Nitrogen Saturation in Northern Forest Ecosystems

BioScience ◽  
1989 ◽  
Vol 39 (6) ◽  
pp. 378-386 ◽  
Author(s):  
John D. Aber ◽  
Knute J. Nadelhoffer ◽  
Paul Steudler ◽  
Jerry M. Melillo
Keyword(s):  
Forest Ecosystems ◽  
Nitrogen Saturation ◽  
Northern Forest

Spatial variability of trace metals in Podzols of northern forest ecosystems: Sampling implications

2003 ◽  
Vol 83 (5) ◽  
pp. 581-587 ◽  
Author(s):  
J. D. MacDonald ◽  
W. H. Hendershot
Keyword(s):  
Trace Metals ◽  
Spatial Variability ◽  
Point Source ◽  
Forest Ecosystems ◽  
Physical Factors ◽  
Individual Plant ◽  
Forest Site ◽  
Organic Carbon Content ◽  
Metal Concentrations ◽  
Northern Forest

The concentrations of metals in soils are spatially heterogeneous and soil sampling carried out when studying metals in forest ecosystems is often inadequate. We examined the spatial variability of Cd, Cu, Mn, Ni, Pb and Zn in northern forest ecosystems on a transect with distance from two point source emitters with the goal of providing basic information about the distribution and variability of metals in these soils. Samples were taken under six sampling points at four depths from three experimental sites on each of the two transects. Soils were analysed for acid digestible metals, pH and organic carbon content. Standard deviation, coefficients of variation, mean and medians were analysed for each horizon of each site. It was observed that Cu and Mn variability is higher in closer proximity to the point source while the variability of Zn increased with decreasing soil pH. In Sudbury, emitted metals Ni and Cu accumulate together in soils, whereas in Rouyn-Noranda, with the exception of Cd and Zn, metal concentrations were not related in forest floors. Observations suggest that physical factors influencing where metals are deposited as well as the inherent variability in soil chemical characteristics, and the distance from the point source can all act together to result in high variability in soil metal concentrations in a single forest site. Sampling in the interest of relating vegetation metal concentrations or response to soil metals should be carried out on an individual plant basis with multiple samples taken for each individual. Soil samples taken at intervals of 1 to 1.7 m will provide relative error in estimating soil concentrations of 10% or 20%, respectively. Key words: Spatial variability, trace metals, podzolic soils, smelter emissions

Insect Defoliators as Periodic Disturbances in Northern Forest Ecosystems

2007 ◽  
pp. 487-525 ◽  
Author(s):  
Barry J. Cooke ◽  
Vincent G. Nealis ◽  
Jacques Régnière
Keyword(s):  
Forest Ecosystems ◽  
Northern Forest ◽  
Periodic Disturbances

Length–biomass and energy relationships of terrestrial gastropods in northern forest ecosystems

1997 ◽  
Vol 75 (3) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Hawkins ◽  
M. W. Lankester ◽  
R. A. Lautenschlager ◽  
F. W. Bell
Keyword(s):  
Boreal Forest ◽  
Efficient Method ◽  
Forest Floor ◽  
Forest Ecosystems ◽  
Northern Forest ◽  
Terrestrial Gastropods ◽  
Power Equation ◽  
Biomass Models ◽  
Energy Relationships ◽  
Underlying Soil

Length–biomass models are a convenient and time-efficient method of estimating the biomass of invertebrates. Our purpose was to develop such a model for terrestrial gastropods that adequately predicted gastropod dry tissue biomass (Y) on the basis of animal length (X). The power equation Y = 0.172X1.688 (r2 = 0.85) proved to be the best model for this purpose. Gastropod dry tissue biomass was 6.52 ± 1.58 mg (mean ± SE) and, based on gastropod densities ranging from 2 to 38/m2 reported in the literature, snails and slugs active on the surface of the forest floor accounted for 2.5 and 6% of the total animal biomass and energy, respectively, of boreal forest ecosystems. However, because densities of gastropods in both the litter and underlying soil can reach 1607/m2, our results suggest that published values for total animal biomass (4.9 g/m2) and caloric energy (104 cal/m2) in boreal forest ecosystems are underestimated.

Photosynthetic efficiency of northern forest ecosystems using a MODIS-derived Photochemical Reflectance Index (PRI)

2016 ◽  
Vol 187 ◽  
pp. 345-366 ◽  
Author(s):  
E.M. Middleton ◽  
K.F. Huemmrich ◽  
D.R. Landis ◽  
T.A. Black ◽  
A.G. Barr ◽  
...  
Keyword(s):  
Photosynthetic Efficiency ◽  
Forest Ecosystems ◽  
Northern Forest ◽  
Photochemical Reflectance Index

Factors Controlling Nitrogen Cycling and Nitrogen Saturation in Northern Temperate Forest Ecosystems

1991 ◽  
Vol 1 (3) ◽  
pp. 303-315 ◽  
Author(s):  
John D. Aber ◽  
Jerry M. Melillo ◽  
Knute J. Nadelhoffer ◽  
John Pastor ◽  
Richard D. Boone
Keyword(s):  
Nitrogen Cycling ◽  
Temperate Forest ◽  
Forest Ecosystems ◽  
Nitrogen Saturation

Symptoms of nitrogen saturation in two central Appalachian hardwood forest ecosystems

1996 ◽  
Vol 35 (3) ◽  
pp. 507-522 ◽  
Author(s):  
William T. Peterjohn ◽  
Mary Beth Adams ◽  
Frank S. Gilliam
Keyword(s):  
Forest Ecosystems ◽  
Nitrogen Saturation ◽  
Hardwood Forest

scholarly journals New data on the distribution and abundance of Dendrolimus sibiricus (Tshetverikov, 1908) (Lepidoptera: Lasiocampidae) in the Komi Republic.

2021 ◽  
Author(s):  
Alexander Lukin
Keyword(s):  
Forest Ecosystems ◽  
Coniferous Forest ◽  
Komi Republic ◽  
Middle Taiga ◽  
Pheromone Traps ◽  
Northern Forest ◽  
The Past ◽  
Synthetic Pheromone ◽  
Preimaginal Stages ◽  
And Control

Abstract The Siberian silkworm (Dendrolimus sibiricus Tschetv.) is a defoliator pest that poses a significant threat to coniferous forest stands. Over the past decades, several large outbreaks of this species have occurred in Siberia (Russia), which has led to changes in forest ecosystems and an increase of expenses involved in reforestation. Adults capture new territories in the process of migration, therefore, a set of measures is needed to register the number and prevent further dispersal of the moth. One of methods of trapping is glue traps with synthetic pheromone. 16 district forestries located in the middle taiga subzone, with a total area of 151 850 hectares, were surveyed as a part of the phytosanitary monitoring of the Siberian silkworm in the Komi Republic (Russia). Analysis of 773 pheromone traps showed 414 males of the target species that were identified by their genitals. The highest indicators of catchability were found in three district forestries. Taking into account the results obtained, it was proposed to continue the monitoring using the pheromone traps, to survey more northern forest districts and to carry out subsequent searches for preimaginal stages of the silkworm in the forest districts of Priluzsky district. The study will be useful for predicting the further spread of the silkworm and for developing optimal containment and control of the pest.

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