scholarly journals A review of reindeer lichen (Cladonia subgenus Cladina) linear growth rates

Rangifer ◽  
2020 ◽  
Vol 40 (1) ◽  
pp. 15-26
Author(s):  
Richard Troy McMullin ◽  
Sean Rapai
Keyword(s):  
Growth Rates ◽  
Linear Growth ◽  
Terrestrial Ecosystems ◽  
Timber Harvesting ◽  
Snow Accumulation ◽  
Disturbed Areas ◽  
Reindeer Lichens ◽  
Substrate Age ◽  
Lichen Growth ◽  
Reindeer Lichen

Cladonia subgenus Cladina (the reindeer lichens) can be a dominant part of terrestrial ecosystems worldwide. They are particularly abundant in arctic-alpine and boreal regions, where they are a primary food source for woodland caribou/reindeer in winter months. Determining the growth rates of reindeer lichen is important for understanding and managing lichen regeneration following disturbances such as timber harvesting, mining, grazing, and wildfire. Regeneration and rehabilitation rates can be calculated with greater accuracy when growth rates are well understood. We provide a summary of 17 studies from 6 countries that determined the linear growth rates of three reindeer lichen groups, Cladonia arbuscula/mitis (mean = 4.7 mm/yr.), C. rangiferina/ C. stygia (mean = 5.1 mm/yr.), and C. stellaris (mean = 4.8 mm/yr.). We use linear growth rates as a proxy for over-all growth and biomass. Variables found to influence lichen growth rates are also discussed, which include light, moisture, temperature, air pollution, acid rain, precipitation, snow accumulation, substrate, age of individuals, and type of disturbance. These results can assist land managers in developing more accurate strategies for restoring lichens in disturbed areas.

scholarly journals Projected decrease in wintertime bearing capacity on different forest and soil types in Finland under a warming climate

2019 ◽  
Vol 23 (3) ◽  
pp. 1611-1631 ◽  
Author(s):  
Ilari Lehtonen ◽  
Ari Venäläinen ◽  
Matti Kämäräinen ◽  
Antti Asikainen ◽  
Juha Laitila ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
21St Century ◽  
Climate Model ◽  
Thick Layer ◽  
Timber Harvesting ◽  
Snow Accumulation ◽  
Point Of View ◽  
Frozen Soil ◽  
Soil Types ◽  
Soil Frost

Abstract. Trafficability in forest terrain is controlled by ground-bearing capacity, which is crucial from the timber harvesting point of view. In winter, soil frost affects the most the bearing capacity, especially on peatland soils which have in general low bearing capacity. Ground frost similarly affects the bearing capacity of forest truck roads. A 20 cm thick layer of frozen soil or 40 cm thick layer of snow on the ground may already be sufficient for heavy forest harvesters. In this work, we studied the impacts of climate change on soil frost conditions and, consequently, on ground-bearing capacity from the timber harvesting point of view. The number of days with good wintertime bearing capacity was modelled by using a soil temperature model with a snow accumulation model and wide set of downscaled climate model data until the end of the 21st century. The model was calibrated for different forest and soil types. The results show that by the mid-21st century, the conditions with good bearing capacity will decrease in wintertime in Finland, most likely by about 1 month. The decrease in soil frost and wintertime bearing capacity will be more pronounced during the latter half of the century, when drained peatlands may virtually lack soil frost in most of winters in southern and western Finland. The projected decrease in the bearing capacity, accompanied with increasing demand for wood harvesting from drained peatlands, induces a clear need for the development of sustainable and resource-efficient logging practices for drained peatlands. This is also needed to avoid unnecessary harvesting damages, like rut formation on soils and damage to tree roots and stems.

COMPARATIVE STUDIES OF NORTH AMERICAN AND EUROPEAN CULTURES OF THE ROOT ROT FUNGUS, FOMES ANNOSUS (FR.) COOKE

1955 ◽  
Vol 33 (5) ◽  
pp. 416-428 ◽  
Author(s):  
D. E. Etheridge
Keyword(s):  
Growth Rate ◽  
North American ◽  
Growth Rates ◽  
Root Rot ◽  
Linear Growth ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Cellulolytic Activity ◽  
Ph Optimum ◽  
Two Cultures

Cultures of Fames annosus originating in Europe could not be distinguished from those originating in North America either by colony appearance, growth rate, pH optimum, or cellulolytic activity. Three growth rate types on 2.5% malt agar were recognized and these are ascribed to individual variation rather than to host or geographical influences. Successive subculturing produced variants that fell into three growth classes. Half of the isolates displayed spontaneous, but reversible, changes in growth rate and colony appearance during subculturing and this is discussed from the standpoint of genetical and environmental influences. Cultures displaying different morphological characteristics and linear-growth rates differed little metabolically; each had a similar pH optimum ranging from 4.6 to 5.5, and each proved capable of altering the initial acidity of the medium to a reaction which was more suitable for growth. Two cultures were characterized by double pH optima at 4.6 and 5.5. Cultures having different linear-growth rates produced about the same dry-weight of mycelium on a cellulose substrate in a semisynthetic nutrient solution. On the basis of a statistical analysis of cellulose utilization by representative isolates it was impossible to distinguish between North American and European cultures.

Abstract 13513: Serial CT Surveillance of Abdominal Aortic Aneurysm Diameter Demonstrates Predominantly Linear Growth (N-TA 3 CT)

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sydney Olson ◽  
Marniker Wijesinha ◽  
Annalise Panthofer ◽  
William Blackwelder ◽  
Gilbert R Upchurch ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Growth ◽  
Growth Patterns ◽  
Aortic Aneurysms ◽  
Transverse Diameter ◽  
Invasive Treatment ◽  
Abdominal Aortic ◽  
Risk Of Rupture ◽  
Serial Ct

Objective: Small abdominal aortic aneurysms (AAAs) have a low risk of rupture. Intervention is indicated when diameters exceed established thresholds. This study assessed the growth rates and patterns of AAAs over 2 years as documented on serial CT scans from the Non-Invasive Treatment of AAA Clinical Trial. Methods: 254 patients, 35 females with baseline AAA maximum transverse diameter (MTD) between 3.5-4.5 cm and 219 males with baseline MTD 3.5-5.0 cm, were included in this study. Linear regressions and segmental growth rates were used to model growth rates and patterns. Results: The yearly growth rates of AAA MTDs had a median of 0.17 cm/yr and mean of 0.19 cm/yr ± 0.14 (Figure 1). 10% of AAA displayed minimal to no growth (< 0.05 cm/yr), 62% low growth (0.05-0.25 cm/yr), 28% high growth (> 0.25 cm/yr). Baseline AAA diameter accounted for only 5.4% of growth rate variance (P<0.001, R 2 0.05). Most AAAs displayed linear growth (70%); large variations in interval growth rates occurred infrequently (3% staccato growth, 4% exponential growth); a minority of subjects’ growth patterns were not clearly classifiable (11% indeterminate-not growing, 12% indeterminate-growing) (Figure 2). No patients with baseline MTD < 4.25 cm exceeded sex-specific repair thresholds (males 0 / 92, [95% CI, 0.00-0.06]; females 0 / 25 [95% CI, 0.00-0.25]) in the course of follow-up for as long as two years. Conclusions: The majority of small AAAs exhibit linear growth; large intra-patient growth rate variations were infrequently observed over 2 years. AAA < 4.25 cm can be followed with a CT scan in 2 years with little chance of exceeding interventional MTD thresholds of 5.5 cm for men.

Preliminary Observations on the Growth of Transplanted Peltigera Canina Under Semi-Natural Conditions

1997 ◽  
Vol 29 (1) ◽  
pp. 91-96 ◽  
Author(s):  
M. Webster ◽  
D. H. Brown
Keyword(s):  
Growth Rates ◽  
Linear Growth ◽  
Natural Conditions ◽  
Peltigera Canina

AbstractPeltigera canina thalli have been successfully transplanted onto soil in a garden and in flowerpots. Garden samples showed marked seasonality and achieved growth rates of 6·4 cm per year. Pot-grown samples showed variation in the growth of individual thallus lobes and established that, under different soil hydration regimes, permanently hydrated thalli could sustain considerable linear growth rates for at least 140 days.

Differential thermal analyses of solid-solid transitions in AgNO3 under hydrostatic pressures to 0.7 Gpa

1981 ◽  
Vol 34 (9) ◽  
pp. 1845 ◽  
Author(s):  
LH Cohen ◽  
Jr W Klement
Keyword(s):  
High Temperature ◽  
Growth Rates ◽  
Linear Growth ◽  
Thermal Analyses ◽  
Quantitative Description ◽  
Initial Slope ◽  
Transition Temperatures ◽  
Cooling Rates ◽  
Zero Rate ◽  
Show Temperature Dependence

Differential thermal analyses have located the transitions between low-temperature I and high-temperature II phases in AgNO3 powder and single crystals under hydrostatic pressures </~0.7 GPa, with heating/cooling rates in the range 0.1-1.5 K s-1. Isobaric transition temperatures plot linearly against heating/cooling rates and, extrapolated to zero rate, show hystereses between I → II and II → I transition temperatures which are comparable with the 'regions of indifference' of Bridgman's isothermal experiments. The present results suggest an initial slope of -0.090 μK Pa-1 and zero initial curvature for the I-II phase boundary. Greater hystereses are observed for the I-II transitions near intersection with the II-II' λ transition at </~0.7 GPa. An improved, quantitative description is achieved for the Kennedy-Schultz data on the linear growth rates of II,II? → I at 0.1 MPa. For II' (with ordered NO3- ions) → I the growth rates show temperature dependence markedly different than growth rates for II(with disordered NO3-) → 1 and I → II.

scholarly journals Effect of Radial Wavevector on Collisional Drift Waves in a Toroidal Heliac

1999 ◽  
Vol 52 (1) ◽  
pp. 71 ◽  
Author(s):  
J. L. V. Lewandowski ◽  
R. M. Ellem
Keyword(s):  
Growth Rate ◽  
Electrostatic Potential ◽  
Growth Rates ◽  
Initial Value Problem ◽  
Linear Growth ◽  
Field Model ◽  
Linear Growth Rate ◽  
Drift Waves ◽  
Initial Value ◽  
Magnetic Shear

A 3-field model for collisional drift waves, in the ballooning representation, for a low-pressure stellarator plasma is presented. In particular, the effect of a finite radial mode number (≡ θk) is studied, and the linear growth rates for the fluctuating plasma density, electrostatic potential and electron temperature are computed numerically by solving the 3-field model as an initial-value problem. Numerical results for a 3-field period stellarator with low global magnetic shear are then presented. It is found that, in a system with small global magnetic shear, the case θk = 0 yields the fastest linear growth rate.

scholarly journals Growth rates of the chokka squid Loligo reynaudii d’Orbigny, 1845 (Cephalopoda: Myopsida: Loliginidae) off South Africa, investigated over two years

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Collette H. Mwanangombe ◽  
Deon Durholtz ◽  
Dawit Yemane ◽  
Jean Githaiga-Mwicigi ◽  
Warwick H. H. Sauer ◽  
...  
Keyword(s):  
South Africa ◽  
Sexual Dimorphism ◽  
Growth Model ◽  
Growth Rates ◽  
Linear Growth ◽  
Maximum Size ◽  
Mantle Length ◽  
Daily Growth ◽  
Males And Females ◽  
Linear Growth Model

Growth of adult chokka squid Loligo reynaudii d’Orbigny was modelled using mantle length and age data derived from samples collected over two years (2003 and 2004) from a single, large cohort of mature and spawning squid. A total of 588 statoliths were examined (310 males, 278 females) from individuals of 71–425 mm mantle length (ML). The maximum size of chokka squid was 425 mm ML for males and 263 mm ML for females. The Francis Growth Model and Linear Growth model were selected for further analysis from six models considered. Males and females attain similar ages, although mantle length-based daily growth rates ranged from 0.75 to 1.02 (0.88 quantile _50) mm/day for males and 0.32–0.45 (0.38 quantile _50) mm/day for females, explaining the sexual dimorphism apparent in the sizes of individuals of this species.

Stability of Silicide Films Under Post-Annealing: a Dopant Effect

1993 ◽  
Vol 309 ◽  
Author(s):  
C.L. Shepard ◽  
W.A. Lanford ◽  
A.K. Pant ◽  
S. P. Murarka
Keyword(s):  
Surface Layer ◽  
Growth Rates ◽  
Thermal Processing ◽  
Linear Growth ◽  
Rapid Thermal Processing ◽  
Oxide Thickness ◽  
Oxide Surface ◽  
Oxide Formation ◽  
Post Annealing ◽  
Backscattering Analysis

AbstractThe formation of PtSi films by rapid thermal processing of e-beam evaporated Pt on <100> Si has been studied. The current study found that PtSi films have the potentially useful property of oxidizing, i.e., forming a surface layer of Si02 which may be useful for patterning. Rapid oxide formation is found with, possibly, linear growth rates when the film is doped with As to 8E15 atoms/cm2 at 80 KeV but insignificant oxidation if the film is undoped or B-doped. Rutherford backscattering analysis shows significant redistribution of the As during silicidation and oxidation with As excluded from the silicide, diffusing to the oxide and especially the oxide surface. Post-silicidation anneals have been done in a conventional tube furnace at 650ºC for up to 60 minutes and form an oxide thickness of up to 200 nm. NiSi films appear stable if Bdoped, oxidize with Ni piling up at the Si02/Si interface if undoped, and are unstable with Ni diffusing deep into the Si if As-doped.

Sign in / Sign up

Export Citation Format

Share Document