Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Estonia.
Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Estonia.
Sci Total Environ. 2019 Dec 1;694:133699. doi: 10.1016/j.scitotenv.2019.133699. Epub 2019 Aug 4.
This paper investigates the full seasonal greenhouse gas (GHG) dynamics of fluxes from three green roof systems (lightweight clay aggregate-based green roof - LR; grass roof - GR; sod roof - SR) and natural control site on shallow Leptosol (NC), using closed static chambers in the period April 2014 to December 2015. CO, CH and NO fluxes are measured and their relationships to meteorological parameters and substrate physicochemical characteristics are quantified. Median CO flux values were 21 (LR), 38 (GR), 62 (SR), and 82 (NC) mg CO-C m h. The results show ecosystem respiration (R) clearly increased until July and then decreased until November. Net ecosystem CO exchange (NEE) was more variable than R, depending on plant growth phase and weather conditions. Median NEE values for study period (from April to November 2015) were -7 (LR), -17 (GR), -136 (SR), and -82 (NC) mg CO-C m h. The percentage of autotrophic respiration (R) in R showed clear rise from LR (35%) to NC (62%). CH consumption dominated resulting in median fluxes as follows: -2 (LR), -1 (GR), -15 (SR), and -23 (NC) μg CH-C m h. NO flux was low and highly variable in time, with median values varying from -0.07 (GR) to 2.18 (NC) μg NO-N m h. During the maximum vegetation growth, NEE exceeded R value. Green roofs are effective CH sinks, but they do not significantly affect NO flux. The main environmental factors determining GHG fluxes in linear models were parameters describing moisture regime, meteorological parameters and soil physical characteristics. These models can be used to predict GHG fluxes from similar green roof systems in analogous climatic conditions. We conclude that green roof technology may be used to mitigate excessive ambient GHG levels in urban areas.
本研究采用密闭静态箱法，于 2014 年 4 月至 2015 年 12 月期间，对三种绿色屋顶系统（轻型粘土骨料绿色屋顶-LR；草屋顶-GR；草坪屋顶-SR）和自然对照浅层淋溶土（NC）的温室气体（GHG）通量进行了全季节性研究。测量了 CO、CH 和 NO 的通量，并量化了它们与气象参数和基质物理化学特性的关系。CO 通量的中值分别为 21（LR）、38（GR）、62（SR）和 82（NC）mg CO-C m h。结果表明，生态系统呼吸（R）明显增加，直到 7 月，然后下降到 11 月。净生态系统 CO 交换（NEE）比 R 更为多变，取决于植物生长阶段和天气条件。研究期间（2015 年 4 月至 11 月）的 NEE 中值分别为-7（LR）、-17（GR）、-136（SR）和-82（NC）mg CO-C m h。R 中自养呼吸（R）的百分比从 LR（35%）到 NC（62%）呈现出明显的上升。CH 消耗占主导地位，导致如下中值通量：-2（LR）、-1（GR）、-15（SR）和-23（NC）μg CH-C m h。NO 通量在时间上很低且变化很大，中值值从-0.07（GR）到 2.18（NC）μg NO-N m h。在最大植被生长期间，NEE 超过了 R 值。绿色屋顶是有效的 CH 汇，但它们对 NO 通量的影响并不显著。线性模型中决定 GHG 通量的主要环境因素是描述水分状况、气象参数和土壤物理特性的参数。这些模型可用于预测类似气候条件下类似绿色屋顶系统的 GHG 通量。我们得出的结论是，绿色屋顶技术可用于缓解城市地区过高的环境 GHG 水平。
