Different vegetation types used for the extensive green roofs have characteristic physiological and morphological traits (e.g., C3, C4, or CAM photosynthesis, deciduous or evergreen). Several Sedum species are recogni...Different vegetation types used for the extensive green roofs have characteristic physiological and morphological traits (e.g., C3, C4, or CAM photosynthesis, deciduous or evergreen). Several Sedum species are recognized as “inducible CAM” type plants. These differences in the physiological and morphological traits have a considerable effect on the carbon sequestration in the green roofs. The objective of the present study was to quantify the carbon sequestration in several green roof plants during the first year after the construction of the green roofs and to clarify the relevance of the physiological and morphological traits to each plant’s ability to sequester carbon in its body using the growth analysis method. We used Zoysia matrella , Ophiopogon japonicus , and Sedum mexicanum species for the study wherein, S. mexicanum was assigned to the wet, dry, and non-irrigation treatments, and Z. matrella and O. japonicus only received the wet treatment. During the first year after the construction, carbon sequestration in the plants and the substrate of S. mexicanum was in the range of 276 to 364 g-C/m2/year, which was similar to that of O. japonicus and the finding of a previous study. In contrast, Z. matrella exhibited the highest carbon sequestration (670 g-C/m2/year), which is also expressed as the relative plant C-sequestration rate per whole-plant C-content (RGRc), because Z. matrella is a C4 plant and exhibits the highest net assimilation rate (NARc) of all species. Significant differences were not observed in RGRc , NARc , and RMF (root mass fraction) in S. mexicanum between the wet and dry treatments. These results suggest that in countries with high rainfall, a high frequency of irrigation has an insignificant effect on the physiological and morphological characteristics, and carbon sequestration in the Sedum green roofs.展开更多
用模拟践踏器研究践踏对沟叶结缕草(Z oy sia m a trella)坪用性状的影响。试验设对照、轻度、中度和重度践踏4个践踏强度,结果表明,对照和轻度践踏下,草层高度、叶片长度和活生物量均明显高于重度践踏;中度践踏强度下草坪草层高度、叶...用模拟践踏器研究践踏对沟叶结缕草(Z oy sia m a trella)坪用性状的影响。试验设对照、轻度、中度和重度践踏4个践踏强度,结果表明,对照和轻度践踏下,草层高度、叶片长度和活生物量均明显高于重度践踏;中度践踏强度下草坪草层高度、叶片长度随着降雨量和灌溉次数变化而呈现波动式消长规律。对照和轻度践踏的草坪密度随着践踏时期的延长而呈现持续下降的趋势,但中度和重度践踏的草坪密度在9月份时呈现增加的趋势,并且重度践踏草坪增加的幅度明显高于中度践踏;轻度、中度、重度践踏草坪的地上活生物量依次增加,但轻度与中度践踏在践踏的前2个月差异不显著(P>0.05),之后出现显著差异(P<0.05);而中度和重度践踏的草坪地上活生物量差异均不显著(P>0.05)。对于沟叶结缕草草坪而言,如果采取较粗放的养护措施,轻度践踏强度比较适宜即75 kg重,每隔4 d践踏10次;如果采取比较好的、适时的养护措施如适时灌溉、施肥和封闭恢复,中度践踏强度(即75 kg重,每隔2 d践踏10次)也可以维持比较好的草坪坪用质量。展开更多
文摘Different vegetation types used for the extensive green roofs have characteristic physiological and morphological traits (e.g., C3, C4, or CAM photosynthesis, deciduous or evergreen). Several Sedum species are recognized as “inducible CAM” type plants. These differences in the physiological and morphological traits have a considerable effect on the carbon sequestration in the green roofs. The objective of the present study was to quantify the carbon sequestration in several green roof plants during the first year after the construction of the green roofs and to clarify the relevance of the physiological and morphological traits to each plant’s ability to sequester carbon in its body using the growth analysis method. We used Zoysia matrella , Ophiopogon japonicus , and Sedum mexicanum species for the study wherein, S. mexicanum was assigned to the wet, dry, and non-irrigation treatments, and Z. matrella and O. japonicus only received the wet treatment. During the first year after the construction, carbon sequestration in the plants and the substrate of S. mexicanum was in the range of 276 to 364 g-C/m2/year, which was similar to that of O. japonicus and the finding of a previous study. In contrast, Z. matrella exhibited the highest carbon sequestration (670 g-C/m2/year), which is also expressed as the relative plant C-sequestration rate per whole-plant C-content (RGRc), because Z. matrella is a C4 plant and exhibits the highest net assimilation rate (NARc) of all species. Significant differences were not observed in RGRc , NARc , and RMF (root mass fraction) in S. mexicanum between the wet and dry treatments. These results suggest that in countries with high rainfall, a high frequency of irrigation has an insignificant effect on the physiological and morphological characteristics, and carbon sequestration in the Sedum green roofs.
文摘用模拟践踏器研究践踏对沟叶结缕草(Z oy sia m a trella)坪用性状的影响。试验设对照、轻度、中度和重度践踏4个践踏强度,结果表明,对照和轻度践踏下,草层高度、叶片长度和活生物量均明显高于重度践踏;中度践踏强度下草坪草层高度、叶片长度随着降雨量和灌溉次数变化而呈现波动式消长规律。对照和轻度践踏的草坪密度随着践踏时期的延长而呈现持续下降的趋势,但中度和重度践踏的草坪密度在9月份时呈现增加的趋势,并且重度践踏草坪增加的幅度明显高于中度践踏;轻度、中度、重度践踏草坪的地上活生物量依次增加,但轻度与中度践踏在践踏的前2个月差异不显著(P>0.05),之后出现显著差异(P<0.05);而中度和重度践踏的草坪地上活生物量差异均不显著(P>0.05)。对于沟叶结缕草草坪而言,如果采取较粗放的养护措施,轻度践踏强度比较适宜即75 kg重,每隔4 d践踏10次;如果采取比较好的、适时的养护措施如适时灌溉、施肥和封闭恢复,中度践踏强度(即75 kg重,每隔2 d践踏10次)也可以维持比较好的草坪坪用质量。
