A transcriptomic comparison between the dwarf mutant and the WT leaves revealed 360 differentially-expressed genes (DEGs), including 62 up-regulated and 298 down-regulated unigenes. The major DEGs related to auxin transportation (e.g., PIN-FORMED1) and cell wall development (i.e., CELLULOSE SYNTHASE1) and expansin homologous genes were all down-regulated, indicating their potential contribution to the phenotypic changes observed in the dwarf mutant. Overall, the results provide information to facilitate a better understanding of the dwarfing mechanism in grasses at physiological and transcript levels. In addition, the results suggest that manipulation of auxin biosynthetic pathway genes can be an effective approach for dwarfing breeding of turf grasses.

Effects of mowing frequency on abundance, genus diversity and community traits of soil nematodes in a meadow steppe in northeast China

Soil nematodes, as key bioindicators, play crucial roles in soil ecological process. Management of grasslands, such as meadow steppes in northeast China, is often done by mowing, which has an impact on soil nematode communities. However, few studies have explored effects of mowing frequency on the community structure and biomass of soil nematodes. Routine field and laboratory methods concerning plant community, soil properties, and soil nematodes were applied in this study. Soil nematode community structure was analyzed by using nonmetric multidimensional scaling (NMDS) and principal component analysis (PCA). The relationships between nematode genus and biotic and abiotic factors were analyzed by redundancy analysis (RDA). High mowing frequency significantly reduced abundance, biomass, and functional or metabolic regimes of soil nematodes in this ecosystem, whereas moderate mowing frequency enhanced those indices and regimes. Our findings showed that changing patterns in nematode indices across the mowing frequency conformed with the intermediate disturbance theory. Variations in soil nematode community were related to changes in belowground biomass, aboveground litter, soil available nitrogen and acidity, and the effects of edaphic and vegetal traits appeared to be trophic or genus-specific. This study has potential benefits for grassland restoration in northeast China.

Effect of Shading and Mowing on the Growth of Indonesia’s Native Zoysia grass in Silty Clay Soil

&lt;p&gt;In general, turfgrass grows well and forms high quality turf under full sun exposure. It is very difficult, however, to grow a warm season turfgrass under shaded condition. Zoysia grass is a popular warm season grass that commonly grow under full sun exposure condition. There are limited information regarding the growth response and turf quality of zoysia grass when grown under shaded condition. This study aims to observe the growth and quality of various zoysia grass local cultivars at different shading intensities and different mowing. This research was carried out using 10 zoysia grass cultivars planted in the rice fields’ vertisol clay with randomized complete block design. The shading used were control, shade-nets with 25% and 65% hole densities. Zoysia grass was fertilized using NPK; 4:1:3 and mowed three times. The results showed that plants without shade, 25% and 65% received on average solar irradiance of 25,141; 12,456 and 3,727 lux. The increase in shade level decreased the shoot fresh weight, dry weight, root dry weight and the plant height. Shading and frequent mowing effected the plant height. Mowing has more effect on plant height in 25% shading than in 65% shading. The increase in shading, in mowed grass showed increased plant height and decreased plant dry weight. Mowing three times can reduce plant height in all shades. The grasses under 25% shading resulted the highest plant dry weight; whereas and shading 65% resulted the lowest. Plant dry weight and uniformity of turf were affected by the cultivars.&lt;/p&gt;

Disentangling landscape and local drivers of ground-dwelling beetle community assembly in an urban ecosystem.

Community assembly is the process by which local communities are organized and maintained from the regional species pool. Understanding processes of insect assembly are of interest in "shrinking" cities where vacant land has become abundant as a result of protracted economic decline and population loss. Vacant land represents a viable conservation space for insects such as beetles that contribute to ecosystem services including pest suppression, decomposition, and nutrient cycling. However, the inherent heterogeneity of cities may pose challenges for beetle dispersal from source populations, while quality of the urban environment may constrain establishment. The objective of this study was to investigate the constraints to ground-dwelling beetle community assembly in vacant lots and pocket prairies of Cleveland, Ohio using a functional trait-based approach. Functional traits with a strong predictive capacity for ecological functions were measured on beetle species collected via pitfall traps. Assembly of beetle communities was primarily constrained by dispersal limitations to colonization. Over 93% of species found within treatments were capable of flight, and functional diversity of beetle communities was higher across all treatments than expected by chance. Once beetles colonized, successful establishment was influenced by heavy metal contamination and mowing frequency, with these disturbances shaping communities based on body size, antennae length, and origin. Colonization of dispersal-limited species could be facilitated by increasing connectivity among greenspaces in cities, while establishment could be enhanced by managing local environmental conditions. Understanding how insect communities are structured in urban ecosystems provides context for observed patterns of biodiversity, advances conservation efforts, and fosters ecosystem services.

Clonal growth strategies of Reynoutria japonica in response to light, shade, and mowing, and perspectives for management

Many of the most invasive plant species in the world can propagate clonally, suggesting clonality offers advantages that facilitate invasion. Gaining insights into the clonal growth dynamics of invasive plants should thus improve understanding of the mechanisms of their dominance, resilience and expansion. Belonging to the shortlist of the most problematic terrestrial invaders, Reynoutria japonica var. japonica Houtt. (Japanese knotweed) has colonized all five continents, likely facilitated by its impressive ability to propagate vegetatively. However, its clonal growth patterns are surprisingly understudied; we still do not know how individuals respond to key environmental conditions, including light availability and disturbance. To contribute to filling this knowledge gap, we designed a mesocosm experiment to observe the morphological variation inR. japonicagrowth in homogeneous or heterogeneous conditions of light stress (shade) and disturbance (mowing). Rhizome fragments were planted in the middle of large pots between two habitat patches that consisted of either one or a combination of the following three environmental conditions: full light without mowing, full light with frequent mowing, or shade without mowing. At the end of the experiment, biomass and traits related to clonal growth (spacer and rhizome lengths, number of rhizome branches, and number of ramets) were measured. After 14 months, all individuals had survived, even those frequently mowed or growing under heavy shade. We showed thatR. japonicaadopts a ‘phalanx’ growth form when growing in full light and a ‘guerrilla’ form when entirely shaded. The former is characteristic of a space-occupancy strategy while the latter is more associated with a foraging strategy. In heterogeneous conditions, we also showed that clones seemed to invest preferentially more in favorable habitat patches rather than in unfavorable ones (mowed or shaded), possibly exhibiting an escape strategy. These observations could improve the management of this species, specifically by illustrating how aggressive early control measures must be, by highlighting the importance of repeated mowing of entire stands, as this plant appears to compensate readily to partial mowing, and by informing on its potential responses towards the restoration of a cover of competitive native plants.

Two sides of the same coin: Does alien Impatiens balfourii fall into an ecological trap after releasing from enemies?

The evolution of increased competitive ability (EICA) hypothesis assumes that recently introduced populations of alien species are under low pressure from enemies, which allows them to reduce investment into defence and re-allocate the saved resources into the improvement of characteristics related to competitive abilities. We performed EICA tests to check if the low dispersal potential of Impatiens balfourii in Europe results from a limited evolution of its capability to release from enemies or from the low phenotypic plasticity of this trait.We tested habitat preferences of the species and compared the levels of enemy pressure in different habitats. This allowed us to determine if the tendency to occur along roadsides is manifested at the European scale in this species and if this preference is determined by a lower pressure of enemies in that habitat. It cannot be ruled out that occurrence along roads can be maladaptive for the species, and this habitat can potentially constitute an ecological trap due to frequent mowing.The study was carried out in six European populations differing in age and in five types of habitat. Enemy pressure was estimated by assessing leaf damage in adult plants and fungal pathogen load at the seed stage. We tested if the saved reserves are invested in the size and/or fertility of adult plants or in the seed quality. Activity of pollinators in different populations and habitats was also assessed.The majority of the results for adult plants indicate that the younger populations of I. balfourii release from enemy pressure better than the older ones. However, we found only weak support that the reserves previously spent on defence against natural enemies could be re-allocated into larger size or increased fertility. Only in the youngest population from Andorra was it largely confirmed. However, at seed stage, we found no support for the EICA assumptions in any of the populations. Thus, in general, the results of our study provide a fairly weak support for the EICA hypothesis.In comparisons between the habitats, we found that in five of the six populations, the species preferred roadsides, which was probably determined by the lower enemy pressure there. However, it cannot be excluded that this preference can be maladaptive and that this habitat can potentially constitute an ecological trap due to frequent mowing. Notably, the species was also abundant along streams, where the plants are less disturbed by human activities. This finding was particularly pronounced at the invasion forefront in Andorra, where the species was completely absent from roadsides. Therefore, we assume that unless control measures are undertaken, streamsides may be more important for the future invasion of I. balfourii than roadsides in that area.The ornamental value of I. balfourii makes it an obvious candidate to replace its banned invasive counterpart I. glandulifera in trade. The increase in popularity in trade and cultivation would inevitably lead to an increase in propagule pressure, which could be crucial for increasing the rate of invasion of I. balfourii on a large scale in Europe.

Management practices for optimal kikuyugrass quality and playing conditions

AbstractKikuyugrass [Cenchrus clandestinus (Hochst. ex Chiov.) Morrone] is considered either an invasive weed or the desired species on many golf courses, athletic fields, and other turf areas along coastal and inland California. A field study was conducted at the University of California, Riverside in 2012 and 2013 on ‘Whittet’ kikuyugrass mowed at 11 mm to identify management practices for producing sufficient turf quality and optimal playing conditions for golf course fairways and athletic fields. The study evaluated the effect of mowing frequency (three vs. six times per week), cultivation practice (verticutting vs. grooming), applications of trinexapac‐ethyl (TE), and nitrogen fertilization rates (96 vs. 240 kg N ha−1 yr−1) on turf quality, Normalized Difference Vegetation Index (NDVI), turf firmness, ball roll distance (BRD), and tensile strength. Mowing six times per week produced the highest turf quality turf during summer when kikuyugrass grows most vigorously, while trends were not clear for cultivation practice effects on turf visual quality. However, verticutting twice per year produced the least scalped and firmest turf, while decreasing BRD. Application of TE increased turf quality, NDVI, and BRD, but decreased tensile strength of the sward. Slightly higher turf quality was detected in plots fertilized at 240 kg N ha−1 yr−1 compared to those fertilized with the low N rate (6.0 vs. 5.8), but results do not seem to justify higher N fertility. Overall, results demonstrated that kikuyugrass available in California could benefit from high input management practices such as TE applications, high mowing frequency, and verticutting.

Water-Soluble Carbohydrates of Cool-Season Grasses: Prediction of Concentrations by Near-Infrared Reflectance Spectroscopy and Evaluation of Effects of Genetics, Management, and Environment

An excess of water-soluble carbohydrates (WSCs) can present a risk for horses prone to pasture-associated laminitis or some other metabolic conditions. Determining WSC concentrations in commonly grazed cool-season grasses, at different times of day and under different fertilization treatments, can help optimize grazing times and management strategies. The goals of this study were to develop a near-infrared reflectance spectroscopy (NIRS) calibration curve for WSC and to apply it to four cool-season grass species. Tall fescue, Kentucky bluegrass, orchardgrass, and perennial ryegrass (10 cultivars) were sampled every two to four weeks from plots with or without added nitrogen, in the morning and afternoon. WSCs were quantified colorimetrically for a sample subset, and these values were used to develop an NIRS calibration predicting WSC concentrations with 90% accuracy. An interaction of species, nitrogen treatment, time of day, and harvest date influenced WSC concentrations in 10 harvests (P = .040). A modest positive relationship was observed between photosynthetically active radiation and WSC concentration when morning and afternoon samples were included (r = 0.503; P = .024). On nine harvest dates, perennial ryegrass or tall fescue were highest in WSC. High-WSC cultivars included “Aberzest” and “Calibra” perennial ryegrass, “Ginger” Kentucky bluegrass, and “Bronson” and “Cajun II” tall fescue. Water-soluble carbohydrates did not exceed 150 g/kg freeze-dried weight, possibly due to assay method, sampling times, or defoliation. The results suggest that minimizing WSC intake for horses may be possible by cultivar choice, grazing time, or mowing frequency.

An Effective Way to Map Land-Use Intensity with a High Spatial Resolution Based on Habitat Type and Environmental Data

Mapping and monitoring agricultural land-use intensity (LUI) changes are essential for understanding their effects on biodiversity. Current land-use models provide a rather coarse spatial resolution, while in-situ measurements of LUI cover only a limited extent and are time-consuming and expensive. The purpose of this study is to evaluate the feasibility of using habitat type, topo-climatic, economic output, and remote-sensing data to map LUI at a high spatial resolution. To accomplish this, we first rated the habitat types across the agricultural landscape in terms of the amount and frequency of fertiliser input, pesticide input, ploughing, grazing, mowing, harvesting, and biomass output. We consolidated these ratings into one LUI index per habitat type that we then related to topo-climatic, economic output, and remote-sensing predictors. The results showed that the LUI index was strongly related to plant indicator values for mowing tolerance and soil nutrient content and to aerial nitrogen deposition, and thus, is an adequate index. Topo-climatic, and, to a smaller extent, economic output and remote-sensing predictors, proved suitable for mapping LUI. Large- to medium-scale patterns are explained by topo-climatic predictors, while economic output predictors explain medium-scale patterns and remote-sensing predictors explain local-scale patterns. With the fine-scale LUI map produced from this study, it is now possible to estimate within unvarying land-use classes, the effect on agrobiodiversity of an increase in LUI on fertile and accessible lands and of a decrease of LUI by the abandonment of marginal agricultural lands, and thus, provide a valuable base for understanding the effects of LUI on biodiversity. Due to the worldwide availability of remote-sensing and climate data, our methodology can be easily applied to other countries where habitat-type data are available. Given their low explanatory power, economic output variables may be omitted if not available.

Effects of frequent fire and mowing on resprouting shrubs of Florida scrub, USA

BackgroundResprouting is an effective strategy for persistence of perennial plants after disturbances such as fire. However, can disturbances be so frequent that they limit resprouting? We examined the effects of fire and mowing frequency on eight species of resprouting shrubs in Florida scrub, USA, using a factorial field experiment. We burned or mowed plots at four disturbance return intervals (DRI): either annually, biennially, every three years, or once in six years (with all plots being treated in the sixth year to control for time since disturbance). We analyzed plant growth responses (height, aboveground biomass, number of stems) based on sampling pre treatment, and six months, one year, two years, and four years post-treatment. We also measured non-structural carbohydrates (NSC) and soil properties to evaluate these factors as potential drivers of resprouting responses.ResultsFire temperatures were hot (mean maxima 414 to 698 °C among burn days), typical of larger fires in Florida scrub. Plant biomass and heights were affected by DRI (being suppressed by frequent disturbance, especially initially) and varied among species with palmettos recovering biomass faster, and species within the same genus generally showing similar responses. Biomass recovery in mown versus burned treatments showed comparable effects of DRI and similar trajectories over time. Numbers of stems were affected by DRI, disturbance type, and species, and increased after disturbances, especially with less frequent disturbances and mowing, and subsequently declined over time. NSC concentrations varied among species and over time and were positively related to biomass. One year post disturbance, soil moisture and organic matter content were higher in mown plots, while pH was higher in burned plots. Given the slightly lower elevation of the mown plots, we interpreted these differences as site effects. Soil properties were not affected by DRI and did not affect biomass responses.ConclusionsAlthough very frequent disturbances reduced shrub growth responses, the magnitude of plant responses was modest and the effects temporary. Because resprouting shrubs in Florida scrub appear resilient to a range of disturbance return intervals, frequent fire or mowing can be used effectively in restorations.

Traditional orchard Management in the Western Carpathians (Slovakia): evolution between 1955 and 2015

Changes in management regime in recent decades have significantly contributed to threats to traditional European agricultural systems, but this has not been studied sufficiently. This paper examines these changes by considering the agroforestry system of traditional orchards in the Myjava-White Carpathian scattered settlement region (Slovakia) between 1955 and 2015. Data on orchard management was collected using structured interviews with 116 local residents in 2015 – 2016. Information was sought on management practices in the following years: 1955, when collectivisation was just beginning, and traditional practices were dominant; 1975, when collectivisation had finished; 1990, when the socialist period had ended; 2000, after the subsequent socio-political changes; and 2015, reflecting the current state of affairs. Traditional orchard management included mowing, grazing, ploughing, fertilising, and litter raking. Management had changed in 75.8 % of the studied orchards between 1955 and 2015. These changes included especially change in frequency of mowing, a drastic decline in grazing, and cessation of ploughing. Also, understorey mulching appeared as a new practice in 1990 and has been growing steadily more common since that time. Our study confirms an escalating risk of extinction of these valuable habitats, whose management is affected by socio-economic changes.

Biennial Mowing Maintains the Biomass and Functional Diversity of Semi-Arid Grassland

Understanding the functional diversity relationship between biomass and plants is a key issue in biodiversity–ecosystem functionality and the utility of grassland. We conducted a five-year mowing experiment to examine the effects of the mowing frequency on biomass, plant species, and functional diversity of a natural plant community in a semiarid region of Inner Mongolia. A secondary objective was to test whether unmowed refuge areas within plots would mitigate the disturbance effect of mowing. The result showed that mowing disturbance reduced biomass by the greatest amount with mowing once every year (M1) and the least with M2. The biomass composition of M2 consisted of a greater mass of perennial species than in the other mowing treatments but was equivalent to the control (CK). However, mowing disturbances increased the plant species richness and M2 had the largest number of species. The community-weighted means (CWM) indices indicated that M2 produced the least detrimental effects on the grassland. Retaining unmowed refuge areas appeared to be ineffective in promoting beneficial community traits under M1 mowing regimes. Based on our results, we recommend that the semi-arid grassland be mowed every other year in order to optimize sustainable production.

Distribution of Medically Relevant Antibiotic Resistance Genes and Mobile Genetic Elements in Soils of Temperate Forests and Grasslands Varying in Land Use.

Antibiotic-resistant pathogens claim the lives of thousands of people each year and are currently considered as one of the most serious threats to public health. Apart from clinical environments, soil ecosystems also represent a major source of antibiotic resistance determinants, which can potentially disseminate across distinct microbial habitats and be acquired by human pathogens via horizontal gene transfer. Therefore, it is of global importance to retrieve comprehensive information on environmental factors, contributing to an accumulation of antibiotic resistance genes and mobile genetic elements in these ecosystems. Here, medically relevant antibiotic resistance genes, class 1 integrons and IncP-1 plasmids were quantified via real time quantitative PCR in soils derived from temperate grasslands and forests, varying in land use over a large spatial scale. The generated dataset allowed an analysis, decoupled from regional influences, and enabled the identification of land use practices and soil characteristics elevating the abundance of antibiotic resistance genes and mobile genetic elements. In grassland soils, the abundance of the macrolide resistance gene mefA as well as the sulfonamide resistance gene sul2 was positively correlated with organic fertilization and the abundance of aac(6′)-lb, conferring resistance to different aminoglycosides, increased with mowing frequency. With respect to forest soils, the beta-lactam resistance gene blaIMP-12 was significantly correlated with fungal diversity which might be due to the fact that different fungal species can produce beta-lactams. Furthermore, except blaIMP-5 and blaIMP-12, the analyzed antibiotic resistance genes as well as IncP-1 plasmids and class-1 integrons were detected less frequently in forest soils than in soils derived from grassland that are commonly in closer proximity to human activities.

Plant community assembly in suburban vacant lots depends on earthmoving legacy, habitat connectivity, and current mowing frequency.

In suburban regions, vacant lots potentially offer significant opportunities for biodiversity conservation. Recently, in Japan, due to an economic recession, some previously developed lands have become vacant. Little is known, however, about the legacy of earlier earthmoving, which involves topsoil removal and ground leveling before residential construction, on plant community composition in such vacant lots. To understand (dis)assembly processes in vacant lots, we studied 24 grasslands in a suburban region in Japan: 12 grasslands that had experienced earthmoving and 12 that had not. We surveyed plant community composition and species richness, and clarified compositional turnover (replacement of species) and nestedness (nonrandom species loss) by distance‐based β‐diversities, which were summarized by PCoA analysis. We used piecewise structural equation modeling to examine the effects of soil properties, mowing frequency, past and present habitat connectivities on compositional changes. As a result, past earthmoving, mowing frequency, soil properties, and past habitat connectivity were found to be the drivers of compositional turnover. In particular, we found legacy effects of earthmoving: earthmoving promoted turnover from native grassland species to weeds in arable lands or roadside by altering soil properties. Mowing frequency also promoted the same turnover, implying that extensive rather than intensive mowing can modify the negative legacy effects and maintain grassland species. Decrease in present habitat connectivity marginally enhanced nonrandom loss of native grassland species (nestedness). Present habitat connectivity had a positive effect on species richness, highlighting the important roles of contemporary dispersal. Our study demonstrates that community assembly is a result of multiple processes differing in spatial and temporal scales. We suggest that extensive mowing at local scale, as well as giving a high conservation priority to grasslands with high habitat connectivity at regional scale, is the promising actions to maintain endangered native grassland species in suburban landscapes with negative legacy effects of earthmoving.