Trees as Indicators of the Urban Heat Island

“城市热岛指标树木”项目包括一项试点研究，以生成和分析不同树木年轮参数（树木年轮宽度、指针年目录、木材解剖特征）的年表。将应用树木气候学方法在柏林的12个城市生态不同地点采集数据。柏林是德国最大的城市热岛效应（UHI）。该项目的目的是调查的质量和增长特征，可以归因于城市热岛效应的确定性的大小。根据树木年代学和时间序列分析中的既定测量方法和数据处理技术，如相关和回归分析、主成分分析和极端年份统计，将为城市地区制定一套方法。通过这种方法，我们的目标是确定和优先考虑的平均气候和极端天气条件（旱季，热浪，烟雾）在不同地点的方法相结合的增长因素。为此，树轮年表以及目录解决极端生长反应和木材解剖特征（冻结圈，密度波动等）。将产生约。150棵树在12个城市生态不同的网站。通过与柏林以外的农村地区进行比较，最终将城市热岛效应与一般气候生长条件分开。除了分析特定的城市树种（梧桐、枫树、小叶林登树和类似树种）之外，区分过程还特别需要分析基本的森林树种，如橡树、山毛榉或松树，以防止所识别的城乡差异因物种特异性差异而模糊。试点研究取得的结果将在两篇硕士论文中进行评估和解释，并在国际知名的同行评审期刊上发表。 目前的研究成功地利用树木气候学来分析城市树木的生长。BIWi项目的创新是基于城市树木和树木气候学技术的应用，用于分析城市气候效应，特别关注城市热岛的演变。如果成功的话，这项试点研究将有助于开展下一个项目。其目标将是开发一个通用程序，利用树木年轮气候学数据调查UHI的空间分布和时空演变。或许，这有助于根据不断变化的气候、人口和城市规划发展，为超高建筑的演变提供回顾性和预测性证据。

The project "Bäume als Indikatoren für die urbane Wärmeinsel (BIWi)" (trees as indicators of the urban heat island) comprises a pilot study for generating and analyzing chronologies of different tree ring parameters (tree-ring width, pointer year catalogs, wood anatomical features). Dendroclimatological methods to acquire data at 12 urban-ecologically different sites in Berlin will be applied. Berlin is the City in Germany with the largest urban heat island (UHI) effect. The objective of the project is to investigate the magnitude of quality and certainty of growth features that can be attributed to UHI effect. Based on established methods of measurement and data processing techniques in dendrochronology and time series analysis such as correlation and regression analysis, principal component analysis and statistics of extreme years a set of methods for urban areas are to be developed. With this approach we aim at determining and prioritizing the growth factors for mean climatic and extreme weather conditions (dry seasons, heat waves, smog) at different sites in a combination of methods. For this purpose, tree-ring chronologies as well as catalogs addressing extreme growth reactions and wood anatomical features (freeze circles, density fluctuations, etc.) will be generated for approx. 150 trees at 12 urban-ecologically different sites. The UHI effects will finally be separated from general climatic growth conditions by comparison with sites from rural sites outside of Berlin. In addition to the analysis of specific urban tree species (plane, maple, littleleaf linden and similar species) the differentiating process particularly also requires the analysis of basic forest tree species such as oak, beech or pine to prevent the identified urban-rural diversities from being blurred by species specific differences. The results achieved by the pilot study will be evaluated and interpreted within two master theses and additionally be published in an internationally established peer-reviewed journal. Current studies use dendroclimatology successfully to analyze the growth of urban trees. The innovation within the BIWi-project is based on the application of urban trees and dendroclimatological techniques for the analysis of urban climatological effects with particular focus on the evolution of the UHI. In case of success, this pilot study will serve for pursuing a subsequent project. Its goal will be the development of a general procedure investigating the spatial distribution and spatio-temporal evolution of UHIs using dendroclimatological data. Perspectively, this can contribute to giving retrospective and projective evidence for the evolution of UHIs in the light of changing climatic, demographic and urban planning developments.