The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Palle Kristoffersen - One of the best experts on this subject based on the ideXlab platform.
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Tree development in Structural Soil – an empirical below-ground in-situ study of urban trees in Copenhagen, Denmark
Plant and Soil, 2017Co-Authors: Oliver Bühler, Morten Ingerslev, Simon Skov, Erik Schou, Iben Margrete Thomsen, Christian Nørgaard Nielsen, Palle KristoffersenAbstract:Aims The purpose of this study is to evaluate root and stem growth, nutrient status and Soil properties of a tree planting in Structural Soil. Methods Root and stem growth were measured at an 10-year-old urban planting of Tilia x europaea L. ‘Pallida’ established in Structural Soil on a paved square in Copenhagen, Denmark. Root abundance was quantified and Soil profiles were established at three different distances from 10 trees (1.0, 1.9, and 2.9 m). Soil and leaf samples were analysed for nutrient concentrations. Results Abundant root presence was measured across the entire profile of Structural Soil (160 × 60 cm) at all distances, provided that Structural Soil layers were constructed correctly. Erroneously constructed Structural Soil layers however, resulted in impaired tree and root growth. Coarse root morphology was affected by the confined growing space in the voids of the stone matrix. The Soil was relatively alkaline with an average pH (CaCl_2) of 7.3. Foliar analysis revealed deficiencies of K and Mn. These deficiencies might be due to a combined effect of high pH and low Soil concentrations of these nutrients. Conclusions The study documents that correctly constructed Structural Soils allow and encourage root growth in load bearing layers.
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Tree development in Structural Soil – an empirical below-ground in-situ study of urban trees in Copenhagen, Denmark
Plant and Soil, 2016Co-Authors: Oliver Bühler, Morten Ingerslev, Simon Skov, Erik Schou, Iben Margrete Thomsen, Christian Nørgaard Nielsen, Palle KristoffersenAbstract:Aims The purpose of this study is to evaluate root and stem growth, nutrient status and Soil properties of a tree planting in Structural Soil.
Oliver Bühler - One of the best experts on this subject based on the ideXlab platform.
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Tree development in Structural Soil – an empirical below-ground in-situ study of urban trees in Copenhagen, Denmark
Plant and Soil, 2017Co-Authors: Oliver Bühler, Morten Ingerslev, Simon Skov, Erik Schou, Iben Margrete Thomsen, Christian Nørgaard Nielsen, Palle KristoffersenAbstract:Aims The purpose of this study is to evaluate root and stem growth, nutrient status and Soil properties of a tree planting in Structural Soil. Methods Root and stem growth were measured at an 10-year-old urban planting of Tilia x europaea L. ‘Pallida’ established in Structural Soil on a paved square in Copenhagen, Denmark. Root abundance was quantified and Soil profiles were established at three different distances from 10 trees (1.0, 1.9, and 2.9 m). Soil and leaf samples were analysed for nutrient concentrations. Results Abundant root presence was measured across the entire profile of Structural Soil (160 × 60 cm) at all distances, provided that Structural Soil layers were constructed correctly. Erroneously constructed Structural Soil layers however, resulted in impaired tree and root growth. Coarse root morphology was affected by the confined growing space in the voids of the stone matrix. The Soil was relatively alkaline with an average pH (CaCl_2) of 7.3. Foliar analysis revealed deficiencies of K and Mn. These deficiencies might be due to a combined effect of high pH and low Soil concentrations of these nutrients. Conclusions The study documents that correctly constructed Structural Soils allow and encourage root growth in load bearing layers.
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Tree development in Structural Soil – an empirical below-ground in-situ study of urban trees in Copenhagen, Denmark
Plant and Soil, 2016Co-Authors: Oliver Bühler, Morten Ingerslev, Simon Skov, Erik Schou, Iben Margrete Thomsen, Christian Nørgaard Nielsen, Palle KristoffersenAbstract:Aims The purpose of this study is to evaluate root and stem growth, nutrient status and Soil properties of a tree planting in Structural Soil.
Lai Fern Ow - One of the best experts on this subject based on the ideXlab platform.
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Growth of Samanea saman: Estimated cooling potential of this tree in an urban environment
Urban Forestry & Urban Greening, 2019Co-Authors: Lai Fern Ow, Subhadip Ghosh, Mohamed Lokman Mohd YusofAbstract:Abstract Trees facilitate cooling of an urban environment through evapotranspiration. Urban trees help mitigate the urban heat island effect. However, urban conditions are often undesirable for tree growth and this negatively impacts on the cooling ability of urban trees. This study investigated foliar and Soil characteristics relating to the growth performance of Samanea saman –commonly planted tropical urban tree. The study was conducted on trees that had been growing for three years under three different growth conditions, in pavement, grass verges, and in Structural Soil. Trees in Structural Soil grew faster, were lusher despite a lower Soil moisture present in the fast-draining engineered blend. The Structural Soil was compacted to meet pavement load bearing requirements. The evapotranspirational cooling by trees in Structural Soil was approximately 75% higher compared with trees planted in pavements, and 50% greater than those in grass verges due to greater leaf area. In April, when temperatures were high and precipitation low, estimated cooling potential of the larger trees in Structural Soil was 8.5 kW while in July when temperatures were slightly lower with no change in rainfall, cooling was estimated to be 28% lower. By comparison, cooling was 76% and 81% lower for trees in pavement during the same period. The greater potential of Structural Soil resulted in evapotranspirational cooling.
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Effects of varying establishment approaches on the growth of urban street trees
Arboricultural Journal, 2018Co-Authors: Lai Fern Ow, Subhadip Ghosh, Yusof Mohamed Lokman Mohd.Abstract:ABSTRACTLimited rooting space is frequently a major impediment to the growth of street trees. Different approaches to enhance the Soil volume accessible to roots have been implemented in urban cities within the last decade. This survey observed the growth and health of trees planted in a) Structural, load-bearing Soil; b) biochar-stone-based load-bearing Soil; and c) planting pits installed with Structural cells. These alternative planting methods were compared against trees grown in conventional planting pits. The experimental trees were either street trees or sited within a plantation with similar Soil conditions. The results indicated that tree growth and health ratings were found to be superior in the order of, planting in pits with Structural cells, load-bearing material of Structural Soil and the biochar-stone blend, and conventional planting pits. Tree growth in Structural cells was found to be 37% higher than conventional planting pits. As such, these approaches can be considered at sites where co...
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Urban tree growth and their dependency on infiltration rates in Structural Soil and Structural cells
Urban Forestry & Urban Greening, 2017Co-Authors: Lai Fern Ow, Subhadip GhoshAbstract:Abstract Expanding tree canopies can be difficult to achieve in built environments because urban land is costly and urban Soil inhospitable to vegetation so engineered planting systems offer a potentially valuable tool for achieving sustainable urban forests. Tree water uptake, performance and root distribution were assessed in systems of Structural Soil and Structural cell. Structural Soil relies on stone and Soil, it is highly porous and designed to support tree root growth and possess pavement strength. The Structural cell is made up of rigid Structural units with 90% void space which is to be filled with Soil. To evaluate tree performance under the conditions of fill and drain regimes in Structural Soil and Structural cell, these two systems were subjected to three simulated infiltration rates. This study was conducted in April 2015 to April 2016 in the tropical equatorial environment of South East Asia. Infiltration rate affected both biomass accumulation and rooting depth. Species and substrate effect was significant for biomass and rooting characteristics but less prominent for transpiration. Biomass was greater for trees in Structural cells, and Pouteria obovata was particularly sensitive to prolonged inundation. Rooting depth was always higher in the rapid infiltration indicating the negative effects inundation had on this parameter. Root system in the Structural cell was deeper while those in the Structural Soil were wider. Samanea saman had better adapted to the drain and fill regimes, and this was despite Pouteria obovata being a coastal species and was expected to be flood tolerant. Species and substrate effect was weak (R2 ranging from 0.20 to 0.28) but moderate drainage consistently led to higher transpiration. We conclude that Structural Soil and Structural cell are potential solutions and provide a tool to overcome suboptimal urban growing conditions. The application of these solutions will allow for seamless integration of greenery with urban infrastructure.
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Tree-pulling experiment: an analysis into the mechanical stability of rain trees
Trees, 2010Co-Authors: Lai Fern Ow, F. R. Harnas, I. G. B. Indrawan, A. Sahadewa, H. Rahardjo, E. C. Leong, Y. K. FongAbstract:Tree-pulling experiments were conducted in Singapore involving 20 rain trees ( Samanea saman ) growing in four different Soil types (1) Structural Soil with 80% granite chips and 20% sandy loam Soil, (2) Structural Soil with 50% granite chips and 50% sandy loam Soil, (3) in situ Soil and (4) top Soil. The trees were pulled over with a winch attached to the stem at a standard height of 1.3 m and the force required to uproot or break the trees were recorded. The physical above and below ground characteristics of the trees were also measured. All 20 trees in this study failed via uprooting without any stem fracture. Analysis of the data showed that the maximum resistive bending moment (BM_max) was positively correlated with the overall size of the root plate, the size (diameter) of the individual roots and the extent of crown spread. The dry mass of crown was significantly greater in the 80:20 Structural Soil treatment while no significant difference was found between the other Soil types. The trunk diameter was not significantly different between treatments. Significant differences were observed in the depth of root plates where those grown in top Soil had significantly deeper root plates as opposed to the other treatments but though deeper, the vast majority of trees planted in top Soil exhibited fibrous rather than Structural roots. The cross-sectional area of roots which is indicative of the size of the individual roots showed a significantly greater value in the 80:20 Structural treatment while the 50:50 Structural and top Soil treatments had the lowest values. Significant differences in BM_max were only observed in the in situ Soil type while the rest of the planting substrates exhibited values that were comparable and not significantly different.
Nina L. Bassuk - One of the best experts on this subject based on the ideXlab platform.
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Sixth- and Tenth-Year Growth Measurements for Three Tree Species in a Load-Bearing Stone-Soil Blend Under Pavement and a Tree Lawn in Brooklyn, New York, U.S.
2020Co-Authors: Jason Grabosky, Nina L. BassukAbstract:In 1997, willow oak (Quercus phellos L.), swamp white oak (Quercus bicolor Willd.), and goldenraintree (Koelreuteria paniculata Laxm.) were planted in the right-of-way on Lorimer Street in Brooklyn, New York, U.S. This was one of the earliest commercial installations of the load-bearing stone–Soil blends (hereafter called Structural Soil) developed at Cornell University’s Urban Horticulture Institute (Grabosky and Bassuk 1995). The north–south street segment bisects McCarren Park between Driggs Avenue and Bayard Street. Trees were planted as 5.1 to 7.6 cm (2 to 3 in) caliper trees on either side of the street. The west side trees were planted in a continuous trench of Structural Soil 0.6 m (2 ft) deep by 2.1 m (6.9 ft) wide down the entire block. The Structural Soil was used as the sidewalk base capped with concrete. Tree openings were 0.9 m by 1.5 m (3 × 5 ft), which were planted after paving and then covered by granite unit block pavers. The east side of the street was a tree lawn planted with the same tree species. The site and the trees have been observed and measured in 1999, 2000, 2003, and 2007. After 3 years, there were no substantial differences in either shoot extension growth or foliage quality between the two sites for the oak species (Grabosky et al. 2002). Goldenraintree was not analyzed or reported in the third year set. This article discusses the trees as observed in Year 6 (2003) and Year 10 (2007).
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Seventeen years’ growth of street trees in Structural Soil compared with a tree lawn in New York City
Urban Forestry & Urban Greening, 2016Co-Authors: Jason Grabosky, Nina L. BassukAbstract:Abstract In 1997, Quercus bicolor and Quercus phellos in a New York City streetscape were planted in CU-Structural Soil under a concrete sidewalk and in a tree lawn with the intention of observing long term plant response as a comparative study of an early installation of the new designed Soil method. The trees have been measured nine times since the second year post-installation. We present the growth of trunk diameter, height and slenderness ratios. To verify root colonization in the Structural Soil under the sidewalk, tree root presence was measured using ground-penetrating radar in 2009, year 12. In the 17th year, trees in the sidewalk were similar in size with a higher level of survivorship as compared to the trees in the tree lawn. Adjusting for year of replacement in the tree lawn, model predictions for diameter of trees 15 years post-installation were no different for Q. bicolor in either the sidewalk (21.38 cm) or the tree lawn (22.05 cm). Q. phellos in the tree lawn were predicted to be slightly larger, 34.29 cm versus 31.34 cm in the sidewalk. Roots had colonized the Structural Soil under the sidewalk to 60 cm, its full depth. This provided evidence that the Structural Soil medium served as an acceptable rooting environment.
Iben Margrete Thomsen - One of the best experts on this subject based on the ideXlab platform.
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Tree development in Structural Soil – an empirical below-ground in-situ study of urban trees in Copenhagen, Denmark
Plant and Soil, 2017Co-Authors: Oliver Bühler, Morten Ingerslev, Simon Skov, Erik Schou, Iben Margrete Thomsen, Christian Nørgaard Nielsen, Palle KristoffersenAbstract:Aims The purpose of this study is to evaluate root and stem growth, nutrient status and Soil properties of a tree planting in Structural Soil. Methods Root and stem growth were measured at an 10-year-old urban planting of Tilia x europaea L. ‘Pallida’ established in Structural Soil on a paved square in Copenhagen, Denmark. Root abundance was quantified and Soil profiles were established at three different distances from 10 trees (1.0, 1.9, and 2.9 m). Soil and leaf samples were analysed for nutrient concentrations. Results Abundant root presence was measured across the entire profile of Structural Soil (160 × 60 cm) at all distances, provided that Structural Soil layers were constructed correctly. Erroneously constructed Structural Soil layers however, resulted in impaired tree and root growth. Coarse root morphology was affected by the confined growing space in the voids of the stone matrix. The Soil was relatively alkaline with an average pH (CaCl_2) of 7.3. Foliar analysis revealed deficiencies of K and Mn. These deficiencies might be due to a combined effect of high pH and low Soil concentrations of these nutrients. Conclusions The study documents that correctly constructed Structural Soils allow and encourage root growth in load bearing layers.
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Tree development in Structural Soil – an empirical below-ground in-situ study of urban trees in Copenhagen, Denmark
Plant and Soil, 2016Co-Authors: Oliver Bühler, Morten Ingerslev, Simon Skov, Erik Schou, Iben Margrete Thomsen, Christian Nørgaard Nielsen, Palle KristoffersenAbstract:Aims The purpose of this study is to evaluate root and stem growth, nutrient status and Soil properties of a tree planting in Structural Soil.
