scholarly journals The differential sensitivity of red pine and quaking aspen to competition

1995 ◽  
Vol 25 (11) ◽  
pp. 1731-1737 ◽  
Author(s):  
Klaus J. Puettmann ◽  
Peter B. Reich
Keyword(s):  
Resource Availability ◽  
Stand Density ◽  
Leaf Size ◽  
Red Pine ◽  
Differential Sensitivity ◽  
Quaking Aspen ◽  
Pine Needle ◽  
Competitive Environments ◽  
Optimal Resource ◽  
The Relationship

Growth of red pine (Pinusresinosa Ait.) and quaking aspen (Populustremuloides Michx.) target trees with varying degrees of competition by neighboring aspen was measured in a 7-year-old clearcut in northeastern Minnesota. Competitive conditions were measured using indices of resource availability (percent open sky) and neighborhood stand density. Three-year diameter growth of target trees was reduced by more than 50% in both species because of competition from neighboring quaking aspen. The last 2 year's height growth was also reduced by approximately 30% for both species. The relationship between growth and percent open sky was convex for red pine and concave for quaking aspen, potentially indicating a greater sensitivity in aspen to any reduction below optimal resource availability. Competition reduced crown size in both species, but self-pruning occurred only in quaking aspen. Needle and leaf size were not affected by competition, but red pine needle density was lower in highly competitive environments. Red pine had a higher specific gravity when growing under competition, partially offsetting the reduction in wood volume.

A model of stand allometry and biomass allocation during the self-thinning process

1986 ◽  
Vol 16 (5) ◽  
pp. 990-995 ◽  
Author(s):  
N. J. Smith
Keyword(s):  
Biomass Allocation ◽  
Stand Density ◽  
Maximum Size ◽  
Red Pine ◽  
Stem Volume ◽  
Allometric Relationships ◽  
Red Alder ◽  
Number Of Stems ◽  
Thinning Process ◽  
The Relationship

A growth model is developed to describe the relationship between any measure of size and number of stems in even-aged, monospecific plant populations during self-thinning. The model is tested on red alder (Alnusrubra Bong.) seedlings and red pine (Pinusresinosa Ait.) stands grown over a range of site qualities and initial spacings. Allometric relationships between plant dimensions are shown to change over time, finally approaching a stable value defined by a generalized self-thinning rule. Because of unique intraspecific plant geometry, allometric relationships appear to be more consistent within than between species. The priorisation for red alder biomass allocation with stand development was as follows (P < 0.05): branches > stem ≥ leaves ≥ root ≥ 2 nodules. For red pine the slope and intercept of the maximum size–density line were greater (P < 0.05) for merchantable versus total stem volume. A new approach for constructing stand density programs is presented.

scholarly journals Relationships between resource availability and elevation vary between metrics creating gradients of nutritional complexity

Oecologia ◽  
2021 ◽  
Vol 195 (1) ◽  
pp. 213-223
Author(s):  
Mark A. Lee ◽  
Grace Burger ◽  
Emma R. Green ◽  
Pepijn W. Kooij
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Resource Availability ◽  
Plant Biomass ◽  
Plant Species Richness ◽  
Mineral Contents ◽  
Nutritive Values ◽  
Animal Community ◽  
Nutritional Chemistry ◽  
The Relationship

AbstractPlant and animal community composition changes at higher elevations on mountains. Plant and animal species richness generally declines with elevation, but the shape of the relationship differs between taxa. There are several proposed mechanisms, including the productivity hypotheses; that declines in available plant biomass confers fewer resources to consumers, thus supporting fewer species. We investigated resource availability as we ascended three aspects of Helvellyn mountain, UK, measuring several plant nutritive metrics, plant species richness and biomass. We observed a linear decline in plant species richness as we ascended the mountain but there was a unimodal relationship between plant biomass and elevation. Generally, the highest biomass values at mid-elevations were associated with the lowest nutritive values, except mineral contents which declined with elevation. Intra-specific and inter-specific increases in nutritive values nearer the top and bottom of the mountain indicated that physiological, phenological and compositional mechanisms may have played a role. The shape of the relationship between resource availability and elevation was different depending on the metric. Many consumers actively select or avoid plants based on their nutritive values and the abundances of consumer taxa vary in their relationships with elevation. Consideration of multiple nutritive metrics and of the nutritional requirements of the consumer may provide a greater understanding of changes to plant and animal communities at higher elevations. We propose a novel hypothesis for explaining elevational diversity gradients, which warrants further study; the ‘nutritional complexity hypothesis’, where consumer species coexist due to greater variation in the nutritional chemistry of plants.

Application of Galvanic Zinc-Iron Coating in the Repair of Transport and Technological Machines

2021 ◽  
Vol 1022 ◽  
pp. 181-193
Author(s):  
Dmitry M. Rozhkov ◽  
Evgenia V. Eltoshkina ◽  
Petr I. Ilyin ◽  
Olga A. Svirbutovich
Keyword(s):  
Experimental Studies ◽  
Iron Alloy ◽  
Resource Saving ◽  
Experimental Base ◽  
Optimal Resource ◽  
Iron Coating ◽  
Saving Mode ◽  
Relationship Of ◽  
The Relationship ◽  
Kinetics Of

The article presents the results of experimental studies to determine the relationship between the electrolysis modes and the properties of electroplating coatings for mathematical modeling of the dynamics of the electrolytic process (MDEP), described by a system of ordinary differential equations due to the complex relationship of the kinetics of chemical reactions, hydrodynamics and mass transfer in the electrolyte flow, the kinematics of electrode plates, and the influence of the electric field of the "anode-cathode" pair on all these processes. At the same time, the experimental base was a series of full-scale experiments to restore the seats of the root supports of cylinder blocks with electroplated coatings. The final result of the research is the procedure for constructing an optimal resource-saving mode of electroplating, which is a zinc-iron alloy.

Hierarchical Load Balancing Model by Optimal Resource Utilization

2021 ◽  
pp. 150-164
Author(s):  
Jagdish Chandra Patni
Keyword(s):  
Load Balancing ◽  
Grid Computing ◽  
Resource Utilization ◽  
Resource Availability ◽  
High Performance ◽  
Low Cost ◽  
Original Form ◽  
Computing Paradigm ◽  
Optimal Resource ◽  
Performance Computing

Powerful computational capabilities and resource availability at a low cost is the utmost demand for high performance computing. The resources for computing can viewed as the edges of an interconnected grid. It can attain the capabilities of grid computing by balancing the load at various levels. Since the nature of resources are heterogeneous and distributed geographically, the grid computing paradigm in its original form cannot be used to meet the requirements, so it can use the capabilities of the cloud and other technologies to achieve the goal. Resource heterogeneity makes grid computing more dynamic and challenging. Therefore, in this article the problem of scalability, heterogeneity and adaptability of grid computing is discussed with a perspective of providing high computing, load balancing and availability of resources.

Relationship between sugar maple budburst phenology and pear thrips damage

1991 ◽  
Vol 21 (7) ◽  
pp. 1043-1048 ◽  
Author(s):  
T. E. Kolb ◽  
D. A. J. Teulon
Keyword(s):  
Leaf Area ◽  
Sugar Maple ◽  
Leaf Size ◽  
Common Garden ◽  
Area Reduction ◽  
The Relationship ◽  
Leaf Area Reduction ◽  
Oviposition Sites ◽  
Damage Symptoms ◽  
Budburst Phenology

The relationship between budburst phenology and damage by the pear thrips (Taeniothripsinconsequens (Uzel) (Thysanoptera: Thripidae)) to sugar maple (Acersaccharum Marsh.) foliage was investigated in two studies. In the first study, seedlings in cages were exposed to adult thrips at different stages of budburst. Compared with uninfested control seedlings, introduction of five adult thrips per bud reduced total leaf area and average leaf size, and caused chlorosis, tattering, and cupping of leaves. Leaf area reduction and damage symptoms were greater for seedlings exposed to thrips when leaf margins were first visible at the tip of the bud compared with earlier and later stages of budburst. In the second study, budburst date and number of thrips oviposition sites on leaves (an index of thrips activity) were measured in a common-garden test of maple saplings from open-pollinated families. Thrips activity was greater on early-breaking than late-breaking buds. Date of opening for these early-breaking buds coincided closely with peak capture of flying thrips. Both budburst date and number of oviposition sites on leaves differed among families. Sugar maple genotypes with late budburst escaped heavy thrips damage. The results indicate that timing of vegetative budburst in sugar maple can influence the degree of thrips damage.

scholarly journals Effects of Initial Stand Density and Climate on Red Pine Productivity within Huron National Forest, Michigan, USA

Forests ◽  
2012 ◽  
Vol 3 (4) ◽  
pp. 1086-1103 ◽  
Author(s):  
Matthew Magruder ◽  
Sophan Chhin ◽  
Andrew Monks ◽  
Joseph O'Brien
Keyword(s):  
Stand Density ◽  
Red Pine ◽  
National Forest
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