نتایج جستجو برای: soil chemistry

تعداد نتایج: 287163  

2007

This section of the Framework provides an overview of how the principles for metals risk assessment apply to ecological risk assessments for terrestrial environments. Receptors typically considered in these assessments include soil invertebrates, plants, and wildlife species. Some assessments also examine effects on microbiota and soil processes. This section of the Framework builds on the info...

Journal: :The Science of the total environment 2007
G R Robinson P L Sibrell C J Boughton L H Yang

Metal and bioessential element concentrations were measured in three species of 17-year periodical cicadas (Magicicada spp.) to determine how cicada tissue chemistry is affected by soil chemistry, measure the bioavailability of metals from both uncontaminated and lead-arsenate-pesticide contaminated soils, and assess the potential risks of observed metal contamination for wildlife. Periodical c...

ژورنال: علوم آب و خاک 2018

The effect of broad-leaved forest trees (Alnus glotinusa, Ulmus glabra, Popolus caspica and Parrotia persica) and their canopy position on soil C and N storage and mineraization in the plain forest areas of Noor was investigated. Soil samples were taken from two positions (near and away from the main stem) with the microplots of 30×30×15 cm. Litter (C and N), soil physical (bulk density, textur...

Journal: :The Science of the total environment 2014
Ariadne Argyraki Efstratios Kelepertzis

Understanding urban soil geochemistry is a challenging task because of the complicated layering of the urban landscape and the profound impact of large cities on the chemical dispersion of harmful trace elements. A systematic geochemical soil survey was performed across Greater Athens and Piraeus, Greece. Surface soil samples (0-10cm) were collected from 238 sampling sites on a regular 1×1km gr...

2013
Kristen M. DeAngelis Dylan Chivian Julian L. Fortney Adam P. Arkin Blake Simmons Terry C. Hazen Whendee L. Silver

Humid tropical forest soils are characterized by low and fluctuating redox, conditions which are thought to inhibit organic matter degradation by microbes. However, evidence suggests that soil microbial communities are adapted to the redox conditions in these ecosystems. In this study we tested the hypothesis that soil oxygen (O2) availability as an index of redox conditions structures patterns...

2017
Dan Naylor Devin Coleman-Derr

Root-associated bacterial communities play a vital role in maintaining health of the plant host. These communities exist in complex relationships, where composition and abundance of community members is dependent on a number of factors such as local soil chemistry, plant genotype and phenotype, and perturbations in the surrounding abiotic environment. One common perturbation, drought, has been ...

2017
LEIGH C. MOORHEAD LARA SOUZA CHRISTOPHER W. HABECK RICHARD L. LINDROTH T. CLASSEN

Herbivores modify their environment by consuming plant biomass and redistributing materials across the landscape. While small mammalian herbivores, such as rodents, are typically inconspicuous, their impacts on plant community structure and chemistry can be large. We used a small mammal exclosure experiment to explore whether rodents in a southeastern old field directly altered the aboveground ...

2004
N. J. Karberg

Global emissions of atmospheric CO2 and tropospheric O3 are rising and expected to impact large areas of the Earth’s forests. While CO2 stimulates net primary production, O3 reduces photosynthesis, altering plant C allocation and reducing ecosystem C storage. The effects of multiple air pollutants can alter belowground C allocation, leading to changes in the partial pressure of CO2 (pCO2) in th...

Journal: :The New phytologist 2013
Richard C Cobb Valerie T Eviner David M Rizzo

Few studies have quantified pathogen impacts to ecosystem processes, despite the fact that pathogens cause or contribute to regional-scale tree mortality. We measured litterfall mass, litterfall chemistry, and soil nitrogen (N) cycling associated with multiple hosts along a gradient of mortality caused by Phytophthora ramorum, the cause of sudden oak death. In redwood forests, the epidemiologic...

2016
William Russell Wieder Russell Wieder

Tropical forests play a substantial role in the global carbon (C) cycle and are projected to experience significant environmental change, highlighting the importance of understanding the factors that control C and N cycling in this biome. Yet interactions between biogeochemical and abiotic variables, notably species diversity and precipitation, remain poorly resolved in the tropics. In a wet lo...

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