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• Wind damage on trees following hurricane Sandy and implications for city landscaping: Glen Ridge - Montclair towns, New Jersey

  1-11

  Faith Justus

  Views:

  67

  Glen Ridge is a small municipality in the Northern New Jersey with a significant number of huge trees lining majority of its streets. The trees have been subject to a wide range of natural and artificial stresses, one being the strong wind associated with superstorm Sandy. On 29th October 2012, a windstorm of extreme intensity struck the Tristate region and brought havoc to the tree population including those in Glen Ridge. A survey was conducted immediately after the storm to collect quantitative information on fallen tree population. The study aimed at understanding the spatial extent of wind damage on trees with reference to location, trunk diameter and soil characteristics. A total of 51 fallen trees with a mean trunk diameter of 100.4 centimetres along streets in study area were surveyed. High damage was noted on trees in Glen Ridge (29 trees) while streets transitioning to Montclair had 22 fallen trees. Majority of the surveyed trees were found on USBOO soils (49%), which are characterised as disturbed urban soils with Boonton substratum-Boonton complexes. BowrB soils had 27.5%, Boob 13.7%, BowrC 7.8% and USDUNB 2.0% of fallen trees. A need for city wide tree inventorying and species mapping is identified as a management implication to further enhance the historical value of the city. Other measures are discussed with a view of engaging appropriate local management partnerships and coordination frameworks to play a role in protecting the remaining large trees.

• Heavy metal loads in the soil of Debrecen

  57-67

  Sándor Szegedi

  Views:

  41

  Results of examinations on the amount, and spatial distribution of heavy metal compounds in the soil of Debrecen, their geographic, pedologic and ecologic aspects are presented in this study. The effects of the differences in traffic conditions, build-up/land use and the density of vegetation on the heavy metal content of the soils have been examined in city of Debrecen and its closer environment. Cadmium-, cobalt-, nickel-, lead-, and copper-contents of the soil samples taken from 88 sites of the sample area have been studied after acidic extraction, using atomic absorption spectrometer with the flame technique. Close-to-background concentrations of heavy metals in unpolluted soils of the forested area of the Nagyerdő were determined. Spatial differences in the heavy metal content of the soils for the whole area of Debrecen have been studied. Influence of soil properties (humus, CalciumCarbonate content, pH and grain size distribution) on the binding and mobility of heavy metals in the soil has been examined. Vertical distribution and mobility of heavy metal compounds in acid sandy soils was determined. Heavy metal content of soil in the most sensitive areas, playgrounds, recreational areas, urban gardens and grazing fields along busy roads has been surveyed.

• Modelling the effects of long-term urban land use change on the water balance

  143-159

  Dagmar Haase

  Views:

  37

  The level of land consumption for housing and transport contrasts sharply with both the necessity and the legal obligation to maintain the ecological potential afforded by open spaces to meet the needs of current and future generations in terms of resource protection and climate change. Owing to the increasing intensity of soil usage, in many urban landscapes the soil conditions has deteriorated. The natural filter and run-off regulating functions of soils are impaired or even disappeared altogether by land surfacing. Since such soil functions closely depend on the soil’s biophysical properties, the decline of water balance functionality caused by urbanisation and increasing imperviousness varies. In response to the demand to sustainably secure urban water resources, it needs to be assessed exactly how land surfacing affects the functions concerned. Analysing and evaluating the urban land use change and the respective imperviousness on the long-term water balance ought to improve our general understanding of the water household related impact of urbanisation. Therefore, the aim of this paper is to assess the impact of urban land use change and land surfacing on the long-term water balance over a 130-year trajectory using the example of Leipzig. In particular, attention is to be paid to evapotranspiration, direct runoff and groundwater recharge.