Seasonal changes in the occurrence of embolisms among broad-leaved trees in a temperate region

Botany ◽  
2018 ◽  
Vol 96 (12) ◽  
pp. 873-881 ◽  
Author(s):  
Toshihiro Umebayashi ◽  
Kenji Fukuda
Keyword(s):  
Water Distribution ◽  
Growth Patterns ◽  
Temperate Region ◽  
Evergreen Species ◽  
Main Determinant ◽  
Freeze Thaw ◽  
Maackia Amurensis ◽  
Broad Leaved Species ◽  
Monsoon Forests ◽  
Diffuse Porous

Sap freeze–thaw events are a main determinant of the distribution of broad-leaved woody plants in cool regions but the effect in other climates remains unknown. We used cryoscanning electron microscopy to examine the differences in plant growth patterns based on seasonal variation in xylem water distribution in four broad-leaved species (one ring-porous and three diffuse-porous species) in a temperate region of Japan. Leaf fall was detected in November for the ring-porous species Maackia amurensis Rupr. et Maxim., although embolisms were detected in large earlywood vessels in January of the following year. The percentage of embolisms in latewood vessels varied significantly between years. By contrast, xylem embolisms in diffuse-porous species (deciduous and evergreen) were barely detectable during winter. In one evergreen species, embolisms and refilling were detected in some vessels during the growing season. Based on the variation in the number of freeze–thaw events among years in Asian monsoon forests, we infer that M. amurensis obtained no benefit from extending leaf phenology because of the occurrence of vessel embolisms in winter. On the other hand, the leaf phenologies of deciduous and evergreen diffuse-porous species were less constrained by winter embolisms. Maackia amurensis persists in cool temperate regions by limiting the photosynthetic period.

Conducting Pathways in North Temperate Deciduous Broadleaved Trees

IAWA Journal ◽  
2008 ◽  
Vol 29 (3) ◽  
pp. 247-263 ◽  
Author(s):  
Toshihiro Umebayashi ◽  
Yasuhiro Utsumi ◽  
Shinya Koga ◽  
Susumu Inoue ◽  
Seizo Fujikawa ◽  
...  
Keyword(s):  
Water Transport ◽  
Water Distribution ◽  
Interspecific Variation ◽  
Annual Rings ◽  
Deciduous Species ◽  
Freeze Dried ◽  
Temperate Deciduous ◽  
The Many ◽  
Earlywood Vessels ◽  
Diffuse Porous

The interspecific variation of dye ascent in the stems of 44 broadleaved deciduous species growing in Japan was studied using freeze-dried samples after dye injection. The dye ascending pattern differed both within and between ring-porous and diffuse-porous species. In large earlywood vessels of all ring-porous species, the dye ascended only in the outermost annual ring, and the inner annual rings had lost their water transport function. The dye ascending pattern within the inner annual rings in the ring-porous species was categorized into three types: i) the dye ascended both in the many latewood vessels throughout the latewood and small earlywood vessels; ii) the dye ascended in the many vessels throughout the latewood; and iii) the dye ascended mainly in the late latewood vessels. In diffuse-porous species, the dye ascending pattern within the annual rings also was categorized into three types: i) the dye ascended throughout the annual rings; ii) the dye ascended mainly in the earlywood vessels; and iii) the dye ascended mainly in the latewood vessels. Xylem water distribution was also examined by cryo-SEM in three ring-porous and three diffuse-porous species that had different dye ascending patterns. The water distribution pattern within annual rings was correlated with the dye ascending pattern except for one diffuseporous species (Salix gracilistyla). In this case, water was distributed in the whole region of the annual rings although dye was mainly distributed in the earlywood. These results showed that the functional area of water transport within annual rings differed among ring-porous species and diffuse-porous species.

Study on Influence of Freeze-Thaw Cycles on the Physical-Mechanical Properties of Loess

2012 ◽  
Vol 442 ◽  
pp. 286-290
Author(s):  
Gui Quan Bi
Keyword(s):  
Mechanical Properties ◽  
Water Content ◽  
Water Distribution ◽  
Early Stage ◽  
Frozen Soil ◽  
Dry Density ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Filling Water

Loess foundations in seasonally frozen soil region are subject to severe effect of freeze-thaw cycles. This often results in water redistribution and structure weakening. So it is very important to study the physical-mechanical properties of loess under freeze-thaw cycles. In this paper, systematic study was carried out using freeze-thaw cycle machine. The impacts of freeze-thaw cycles on the physical-mechanical properties of loess including deformation, water distribution and dry density under the condition of filling water to loess samples were investigated. The results proved that the freeze-thaw cycles can increase the water content gradually from the bottom to the top in the loess samples under water supplied condition. The water content gradient reaches maximum at the freeze-thaw interface. The loess samples deform sharply at the early stage of the freeze-thaw cycles and then reach a stable status. The freeze-thaw cycles decrease the dry density of the loess samples gradually. The dry density at the top is lower than that at the bottom, due to more severe freeze-thaw effect at the top of the samples.

scholarly journals Timing of vessel formation in twigs and trunks in relation to porosity and leaf flushing

IAWA Journal ◽  
2016 ◽  
Vol 37 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Sayaka Takahashi ◽  
Erina Takahashi
Keyword(s):  
Temperate Forest ◽  
Late Summer ◽  
Early Spring ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Vessel Formation ◽  
Leaf Flushing ◽  
Leaf Appearance ◽  
Weak Tendency ◽  
Diffuse Porous

In order to understand the coordination of leaf phenology and functional xylem anatomy, the timing of vessel wall lignification in twigs and stems in relation to leaf appearance was studied in nine species with different porosity patterns. Cylindrical stem cores and twigs were collected from early spring through late summer from deciduous (Quercus serrata, Liquidambar styraciflua, and Acanthopanax sciadophylloides), and evergreen (Castanopsis cuspidata; Cinnamomum camphora, Ilex pedunculosa, Symplocos prunifolia, Quercus glauca and Quercus myrsinifolia) species in a temperate forest. The first-formed twig vessels lignified at the time of leaf appearance or before in all species. The timing of stem vessel lignification in relation to leaf appearance in semi-ringporous deciduous species was overlapping with that of ring-porous deciduous species and diffuse-porous deciduous species. Evergreen species showed a great variation in the timing of stem vessel lignification, relative to leaf flushing. The main conclusions are that 1) Vessel lignification occurs much earlier in twigs than in trunks of the same trees, with hardly any overlap between the two; 2) Deciduous trees do not differ much from evergreen species, but there is a weak tendency for evergreen species to have later vessel differentiation than deciduous species; 3) The timing of vessel formation shows little relation with porosity patterns and overlaps between diffuse-porous and ring-porous species. This suggests a much greater intergradation of timing of vessel formation in species of different porosity pattern in evergreen and deciduous species than recognized in the literature.

Microbial Diversity and their Biofilm Formation Potential in Pipes of Water Distribution System

2020 ◽  
Vol 17 (4) ◽  
pp. 113-117
Author(s):  
Rajanbir Kaur ◽  
Rajinder Kaur
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Biofilm Formation ◽  
Distribution Systems ◽  
Water Distribution ◽  
Potable Water ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Growth Patterns ◽  
Water Borne

Microbes are ubiquitous in surface as well as in ground water and some of them can make their way into potable water distribution systems. Contaminated soil with human and animal fecal matter, ill-maintained water and sewage pipelines, poor sanitation and personal hygiene are the main factors responsible for the presence of microbial pathogens in the drinking water. The presence of water-borne microbes in the potable drinking water systems determines its quality. Common microbes present in contaminated water are Shigella, Escherichia coli, Vibrio cholerae, Pseudomonas sp, Salmonella sp etc. The water-borne pathogens that reside and reproduce in water distribution system causes infection of gastrointestinal tract, urinary tract, skin, and lymph nodes. When these pathogens enter into the water distribution system pipelines they form biofilms. The formation of biofilm is a key component in microbial studies. Biofilm is the sessile aggregation of bacterial cells that adhere to each other on living or non-living surfaces and forms extracellular polymeric substances (EPS). The surface physico-chemical properties of both bacteria and substratum were important for the establishment of bacterial adhesion. Bacteria forming biofilms possesses different growth patterns, responds to specific micro-environmental conditions for the formation of structurally complex mature biofilms. In water distribution systems, adhesion of microbes to the water pipelines initiate biofilm formation which in return reduces the quality of potable water and increases the corrosion of pipes.

scholarly journals A new mechanistic understanding of ecophysiological patterns in a widespread alpine dwarf shrub – Refining climate-growth relationships

2021 ◽  
Author(s):  
Svenja Dobbert ◽  
Roland Pape ◽  
Jörg Löffler
Keyword(s):  
Thermal Conditions ◽  
Frost Damage ◽  
Growth Patterns ◽  
Environmental Data ◽  
Annual Growth ◽  
Dwarf Shrub ◽  
Environmental Drivers ◽  
Growth Responses ◽  
Evergreen Species ◽  
Early Season

Abstract. Considering the recent widespread greening associated with dwarf shrubs in arctic and alpine ecosystems, further understanding of how these shrubs respond to environmental conditions is of crucial importance. Here we present novel insights and propose a new method to monitor shrub growth, using high-precision point dendrometers. We analyzed intra- and inter-annual growth patterns of a common evergreen species (Empetrum nigrum ssp. hermaphroditum) by measuring its hourly radial stem variability at a micrometer scale over four successive years on exposed ridge positions and along a steep elevational gradient. With the same temporal resolution, we collected near-ground micro-environmental data and identified environmental drivers controlling growth behaviour. Overall, we found high inter-plant variability in growth-defining parameters, but high similarities in growth responses to the micro-environment. Early-season radial growth in spring exhibited high sensitivity to winter thermal conditions and prolonged ground-freezing in spring, suggesting that the evergreen species E. hermaphroditum remains photosynthetically active during the snow-free period, which increases carbohydrate accumulation for early season physiological activities. We discovered a phase of radial stem shrinkage during the winter months, which can be attributed to an active cell water reduction to protect the plant from frost damage. We present the first fine-scale intra-annual growth curves for an alpine dwarf shrub and identify soil moisture availability and winter freezing conditions as the main drivers of radial stem variability, thus forwarding the ongoing debate on the functional mechanisms of greening and browning in arctic and alpine regions.

scholarly journals Impact of planning horizon on water distribution network design

2021 ◽  
Author(s):  
F. Zeng ◽  
K. Li ◽  
X. Li ◽  
E. W. Tollner
Keyword(s):  
Interest Rate ◽  
Interest Rates ◽  
Exponential Growth ◽  
Water Distribution ◽  
Linear Growth ◽  
Water Distribution Network ◽  
Planning Horizon ◽  
Growth Patterns ◽  
Optimum Planning ◽  
Planning Horizons

Abstract The continuous expansion of Water Distribution Network (WDN) makes its design a dynamic process performed within many planning horizons. An appropriate planning horizon is important to save costs and avoid over-design. Typically, a master plan is practiced around every 20 years. The complexity of WDN and computational demands have prevented a full network study of the impact of planning horizon on system cost and efficiency. In this paper, a dynamic network model was employed to simulate the growth of WDN under different growth patterns (exponential and linear) and planning horizons to explore the optimum planning horizon under different interest rates. It is found that the choice of the optimum (i.e. least costly) planning horizon is sensitive to the interest rate. For both growth patterns, a shorter planning horizon is favored with higher annual interest rates while a longer planning horizon is favored with lower rates. With the same interest rate, exponential growth pattern generally favors a shorter planning horizon than linear growth pattern due to more excess capacity provided at the beginning of the study period. The optimum planning horizon is longer than 20 years when interest rate is lower than 3.0% for linear growth or 2.0% for exponential growth.

Assessing intraspecific phenological synchrony in zoochorous trees from the monsoon forests of northern Australia

2006 ◽  
Vol 22 (4) ◽  
pp. 419-429 ◽  
Author(s):  
Donald C. Franklin ◽  
Christine S. Bach
Keyword(s):  
Forest Tree ◽  
Environmental Cues ◽  
Plant Responses ◽  
Northern Australia ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Additional Information ◽  
Monsoon Forest ◽  
Leaf Flush ◽  
Monsoon Forests

Intraspecific synchrony in the phenology of tropical forest trees has implications for satiation of browsers and seed predators, pollination, dispersal and interpreting plant responses to environmental cues and stresses. Community phenological studies have been constrained in their consideration of these issues by the lack of concise quantitative measures of intraspecific synchrony. We propose a novel application of Colwell's predictability indices to overcome this deficiency. Its application is demonstrated by evaluating the leaf and reproductive phenologies of 8–16 individuals of each of 20 monsoon forest tree species from northern Australia monthly for 30 mo. The indices yielded substantial additional information over that provided by summaries averaged amongst conspecifics. Marked intraspecific asynchronies in leaf flush or flowering occurred in five evergreen species and two deciduous fig species, and were associated with prolonged individual commitments to these states. Five partly deciduous species exhibited marked intraspecific variation in the seasonal extent of leaf loss. We interpret the observed variation in intraspecific synchrony in terms of contrasting water-use and pollination strategies. The synchronicity indices are concise and robust to small and variable sample sizes, and may thus enhance studies of species-rich assemblages.

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