{'fraction_non_alphanumeric': 0.018963337547408345, 'fraction_numerical': 0.0012642225031605564, 'mean_word_length': 5.332, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Tree measurements in the urban environment: insights from traditional and digital field instruments to smartphone applications

Urban forests can provide essential environmental and social functions if properly planned and managed. Tree inventory and measurements are a critical part of assessing and monitoring the size, growth, and health condition of urban trees. In this context, the parameters usually collected are DBH and total height, but additional data about crown dimensions (width, length, and crown projection) are required for a comprehensive tree assessment. These data are generally collected by urban foresters through field surveys using tree caliper or diameter tape for DBH, and the electronic ipsometer/clinometer to measure tree height and crown size. Greater detail could be achieved using a digital instrument as Field-Map, a portable computer station to quickly realize dimensional and topographic surveys of trees and forest stands. Finally, the incorporation of the LIDAR scanner into smartphone, as the iPhone 12 Pro, has made this device able to measure tree attributes, as well as additional spatial data in the field. In this study, we tested these three different measurement systems in a field sampling of an urban forest and compared them in terms of measurable parameters, accuracy, cost, and time efficiency. Furthermore, we discussed the pros and cons of each measurement approach and how the resulted data can be used to evaluate ecosystem services of trees and provide guidance on tree management also to reduce potential risks or disservices.