## 1 Introduction
### Remote Sensing Perspective  
It is crucial to improve our understanding of how climate change and EWEs affect temperate forests. Remote sensing allows for efficient forest health assessment of large areas [53], the monitoring of otherwise inaccessible areas [54], and offers the possibility of repeated measurements [55], which means that changes due to climate change or EWEs can be tracked particularly effectively. This makes remote sensing an indispensable tool for environmental monitoring. A number of large open data archives, such as those of the AVHRR (Advanced Very High Resolution Radiometer), MODIS (Moderate ResolutionImaging Spectroradiometer), or Landsat missions, have expanded the possibilities of forest research from the local to the global level in high temporal and spatial resolution [56; 57].  
For forestry research, this allows for the possibility to investigate the causes of forest damage and to analyze the dynamics of forest recovery [58; 53]. The high temporal availability enables timely monitoring of forest damage, and thus the rapid adaptation of forest management [59]. The use of remote sensing technologies to evaluate forest information is not a new phenomenon [55]. Since the 1980s, AVHRR has allowed for the monitoring of forests on a global scale with a repeat rate of one to two days [60; 61; 62]. MODIS provides the same frequency with increased spectral and spatial resolution [63]. Based on the MODIS timeseries, a large number of forest products have been produced since the turn of the millennium, such as the MODIS Fire Products [64; 65], the Vegetation Continuous Fields product [66], or the MODIS Land Cover Dynamics product [67; 68]. Even longer timeseries with higher spatial resolution are provided with Landsat, a satellite series that has offered comprehensive information on forest condition, cover, and structure since 1972 [69; 70]. Optical data with higher spatial, spectral, and temporal resolution is the Sentinel-2 observation satellite pair, which has a wide range of applications in the context of forest disturbances [71; 72; 73; 74] or environmental monitoring in general [75; 76]. By harmonizing several sensors, such as Sentinel-2 and Landsat 8, changes in the environment can be detected more effectively [77; 78]. The latest generations of satellites, such as PlanetScope and Worldview (both commercial), allow for the monitoring of trees at the individual/species level [79; 80], as well as the near real-time detection of forest changes [71], and their potential benefits are just beginning to be realized.  
In addition to the optical sensors mentioned above, other types of sensors offer a wide range of possibilities to monitor the effects of climate change and associated EWEs on temperate forests. For example, satellite or airborne LiDAR images can serve as important indicators of forest disturbances [81; 82]. Also, UAVs with different sensors are increasingly being used for very high-resolution studies, such as health and species classification of individual trees [83; 84]. Weather-independent SAR data, and thus uninterrupted time-series, such as those from Sentinel-1, are valuable in the context of forest monitoring and disturbance mapping [85; 86; 87]. Overall, remote sensing offers great potential for research on the effects of climate change and EWEs. The development of increasingly advanced spatial, temporal, and spectral sensor systems, coupled with the growth of open-access data archives, is enabling a better understanding of forest ecosystem functioning and its response to changing environmental influences.