Effects of Nitrogen on Temporal and Spatial Patterns of Nitrate in Streams and Soil Solution of a Central Hardwood Forest

This study examined changes in stream and soil water and their relationship to temporal and spatial patterns of in soil solution of watersheds at the Fernow Experimental Forest, West Virginia. Following tenfold increases in stream concentrations over a 13-year period (1969–1981) on untreated WS4, concentrations have declined through 2006. Following fourfold increases in stream on treatment WS3 from pretreatment levels to a 1998 maximum, concentrations have declined through 2006, despite additions of N. Concentrations of soil water were consistently lower for WS4 compared to WS3. Data for soil water on WS3 versus WS4 followed patterns of net mineralization and nitrification for these watersheds. Nitrogen additions to WS3 decreased spatial heterogeneity of N processing, which was largest in the pretreatment year and decreased significantly to a minimum by 2000-2001. Concurrently, soil water increased on WS3 from 1.3 mg -N L−1 in pretreatment 1989 to a maximum of 6.4 mg -N L−1 in 2001. Spatial heterogeneity in soil water on WS4 remained high during this period. Data suggest that temporal patterns of stream may be influenced by spatial heterogeneity of watershed processes which vary over time in response to N availability.

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Temporal and spatial patterns of soil water following wildfire-induced changes in plant communities in the Great Basin in Nevada, USA

Plant and Soil ◽

10.1023/b:plso.0000037026.93675.a2 ◽

2004 ◽

Vol 262 (1/2) ◽

pp. 1-12 ◽

Cited By ~ 24

Author(s):

Daniel Obrist ◽

Dan Yakir ◽

John A. Arnone III

Keyword(s):

Soil Water ◽

Great Basin ◽

Plant Communities ◽

Spatial Patterns ◽

Temporal And Spatial Patterns ◽

Temporal And Spatial ◽

Induced Changes

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Temporal and spatial variation of nitrogen transformations in nitrogen-saturated soils of a central Appalachian hardwood forest

Canadian Journal of Forest Research ◽

10.1139/x01-106 ◽

2001 ◽

Vol 31 (10) ◽

pp. 1768-1785 ◽

Cited By ~ 58

Author(s):

Frank S Gilliam ◽

Bradley M Yurish ◽

Mary Beth Adams

Keyword(s):

Soil Moisture ◽

Spatial Variability ◽

Soil Water ◽

Spatial Patterns ◽

N Saturation ◽

Net N Mineralization ◽

Nitrogen Transformations ◽

N Dynamics ◽

Temporal And Spatial ◽

Nitrogen Additions

We studied temporal and spatial patterns of soil nitrogen (N) dynamics from 1993 to 1995 in three watersheds of Fernow Experimental Forest, W.V.: WS7 (24-year-old, untreated); WS4 (mature, untreated); and WS3 (24-year-old, treated with (NH4)2SO4 since 1989 at the rate of 35 kg N·ha1·year1). Net nitrification was 141, 114, and 115 kg N·ha1·year1, for WS3, WS4, and WS7, respectively, essentially 100% of net N mineralization for all watersheds. Temporal (seasonal) patterns of nitrification were significantly related to soil moisture and ambient temperature in untreated watersheds only. Spatial patterns of soil water NO3 of WS4 suggest that microenvironmental variability limits rates of N processing in some areas of this N-saturated watershed, in part by ericaceous species in the herbaceous layer. Spatial patterns of soil water NO3 in treated WS3 suggest that later stages of N saturation may result in higher concentrations with less spatial variability. Spatial variability in soil N variables was lower in treated WS3 versus untreated watersheds. Nitrogen additions have altered the response of N-processing microbes to environmental factors, becoming less sensitive to seasonal changes in soil moisture and temperature. Biotic processes responsible for regulating N dynamics may be compromised in N-saturated forest ecosystems.

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Hawk kite as potential bird scare device (the case of pigeons and grain processing factory)

Ukrainian Journal of Ecology ◽

10.15421/2018_350 ◽

2018 ◽

Vol 8 (2) ◽

pp. 334-336

Author(s):

A. V. Matsyura

Keyword(s):

Spatial Patterns ◽

Repellent Effect ◽

Preliminary Results ◽

Temporal And Spatial Patterns ◽

Grain Processing ◽

Feral Pigeons ◽

Temporal And Spatial ◽

Bird Behavior ◽

Hooded Crows

Here we presented the preliminary results of hawk kite usage against the feral pigeons in some grain processing factory. We studied the temporal and spatial patterns of repellent effect and bird behavior. We suggested the feral pigeons gradually increase the level of tolerance towards the hawk kite if no additional repellent measures were undertaken. Moreover, even initially the feral pigeons demonstrate higher tolerance towards the hawk kite compared to the Rooks or Hooded Crows.

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