نتایج جستجو برای: soil formation

تعداد نتایج: 703087  

Journal: :Forests 2023

Nitrogen plays a crucial role in limiting plant growth and determining net primary productivity forest ecosystems. However, variations influencing factors of soil nitrogen distribution on the aggregate scale pure mixed Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) plantations remain unclear. This study aimed to explore how composition, geometric mean diameter (GMD), weight (MWD), total (TN...

2017
Bing Yang Xueyong Pang Bin Hu Weikai Bao Guanglong Tian

Although the effects of gap formation resulting from thinning on microclimate, plant generation and understory plant community have been well documented, the impact of thinning on soil microbial community and related ecological functions of forests particularly in subalpine coniferous region is largely unknown. Here, the effects of thinning on soil microbial abundance and community structure us...

ژورنال: علوم آب و خاک 2022

The objective of this study was to investigate how the earth dam is destroyed due to the effect of upstream and downstream slope of the body in overflow conditions. Therefore, eight models were provided that each model is constructed from the embankment dam with different upstream and downstream slopes (1:1, 2:1) and the soil properties (Sc) on breach formation. The time and method of dam break...

2010
B. A. Stevenson E. F. Kelly

Oxygen isotope ratios of pedogenic carbonates were analyzed along a climatic gradient in the Palouse region of eastern Washington State to evaluate changes in their isotopic composition with changing climate. A modern analog approach was used to assess the relationship between the istotope ratios in the pedogenic carbonates with those in soil water (measured in June when we anticipated carbonat...

2013
Ivan N. da Silva José Ângelo Cagnon Nilton José Saggioro

Many communities obtain their drinking water from underground sources called aquifers. Official water suppliers or public incorporations drill wells into soil and rock aquifers look‐ ing for groundwater contained there in order to supply the population with drinking water. An aquifer can be defined as a geologic formation that will supply water to a well in enough quantities to make possible th...

2007
Fred Pearce Mark Willis Dan Burns

The nonlinear behavior of soils can significantly modify the wavelet radiated from vibrator trucks. In this paper, we describe a field experiment designed to measure the nonlinear response of a natural soil formation in the near-field of a vibrator truck. A 267-kN (30-ton) vibrator truck performed a step-sweep through a set of 201 discrete frequencies from 50-Hz to 10-Hz, which was repeated at ...

2015

Land degradation and soil erosion threaten agricultural productivity, food security and environmental sustainability. Because formation of new soil takes place over a period of thousands of years, in human terms it is essentially a finite resource. Human activity has accelerated erosion rates through inappropriate land management practices, most importantly soil sealing, deforestation and inten...

2015
Jouni Lehtoranta Petri Ekholm Stella Wahlström Petra Tallberg Risto Uusitalo

Coastal eutrophication is expected to increase due to expanding and intensifying agriculture which causes a large amount of soil-associated P to be transported into aquatic systems. We performed anaerobic long-term incubations on field soil to mimic the conditions that eroded soil encounters in brackish sediments. The release of P from soil increased with the amount of labile organic C (acetate...

2004
Melissa D. Lane M. Darby Dyar Janice L. Bishop

[1] Despite in situ analyses by several landers, the composition of the Martian soil remains unclear. Recently, constituent minerals in the soil have been proposed from thermal emissivity and Mössbauer spectroscopic data from Mars. These data were interpreted to show spectral evidence for carbonate and an unspecified mineral containing bound water, as well as olivine. Here we present an alterna...

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