scholarly journals Nitrogen Deposition and Responses of Forest Structure to Nitrogen Deposition in a Cool-Temperate Deciduous Forest

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 631 ◽  
Author(s):  
Ruoming Cao ◽  
Siyu Chen ◽  
Shinpei Yoshitake ◽  
Toshiyuki Ohtsuka
Keyword(s):  
Nitrogen Deposition ◽  
Forest Canopy ◽  
Forest Ecosystems ◽  
Deciduous Forest ◽  
N Deposition ◽  
Organic N ◽  
Dwarf Bamboo ◽  
Temperate Deciduous Forest ◽  
Total N ◽  
Cool Temperate

Few studies have reported the estimation of nitrogen (N) deposition, including dissolved organic N (DON) fluxes, through water flows and the contribution of snowfall in Asia. In this study, the concentrations and fluxes of DON and dissolved inorganic N (DIN) in bulk precipitation (BP), the throughfall (TF) of trees and understory dwarf bamboo, and stemflow (SF) were evaluated in a cool-temperate forest over three years to clarify N fluxes via precipitation and responses of trees and understory canopies to N deposition. The input of N to the study site in BP was 11.1 ± 1.71 kg N ha−1 year−1, with a significant contribution from DON (78%). Snowfall fluxes contributed up to 46% of the total N input, with variations related to the amount of snowfall (2.08–5.52 kg N ha−1 year−1). The forest canopy enriched DON (2.11 ± 0.42 kg N ha−1 year−1) but consumed NO3 + NO2–N (−0.73 ± 0.19 kg N ha−1 year−1). In contrast, through the understory bamboo canopy, DON (−1.02 ± 0.55 kg N ha−1 year−1) decreased while DIN (0.35 ± 0.44 kg N ha−1 year−1) increased. This study indicates that DON and snowfall should not be neglected when evaluating total N deposition into forest ecosystems, especially in remote regions. The canopy processes related to the dissolved N in the presence of understory plants might have significant implications for the internal N cycle in forest ecosystems.

scholarly journals Exchange of reactive nitrogen compounds: concentrations and fluxes of total ammonium and total nitrate above a spruce forest canopy

2009 ◽  
Vol 6 (6) ◽  
pp. 10663-10706
Author(s):  
V. Wolff ◽  
I. Trebs ◽  
T. Foken ◽  
F. X. Meixner
Keyword(s):  
Forest Canopy ◽  
N Deposition ◽  
Reactive Nitrogen ◽  
Nitrogen Compounds ◽  
Spruce Forest ◽  
Gaseous Species ◽  
Total N ◽  
Fog Water ◽  
Dry Conditions ◽  
Total Ammonium

Abstract. Total ammonium (tot-NH4+) and total nitrate (tot-NO3−) provide a chemically conservative quantity in the measurement of exchange processes of reactive nitrogen compounds ammonia (NH3), particulate ammonium (NH4+), nitric acid (HNO3), and particulate nitrate (NO3−), using the aerodynamic gradient method. Total fluxes were derived from concentration differences of total ammonium (NH3 and NH4+) and total nitrate (HNO3 and NO3−) measured at two levels. Gaseous species and related particulate compounds were measured selectively, simultaneously and continuously above a spruce forest canopy in south-eastern Germany in summer 2007. Measurements were performed using a wet-chemical two-point gradient instrument, the GRAEGOR. Median concentrations of NH3, HNO3, NH4−, and NO3− were 0.57, 0.12, 0.76, and 0.48 μg m−3, respectively. Total ammonium and total nitrate fluxes showed large variations depending on meteorological conditions, with concentrations close to zero under humid and cool conditions and higher concentrations under dry conditions. Mean fluxes of total ammonium and total nitrate in September 2007 were directed towards the forest canopy and were −65.77 ng m−2 s−1 and −41.02 ng m−2 s−1 (in terms of nitrogen), respectively. Their deposition was controlled by aerodynamic resistances only, with very little influence of surface resistances. Including measurements of wet deposition and findings of former studies at the study site on occult deposition (fog water interception), the total N deposition in September 2007 was estimated to 5.86 kg ha−1.

Biometric based estimates of net primary production (NPP) in a cool-temperate deciduous forest stand beneath a flux tower

2005 ◽  
Vol 134 (1-4) ◽  
pp. 27-38 ◽  
Author(s):  
Toshiyuki Ohtsuka ◽  
Tsuyoshi Akiyama ◽  
Yasushi Hashimoto ◽  
Motoko Inatomi ◽  
Toru Sakai ◽  
...  
Keyword(s):  
Primary Production ◽  
Deciduous Forest ◽  
Net Primary Production ◽  
Forest Stand ◽  
Temperate Deciduous Forest ◽  
Flux Tower ◽  
Cool Temperate ◽  
Temperate Deciduous
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