The role of gross and net N transformation processes and NH4+and NO3-immobilization in controlling the mineral N pool of a temperate mixed deciduous forest soil

Observations of a Humo-Ferric Podzol within a mixed deciduous forest in central Ontario showed vertical penetration of the parent C horizon by a tonguing Bf layer to depths greater than 2.5 m, in numerous localized areas of the soil. The tonguings were possibly initiated as white pine root casts formed by windthrow or in situ decay of undisturbed taproots. The role of these tonguings in the movement of water and solutes through the soil was assessed by comparing the physical and chemical properties of tonguing (Bf) and parent C2 horizons. In terms of the physical properties, there are only two distinct layers in the profile (the A + B and the BC + C1), while for CEC, organic matter and soil pH, there are four horizons (A, B, BC, and C1). The data suggest that tonguings are major conduits for water and solutes moving through the soil, and that processes such as nutrient cycling are concentrated within the tonguings, with little activity in adjacent C horizons. Key words: Podzol, tonguing, acidification

Download Full-text

Scaling leaf photosynthesis to canopy in a mixed deciduous forest. I. model description

Silva Gandavensis ◽

10.21825/sg.v62i0.842 ◽

1997 ◽

Vol 62 ◽

Author(s):

R. Samson ◽

S. Follens ◽

R. Lemeur

Keyword(s):

Temperature Dependence ◽

Quercus Robur ◽

Deciduous Forest ◽

Growing Season ◽

Model Description ◽

Canopy Photosynthesis ◽

Leaf Photosynthesis ◽

Layer Model ◽

Mixed Deciduous Forest ◽

Leaf Level

A multi-layer model (FORUG) was developed, to simulate the canopy photosynthesis of a mixed deciduous forest during the growing season. Measured photosynthesis parameters, for beech (Fagus sylvatica), oak (Quercus robur) and ash (Fraxinus excelsior), were used as input to the model. This information at the leaf level is then scaled up to the level of the canopy, taking into account the radiation profiles (diffuse and direct PAR) in the canopy, the vertical LAI distribution, the evolution of the LAI and the photosynthesis parameters during the growing season, and the temperature dependence of the latter parameters.

Download Full-text

Site quality and vegetation biomass in the tropical Sal mixed deciduous forest of Central India

Landscape and Ecological Engineering ◽

10.1007/s11355-021-00450-1 ◽

2021 ◽

Author(s):

Abhishek Raj ◽

Manoj Kumar Jhariya

Keyword(s):

Deciduous Forest ◽

Central India ◽

Site Quality ◽

Vegetation Biomass ◽

Mixed Deciduous Forest

Download Full-text

Sudden Phytophthora Dieback of Wild Cherry Trees in Northwest Hungary

Acta Silvatica et Lignaria Hungarica ◽

10.1515/aslh-2016-0010 ◽

2016 ◽

Vol 12 (2) ◽

pp. 117-124

Author(s):

Judit Sárándi-Kovács ◽

László Nagy ◽

Ferenc Lakatos ◽

György Sipos

Keyword(s):

Prunus Avium ◽

Deciduous Forest ◽

Flood Plain ◽

Phytophthora Species ◽

Soil Conditions ◽

Wild Cherry ◽

Plain Area ◽

Phytophthora Spp ◽

Mixed Deciduous Forest ◽

Cherry Trees

Abstract During a regular survey of declining forests in 2011, sudden dieback symptoms were observed on scattered wild cherry trees (Prunus avium) in a mixed deciduous forest stand, located in the flood plain area of the Rába River, in northwest Hungary. In this study, we correlated both soil conditions and presence of Phytophthora spp. to dieback of cherry trees. Two Phytophthora species, P. polonica and P. plurivora, were isolated from the rhizosphere soil of the dying trees. By contrast, only P. polonica was recovered from the necrotic tissues of symptomatic roots. Stem and root inoculation tests on cherry seedlings showed pathogenicity of both species, although P. polonica proved to be more virulent. This is the first report of natural infections of P. polonica.

Download Full-text