Many cities face a struggle to reconcile ambitious tree canopy cover targets with urban development pressures. Canopy cover in The City of Melbourne, Australia, which has a target of 40 % canopy cover on public land by 2040, was analysed together with individual tree removal data, with particular focus on how many street trees were removed near major development sites between 2008 and 2017.

We observed major gains and losses of canopy, resulting in small net changes.

Our analyses showed a net gain in tree canopy cover in public streets and a net loss of canopy cover in public parks and private properties. The most frequently removed trees in both public parks and streets were small (<15 cm stem diameter). In contrast, more large, exotic trees were removed from public parks than public streetscapes. These large park trees represented a small proportion of total tree removals, but had larger stem basal areas and therefore large canopies. From 2008 to 2017, almost 2000 street trees were removed within 10 m of major development sites, equivalent to almost 20 % of all street trees removed in that time period, but this constituted only 8% of streetscape tree canopy cover losses.

These findings suggest that in The City of Melbourne, mature tree succession and removal in parks has the greatest potential to hinder the achievement of canopy cover targets. Canopy cover gains could be maximised through improvements in the establishment and survival of replacement trees in both parks and streetscapes. The protection of the existing urban forest, through policy and practice, will also be critical for the retention and enhancement of tree canopy cover.

许多城市都在努力调和雄心勃勃的树冠覆盖目标与城市发展压力。对澳大利亚墨尔本市的树冠覆盖率（目标是到2040年将公共土地上的树冠覆盖率达到40％）进行了分析，并结合了单独的树木清除数据，特别着重于2008年之间在主要开发地点附近清除了多少棵街树和2017年。

我们观察到了冠层的主要得失，导致了很小的净变化。

我们的分析显示，公共街道的树冠覆盖净收益，公共公园和私人财产中的树冠覆盖净损失。在公园和街道上，最经常被砍伐的树木很小（茎径小于15厘米）。相比之下，从公园中移除的大型奇异树木比公共街道景观更大。这些大型公园树木占树木清除总量的一小部分，但茎基部面积较大，因此冠层较大。从2008年到2017年，在主要开发场所的10 m内清除了近2000棵街树，几乎占该时期内所有街树的20％，但这仅占街景树冠覆盖损失的8％。

这些发现表明，在墨尔本市，成熟的树木演替和公园清除有最大的潜力阻碍树冠覆盖目标的实现。可以通过改善公园和街道景观中替代树木的建立和生存来最大程度地提高树冠覆盖率。通过政策和实践来保护现有的城市森林对于保持和增强树冠覆盖率也至关重要。