Relationships between the Diversity of Acacia Rhizobia and the Tree Growth Characteristics and the Environmental Conditions

2012 ◽  
Author(s):  
Chengqun Lv ◽  
Baoling Huang
Keyword(s):  
Tree Growth ◽  
Environmental Conditions ◽  
Growth Characteristics

scholarly journals Direct and indirect effects of environmental limitations on white spruce xylem anatomy at treeline

2021 ◽  
Author(s):  
Timo Pampuch ◽  
Mario Trouillier ◽  
Alba Anadon-Rosell ◽  
Jelena Lange ◽  
Martin Wilmking
Keyword(s):  
Tree Growth ◽  
Environmental Conditions ◽  
Indirect Effects ◽  
Tree Height ◽  
White Spruce ◽  
Vegetation Period ◽  
Lumen Diameter ◽  
Xylem Anatomy ◽  
Direct And Indirect Effects ◽  
Mixed Effect

<p>Treeline ecosystems are of great scientific interest to study the direct and indirect influence of limiting environmental conditions on tree growth. However, tree growth is complex and multidimensional, and its responses to the environment depend on a large number of abiotic and biotic factors and their interactions.</p><p>In this study, we analyze the growth and xylem anatomy of white spruce trees (<em>Picea glauca</em> [Moench] Voss) from three treelines in Alaska (one warm and drought-limited, and two cold and temperature-limited treelines). We hypothesized (1) no difference between the treelines regarding the relationship between tree DBH and height, yet in general (2) faster growing trees at the warmer site. Additionally, we expected to find differences in xylem anatomical traits with trees from the drought-limited site having adapted to drought conditions by (3) forming smaller lumen diameter due to water deficit but (4) a higher xylem anatomical density due to higher temperatures and a longer vegetation period.</p><p>Regarding growth in height and diameter, trees at the drought-limited treeline grew relatively (1) taller and (2) faster compared to trees at the temperature-limited treelines. Raw xylem anatomical measurements showed (3) smaller lumen diameters and (4) higher density in trees at the drought-limited treeline. However, using linear mixed-effect models, we found that (i) traits related to water transport like lumen diameter were not significantly correlated with the actual amount of precipitation during the vegetation period but with tree height. We also found that (ii) traits related to mechanical support like density were mainly positively influenced by the mean temperature during the vegetation period.</p><p>The differences in lumen diameter found in the raw data can be explained by differences in the growth rates of the trees, since lumen diameter at the lower part of the tree stem needs to increase over time with increasing tree height. The greater wood density at the drought-limited treeline is probably caused by the higher temperature that leads to more biomass production, and potentially longer vegetation periods.</p><p>Our study shows that xylem anatomical traits in white spruce can be directly and indirectly controlled by environmental conditions. While lumen diameter is not directly influenced by environmental conditions but indirectly through tree height, other traits like anatomical density show a direct correlation with environmental conditions. Our results highlight the importance of approaching tree growth in a multidimensional way and considering direct and indirect effects of environmental forcing.</p>

scholarly journals Spatial distribution of spruce trees in the nature reserve 'Jankove bare' on mt. Kopaonik

2009 ◽  
pp. 191-204
Author(s):  
Branko Stajic ◽  
Milivoj Vuckovic ◽  
Marko Smiljanic
Keyword(s):  
Spatial Distribution ◽  
Tree Growth ◽  
Environmental Conditions ◽  
National Park ◽  
Nature Reserve ◽  
Distance Methods ◽  
Study Results

The methodology and applicability of the study of spatial distribution of trees in Serbian forestry have been insufficiently reported and presented. This paper, based on mathematical?statistical principles, analyses the method of spatial distribution of spruce trees in the Nature Reserve 'Jankove Bare' in the National Park 'Kopaonik'. The following methods in the group of distance methods were applied: Kotar's method (1993), T2?method, and the index of distance dispersion (Johnson, Zimmer, 1985). The study results in a pure uneven-aged spruce stand based on all three methods showed that spruce trees are randomly distributed over the stand area. Therefore, environmental conditions in the study stand can be regarded as homogeneous and equally suitable for tree growth, and there are no significant interactions between the trees, which could cause a higher competition between the trees for nutrients, water, etc.

scholarly journals Vibrio parahaemolyticus Growth under Low-Iron Conditions and Survival under High-Magnesium Conditions

2006 ◽  
Vol 69 (5) ◽  
pp. 1040-1045 ◽  
Author(s):  
CHIA-HSIN JU ◽  
P. S. MARIE YEUNG ◽  
JESSICA OESTERLING ◽  
DANIEL A. SEIGERMAN ◽  
KATHRYN J. BOOR
Keyword(s):  
Environmental Conditions ◽  
Vibrio Parahaemolyticus ◽  
Human Exposure ◽  
Growth Characteristics ◽  
Clinical Isolates ◽  
Food Sources ◽  
Entire Group ◽  
Phenotypic Characteristic ◽  
Environmental Survival ◽  
Recent Emergence

Since 1996, Vibrio parahaemolyticus serotype O3:K6 and closely related strains have been associated with an increased incidence of V. parahaemolyticus gastroenteritis worldwide, suggesting the emergence of strains with enhanced abilities to cause disease. One hypothesis for the recent emergence of V. parahaemolyticus O3:K6 and related strains is an enhanced capacity for environmental survival relative to other strains, which might result in increased human exposure to these organisms. Therefore, the objective of this study was to test the hypothesis that survival or growth characteristics of clinical V. parahaemolyticus isolates differ from those of nonclinical isolates under different environmental conditions. Twenty-six V. parahaemolyticus isolates selected to represent either clinical or food sources were monitored for either survival following exposure to high magnesium (300 mM) or growth under iron-limited conditions. Isolates in each category (clinical or food) differed widely in survival capabilities following 24 h of exposure to 300 mM Mg2+. Although 4 of 15 clinical isolates grew better at approximately 0.96 μM Fe2+ (iron-limited conditions) than at 50 μM Fe2+ (iron-rich conditions), as an entire group clinical isolates in this study were not more effective at growing under iron-limited conditions than were strains not associated with disease. Within the diverse collection of strains examined in these experiments, neither growth characteristics in low-iron environments nor survival capabilities following exposure to high magnesium concentrations were uniformly different between clinical and nonclinical V. parahaemolyticus isolates. Therefore, neither phenotypic characteristic can be used to reliably differentiate potentially pathogenic V. parahaemolyticus strains.

Development of System for High Quality Wood Grain Design

2011 ◽  
Author(s):  
Takuya Mori ◽  
Satoshi Shibasaki ◽  
Hideki Aoyama
Keyword(s):  
Computer Graphics ◽  
Tree Growth ◽  
Wood Surface ◽  
Environmental Conditions ◽  
Tree Species ◽  
Growth Conditions ◽  
High Quality ◽  
New Approach ◽  
Conventional Methods ◽  
Wood Grain

Various approaches for generating woodgrain patterns using computer graphics have been proposed so far. However, it is difficult to reproduce real woodgrain patterns using such conventional methods. In this paper, a new approach for generating woodgrain patterns is proposed. Virtual trees are generated by simulating tree growth in consideration of environmental conditions. Moreover, fine tree tissues and reflection properties at the wood surface are modeled. By applying these modeled factors, more diverse and accurate woodgrain patterns can be generated. With this approach, various types of virtual trees can be obtained by changing growth conditions such as period and location of growth or form of tissue in trees without the need to reset complicated parameters of each tree species. After this, the virtual trees can be cut at arbitrary areas, thus allowing a variety of woodgrain patterns to be generated by easy parameter setup.

scholarly journals Production and Germination of Conidia of Trichoderma stromaticum, a Mycoparasite of Crinipellis perniciosa on Cacao

2002 ◽  
Vol 92 (10) ◽  
pp. 1032-1037 ◽  
Author(s):  
S. Sanogo ◽  
A. Pomella ◽  
P. K. Hebbar ◽  
B. Bailey ◽  
J. C. B. Costa ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Growth Characteristics ◽  
Fruiting Bodies ◽  
High Moisture ◽  
Crinipellis Perniciosa ◽  
Broom Disease ◽  
Moisture Conditions ◽  
Incubation Temperatures

Growth characteristics of the fungus Trichoderma stromaticum, a mycoparasite on the mycelium and fruiting bodies of Crinipellis perniciosa, the causal agent of witches'-broom disease of cacao, were evaluated under controlled environmental conditions. The ability of T. stromaticum to produce conidia and germinate on dry brooms was evaluated at three constant temperatures (20, 25, and 30°C) and two constant relative humidities (75 and 100%). T. stromaticum produced abundant conidia on brooms at 100% relative humidity and incubation temperatures of 20 and 25°C, but none at 30°C. Sporulation of T. stromaticum was not observed at 75% relative humidity at any temperature. At 100% relative humidity and either at 20 or 25°C, treatment of brooms with T. stromaticum suppressed C. perniciosa within 7 days. In contrast, at 30°C, treatment with T. stromaticum had no effect on the pathogen in brooms maintained at either 75 or 100% relative humidity. Mycelium of C. perniciosa grew from brooms at all temperatures at 100% relative humidity. Conidial germination on broom tissue approximated 80% at temperatures from 20 to 30°C. Results suggest that applying T. stromaticum under high-moisture conditions when the air temperature is below 30°C may enhance the establishment of this mycoparasite in cacao plantations.

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