Presettlement Vegetation Patterns along the 5th Principal Meridian, Missouri Territory, 1815

1997 ◽  
Vol 137 (1) ◽  
pp. 79 ◽  
Author(s):  
John C. Nelson
Keyword(s):  
Vegetation Patterns ◽  
Presettlement Vegetation

The vegetation and chemical properties of patterned fens in the Swan Hills, north central Alberta

1975 ◽  
Vol 53 (23) ◽  
pp. 2776-2795 ◽  
Author(s):  
D. H. Vitt ◽  
P. Achuff ◽  
R. E. Andrus
Keyword(s):  
Picea Mariana ◽  
Vascular Plants ◽  
Chemical Properties ◽  
Vegetation Patterns ◽  
North Central ◽  
Water Flows ◽  
Sphagnum Magellanicum ◽  
Ledum Groenlandicum ◽  
Menyanthes Trifoliata ◽  
And Chemical Properties

Three patterned fens in north central Alberta were analyzed to elucidate vegetation patterns in vascular plants and bryophytes. Two flark associations dominated by Menyanthes trifoliata and Carex limosa, both of which had Sphagnum jensenii and Drepanocladus exannulatus phases, were recognized. The strings consist of two associations; one is dominated by Betula glandulosa, Tomenthypnum falcifolium, and Aulacomnium palustre; the second is dominated by Picea mariana, Sphagnum magellanicum, and Ledum groenlandicum. An intensive analysis of one fen reveals that these mires are ‘poor fens’ with a mean pH of 5.2 and Ca2+concentration of 2.3 ppm. The fens occur on low drainage divides and Ca2+ is depleted as water flows through the fens. An ecological series of bryophytes is described in the transitions between flarks and strings.

scholarly journals Stabilizing a homoclinic stripe

2018 ◽  
Vol 376 (2135) ◽  
pp. 20180110 ◽  
Author(s):  
Theodore Kolokolnikov ◽  
Michael Ward ◽  
Justin Tzou ◽  
Juncheng Wei
Keyword(s):  
Reaction Diffusion ◽  
Dissipative Structures ◽  
Vegetation Patterns ◽  
Theme Issue ◽  
One Dimensional ◽  
Reaction Diffusion Systems ◽  
Diffusion Systems ◽  
Schnakenberg Model ◽  
Break Up ◽  
Variable Substrate

For a large class of reaction–diffusion systems with large diffusivity ratio, it is well known that a two-dimensional stripe (whose cross-section is a one-dimensional homoclinic spike) is unstable and breaks up into spots. Here, we study two effects that can stabilize such a homoclinic stripe. First, we consider the addition of anisotropy to the model. For the Schnakenberg model, we show that (an infinite) stripe can be stabilized if the fast-diffusing variable (substrate) is sufficiently anisotropic. Two types of instability thresholds are derived: zigzag (or bending) and break-up instabilities. The instability boundaries subdivide parameter space into three distinct zones: stable stripe, unstable stripe due to bending and unstable due to break-up instability. Numerical experiments indicate that the break-up instability is supercritical leading to a ‘spotted-stripe’ solution. Finally, we perform a similar analysis for the Klausmeier model of vegetation patterns on a steep hill, and examine transition from spots to stripes. This article is part of the theme issue ‘Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)’.

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