Concept and methodology of characterising infrared radiative performance of urban trees using tree crown spectroscopy
Concept and methodology of characterising infrared radiative performance of urban trees using tree crown spectroscopy
复制标题
树冠光谱表征城市树木红外辐射性能的概念和方法
DOI：
10.1016/j.buildenv.2019.04.056
复制
发表时间：
2019
影响因子：
7.4
通讯作者：
Deng J
中科院分区：
文献类型：
--
作者：
Deng J
城市树木在冷却城市小气候和调节室外热舒适方面发挥着重要作用。为了更好地了解它们对这些过程的贡献，阐明城市树木的辐射热性能至关重要，特别是在红外（IR）区域（约占太阳辐射的50%）。然而，由于概念和方法上的重大挑战，对树木辐射性能的研究主要集中在单个叶子上，而不是树冠水平的特征。在这里，我们应用了一个新颖的概念和方法框架来表征10棵椴树（tila cordata）的树冠级红外辐射性能，椴树是英国和欧洲常见的城市树木。研究结果表明，叶片反射和透射的太阳能以红外辐射为主（约70%）。在叶片水平上，树木之间的透射和反射光谱相似（IR区差异通常为 < 10%），包括在显著不同的城市胁迫条件下的树木。然而，在树冠水平，树木之间的红外透射光谱存在显著差异（红外区最大差异 > 40%）。这些变化主要是由于树冠结构差异（叶片数、密度、角度），而不是叶片太阳相互作用特征（叶片透光率或反射率、叶片颜色）。四个基本方向测量的树冠透射率在红外区差异显著（最大差异约30%），且随太阳时间变化较大。因此，树木周围的环境接收到的太阳红外辐射水平是非常不同的，而且与时间有关。这些发现对城市小气候的物种选择和环境胁迫因子的控制具有重要意义。
Urban trees play an important role in cooling urban microclimates and regulating outdoor thermal comfort. To better understand their contribution to these processes, it is crucial to elucidate urban trees' radiative thermal performance, especially in the infrared (IR) region (approximately 50% of solar radiation). Yet, owing to significant conceptual and methodological challenges, studies on the radiative performance of trees have mainly focused on individual leaves rather than crown-level characteristics. Here we applied a novel conceptual and methodological framework to characterise the crown-level IR radiative performance of 10 lime trees (Tilia cordata), a common urban tree in the UK and Europe. Our results show that reflected and transmitted solar energy from leaves is dominated (>70%) by IR radiation. At the leaf level, transmission and reflection spectra are similar between trees (differences typically < 10% in IR region), including those under significantly different urban stress conditions. However, at the crown-level, substantial variations in IR transflectance spectra (maximum difference > 40% in IR region) were found between trees. These variations were largely due to crown structural differences (leaf number, density, angles), rather than leaf solar interaction character (leaf-level transmittance or reflectance, leaf colour). Crown transflectance measured from the four cardinal directions was significantly different in the IR region (maximum differences circa 30%), and changed substantially with solar time. Hence, a tree's surroundings received very different, and time dependent, levels of solar IR radiation. These findings have significant implications for species selection and control of environmental stress factors in urban microclimates.
登录
查看更多内容
功能性绿色屋顶：植物选择对于最大限度地发挥夏季环境降温和基材隔热潜力的重要性
影响因子：
6.7
作者：
Vaz Monteiro M
通讯作者：
Vaz Monteiro M
比利时工业栖息地中两种落叶树种沿垂直树冠梯度的叶片反射率变化。
影响因子：
8.9
作者：
A. Khavaninzadeh;Frank Veroustraete;Shari Van Wittenberghe;J. Verrelst;R. Samson
通讯作者：
R. Samson
城市森林和树木
影响因子：
11.2
作者：
C. Konijnendijk;K. Nilsson;T. Randrup;J. Schipperijn
通讯作者：
J. Schipperijn
森林冠层光谱定向反射率的测量：方法回顾和实际应用
DOI：
--
发表时间：
1994
期刊：
影响因子：
--
作者：
E. Milton;G. A. Blackburn;E. Rollin;F. Danson
通讯作者：
F. Danson
影响因子：
6.4
作者：
Zhao, Qunshan;Sailor, David J.;Wentz, Elizabeth A.
通讯作者：
Wentz, Elizabeth A.