IDENTIFICATION OF SOIL ERODIBILITIES FOR AN APPLICATION OF WEPP MODEL WITH BIOLOGICAL GROUND COVER BY ALGAE AND FUNGI

2018 ◽  
Vol 74 (5) ◽  
pp. I_233-I_239
Author(s):  
Rui KOJIMA ◽  
Kazutoshi OSAWA ◽  
Maki MATSUURA ◽  
Hisako FUJISAWA ◽  
Mineto TOMISAKA ◽  
...  
Keyword(s):  
Ground Cover

Multitemporal distribution analysis of Dodonaea viscosa (L.) Jacq. by remote sensing in Durango, Mexico

2020 ◽  
Vol 13 (8) ◽  
Author(s):  
Marco, A. Márquez-Linares ◽  
Jonathan G. Escobar--Flores ◽  
Sarahi Sandoval- Espinosa ◽  
Gustavo Pérez-Verdín
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Design Methodology ◽  
Supervised Classification ◽  
Satellite Images ◽  
Ground Cover ◽  
Distribution Analysis ◽  
Dodonaea Viscosa ◽  
Artificial Neural ◽  
Landsat Satellite

Objective: to determine the distribution of D. viscosa in the vicinity of the Guadalupe Victoria Dam in Durango, Mexico, for the years 1990, 2010 and 2017.Design/Methodology/Approach: Landsat satellite images were processed in order to carry out supervised classifications using an artificial neural network. Images from the years 1990, 2010 and 2017 were used to estimate ground cover of D. viscosa, pastures, crops, shrubs, and oak forest. This data was used to calculate the expansion of D. viscosa in the study area.Results/Study Limitations/Implications: the supervised classification with the artificial neural network was optimal after 400 iterations, obtaining the best overall precision of 84.5 % for 2017. This contrasted with the year 1990, when overall accuracy was low at 45 % due to less training sites (fewer than 100) recorded for each of the land cover classes.Findings/Conclusions: in 1990, D. viscosa was found on only five hectares, while by 2017 it had increased to 147 hectares. If the disturbance caused by overgrazing continues, and based on the distribution of D. viscosa, it is likely that in a few years it will have the ability to invade half the study area, occupying agricultural, forested, and shrub areas

Evoluzione della copertura vegetale in aree alpestri del Canton Ticino nel periodo 1971–2001 | Evolution of Vegetation Cover in the Alpine Regions of Canton Tessin: 1971–2001

2004 ◽  
Vol 155 (7) ◽  
pp. 284-289 ◽  
Author(s):  
Pietro Stanga ◽  
Niklaus Zbinden
Keyword(s):  
Initial Conditions ◽  
Ground Cover ◽  
Climatic Conditions ◽  
Human Pressure ◽  
Aerial Photos ◽  
Alpine Regions ◽  
Subsequent Decrease ◽  
Site Fertility ◽  
Strong Expansion ◽  
Evolution Of Vegetation

The retrospective study based on aerial photos (1971–2001) of the Canton Tessin made it possible to measure and analyze the evolution of the vegetation of eleven Alpine zones. The analysis shows a strong expansion of the arborescent vegetation and, at the same time, a decrease in other forms of ground cover (bush, shrub, meadow and unproductive spaces). Analysis of the data gives rise to the conjecture that the strong evolutionary dynamism evidenced by the areas under investigation is a result of the vast clearings carried out in past centuries to create pastures. Following the subsequent decrease in human pressure, nature today is attempting to rebalance the level of the biomass. These processes manifest themselves in different ways and with various intensity, depending on the interaction of numerous factors (e.g. climatic conditions, site fertility, initial conditions, evolution of anthropological pressure, etc.).

Genetic Diversity of Ground Cover Plant Potentilla anserina L.

2010 ◽  
Vol 30 (4) ◽  
pp. 473-479
Author(s):  
Rui-Jun MA ◽  
Jian-Ying LU
Keyword(s):  
Genetic Diversity ◽  
Ground Cover ◽  
Potentilla Anserina ◽  
Ground Cover Plant

Long-term Performance of Asian Pear Trees in Maryland

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 548b-548
Author(s):  
C.S. Walsh ◽  
A.J. Barton ◽  
M. Newell ◽  
G.R. Welsh
Keyword(s):  
Ground Cover ◽  
Organic Production ◽  
Alternative Crop ◽  
Asian Pear ◽  
Marketable Fruit ◽  
Long Term Performance ◽  
Organic Fruit ◽  
Term Performance ◽  
Direct Market

Three Asian pear plantings were set during the past decade. Plantings included an initial cultivar planting on OH × F rootstock, the SE Zonal planting, and a rootstock by cultivar factorial. Fireblight susceptibility and survival were assessed in the first two plantings following a summer hailstorm. Trees were compared to Magness, a blight-tolerant buttery pear. Shin Li, Daisu Li, Shinsui, and Olympic were more resistant than Magness, while Chojuro and Niitaka were nearly as tolerant. Eleven other cultivars showed greater field-susceptibility. The most-susceptible cultivars were Ya Li and Ts'e Li. The third planting, which was managed “organically,” was set at a different University farm. Trees there were precocious and productive. A high percentage of marketable fruit was picked from that planting over a 4-year period. Fireblight damage in this planting was low, despite its “organic” production. Limited damage was attributed to early bloom date, ground cover management, and a lack of insect vectors to transmit the bacteria. Hosui, Seuri and Ts'e Li produced large-sized fruit. Shinko, 20th Century, Ya Li and Shinseiki fruit were too small to be marketable without heavy hand-thinning. Asian pears are an interesting alternative crop which are suited to direct-market enterprises or to specialty growers interested in producing organic fruit in the mid-Atlantic region.

Ecosystem modeling of methane and carbon dioxide fluxes for boreal forest sites

2001 ◽  
Vol 31 (2) ◽  
pp. 208-223 ◽  
Author(s):  
Christopher Potter ◽  
Jill Bubier ◽  
Patrick Crill ◽  
Peter Lafleur
Keyword(s):  
Carbon Dioxide ◽  
Boreal Forest ◽  
Land Surface ◽  
Net Primary Production ◽  
Ground Cover ◽  
Methane Flux ◽  
Growing Season ◽  
Ecosystem Model ◽  
Heat Fluxes ◽  
Water Levels

Predicted daily fluxes from an ecosystem model for water, carbon dioxide, and methane were compared with 1994 and 1996 Boreal Ecosystem–Atmosphere Study (BOREAS) field measurements at sites dominated by old black spruce (Picea mariana (Mill.) BSP) (OBS) and boreal fen vegetation near Thompson, Man. Model settings for simulating daily changes in water table depth (WTD) for both sites were designed to match observed water levels, including predictions for two microtopographic positions (hollow and hummock) within the fen study area. Water run-on to the soil profile from neighboring microtopographic units was calibrated on the basis of daily snowmelt and rainfall inputs to reproduce BOREAS site measurements for timing and magnitude of maximum daily WTD for the growing season. Model predictions for daily evapotranspiration rates closely track measured fluxes for stand water loss in patterns consistent with strong controls over latent heat fluxes by soil temperature during nongrowing season months and by variability in relative humidity and air temperature during the growing season. Predicted annual net primary production (NPP) for the OBS site was 158 g C·m–2 during 1994 and 135 g C·m–2 during 1996, with contributions of 75% from overstory canopy production and 25% from ground cover production. Annual NPP for the wetter fen site was 250 g C·m–2 during 1994 and 270 g C·m–2 during 1996. Predicted seasonal patterns for soil CO2 fluxes and net ecosystem production of carbon both match daily average estimates at the two sites. Model results for methane flux, which also closely match average measured flux levels of –0.5 mg CH4·m–2·day–1 for OBS and 2.8 mg CH4·m–2·day–1 for fen sites, suggest that spruce areas are net annual sinks of about –0.12 g CH4·m–2, whereas fen areas generate net annual emissions on the order of 0.3–0.85 g CH4·m–2, depending mainly on seasonal WTD and microtopographic position. Fen hollow areas are predicted to emit almost three times more methane during a given year than fen hummock areas. The validated model is structured for extrapolation to regional simulations of interannual trace gas fluxes over the entire North America boreal forest, with integration of satellite data to characterize properties of the land surface.

scholarly journals 115 Nitrogen fertilizer effects on above ground sward characteristics and beef heifer performance from native warm-season grass blends

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 26-27
Author(s):  
Caroline Chappell ◽  
Landon Marks ◽  
Katie Mason ◽  
Mary K Mullenix ◽  
Sandra L Dillard ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Warm Season ◽  
Ground Cover ◽  
Application Rate ◽  
Light Interception ◽  
Botanical Composition ◽  
Forage Production ◽  
Beef Heifers ◽  
Fertilizer Application Rate ◽  
Canopy Light Interception

Abstract A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P < 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.

scholarly journals A review of modelling methodologies for flood source area (FSA) identification

2021 ◽  
Author(s):  
Amrie Singh ◽  
David Dawson ◽  
Mark Trigg ◽  
Nigel Wright
Keyword(s):  
Flood Risk ◽  
Risk Mitigation ◽  
Ground Cover ◽  
Source Area ◽  
Urban Environments ◽  
Weather Patterns ◽  
Complex Process ◽  
Average Annual Loss ◽  
Flood Source ◽  
Modelling Approaches

AbstractFlooding is an important global hazard that causes an average annual loss of over 40 billion USD and affects a population of over 250 million globally. The complex process of flooding depends on spatial and temporal factors such as weather patterns, topography, and geomorphology. In urban environments where the landscape is ever-changing, spatial factors such as ground cover, green spaces, and drainage systems have a significant impact. Understanding source areas that have a major impact on flooding is, therefore, crucial for strategic flood risk management (FRM). Although flood source area (FSA) identification is not a new concept, its application is only recently being applied in flood modelling research. Continuous improvements in the technology and methodology related to flood models have enabled this research to move beyond traditional methods, such that, in recent years, modelling projects have looked beyond affected areas and recognised the need to address flooding at its source, to study its influence on overall flood risk. These modelling approaches are emerging in the field of FRM and propose innovative methodologies for flood risk mitigation and design implementation; however, they are relatively under-examined. In this paper, we present a review of the modelling approaches currently used to identify FSAs, i.e. unit flood response (UFR) and adaptation-driven approaches (ADA). We highlight their potential for use in adaptive decision making and outline the key challenges for the adoption of such approaches in FRM practises.

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