Lawn

This four-year field study evaluated the influence of grass species and endophyte infection on weed density and cover in stands of tall fescue and perennial ryegrass managed as low maintenance lawns. Bare ground, turfgrass cover, and weed cover varied over time with grass species. Stands of tall fescue generally had more bare ground, greater weed cover, and less grass cover than stands of perennial ryegrass during the first year following seeding. However, this trend was reversed over time with stands of perennial ryegrass having more bare ground, more weed cover, and less turfgrass cover compared to stands of tall fescue after four years. The influence of endophyte infection was much weaker than predicted having a significant negative influence only on cover by one weed species, Cerastium vulgatum. Results indicated that grass species and fungal endophyte infection may influence patterns of weed occurrence in low maintenance lawns, although the influence of grass species is likely far more important in this regard. Observed patterns in plant cover and density mainly reflected establishment and growth characteristics of the two primary grass species planted. Published by Elsevier B.V.

Question: How well does the use of NDVI predict secondary productivity at landscape scales? What is the influence of vegetation quality and phenology over secondary productivity? Location: Magellanic steppe in Tierra del Fuego, Argentina. (52°45' to 54° S, 68°15' to 67°30' W). Methods: Monthly and yearly integrated NDVI (NDVI-I) were calculated from AVHRR/NOAA 14, as estimators of phenology and aerial net primary productivity respectively. From a vegetation map we obtained the proportional cover of different physiognomic types and calculated the palatable fraction (forage) productivity that were used as estimators of vegetation quality. Data were analysed through correlations and regressions. Results: NDVI-I was not related with secondary productivity indices, while December and annual maximum NDVI, proportion of lawns and tussock grasslands and forage productivity were positively related with secondary productivity. A negative relationship was found between the proportion of heathlands and secondary productivity, but a positive relationship between heathland's proportion and NDVI-I was found. Conclusions: NDVI-I is not a good predictor of secondary productivity at the scale of our study. These results could be due to: (1) NDVI-I is not related to primary productivity and (2) primary productivity is not related to secondary productivity.

Urban green spaces provide important ecosystem services, such as amenity, biodiversity, productivity, climate amelioration, hydrological and biogeochemical cycling. Intensively managed urban gardens can sequester carbon through vegetation growth and soil C increase, but may experience nitrous oxide (N2O) emissions and reduced soil methane (CH4) uptake from irrigation and fertiliser use. Soil atmosphere exchange of N2O, CH4 and carbon dioxide (CO2) was measured in lawn and wood chip mulched garden areas in Melbourne, Australia in winter, spring and summer under various water and fertiliser regimes. Gas exchange before and after lawn fertiliser application was measured continuously for three weeks using an automated chamber system. Applying fertiliser led to a peak N2O emission of >60 μg N m−2 h−1, but overall only weekly irrigation (10 mm) significantly increased mean soil N2O emissions above that in other treatments. Under mulch, mean soil N2O emissions (14.0 μg N m−2 h−1) were significantly smaller than from irrigated lawn (27.9 μg N m−2 h−1), whereas mean soil CH4 uptake under mulch (−30.7 μg C m−2 h−1) was significantly greater (p < 0.01) than in any lawn treatment. Lawns were either a weak CH4 sink or source. Soil C density (0–25 cm) under mulch (12.5 kg C m−2) was greater that under lawn (8.0 kg C m−2). On a carbon dioxide equivalent (CO2-e) basis, soil N2O emissions offset the benefits of soil CH4 uptake. Mulched garden areas provide greatest C sequestration potential in soil and vegetation and the smallest non-CO2 emissions, as soil CH4 uptake offsets a large fraction of soil N2O emissions. Results of this study suggest that reducing the irrigation and fertiliser application to lawns can help mitigate GHG emissions from urban garden systems, and increasing the area of mulched perennial garden beds can also provide net GHG benefits; however, this needs to be tested in other garden systems with different soil types and environmental conditions.

Understanding of ecological differences among ur-ban land covers can guide the sustainable man-agement of urbanized landscapes for conservation of ecosystem services. The objective of our study was to compare ecosystem properties at the aboveground–belowground ...

Globalisation and urbanisation are driving the worldwide homogenisation of urban landscapes. The flora and fauna of cities in different parts of the world are very similar, irrespective of geography and climate. One of the most powerful symbols of modern urban landscapes is the lawn. There are just a few management options for urban lawns, regardless of how they are used and where in the city they are situated. Today, lawns occupy much of the green open spaces in cities (70-75%) and are located in private front and rear gardens, public parks, cemeteries, golf courses and along roads. Most people in the Western world view lawns as a 'natural' and even compulsory element of the urban landscape, without questioning their social, symbolic, ecological or aesthetic values. In this article we discuss the conceptual framework and methodological approaches being used in an ongoing transdisciplinary collaboration project including stakeholders to study lawns in Sweden as a social and ecological phenomenon. The overall aim is to understand the role of lawns in sustainable urban planning, design and management. The transdisciplinary approach allows us to exchange knowledge between scientific disciplines in order to influence the studies within each subject throughout the project and to achieve a multi-dimensional understanding of the lawn as a phenomenon. The involvement and close collaboration of stakeholders in the project allows us to obtain first-hand information on planning issues connected to lawns and existing planning data from cities and to focus on true implementation aspects rather than just theoretical recommendations.

Lawns are a long-established component of domestic gardens but could now become a vehicle by which climate change becomes 'real' for many urban and suburbanised people. Within this context, field trials were set up on lawns in Cambridge University Botanic Garden with replicate plots having combinations of induced warming to þ3 C and drought conditions together with varying fertiliser and grass clippings managements. Lawn resilience was assessed using a chroma meter to measure browning and greening. All replicate plots recovered to pre-drought green colour after a 3-month induced summer drought. The use of fertiliser in spring lead to greater susceptibility to browning during drought and slower recovery but post-drought fertiliser application tended to aid recovery. Returning grass clippings to the surface led to an increased resistance to browning during drought, aided faster recovery and lowered levels of nitrate leaching. We conclude that under the conditions tested, the lawn plots showed a high degree of physical resilience which could be enhanced by management approaches.

Soil organic carbon (SOC) sequestration and the impact of carbon (C) cycling in urban soils are themes of increasing interest. A model was developed to investigate the potential of C sequestration in home lawns. The model contrasted gross C sequestered versus the hidden C costs (HCC) associated with typical lawn maintenance practices. The potential of SOC sequestration for U.S. home lawns was determined from SOC sequestration rates of turfgrass and grasslands. Net SOC sequestration in lawn soils was estimated using a simple mass balance model derived from typical homeowner lawn maintenance practices. The average SOC sequestration rate for U.S. lawns was 46.0 to 127.1 g C/m2/year. Additional C sequestration can result from biomass gains attributable to fertilizer and irrigation management. Hidden C costs are the amount of energy expended by typical lawn management practices in grams of carbon equivalents (CE)/m2/year and include practices including mowing, irrigating, fertilizing, an...

Use of PRE herbicides for control of annual grassy weeds during commercial sod production has been limited. Research was conducted from 2010 to 2013 evaluating the effects of pendimethalin (3.36 kg ai ha−1), dithiopyr (0.56 kg ai ha−1), prodiamine (0.6 kg ai ha−1), oxadiazon (3.36 kg ai ha−1), prodiamine + sulfentrazone (0.84 + 0.41 kg ai ha−1), dimethenamid-P (1.68 kg ai ha−1), and indaziflam (0.03 and 0.05 kg ai ha−1) applications at sprigging on the establishment rate and tensile strength of ‘Tifway&#39; hybrid bermudagrass sod at harvest (377 d after sprigging). All herbicides increased the days required to reach 50% hybrid bermudagrass cover compared with the nontreated control. Days required to reach 50% hybrid bermudagrass cover were lowest for oxadiazon and prodiamine (39 to 44 d), greatest for both rates of indaziflam (65 to 141 d), with dimethenamid-P, prodiamine plus sulfentrazone, pendimethalin, and dithiopyr ranking intermediate (45 to 63 d). Both rates of indaziflam re...

We compared the National Land Cover Database (NLCD) 2001 land cover, impervious, and canopy data products to land cover data derived from 0.6-m resolution three-band digital imagery and ancillary data. We conducted this comparison at the 1 km 2 , 9 km 2 , and gauged watershed scales within the Baltimore Ecosystem Study to determine the usefulness and limitations of the NLCD in heterogeneous urban to exurban environments for the determination of land-cover information for hydrological applications. Although the NLCD canopy and impervious data are significantly correlated with the high-resolution land-cover dataset, both layers exhibit bias at <10 and >70% cover. The ratio of total impervious area and connected impervious area differs along the range of percent imperviousness -at low percent imperviousness, the NLCD is a better predictor of pavement alone, whereas at higher percent imperviousness, buildings and pavement together more resemble NLCD impervious estimates. The land-cover composition and range for each NLCD urban land category (developed open space, low-intensity, medium-intensity, and high-intensity developed) is more variable in areas of low-intensity development. Fine-vegetation land-cover ⁄ lawn area is incorporated in a large number of land use categories with no ability to extract this land cover from the NLCD. These findings reveal that the NLCD may yield important biases in urban, suburban, and exurban hydrologic analyses where land cover is characterized by fine-scale spatial heterogeneity.

1. Grazing lawns are short grassland areas where intense grazing maintains grass in an early growth stage. These areas represent a source of high-quality forage for herbivores. However, as herbivores continually remove nearly all the newly accumulated biomass, instantaneous resource availability depends on the dynamics of grass growth. 2. In this study, we investigate how production and consumption inside grazing lawns are synchronized. We then explore how that synchronization affects the ability of large herbivores to use these lawns. We also provide a critical comparison between grazing lawns and intensively managed grasslands in livestock farms. 3. We investigated vegetation production and herbivore grazing activity during a wet and a dry season using clipping experiments and direct observation in two grazing lawns in a South African savanna. 4. Weekly total grazing activity by unit area was strongly and positively related to short-term primary production. This indicates a close synchronization between these two processes. In contrast, grazing activity was poorly related to standing biomass. Primary production had a threshold response to the weekly pattern of rainfall, implying a stochastic dynamics of grass growth. 5. The dynamics of grass production and consumption of grazing lawns is similar to the one of continuously stocked grazing systems from intensively managed grasslands. But the mechanisms regulating the two systems lead to different equilibrium points between production and consumption. The two systems also have opposed nutritional functions within the animal diet. 6. Synthesis. The close synchronization between resource production and consumption inside grazing lawns indicates that instantaneous resource availability is a direct function of the short-term rate of grass growth. In tropical savannas, the main source of variability of lawn grass primary productivity is the stochastic nature of short-term rainfall. As a result, herbivores' ability to use grazing lawns is poorly predictable in time. This has important consequences on the degree of information herbivores can use in the elaboration of their foraging strategies, and on the potential interest of grazing lawns.

BACKGROUND: Turfgrass management practices, especially the use of chemical pesticides, may be detrimental to beneficial arthropods such as predators and decomposers. However, little is known about the impact of other practices or pest control products on these beneficials. The impact of four different management regimes, consisting of synthetic pesticide cover sprays or combinations of more targeted applications of natural pesticides, on selected groups of non-targeted arthropods in lawns of different age was studied over 3 years. The short-term effect of diazinon and carbaryl on Carabidae and Collembola was also evaluated.

1. Plant-microbe competition for available nitrogen (N) has been suggested to be an important mechanism controlling N limitation of plants in a variety of ecosystems. However, spatio-temporal patterns of competition between plants and microbes for soil N remain unclear. 2. Short-term 15 N tracer experiments were conducted during a growing season (July, August and September) in an alpine meadow on the Tibetan Plateau to unravel spatio-temporal patterns of plant-microbe competition for NH 4 + and NO 3 )