نتایج جستجو برای: soil chemistry

تعداد نتایج: 287163  

2017
Pierre Pétriacq Alex Williams Anne Cotton Alexander E McFarlane Stephen A Rolfe Jurriaan Ton

Rhizosphere chemistry is the sum of root exudation chemicals, their breakdown products and the microbial products of soil-derived chemicals. To date, most studies about root exudation chemistry are based on sterile cultivation systems, which limits the discovery of microbial breakdown products that act as semiochemicals and shape microbial rhizosphere communities. Here, we present a method for ...

Journal: :Tree physiology 2011
W John Calder Kevin J Horn Samuel B St Clair

Disturbance patterns strongly influence plant community structure. What remains less clear, particularly at a mechanistic level, is how changes in disturbance cycles alter successional outcomes in plant communities. There is evidence that fire suppression is resulting in longer fire return intervals in subalpine forests and that these lengthened intervals increase competitive interactions betwe...

2015
Zia Mehrabi Thomas Bell Owen T Lewis

Intraspecific negative feedback effects, where performance is reduced on soils conditioned by conspecifics, are widely documented in plant communities. However, interspecific feedbacks are less well studied, and their direction, strength, causes, and consequences are poorly understood. If more closely related species share pathogens, or have similar soil resource requirements, plants may perfor...

2015
Jean H. Burns Brian L. Anacker Sharon Y. Strauss David J. Burke

Soil ecologists have debated the relative importance of dispersal limitation and ecological factors in determining the structure of soil microbial communities. Recent evidence suggests that 'everything is not everywhere', and that microbial communities are influenced by both dispersal limitation and ecological factors. However, we still do not understand the relative explanatory power of spatia...

2009
QUENTIN D. READ

Changes in soil chemistry due to historic large-scale disturbances, e.g. pollution inputs, storm damage, and logging, have previously been shown to cause similar changes in the nutrient concentrations found in tree rings. Repeated soil sampling in a reference watershed at the Coweeta Hydrologic Laboratory (Otto, NC) in 1970, 1990, and 2004 showed significant decreases in cation concentrations a...

2004
Laurens Ganzeveld Jos Lelieveld

[1] A single-column chemistry and climate model has been used to study the impact of deforestation in the Amazon Basin on atmospheric chemistry. Over deforested areas, daytime ozone deposition generally decreases strongly except when surface wetness decreases through reduced precipitation, whereas nocturnal soil deposition increases. The isoprene and soil nitric oxide emissions decrease althoug...

Journal: :international journal of environmental research 2014
m. ghadaksaz zadeh m.s. sekhavatjou a. hosseini alhashemi a. taghinia hejabi

mercury is a dangerous and an extremely toxic element, which can transfer to the food chain.presence of this element in the atmosphere particularly during the rainy seasons cause soil and environmental pollution, therefore this research will evaluate the transformation of mercury vapor from the atmosphere through precipitation into the soil. in the present study, mercury concentrations were det...

Journal: :Applied and environmental microbiology 2011
Marketa Sagova-Mareckova Marek Omelka Ladislav Cermak Zdenek Kamenik Jana Olsovska Evelyn Hackl Jan Kopecky Franz Hadacek

Plant and microbial community composition in connection with soil chemistry determines soil nutrient cycling. The study aimed at demonstrating links between plant and microbial communities and soil chemistry occurring among and within four sites: two pine forests with contrasting soil pH and two grasslands of dissimilar soil chemistry and vegetation. Soil was characterized by C and N content, p...

Journal: :Ecology 2006
Valerie T Eviner F Stuart Chapin Charles E Vaughn

It is well established that plant species influence ecosystem processes, but we have little ability to predict which vegetation changes will alter ecosystems, or how the effects of a given species might vary seasonally. We established monocultures of eight plant species in a California grassland in order to determine the plant traits that account for species impacts on nitrogen and phosphorus c...

2017
Abdul Nishar Martin K.-F. Bader Eoin J. O’Gorman Jieyu Deng Barbara Breen Sebastian Leuzinger

Understanding the effects of increasing temperature is central in explaining the effects of climate change on vegetation. Here, we investigate how warming affects vegetation regeneration and root biomass and if there is an interactive effect of warming with other environmental variables. We also examine if geothermal warming effects on vegetation regeneration and root biomass can be used in cli...

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