scholarly journals Activity density at a continental scale: What drives invertebrate biomass moving across the soil surface?

Ecology ◽  
2021 ◽  
Author(s):  
Michael Kaspari ◽  
Michael D. Weiser ◽  
Katie E. Marshall ◽  
Matthew Miller ◽  
Cameron Siler ◽  
...  
Keyword(s):  
Soil Surface ◽  
Continental Scale ◽  
Activity Density ◽  
Invertebrate Biomass

Ground Predator Activity-Density and Predation Rates Are Weakly Supported by Dry-Stack Cow Manure and Wheat Cover Crops in No-Till Maize

2020 ◽  
Author(s):  
Elizabeth K Rowen ◽  
John F Tooker
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Organic Fertilizer ◽  
Plant Cover ◽  
Soil Surface ◽  
Alternative Prey ◽  
Cow Manure ◽  
No Till ◽  
Activity Density ◽  
Soil Mite

Abstract Because it keeps land in production, conservation programs that focus on in-field habitat manipulations may help farmers better support predators than by building predator habitat around fields. We investigated two in-field habitat manipulations that benefit producers and soil quality: fertilizing with dry-stack cow manure and planting a wheat cover crop. We hypothesized that, compared with inorganic fertilizer and fallow plots, both treatments augment habitat and residue and support more small arthropods that can serve as alternative prey for larger predators. As a result, we expected manure and the cover crop to increase ground-active predators. In turn, these predators could provide biological control of pests. Each year in a 3-yr field experiment, we applied manure and in 2 yr planted a wheat cover crop. We found that both planting a cover crop and applying dry-stack manure increased the plant cover in May. In the last year, this translated to greater soil mite (Acari) density. At the end of the experiment, however, neither manure nor the wheat cover crop had increased residue on the soil surface. As a result, our treatments had inconsistent effects on predator activity-density, especially for carabids and spiders. We observed strong edge effects from neighboring grass alleys on carabid activity-density. Regardless of treatment, we observed high predation of sentinel prey. We conclude that even without cover crops or organic fertilizer, the stability of no-till maize and increased weeds in fallow treatments generate sufficient habitat complexity and alternative prey to support robust predator communities.

scholarly journals The resilience of weed seedbank regulation by carabid beetles, at continental scales, to alternative prey

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Benjamin Carbonne ◽  
Sandrine Petit ◽  
Veronika Neidel ◽  
Hana Foffova ◽  
Eirini Daouti ◽  
...  
Keyword(s):  
Seed Predation ◽  
Carabid Beetles ◽  
Generalist Predators ◽  
Alternative Prey ◽  
Weed Seed ◽  
Agricultural Ecosystem ◽  
Continental Scale ◽  
Activity Density ◽  
Soil Seedbank ◽  
Cereal Fields

Abstract Carabids are generalist predators that contribute to the agricultural ecosystem service of seedbank regulation via weed seed predation. To facilitate adoption of this ecosystem services by farmers, knowledge of weed seed predation and the resilience of seedbank regulation with co-varying availability of alternative prey is crucial. Using assessments of the seedbank and predation on seed cards in 57 cereal fields across Europe, we demonstrate a regulatory effect on the soil seedbank, at a continental scale, by groups formed of omnivore, seed-eating (granivore + omnivore) and all species of carabids just prior to the crop-harvest. Regulation was associated with a positive relationship between the activity-density of carabids and seed predation, as measured on seed cards. We found that per capita seed consumption on the cards co-varied negatively with the biomass of alternative prey, i.e. Aphididae, Collembola and total alternative prey biomass. Our results underline the importance of weed seedbank regulation by carabids, across geographically significant scales, and indicate that the effectiveness of this biocontrol may depend on the availability of alternative prey that disrupt the weed seed predation.

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.

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

The Determinants of Entrepreneurship Development in Spatial Systems

2017 ◽  
Vol 13 ◽  
pp. 8-24
Author(s):  
Zbigniew Zioło
Keyword(s):  
Spatial Scales ◽  
Institutional Barriers ◽  
Entrepreneurship Development ◽  
Continental Scale ◽  
Spatial Systems ◽  
Business Conditions ◽  
Mutual Relations ◽  
Growth Shape ◽  
Strategic Goal

The processes of technological  progress create new opportunities for economic, social and cultural growth, shape new relations between economic  entities and their environment,  and influence changes in the determinants  of entrepreneurship development.  These processes vary significantly in certain geographic locations, characterised by an enormous  diversity of natural, social, economic and cultural structures. As a consequence, this creates different opportunities  and different conditions for the development of entrepreneurship in certain spatial scales, from the continental scale, through national and regional to local scales. The article presents complex conditions  for the development of entrepreneurship, highlights its limitations resulting from institutional  barriers, and the importance of knowing the mechanisms of mutual relations between spatial systems and the influence of control instruments. The quality of central and local government authorities is of particular significance here, which do not always properly use the mechanisms of rational business support. A serious barrier to the development of entrepreneurship is the low quality of social capital, manifested in a lack of trust in institutional authorities and reluctance to engage in entrepreneurship and business development. The conclusions point out that further research should be developed that will take into account changing business conditions, with a defined strategic goal of raising the quality and standard of living, international competitiveness of the country and products in different market categories.

A Solvent Free Synthetic Route for Cerium(IV) Metal-Organic Frame-works with UiO-66 Architecture and Their Photocatalytic Application

2019 ◽  
Author(s):  
Matteo Campanelli ◽  
Tiziana Del Giacco ◽  
Filippo De Angelis ◽  
Edoardo Mosconi ◽  
Marco Taddei ◽  
...  
Keyword(s):  
Density Functional ◽  
Chemical Oxidation ◽  
Solvent Free ◽  
Cerium Ammonium Nitrate ◽  
Benzylic Alcohols ◽  
Near Ultraviolet ◽  
Photocatalytic Application ◽  
Activity Density ◽  
Ultraviolet Light Irradiation ◽  
Metal Organic

<div> <p>A novel solvent-free synthesis for Ce-UiO-66 metal-organic frameworks (MOFs) is presented. The MOFs are obtained by simply grinding the reagents, cerium ammonium nitrate (CAN) and the carboxylic linkers, in a mortar for few minutes with the addition of a small amount of acetic acid (AcOH) as modulator (1.75 eq, o.1 ml). The slurry is then transferred into a 1 ml vial and heated at 120°C for 1 day. The MOFs have been characterized for their composition, crystallinity and porosity and employed as heterogenous catalysts for the photo-oxidation reaction of substituted benzylic alcohols to benzaldaldehydes under near ultraviolet light irradiation. The catalytic performances, such as yield, conversion and kinetics, exceed those of similar systems studied by chemical oxidation and using Ce-MOF as catalyst. Moreover, the MOFs were found to be reusable up to three cycles without loss of activity. Density functional theory (DFT) calculations gave an estimation of the band-gap shift due to the different nature of the linkers used and provide useful information on the catalytic activity experimentally observed.</p> </div>

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