Although urban parks sequester carbon by vegetation growth, they emit carbon due to materials production, transport, construction, management, demolition, and disposal throughout their life cycle. This study estimated the carbon budget of urban parks over their life cycle according to land cover type and explored ecological design and construction strategies to maximize carbon reduction. After setting up the scope of the life cycle, the energy and material used for each stage were analyzed on the basis of field survey, design and construction details, and literature review of 30 study parks. The net carbon uptake per unit of park area averaged 8.51 kg/m², with urban parks playing an important role as a source of carbon uptake to mitigate the climate change. This study suggested ecological design and construction strategies including the expansion of tree planting spaces through the minimization of grass and impervious areas, the minimization of changes to existing topography, and the utilization of local materials. As a result of applying these strategies to study parks, the net carbon uptake increased approximately 9.2 times. These study results are expected to be useful as information for the implementation of carbon-neutral policies and greenspace establishment projects.

J. Neurochem.(2010)114, 1085–1096. Ginsenoside Rb1, a major ingredient of ginseng saponins, can affect various brain functions, including learning and memory. When ingested orally, ginsenoside Rb1 is not found in plasma as well as urine, but its metabolite compound K (ComK) reaches the systemic circulation in animals and human. Nevertheless, the pharmacological actions of ComK are still poorly known. In the present study, we investigated the effect of ComK on GABAergic spontaneous miniature inhibitory post‐synaptic currents (mIPSCs) in acutely isolated rat hippocampal CA3 pyramidal neurons using a conventional whole‐cell patch‐clamp technique. While ComK significantly increased mIPSC frequency in a concentration‐dependent manner, it had no effect on the current amplitude, suggesting that ComK acts pre‐synaptically to increase the probability of spontaneous GABA release. ComK still increased mIPSC frequency even in a Ca²⁺‐free external solution, suggesting that the ComK‐induced increase spontaneous GABA release is not related to Ca²⁺influx from the extracellular space. However, the ComK‐induced increase mIPSC frequency was significantly decreased after the blockade of either sarcoplasmic/endoplasmic reticulum Ca²⁺‐ATPase or Ca²⁺release channels. These results strongly suggest that ComK enhances spontaneous GABA release by increasing intraterminal Ca²⁺concentration via Ca²⁺release from pre‐synaptic Ca²⁺stores. The ComK‐induced modulation of inhibitory transmission onto CA3 pyramidal neurons could have a broad impact on the excitability of CA3 pyramidal neurons and affect the physiological functions mediated by the hippocampus.

Landscape trees sequester carbon during their growth processes, but they emit carbon through production in nurseries, which may offset carbon uptake. This study quantified the carbon footprint of landscape tree production. After determining the scope of life cycle for landscape tree production, the energy and material used to produce trees of a target size were analyzed by conducting a field survey of 35 nurseries. This energy consumption and input material were converted to an estimate of carbon emitted using data on carbon emission coefficients. The net carbon uptake was 4.6, 12.2, and 24.3 kg/tree for trees with a DBH of 7, 10, and 13 cm, respectively. Thus, even though carbon is emitted during the production process, landscape trees can act as a source of carbon uptake in cities that have high energy consumption levels. This study broke new ground for quantifying the carbon footprint of landscape tree production by overcoming limitations of the past studies that only considered carbon uptake due to absence of data on energy consumption and difficulty of field survey. These study results are expected to provide information on the carbon footprint of landscape trees and to be useful in determining optimal greenhouse gas emissions reduction goal through urban greenspaces.

Urban parks are essential for offsetting high carbon emissions in cities, which are known to be high emitters. This study quantified carbon uptake and storage in Daejeon and Daegu, two major metropolitan cities in South Korea, and explored planting strategies to promote carbon offset services. Mean carbon uptake and storage per unit area in the study parks were 2.6 ± 0.1 t/ha/yr and 29.9 ± 1.7 t/ha, respectively. The urban park trees of a metropolitan city in South Korea were estimated to annually sequester and store 50 kt/yr and 572 kt of carbon, respectively. This carbon uptake equaled 1.5% of the total annual carbon emissions from residential energy consumption. The economic value of the carbon uptake was equivalent to $3.3 million/yr, which is 1.50% of the annual establishment budget of urban forests of the Korea Forest Service. Planting strategies included reducing unnecessary grass and pavement areas, the active planting of trees in the potential planting space, multilayered planting, and planting tree species with high growth rates. These results are expected to guide policies related to carbon credits, which have recently emerged as major concerns, and to provide useful information for quantifying carbon offset services in greenspace establishment projects.

This study developed a pit planting technique in which only planting spots were dug to reduce earthwork costs and to enhance tree growth. This technique, in which pits of different depths were dug, was actually applied to a semi-arid experiment site to analyze its effects on soil moisture and tree growth. The soil moisture content in the pit planting 30 cm in depth (30 cm pit planting) and 50 cm in depth (50 cm pit planting) was 6.5 ± 0.1% and 6.7 ± 0.1%, respectively, which was at least 1.3 times higher (P < 0.01) than that of the control plot (surface planting). The crown growth rate of Populus sibirica trees for 2 years following the planting was 733.5 ± 43.3% in the 30 cm pit planting and 889.4 ± 58.5% in the 50 cm pit planting which, at their maximum, were 1.7 times higher than in the control plot. The stem diameter growth and the new shoot length were maximally 1.5 times better in the pit planting than in the control plot. The pit planting technique developed will be widely useful to promote the rooting and growth of trees in planting areas with problems of strong winds and dryness.