scholarly journals Introducing ground cover management in pesticide emission modeling

2021 ◽  
Author(s):  
Céline Gentil‐Sergent ◽  
Claudine Basset‐Mens ◽  
Christel Renaud‐Gentié ◽  
Charles Mottes ◽  
Carlos Melero ◽  
...  
Keyword(s):  
Ground Cover ◽  
Emission Modeling

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.).

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.

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

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.

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