桂花滞尘效应及其生理生态响应研究进展
杨建欣, 郭帅龙, 马长乐, 李瑞, 高灿, 康新玲, 李福泷
桂花滞尘效应及其生理生态响应研究进展
Research progress on the dust retention effect and physiological-ecological response of Osmanthus fragrans
植被通过“直接”和“间接”两种方式实现对空气颗粒物的有效移除,不同作用方式和移除过程有着明显不同的作用机制。桂花(Osmanthus fragrans)是我国十大传统名花之一,广泛分布于秦岭以南的亚热带地区,对其滞尘效应的研究表明,桂花能有效滞留大气颗粒物,对消减大气颗粒物污染并改善空气质量具有重要的作用。笔者在对桂花种质资源与形态结构分析的基础上,重点关注桂花单位叶面积滞尘量、单叶滞尘量等重要量化指标,以及叶片对不同粒径颗粒物的滞留能力,综合分析了桂花滞尘效应的时空变化规律,滞尘对光谱特性、形态结构和生理生态的影响等,认为不同品种或不同生境的桂花因遗传特性和环境资源的差异,受环境大气污染程度、叶片形态结构、叶面积、叶序、叶面倾角和冠形等因素的影响,其叶片滞尘量差异较为显著,具体表现为:①单位面积滞尘量与环境污染背景值正相关;②单叶滞尘量与叶片形态特征、环境因子等因素直接相关,但单叶面积大小与滞留颗粒物能力无显著相关;③由于不同规格、不同生长季节、不同健康状况等条件下总叶面积的差异,不同城市及不同采样点桂花的单株滞尘量有较大差别;④桂花叶片对粗颗粒物的滞纳能力较细颗粒物大,且滞尘效应存在一定的时空变化规律,即日变化和季节变化特征与大气颗粒物的日变化、季节变化趋势基本一致,达到饱和滞尘量的时间有物种特异性和地域差异;⑤颗粒物的滞留可使桂花叶片光谱特性发生改变,也会影响叶形态特征和功能性状,进而影响对颗粒物的吸附能力,并对桂花生理生态、生长发育和花香产生影响,削弱其观赏价值。
Vegetation effectively removes airborne particulate matter through “direct” and “indirect” pathways, each with distinct mechanisms and processes. Osmanthus fragrans, one of the top ten traditional flowers in China, is widely distributed in south of the Qinling Mountains across the subtropical regions. Research results indicate that this species plays a significant role in mitigating atmospheric particulate pollution and improving air quality by retaining particulate matter. We analyzed and summarized advancements in understanding the dust retention capacity of O. fragrans, emphasizing key quantitative indicators such as dust retention per unit leaf area, per single leaf, and the ability to retain particulates of various sizes. This study also explored spatiotemporal variations in dust retention and its impact on spectral characteristics, morphological structure, and physiological ecology. Differences in dust retention among O. fragrans varieties and habitats were attributed to genetic traits and environmental factors, including air pollution levels, leaf morphology, leaf area, phyllotaxy, inclination angle and crown shape. Key findings include the following:(1) Correlation with environmental pollution. Dust retention per unit leaf area was positively correlated with the background level of air pollution. (2) Influence of morphological traits: dust retention per single leaf was determined by leaf morphology and environmental conditions, though no significant correlation was found between single-leaf area and particulate retention capacity. (3) Plant-level variation. Total dust retention varied significantly among plants due to differences in leaf area across growth stages, health conditions, and locations. (4) Particulate size specificity. Leaves retained coarse particulates more effectively than fine ones, and dust retention showed predictable spatiotemporal variation. Diurnal and seasonal trends aligned with fluctuations in airborne particulate matter, with species- and region-specific saturation times. (5) Impact on leaf traits. Particulate retention altered leaf spectral characteristics, affecting morphology, functional traits, and adsorption capacity. These changes influenced physiological ecology, growth, floral fragrance, and ornamental value.