花境植物固碳能力及碳收支评估

Assessments of Carbon Sequestration Capacity and Carbon Budget of Flower Borders

花境在城市绿地中的应用越来越广泛,但花境的碳汇效益仍然存在争议。为评价和预测花境的碳收支效益提供科学依据,基于对植物固碳量和群落碳收支的测算,以天津市常见的50种花境植物和5个花境样地为例,构建花境群落碳收支评估模型,评估并模拟花境的碳收支情况,分析花境碳收支与碳排放活动、群落特征之间的关系。结果表明:1)一年生植物与多年生植物的年固碳量平均值近似,高固碳植物有硫华菊、柳枝稷、月季等15种;2)由于运输碳排放较高等原因,大部分实际营造的花境仍是碳源;3)花境的碳汇效益受植物固碳能力、植物生活型比例、花境面积、运输距离、更新频率等多重因素影响。3)合理配置的花境能够在3~5年内实现碳平衡。最后针对研究存在的不足提出展望,即还需更多样本来验证结论,花境的长期碳收支预测应考虑更多的影响因素,以及生态效益评估应与经济效益、美学价值相结合。

Flower border has been increasingly applied,but currently people have few scientific understandings of their carbon sequestration capacity.Based on the calculation of vegetation's carbon sequestration and plant community's carbon budget,this paper constructs a simple model to evaluate flower border carbon budget using 50 plants commonly used in flower borders and 5 flower borders in Tianjin,and analyzes the relationship between carbon budget of flower borders and carbon emission activities as well as community characteristics.It aims to provide the science base for evaluate and forecast the benefits brought in by the carbon budget of flower border.The results indicate:1)Annual and perennial plants have similar average carbon sink,while there are significant differences in carbon sequestration capacity between plants of the same life form.And there are 15 species of high carbon-storage plants,such as Cosmos sulphureus,Panicum virgatum and Rosa chinensis;2)Due to high carbon emissions of transportation,small areas of flower border,and unreasonable living facilities configuration,the majority of flower borders created are still carbon sources;and 3)To achieve a carbon-balanced flower border within 3-5 years,the following conditions should be usually met:the area exceeds 150 square meters,the distance to transportation area is within 82 kilometers,the renewal model is adopted that the annual plants are replaced by perennial herbaceous plants and shrubs,the proportion of annual herbaceous plants is less than or equal to 50% in area,the proportion of perennial herbaceous plants is less than or equal to 60% or greater than 80% in area,and the area of shrubs is not limited.