Abstract:
Urban street trees offer cities critical environmental and social benefits. In New York City (NYC), a decadal census of every street tree is conducted to help understand and manage the urban forest. However, it has previously been impossible to analyze growth of an individual tree because of uncertainty in tree location. This study overcomes this limitation using a three-step alignment process for identifying individual trees with ZIP Codes, address, and species instead of map coordinates. We estimated individual growth rates for 126,362 street trees (59 species and 19% of 2015 trees) using the difference between diameter at breast height (DBH) from the 2005 and 2015 tree censuses. The tree identification method was verified by locating and measuring the DBH of select trees and measuring a set of trees annually for over 5 years. We examined determinants of tree growth rates and explored their spatial distribution. In our newly created NYC tree growth database, fourteen species have over 1000 unique trees. The three most abundant tree species vary in growth rates; London Planetree (n = 32,056, 0.163 in/yr) grew the slowest compared to Honeylocust (n = 15,967, 0.356 in/yr), and Callery Pear (n = 15,902, 0.334 in/yr). Overall, Silver Linden was the fastest growing species (n = 1,149, 0.510 in/yr). Ordinary least squares regression that incorporated biological factors including size and the local urban form indicated that species was the major factor controlling growth rates, and tree stewardship had only a small effect. Furthermore, tree measurements by volunteer community scientists were as accurate as those made by NYC staff. Examining city wide patterns of tree growth indicates that areas with a higher Social Vulnerability Index have higher than expected growth rates. Continued efforts in street tree planting should utilize known growth rates while incorporating community voices to better provide long-term ecosystem services across NYC.
摘要:
城市行道树为城市提供了重要的环境和社会效益。在纽约市(NYC),对每棵街道树进行十年普查,以帮助了解和管理城市森林。然而,由于树木位置的不确定性,以前无法分析单个树木的生长。这项研究克服了这一限制,使用三步对齐过程来识别单个树木的邮政编码,地址,和物种而不是地图坐标。我们使用2005年和2015年树木普查的胸高直径(DBH)之间的差异估算了126,362棵行道树(59种,占2015年树木的19%)的个体生长速率。通过定位和测量选定树木的DBH并在5年内每年测量一组树木,验证了树木识别方法。我们研究了树木生长速率的决定因素,并探索了它们的空间分布。在我们新创建的纽约市树木生长数据库中,十四个物种有超过1000种独特的树木。三种最丰富的树种的生长速度各不相同;伦敦Planetree(n=32,056,0.163in/yr)与Honeyocust(n=15,967,0.356in/yr)相比增长最慢,和Callery梨(n=15,902,0.334in/yr)。总的来说,银林登是增长最快的物种(n=1,149,0.510in/yr)。结合了包括大小和当地城市形态在内的生物学因素的普通最小二乘回归表明,物种是控制生长速度的主要因素,和树木管理只有一个小的影响。此外,志愿社区科学家对树木的测量与纽约市工作人员的测量一样准确。检查城市范围内的树木生长模式表明,社会脆弱性指数较高的地区的增长率高于预期。在种植行道树方面的持续努力应利用已知的增长率,同时结合社区的声音,以更好地在整个纽约市提供长期的生态系统服务。