Soil-Surface Characteristics, Microtopography and Proximity to Mature Shrubs: Effects on Survival of Several Cohorts of Atriplex Vesicaria Seedlings

Abstract We present the MARAS (Environmental Monitoring of Arid and Semiarid Regions) dataset, which stores vegetation and soil data of 426 rangeland monitoring plots installed throughout Patagonia, a 624.500 km2 area of southern Argentina and Chile. Data for each monitoring plot includes basic climatic and landscape features, photographs, 500 point intercepts for vegetation cover, plant species list and biodiversity indexes, 50-m line-intercept transect for vegetation spatial pattern analysis, land function indexes drawn from 11 measures of soil surface characteristics and laboratory soil analysis (pH, conductivity, organic matter, N and texture). Monitoring plots were installed between 2007 and 2019, and are being reassessed at 5-year intervals (247 have been surveyed twice). The MARAS dataset provides a baseline from which to evaluate the impacts of climate change and changes in land use intensity in Patagonian ecosystems, which collectively constitute one of the world´s largest rangeland areas. This dataset will be of interest to scientists exploring key ecological questions such as biodiversity-ecosystem functioning relationships, plant-soil interactions and climatic controls on ecosystem structure and functioning.

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Grazing system and stocking rate effects on the productivity, botanical composition and soil surface characteristics of alfalfa-grass pastures

Canadian Journal of Animal Science ◽

10.4141/a96-122 ◽

1997 ◽

Vol 77 (4) ◽

pp. 669-676 ◽

Cited By ~ 8

Author(s):

J. D. Popp ◽

W. P. McCaughey ◽

R. D. H. Cohen

Keyword(s):

Soil Surface ◽

Surface Characteristics ◽

Botanical Composition ◽

Stocking Rate ◽

Forage Production ◽

Basal Cover ◽

Grazed Pastures ◽

Litter Cover ◽

Grazing System ◽

Stocking Rates

A 4-yr experiment was conducted (1991 to 1994) near Brandon, MB, to determine the effects of grazing system (continuous and rotational) and stocking rate [light (1.1 steers ha−1); heavy (2.2 steers ha−1)] on the productivity, botanical composition and soil surface characteristics of an alfalfa (Medicago sativa L.; approximately 70%), meadow bromegrass (Bromus biebersteinii Roem & Schult.; 25%) and Russian wild ryegrass [Psathyrostachys juncea (Fisch.) Nevski; 5%] pasture. Grazing season length was shorter (P < 0.05) for cattle in continuously compared with rotationally stocked pastures in 1991, while in 1993 and 1994 it was shortest (P < 0.05) in heavily stocked continuously grazed pastures. Carrying capacity (steer days ha–1) was greater (P < 0.05) in heavily stocked rotationally grazed pastures compared with other treatments in 1991, 1993 and 1994. In 1992, it was greater (P < 0.05) in heavy than light stocking rate treatments for both rotationally and continuously grazed pastures. Cattle usually gained more (P < 0.05) per day (kg d−1) and during the season (kg hd−1) at light than at heavy stocking rates, while total liveweight production (kg ha−1) was greater (P < 0.05) at heavy than at light stocking rates. Forage production and disappearance did not differ (P > 0.05) within grazing systems and stocking rates from 1991 to 1993, but in 1994, production and disappearance were greater (P < 0.05) at heavy than at light stocking rates. Mean seasonal herbage mass available and carry-over were greater (P < 0.05) in lightly stocked pastures than heavily stocked pastures from 1991 to 1994. After the first year of grazing, the proportion of alfalfa increased (P < 0.05), while grasses declined (P < 0.05) within all grazing treatments. In subsequent years, a trend was observed, where alfalfa declined and grasses increased in all pastures, except those stocked heavily and grazed continuously, which by 1994 had the greatest (P < 0.05) percentage of alfalfa. As years progressed, increases (P < 0.05) in basal cover concurrent with declines in bare ground were recorded on all grazing treatments, while litter cover often did not differ (P > 0.05) within either grazing system or stocking rate, except in 1992, when basal cover was lowest (P < 0.05), while litter cover was greatest (P < 0.05) on lightly stocked continuously grazed pastures compared with other treatments. Stocking rates were a key factor to optimizing individual animal performance and/or gain per hectare on alfalfa grass pastures, however differences in the effect of continuous and rotational stocking on pasture productivity were minimal. Key words: Alfalfa, grazing, stocker cattle, production

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A study of soil surface characteristics in a small watershed in the hilly, gullied area on the Chinese Loess Plateau

CATENA ◽

10.1016/s0341-8162(03)00055-9 ◽

2003 ◽

Vol 54 (1-2) ◽

pp. 31-44 ◽

Cited By ~ 31

Author(s):

Guobin Liu ◽

Mingxiang Xu ◽

Coen Ritsema

Keyword(s):

Loess Plateau ◽

Soil Surface ◽

Surface Characteristics ◽

Chinese Loess Plateau ◽

Small Watershed ◽

Chinese Loess ◽

The Chinese Loess Plateau

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Effects of Near Soil Surface Characteristics on Soil Detachment by Overland Flow in a Natural Succession Grassland

Soil Science Society of America Journal ◽

10.2136/sssaj2013.09.0392 ◽

2014 ◽

Vol 78 (2) ◽

pp. 589-597 ◽

Cited By ~ 35

Author(s):

Bing Wang ◽

Guang-Hui Zhang ◽

X.C. Zhang ◽

Zhen-Wei Li ◽

Zi-Long Su ◽

...

Keyword(s):

Overland Flow ◽

Soil Surface ◽

Surface Characteristics ◽

Natural Succession

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SURFACE CHARACTERISTICS OF MAPPING UNITS RELATED TO AERIAL IMAGING OF SOILS

Canadian Journal of Soil Science ◽

10.4141/cjss73-039 ◽

1973 ◽

Vol 53 (3) ◽

pp. 249-257 ◽

Cited By ~ 3

Author(s):

J. CIHLAR ◽

R. PROTZ

Keyword(s):

Organic Matter ◽

Spectral Response ◽

Spectral Characteristics ◽

Soil Surface ◽

Surface Characteristics ◽

Aerial Images ◽

Recording Device ◽

Color Coordinates ◽

Additional Information ◽

Mapping Units

Successful detection of boundaries of soil mapping units (SMU's) using differences in spectral characteristics of surface soils requires that any given SMU appears homogeneous but different from all other SMU's as viewed by the recording device. The purpose of this study was to assess surface characteristics affecting aerial images of soils and the degree to which they differ among SMU's. Soil surface samples were collected along four transects (crossing 11 SMU's) at 10-m intervals. Munsell color coordinates (dry soils) and organic matter, oxalate iron, sand, silt and clay contents were subjected to a statistical analysis. The results showed that except for Munsell hue, more than 50% of the total variability occurred among SMU's. Distinct groups of SMU's were denned on the basis of Munsell value, organic matter, sand, and silt content, but in no case were all SMU s distinguished from one another. This and related studies suggest that these soils could not be mapped accurately on the basis of their spectral response alone but spectral differences would provide additional information on soil distribution Since soil reflectance characteristics are described in terms of Munsell color coordinates and other properties measured by pedologists, these results may be extrapolated into various areas with similar soils.

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Wind erosion of microplastics from soils: linking soil surface properties with microplastic flux

10.5194/egusphere-egu2020-17818 ◽

2020 ◽

Author(s):

Annie Ockelford ◽

Joanna Bulalrd ◽

Cheryl McKenna-Neuman ◽

Patrick O'Brien

Keyword(s):

Surface Roughness ◽

Wind Tunnel ◽

Wind Erosion ◽

Soil Surface ◽

Surface Characteristics ◽

Test Material ◽

Mineral Particle ◽

Test Bed ◽

Transport Pathway ◽

Soil Surface Roughness

Recent studies of soils in the Alps and Middle East indicate airborne transport of microplastics following wind erosion may be significant.&#160; Where microplastics have been entrained by wind they show substantial enrichment ratios compared to mineral particle erosion.&#160; Further, microplastic shape affects enrichment ratios with those for fibres greater than for microbeads which may reflect the lower density and asymmetric shape of microplastics compared to soil particles. This suggests that terrestrial to atmospheric transfer of microplastics could be a significant environmental transport pathway. However, currently we have very little understanding of how the properties, in particular the surface characteristics, of the sediment which they are being eroded from affects their entrainment potential.This paper reports wind tunnel studies run to explore the impacts of soil surface characteristics on microplastic flux by wind erosion.&#160; Experiments were performed in a boundary layer simulation wind tunnel with an open-loop suction design.&#160; The tunnel has a working section of 12.5m x 0.7m x 0.76m and is housed in an environmental chamber which, for this study, was held constant at 20 oC and 20% RH. In experiments two types of low density microplastic (microbeads and fibres) were mixed into a poorly-sorted soil containing 13% organics.&#160; The polyethylene microbeads had a size range of 212-250 microns and density of 1.2 g cm3 and the polyester fibres were 5000 microns long and 500-1000 microns in width with a density of 1.38 g cm3.&#160; Microplastics were mixed into the sediment in concentrations ranging from 40-1040 mg kg-1. For each experiment, test surfaces were prepared by filling a 1.0m x 0.35m x &#160;0.025m metal tray with the given mixture of test material which was lowered into the wind tunnel such that it was flush with the tunnel floor and levelled. The wind tunnel was then switched on and run with increasing wind speeds using 0.25 m s-1 increments until continuous saltation occurred.&#160; Soil surface roughness was scanned prior to and after each experiment using a high resolution laser scanner (0.5mm resolution over the entire test section). &#160;Transported soil and microplastic particles were captured in bulk using a 2 cm wide by 40 cm tall Guelph-Trent wedge trap that was positioned 2 m downwind of the test bed.&#160;Discussion concentrates on linking the changes in soil surface topography to the magnitude of microplastic flux where data shows that there is a correlation between the development of the soil surfaces and overall microplastic flux.&#160; Specifically, soil surface roughness is seen as a significant control on microplastic flux where it has a greater overall effect on microplastic fibre flux as compared to the microplastic beads.&#160; The outcome of this research is pertinent to developing understanding surrounding the likely controls and hence propensity of microplastics to be entrained from soil by wind erosion. &#160;

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Surface runoff, soil and nutrient losses from farming systems in the Australian semi-arid tropics

Australian Journal of Experimental Agriculture ◽

10.1071/ea9961003 ◽

1996 ◽

Vol 36 (8) ◽

pp. 1003 ◽

Cited By ~ 19

Author(s):

M Dilshad ◽

JA Motha ◽

LJ Peel

Keyword(s):

Surface Runoff ◽

Soil Conservation ◽

Soil Loss ◽

Soil Surface ◽

Farming Systems ◽

Surface Characteristics ◽

Control Surface ◽

Arable Soils ◽

North West ◽

Semi Arid

Most soils suitable for dryland agriculture in north-west Australia occur in the Daly Basin. These are sesquioxidic soils which include red, yellow and grey earths, and soils related to yellow and red earths. The potential, for these arable soils to be degraded by highly erosive rainfalls, common to the region, is high. Farming practices strongly influence the soil surface characteristics (vegetation cover, roughness, soil strength), which in turn control surface runoff, and sediment detachment and transport. In studies conducted during 1984-89 in the Daly Basin, conventionally tilled catchments, produced 1.5-2 times more runoff and lost 1.5-6 times more soil than their no-tillage counterparts (all catchments were within soil conservation banks). In these conventionally tilled catchments, soil loss was <8.1 t/ha.year. Other studies in the region have shown that, without soil conservation banks, soil loss can be around 100/ha.year under conventional tillage. Little work, however, has been undertaken on farms in the Australian semi-arid tropics to study the movement of nutrients and herbicides (in ionic and adsorbed forms) and further research is warranted.

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Monitoring the variations of evapotranspiration due to land use/cover change in a semiarid shrubland

Hydrology and Earth System Sciences ◽

10.5194/hess-21-863-2017 ◽

2017 ◽

Vol 21 (2) ◽

pp. 863-877 ◽

Cited By ~ 15

Author(s):

Tingting Gong ◽

Huimin Lei ◽

Dawen Yang ◽

Yang Jiao ◽

Hanbo Yang

Keyword(s):

Land Use ◽

Vegetation Change ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Hydrological Cycle ◽

Vegetation Type ◽

Soil Surface ◽

Surface Characteristics ◽

Observation Data ◽

Semiarid Shrubland

Abstract. Evapotranspiration (ET) is an important process in the hydrological cycle, and vegetation change is a primary factor that affects ET. In this study, we analyzed the annual and inter-annual characteristics of ET using continuous observation data from eddy covariance (EC) measurement over 4 years (1 July 2011 to 30 June 2015) in a semiarid shrubland of Mu Us Sandy Land, China. The Normalized Difference Vegetation Index (NDVI) was demonstrated as the predominant factor that influences the seasonal variations in ET. Additionally, during the land degradation and vegetation rehabilitation processes, ET and normalized ET both increased due to the integrated effects of the changes in vegetation type, topography, and soil surface characteristics. This study could improve our understanding of the effects of land use/cover change on ET in the fragile ecosystem of semiarid regions and provide a scientific reference for the sustainable management of regional land and water resources.

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