scholarly journals Establishing Maximum Size Expectations for Urban Trees with Regard to Designed Space

2013 ◽  
Vol 39 (2) ◽  
Author(s):  
Jessica Sanders ◽  
Jason Grabosky ◽  
Paul Cowie
Keyword(s):  
Urban Landscape ◽  
Maximum Size ◽  
Tree Canopy ◽  
Urban Trees ◽  
Tree Age ◽  
Site Type ◽  
Large Size ◽  
Significant Difference ◽  
Species Specific ◽  
Site Types

One issue confronting the application of forest management principles to urban tree canopy management decisions is the lack of data correlating site, tree size, and tree age. Researchers tested whether terminal size (stem diameter) can be linked to site type for informed management and design decisions. Data were considered from eleven New Jersey, U.S. communities. Diameter breast height (DBH) distribution established regionalized service life expectancies of commonly planted species by site type and expected maximum DBH. The goal was to develop a method to identify trees approaching senescence within an inventory. Three common urban landscape site types were used: tree pit, planting strip, and unlimited soil. Thirty-one taxa were present in large enough populations to use in species-specific analysis. The species were classified into small, medium, and large size categories based on published growth expectations. The study authors developed DBH occurrence percentiles, and DBH within the ninety-fifth were described as a maximum size range. There was a significant difference in maximum sizes between planting site types. Regardless of the size class of the tree, the data showed reduced planting space resulted in reduced maximum size.

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

scholarly journals Responses of Bat Communities (Mammalia: Chiroptera) to Forest Loss and Habitat Conversion in Southern Cameroon

2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou
Keyword(s):  
Secondary Forest ◽  
Biosphere Reserve ◽  
Abundant Species ◽  
Primary Forest ◽  
Habitat Types ◽  
Habitat Transformation ◽  
Significant Difference ◽  
Southern Cameroon ◽  
Habitat Conversion ◽  
Species Specific

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.

scholarly journals Randomised trial on clinical performances and biocompatibility of four high-flux hemodialyzers in two mode treatments: hemodialysis vs post dilution hemodiafiltration

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marion Morena ◽  
Caroline Creput ◽  
Mouloud Bouzernidj ◽  
Annie Rodriguez ◽  
Lotfi Chalabi ◽  
...  
Keyword(s):  
Primary Outcome ◽  
Randomised Trial ◽  
High Flux ◽  
Β2 Microglobulin ◽  
Inflammatory Parameters ◽  
Large Size ◽  
Significant Difference ◽  
Good Biocompatibility ◽  
Very High ◽  
Solute Clearance

AbstractThis prospective multicenter randomized comparative cross-over trial aimed at evaluating the influence of hemodialysis vs post-dilution hemodiafiltration with high-flux dialyzers in solute clearance and biocompatibility profile. 32 patients were sequentially dialyzed with Leoceed-21HX, Polypure-22S+, Rexsys-27H and VIE-21A. Primary outcome was β2-microglobulin removal. Secondary outcomes were (i) extraction of other uremic solutes (ii) parameters of inflammation and nutrition and (iii) comparative quantification of perdialytic albumin losses (using total ‘TDC’ vs partial ‘PDC’ collection of dialysate). Significant increases in removal rates of β2-microglobulin (84.7 ± 0.8 vs 71.6 ± 0.8 mg/L), myoglobin (65.9 ± 1.3 vs 38.6 ± 1.3 µg/L), free immunoglobulin light chains Kappa (74.9 ± 0.8 vs 55.6 ± 0.8 mg/L), β-trace protein (54.8 ± 1.3 vs 26.8 ± 1.4 mg/L) and orosomucoid (11.0 ± 1.1 vs 6.0 ± 1.1 g/L) but not myostatin (14.8 ± 1.5 vs 13.0 ± 1.5 ng/mL) were observed in HDF compared to HD when pooling all dialyzers. Rexsys and VIE-A use in both HD and HDF subgroups was associated to a better removal of middle/large-size molecules compared to Leoceed and Polypure, except β2-microglobulin for Rexsys. Inflammatory parameters were unchanged between dialyzers without any interaction with dialysis modality. Mean dialysate albumin loss was comparable between TDC and PDC (1.855 vs 1.826 g/session for TDC and PDC respectively). In addition, a significant difference in albumin loss was observed between dialyzers with the highest value (4.5 g/session) observed using Rexsys. Use of all dialyzers was associated with good removals of the large spectrum of uremic toxins tested and good biocompatibility profiles, with an additional gain in removal performances with HDF. Larger surface area, thinner wall and resultant very high ultrafiltration coefficient of Rexsys should be taken into account in its clear performance advantages.

Changes in DOC and DON fluxes in response to harvest intensity of black-spruce-dominated forest ecosystems in northwestern Ontario

2009 ◽  
Vol 89 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Dave M Morris
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Black Spruce ◽  
Site Type ◽  
Northwestern Ontario ◽  
Clearcut Harvesting ◽  
Second Year ◽  
Forest Floors ◽  
Source Sink ◽  
Site Types

The current study was conducted to quantify and compare dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fluxes through black-spruce-dominated forests, to compare the source/sink characteristics of sphagnum- versus feathermoss-dominated forest floors, and to identify changes in DOC and DON flow patterns occurring as a result of clearcut harvesting. After 2 yr of pre-harvest monitoring, replicated, experimental harvests of varying intensities of biomass removals were conducted followed by 4 yr of post-harvest sampling. Prior to harvest, the upland site type, dominated by feathermoss, was a significant source of DOC and DON, whereas, the wet-sphagnum-dominated sites exported minor amounts of these solutes. After harvest, DOC and DON fluxes peaked in the second year, but then dropped off significantly to at or below pre-harvest levels. On the upland site type, chipper debris appeared to be a major source of DOC and DON generating fluxes well above the pre-harvest levels. On the wetter site types, it appeared that microclimate differences between harvest treatments had a stronger influence on DOC and DON production than did the amount or type of harvest residue. Full-tree harvesting did not significantly alter the production of DOC and DON when compared with stem-only harvesting on the sites included in this study. Key words: DOC, DON, forest floor leachate, black spruce, harvesting response

Alpha Radioactivity Monitor Using Ionized Air Transportation for Large Size Uranium Waste: Part 1—Large Measurement Chamber and Evaluation of Detection Performance

2010 ◽  
Author(s):  
Susumu Naito ◽  
Shuji Yamamoto ◽  
Mikio Izumi ◽  
Yosuke Hirata ◽  
Yukio Yoshimura ◽  
...  
Keyword(s):  
Maximum Size ◽  
Air Transportation ◽  
Detection Performance ◽  
Practical Applications ◽  
Large Size ◽  
Large Measurement ◽  
Alpha Radioactivity ◽  
Clearance Level ◽  
Ionized Air ◽  
Measurement Chamber

We present an ionized air transportation type alpha radioactivity monitor to efficiently perform the clearance level inspection for large size uranium waste and its detection performance. In previous work, we developed a prototype monitor with an about 1000 mm cubic measurement chamber to measure the cut waste. However, in a survey of target waste, we found that it is desired to measure not only the cut waste but also the lengthy waste such as uncut cylinders. Therefore, we developed an alpha radioactivity monitor with a long and large measurement chamber (effective sizes: 500 mm x900 mm x3200 mm) for long and large cylindrically-shaped waste (maximum size: 300 mm in diameter and 3000 mm in length, weight: 10 to 200 kg). We aimed <1000 Bq as the target value of Alpha radioactivity Detection Limit (ADL), which is one-tenth of the clearance level (1 Bq/g) for 10 kg waste. The issue to size up the measurement chamber was to suppress the reduction in sensitivity of alpha radioactivity. To overcome this, we enhanced an air fan power and optimized an ion sensor design. Using this monitor, we measured and evaluated ADLs for several cases supposing the practical applications (long cylinders with a smooth surface, bump, or concavity and convexity, and pipes with several small diameters). The resulting ALD ranged from 60 Bq to 120 Bq and sufficiently satisfied the target ALD (<1000 Bq). In conclusion, this monitor has sufficient performance for the clearance level inspection for large uranium waste.

scholarly journals Standortkartierung im Lehr- und Forschungswald der ETH in Sedrun | Site mapping in the ETH Research Forest of Sedrun

2009 ◽  
Vol 160 (2) ◽  
pp. 27-36
Author(s):  
Jacques Doutaz ◽  
Hans-Ulrich Frey ◽  
Harald Bugmann
Keyword(s):  
Classification System ◽  
Sustainable Forest Management ◽  
Structural Characteristics ◽  
Site Classification ◽  
Classification Methods ◽  
Site Type ◽  
Forest Sites ◽  
Site Mapping ◽  
A Site ◽  
Site Types

Phytosociology has advanced in various respects since the fundamental groundwork was laid, which was mainly concerned with developing a classification system of vegetation units. Current site classification methods for forests consider not only floristic aspects, but also pedological, topographic and structural characteristics of forest stands. During the summer of 2007, a site mapping was carried out in the ETH Research Forest near Sedrun (Switzerland). This paper describes the methods employed, and it evaluates the applicability thereof based on case studies. Site mapping is based on expert opinion, and as such it includes a certain degree of generalization and subjectivity in the evaluation of stands and their assignment to a site type. However, we propose that site classification constitutes a suitable tool for describing and characterizing the complexity of forest sites. The accurate description of site types strongly facilitates the interpretation and the applicability of a classification system in decision support for sustainable forest management.

scholarly journals Deskripsi dan Preferensi Habitat Udang Air Tawar Macrobrachium rosenbergii (De Man, 1879) dari Sungai Maraja, Toli-Toli, Sulawesi Tengah

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Aswandi Aswandi ◽  
Annawaty Annawaty
Keyword(s):  
Carapace Length ◽  
Economic Value ◽  
Line Drawing ◽  
Macrobrachium Rosenbergii ◽  
Maximum Size ◽  
Morphological Characters ◽  
Freshwater Prawn ◽  
Large Size ◽  
De Man ◽  
Central Sulawesi

Macrobrachium rosenbergii (De Man, 1879) is a freshwater prawn species that have a high economic value because of its relatively large size compared to the other freshwater prawn species. Exploration to find this species in the Maraja River, Toli-Toli, Central Sulawesi was carried out in January 2019. Sample collected using tray net. Two male specimens of M. rosenbergii were found in the river, with maximum size of carapace length reaching 45.94 mm. Macrobrachium rosenbergii has been found in habitats with clay substrate and slow flowing current. This record extended the distribution of M. rosenbergii, whose spread in Sulawesi has been known only in the southern part of the island, such as in Makassar, Bone, Pinrang, Wajo and Luwu. In this paper, the morphological characters and line drawing of some character M. rosenbergii from the Maraja River were provided.

scholarly journals Probable Maximum Sizes of Inclusions Predicted by SEV and PSD for BH Steels of Automobile Exposed Panel with Different Sulfur Contents

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 637
Author(s):  
Xiaoqian Pan ◽  
Jian Yang
Keyword(s):  
Size Distribution ◽  
Exponential Function ◽  
Molten Steel ◽  
Extreme Values ◽  
Maximum Size ◽  
Low Carbon ◽  
Number Density ◽  
Bake Hardening ◽  
High Number Density ◽  
Large Size

This study attempted to estimate the maximum size of inclusions in the ultra-low carbon Bake Hardening (BH) steels of automobile exposed panel. The Probable Maximum Sizes (PMS) of inclusions at the different steelmaking stages for BH steel with different sulfur contents were predicted by two methods of Statistics of Extreme Values (SEV) and Particle Size Distribution (PSD). The S content does not show a relationship with the PMS prediction of inclusions in the molten steel in which Al2O3 is the main inclusion, while the higher content of S leads to a larger PMS value in the slab, due to more number of large-sized Al2O3-MnS inclusions formed during solidification. The PMS value in the slab is greater than that in the molten steel for BH steel. Thus, the PMS of inclusions in the slab cannot be estimated from the molten steel samples. The SEV can be used to predict well the PMS values at different steelmaking stages for BH steels. However, the PSD of exponential function cannot predict well the PMS value in the slab for BH steel when considering all kinds of inclusions due to the large influence of small-sized MnS with high number density on the PSD of exponential function. When only considering Al2O3-MnS inclusions, the PSD of exponential function can make a reasonable PMS prediction in the slab, because the size distribution of Al2O3-MnS with large size can follow the exponential function.

scholarly journals Mechanisms by Which Pre-Commercial Thinning Increases Black Spruce Growth in Different Climates and Soil Types

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 599
Author(s):  
Amy Wotherspoon ◽  
Robert L. Bradley ◽  
Daniel Houle ◽  
Stéphane Tremblay ◽  
Martin Barrette ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Black Spruce ◽  
Canopy Openness ◽  
Soil N ◽  
Site Type ◽  
Commercial Thinning ◽  
Soil Moisture Availability ◽  
N Fertility ◽  
Competition For Resources ◽  
Site Types

In the province of Québec (Canada), pre-commercial thinning (PCT) is a common silvicultural practice applied to young black spruce (Picea mariana (Mill.) BSP) stands. PCT removes some of the competing vegetation and smaller black spruce stems, in order to improve growth rates and reduce forest rotation intervals. It is uncertain whether this positive response in black spruce growth is primarily due to lower competition for resources or to other mechanisms, which may vary according to climate or edaphic conditions. We sampled soils and black spruce needles in PCT-treated and non-treated control plots occurring in two climate regimes, as well as on two contrasting soil parent materials within one of these two climate regimes (i.e., three “site types”). We performed our sampling approximately 20 years after treatment. Paired treatment plots (i.e., PCT vs. control) were replicated at four independent sites in each of the three site types, for a total of 24 plots. Over two consecutive years, we measured stand structural characteristics, indices of soil N fertility, soil microbial activity, indices of soil moisture availability, canopy openness, and foliar characteristics in each plot. In each site type, PCT decreased total basal area but increased radial growth of individual trees. Across all plots, soil N mineralization rates measured in 2016 were positively related to foliar N concentrations of one-year-old needles collected in 2017. Annual precipitation, drainage class, potential evapotranspiration, and climate moisture index all indicated that plots occurring in the drier climate and on glacial till deposits were more prone to summer moisture deficits. Accordingly, PCT increased forest floor moisture only in this site type, which may benefit tree growth. In the wetter climate and on poorly drained soils, however, we found evidence that PCT reduces soil N fertility, presumably by increasing the spread of ericaceous shrubs in the understory. In the dry fertile site type, the range in canopy openness was substantially higher (12–37%) and correlated negatively with tree diameter, suggesting that greater light availability did not improve tree growth. Taken collectively, our data suggest that PCT increases black spruce growth across a broad range of site conditions found in Québec, presumably by lowering intraspecific competition for resources. However, on drier sites, PCT may also benefit trees by increasing soil moisture availability, whereas wetter climates may mitigate the beneficial effect of PCT due to a loss of soil N fertility.

Effect of seed size on germination in three species from arid Arabian deserts

Botany ◽  
2020 ◽  
Author(s):  
Sanjay Gairola ◽  
Tamer Mahmoud ◽  
Hatem A. Shabana ◽  
Asma AlKetbi ◽  
Shyam Phartyal
Keyword(s):  
Seed Size ◽  
Low Temperatures ◽  
Germination Percentage ◽  
Light Regime ◽  
Salvadora Persica ◽  
Large Size ◽  
Significant Difference ◽  
Brassica Tournefortii ◽  
The Mean ◽  
Study Species

In many species, seeds with different sizes show diverse responses in their requirements for temperature and light for optimal germination. In this study, the effect of seed size (i.e., small and large) on germination was tested in seeds of Brassica tournefortii Gouan., Lotus garcinii DC., and Salvadora persica L. from arid Arabian Desert habitats. The mean seed size of all three study species differs significantly between small and large-sized seeds. Differences were observed in seed germination between large and small seeds of B. tournefortii and L. garcinii. We found that large-size seeds of B. tournefortii and L. garcinii showed higher germination at all tested temperatures than that displayed by small-sized seeds. However, both small and large seeds of S. persica germinated equally (100%) well under all incubated conditions. Our results show significant differences in germination percentage between small and large-sized seeds of B. tournefortii at 25/35°C under a 12-hour light regime. However, L. garcinii has a significant difference in germination percentage at low temperatures (15/25°C) under a 12-hour light regime.

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