Urban Planting in a Warming Climate – long-term planning
The Tree Trust is currently working with the Waipa District Council arborist, James Richardson, to grow oaks that will be able to withstand the hotter and often drier summers that we are likely to experience in the next 100 years and beyond. Many of our favourite oaks in Cambridge prefer cooler climes, such as the English oak (Quercus robur) and some of the North American ones like northern red oak (Q. rubra). As the average temperature rises these species may begin to suffer stress.
From the oak arboretum across the road from Cambridge High School, James has collected acorns from a number of species that originate in warmer parts of the world. Germinated last spring, many have grown extremely well and it is hoped that some will be ready to plant as early as 2026. Species include several from the USA such as Q. falcata (southern red oak), acutissima (saw tooth oak), macrocarpa (bur oak), and also Q. canariensis (Algerian oak), variabilis (Chinese cork bark oak – see photo), faginea (Portuguese oak), affinis (Mexican evergreen oak).
Of course, many of the trees that are already common in our parks and streets will probably survive including most of the eucalypts, liquidambers, evergreen and claret ashes, the oriental plane, the Taiwanese cherry. Unfortunately many of the cultivars of the Japanese maple (Acer palmatum) will not enjoy the increasing heat, although the nuggety little trident maple (A. buergerianum) should be okay. Amongst our native trees expect to see those tough-as-old-boots species, totara and kanuka, come to the fore, along with species more often associated with the north – pohutukawa and puriri (kererū will love that).
