The impacts of vegetation on the soil surface freezing-thawing processes at permafrost southern edge simulated by an improved process-based ecosystem model

2021 ◽  
Vol 456 ◽  
pp. 109663
Author(s):  
Zhenhai Liu ◽  
Bin Chen ◽  
Shaoqiang Wang ◽  
Qinyi Wang ◽  
Jinghua Chen ◽  
...  
Keyword(s):  
Soil Surface ◽  
Ecosystem Model ◽  
Thawing Processes ◽  
Surface Freezing

scholarly journals How plant production in the Mongolian grasslands is affected by wind-eroded coarse-textured topsoil

2020 ◽  
Author(s):  
Kaman Kong ◽  
Banzragch Nandintsetseg ◽  
Masato Shinoda
Keyword(s):  
Field Condition ◽  
Root Zone ◽  
Soil Surface ◽  
Ecosystem Model ◽  
Water Dynamics ◽  
Plant Production ◽  
Desert Steppe ◽  
Vegetation Growth ◽  
Growing Seasons ◽  
Actual Field

Abstract While it is known that soil erosion by wind in drylands results in soil loss and redistribution and changes the texture of topsoil, there is little information about how these changes in the topsoil might affect the productivity of vegetation and if they result in degradation of the grasslands in wind-eroded regions such as Mongolian grasslands. In this study, we compared two different scenarios of vegetation growth, namely a wind-eroded scenario and an actual field condition, on two different grasslands in Mongolia (steppe and desert steppe) using an ecosystem model. The simulations of the wind-eroded scenario were based on a topsoil (0–0.1 m depth) with 1% clay and 99% sand, designed to represent an extremely wind-eroded soil surface that had permanently lost the fine clay particles and had gained sand particles. The effects of temperature, nutrient and water stresses on plant production were quantitively estimated. The model gave reasonably good simulations of the vegetation and soil water dynamics during the growing seasons (April–September) from 2002–2011. The simulation results showed that water had more effect on plant production than nitrogen and temperature at the two sites, and stresses because of a lack of water and nutrients generally affected plant production in the wind-eroded coarse-textured topsoil. Plant production was 20.2% lower in the wind-eroded scenario than in the actual field condition in the desert steppe under water-stressed conditions but plant production was slightly higher (5.0%) in the wind-eroded scenario on the steppe that received more rainfall, because of a reverse texture effect, where water continues to infiltrate from the coarse topsoil (0–0.1 m depth) to the deeper root-zone (0.1–0.3 m depth) because of lower evapotranspiration from soil, and facilitates growth. When this happens, there is enough soil moisture in the root-zone, and plant growth is mostly affected by the nitrogen supply.

Modelling the mineralisation of plant residues on the soil surface

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 711-722 ◽  
Author(s):  
Axel Berkenkamp ◽  
Eckart Priesack ◽  
Jean Charles Munch
Keyword(s):  
Soil Surface ◽  
Plant Residues

Status and development prospects of standard means for reproducing units of volumetric activity of radon and thoron and radon flux density from the soil surface

2020 ◽  
pp. 69-73
Author(s):  
S.G. Birjukov ◽  
O.I. Kovalenko ◽  
A.A. Orlov
Keyword(s):  
Flux Density ◽  
Soil Surface ◽  
National Standards ◽  
Measuring Instruments ◽  
Volumetric Activity ◽  
Standard Means ◽  
Radon Flux ◽  
Technical Solutions ◽  
Development Prospects ◽  
Physical Principles

The approach to creating standard means for reproducing units of volumetric activity of radon and thoron and flux density of radon from the soil surface is described based on the physical principles of reproducing these units of quantities and using as technical means for reproducing bubblers with a radioactive solution of radium salt, reference capacities of known volume, emanation chambers for generation of a toron, a gamma spectrometer with a semiconductor detector from highly pure germanium and radon radiometers. Reproduction consists in the physical realization of units in accordance with their definition as applied to the formation of radon and thoron in the radioactive rows of radium and thorium. The proposed approach will allow to determine the structural, structural and other technical solutions of standard measuring instruments, as well as specific techniques and methods of working with them. The creation of standard tools and technologies for reproducing units of volumetric activity of radon and thoron and the density of radon flux from the soil surface will ensure the unity and reliability of measurements in the field of ionizing radiation, traceability of units and bringing the characteristics of national standards in line with world achievements.

VEMAP 2: MONTHLY ECOSYSTEM MODEL RESPONSES TO U.S. CLIMATE CHANGE, 1994-2100

2005 ◽  
Author(s):  
S. AULENBACH ◽  
C. DALY ◽  
H. H. FISHER ◽  
W. P. GIBSON ◽  
C. KAUFMAN ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Model

VEMAP 2: ANNUAL ECOSYSTEM MODEL RESPONSES TO U.S. CLIMATE CHANGE, 1994-2100

2005 ◽  
Author(s):  
S. AULENBACH ◽  
C. DALY ◽  
H. H. FISHER ◽  
W. P. GIBSON ◽  
C. KAUFMAN ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Model

Relationship between morphometrics and trophic levels in deep-sea fishes

2020 ◽  
Vol 637 ◽  
pp. 225-235 ◽  
Author(s):  
MA Ladds ◽  
MH Pinkerton ◽  
E Jones ◽  
LM Durante ◽  
MR Dunn
Keyword(s):  
Stable Isotopes ◽  
Trophic Level ◽  
Deep Sea ◽  
Strong Relationship ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Fish Size ◽  
Wide Range ◽  
Gape Size ◽  
Morphological Variables

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.

Restoration of Ecosystem Function by Soil Surface Inoculation with Biocrust in Mesic and Xeric Alpine Ecosystems

2019 ◽  
Vol 37 (2) ◽  
pp. 101-112 ◽  
Author(s):  
Annie-Claude Letendre ◽  
Darwyn S. Coxson ◽  
Katherine J. Stewart
Keyword(s):  
Ecosystem Function ◽  
Soil Surface ◽  
Alpine Ecosystems

REHABILITATION OF THE SOIL STRUCTURE WITH THE DIRECT SOWING IN THE STAVROPOL REGION DRY ZONE

1970 ◽  
pp. 27-31
Author(s):  
V. P. Belobrov ◽  
S. А. Yudin ◽  
V. А. Kholodov ◽  
N. V. Yaroslavtseva ◽  
N. R. Ermolaev ◽  
...  
Keyword(s):  
Cover Crops ◽  
Soil Surface ◽  
Plant Residues ◽  
Agricultural Technologies ◽  
Row Crops ◽  
Dry Zone ◽  
Erosion Effect ◽  
Stavropol Region ◽  
Dry Conditions ◽  
Direct Sowing

The influence of different systems of soil cultivation is considered - traditional (recommended) technology and direct sowing, which is increasingly used under dry conditions of the region. The rehabilitation of the degraded southern chernozems and dark chestnut soils structure during 13 and 7 years of direct sowing, respectively, has not been established. It takes much longer to rehabilitation the aggregate state of soils, which is currently in a critical condition of the content of aggregates> 10 mm in size and the sum of agronomically valuable aggregates. The soils under 60-year treeline, as a control, showed a satisfactory range of aggregates, which indicates a high degree of soil degradation in the past and a long period of their recovery time. The effectiveness of direct sowing usage in the cultivation of a wider range of grain and row crops (winter wheat, sunflower, peas, chickpeas, rapeseed, buckwheat, corn) is due to the peculiarities of agricultural technologies. Abandoning of naked fallows and soil treatments with the simultaneous use of plant residues and cover crops on the soil surface between the harvest and sowing of winter crops provides an anti-erosion effect and, as a consequence, a decrease in physical evaporation, an increase in moisture and biota reserves, an increase in microbiological processes, which are noted in the form trends in improving the agrochemical and agrophysical properties of soils.

Sign in / Sign up

Export Citation Format

Share Document