Syzygium maire

This scale provides information on the resilience of species to the projected future climate in New Zealand – using the Auckland Botanic Gardens as the central location for projected future temperatures. This projection is based upon the ‘Business as Usual’ climate change scenario that uses the SSP3 or RCP7.0 emission scenario as laid out by the IPCC. It is a ‘worst case scenario’ and predicts the climate of 2090 — 70 years into the future — assuming that no steps have been taken to curb global emissions. The analysis of climate suitability of species is based on Mean Annual Temperature (MAT). The MAT for the Auckland Botanic Gardens under the ‘Business as Usual’ climate change scenario is projected to be 18.8 °C.

Highly resilient indicates that the species is mostly found growing within this MAT, meaning that at this MAT the species is expected to be within its preferred temperature range. Bear in mind that the MAT does not necessarily account for extreme weather events, such as heatwaves or frosts/freezes, and droughts. A species’ precipitation needs should be considered as well.

Resilient indicates that the species does occur at this temperature. It may not be the species’ most preferred climate, but it is anticipated to be well suited to this MAT.

Limited resilience indicates that there are known occurrences of the species growing at this MAT, but this MAT is near the limit of known occurrences. The species may be able to be grown at this temperature, but care regarding its microclimate, context and vulnerability to other factors such as pests and diseases may be required.

Not currently recorded indicates that there are no current records of the species growing at this MAT. If there are very few records for a specific species, this may simply be an indication of a lack of recorded observations, and not plant performance.

It is important to note that there are, generally speaking, more records occurring in the Northern Hemisphere and in cooler climates than there are for the Southern Hemisphere and the southern predominance of warmer climates. This can lead to a potential skewing in the data and results may be biased toward colder climates, indicating less heat tolerance than is true of the species.

This information gleaned from the Climate Assessment Tool aims to provide guidance and support for decisions; it is not an absolute answer, and while the predictions are based on rigorous scientific data, they are just that — predictions. The information will give you an idea of what is more likely to suit New Zealand’s future climate, but trialling of plants in the landscape is still a necessity.

Information sourced from the Climate Assessment Tool provided by the Botanic Gardens Conservation International organisation and can be accessed here: https://cat.bgci.org

Evergreen plants retain foliage year-round but still shed and replace some leaves gradually as part of their normal growth cycle, rather than losing them all at once.

Deciduous plants shed all their leaves for part of the year (usually in autumn and winter), usually in response to colder temperatures or dry seasons, often producing seasonal colour before leaf drop.

Semi-evergreen plants sit between the two, keeping most of their foliage but losing some or all leaves briefly under cooler or drier conditions before quickly regrowing them.

Most temperate deciduous trees can cope with several weeks of waterlogging during the period of winter dormancy as metabolic activity is minimal. However, waterlogging during active growth is more serious because roots are more active and require aerobic soils. In general, the more active the growth, the more rapidly the effects of waterlogging can be seen. Factors such as the water oxygenation status and temperature will also affect how acutely waterlogging stress develops so there can be a great deal of variation around how trees experience waterlogging stress.

Tolerant species can survive consistent waterlogging for the duration of the growing season.

Moderately tolerant species can survive consistent waterlogging for approximately one month during the growing season.

Moderately sensitive species are only likely to survive if the waterlogging event is less than two weeks during the growing season.

Sensitive species are only likely to survive if the waterlogging event is less than a few days during the growing season.

It is important to note that as this scale relates to the likely time-course to tree mortality, symptoms of waterlogging (and associated dysfunction) will be apparent within a shorter period of time.

Information sourced from the Tree Species Selection for Green Infrastructure guide produced by the Trees & Design Action Group. Find the guide here: https://www.tdag.org.uk/tree-species-selection-for-green-infrastructure.html