Heenan et al. (2024), on the basis of molecular data, used in isolation of other lines of evidence elected to treat all Aotearoa / New Zealand Kunzea as one species K. ericoides. Their work did not consider the morphological and cytological disparity, nor the sympatry / syntopy between K. amathicola and K. ericoides, K. linearis  and K. robusta (de Lange 2014), and the analyses used to derive their conclusions have been disputed by others. The species is accepted by the New Zealand Plant Conservation Network (www.nzpcn.org.nz) and New Zealand Indigenous Vascular Plant Threat Listing Panel.

Kunzea amathicola is a shrub or small tree, endemic to Aotearoa / New Zealand where it occurs on Te Ika a Maui / North Island and Te Wai Pounamu / South Island, North West Nelson. The population size is estimated to be more than 100,000 mature individuals. The existing main threats to the species are clearance for plantation forestry, felling for firewood, wild fires, invasive weeds and fallow deer (Dama dama). However, an extreme decline of the species is anticipated in the near future from the rust Austropuccinia psidii, for which there is no known cure. Based on an ongoing suspected decline of up to 30 % over three generations, this the species is assessed as Near Threatened.

This species is endemic to Aotearoa / New Zealand where it occurs on Te Ika a Maui / North Island (westerly from Te Aupouri south to Kawhia, thence disjunct to the Manawatu / Horowhenua) and Te Wai Pounamu / South Island, North West Nelson (Farewell Spit to Anatori River, east to Abel Tasman National Park). Distribution map is generalised.

No accurate counts of individuals have been made. However, the species is still widespread over large parts of the sand country of Te Aupouri, western Northland (especially the Pouto and Kaipara Peninsulas) and Farewell Spit. There are likely to be >100,000 mature individuals based on the species dominance and the areas occupied. However over large parts of this species' range it has declined from land conversion to farmland / plantation forestry, and trees are still felled for firewood. Recruitment is often lacking due to the suppressing effects of weeds, or because stands are under browsed by livestock. The species was assessed as ‘Threatened / Nationally Vulnerable’ qualified ‘De’ [Designated], ‘DP’ [Data Poor] by de Lange et al. (2018) mainly because of the threat posed by Austropuccinia psidii (see under Threats) but without data to confirm this assessment. Decline rates historically would have been considerable. The decline is now probably <5% within the species' remaining range as a functional species. Decline is ongoing in sites of plantation forestry, though pine felling temporarily provides opportunities for regeneration, provided remnant trees are not felled for firewood. 

This species is likely to live for over 50 years. There is no information available on when the species begins to reproduce. Consequently a generation length of 20–30 years is given to measure continuing decline. This also reflects that this is a small species of tree. The population decline is measured over a moving window considering two generations in the past and one generation into the future as the decline is continuing (1960–2050). If, or more likely when, Austropuccinia psidii affects Kunzea amathicola in situ, it is thought that across this time the population is suspected to experience a decline of up to 30%.

Kunzea amathicola is primarily a coastal species of mobile sand and, usually Pleistocene-aged, stable sand dune systems. In the south-western portion of Te Ika a Maui / North Island and north-western Te Wai Pounamu / South Island, however, it also colonises greywacke soils, calcareous rocks, coal measures and their associated clay soils. It also colonises tidal river banks, coastal freshwater wetlands, estuaries (where it usually grows in the upper reaches of salt marshes with species such as Olearia solandri and Plagianthus divaricatus), and may be prominent on exposed coastal headlands, cliff faces, and slip scars. More rarely it extends inland along river valleys where it colonises alluvial terraces. It reaches its maximum altitudinal limit on the windswept gumland scrub of the Ahipara Plateau where it has spread from the adjoining sand country up on to the plateau. This habitat is probably more induced than truly natural, because at this location K. amathicola is occupying ground that was once covered in kauri (Agathis australis) forest and which was burned repeatedly from the mid-1800's to early 1900's to facilitate better access for gum diggers (de Lange 2014).

K. amathicola is often the dominant tree species of dune systems in the western part of Te Ika a Maui / North Island and northern Te Wai Pounamu / South Island, where it routinely forms a distinct, stable vegetation type. K. amathicola is well adapted for the sand environment. Plants grow quickly to form a dense ball of branchlets with no obviously dominant stem. Plants bearing juvenile foliage and flowers and fruits have been collected on mobile sand, on exposed coastal headlands (de Lange 2023), or even as part of the shrub tier under adult stands of the same species.

The key threats to the species are clearance for farmland and plantation forestry, felling for firewood, wild fires, invasive weeds, fallow deer (Dama dama) and Austropuccinia psidii. This rust is now the most serious threat. It reached Aotearoa / New Zealand from Australia in 2017. The impact of this rust on Myrtaceae worldwide is serious, and it is known to kill inoculated Kunzea species in cultivation susceptibility trials, so it is regarded as a serious threat to members of the genus and indeed all of the indigenous Myrtaceae in Aotearoa / New Zealand (de Lange et al. 2018). It is solely for this reason that Kunzea amathicola has such a high threat listing in Aotearoa / New Zealand. Currently there is no cure for this disease either. At this stage wild occurring infected Kunzea have yet to be reported but it is inevitable that occurrences will happen. Once they are recorded the impact and long-term survival of Kunzea amathicola and other allied species must be regarded as uncertain. In the case of Kunzea amathicola the species is further threatened by ongoing habitat deterioration from invasive weeds, and loss of trees for firewood, and through land clearance for plantation forestry remain issues. Ignorance is often an issue, even with assumed secure sites, for example the type locality, located within a New Zealand / Department of Conservation managed farm was destroyed for a car park.

This species is felled for firewood.

The key threat to Kunzea amathicola will inevitably be Austropuccinia psidii. All other known threats can be effectively managed but the rust, so far, has not been. The impact on wild Kunzea is as yet unknown but it is believed that it will be severe; infections of inoculated cultivated plants result in the death of seedlings and saplings within less than a year from the first infection. As the rust continues to spread, and infections increase, there will be more spores spread, so the severity in infections of host plants is anticipated to increase. Currently there is no known cure for Austropuccinia, all that can be hoped for is that some lineages of host plants have or develop resistance. To date there has been no evidence for this.

As the rust is wind dispersed quarantine measures are also ineffective. The seed of Kunzea has short-term viability and viability is affected by desiccation and freezing, so conventional seed banking is of limited value. Current measures to secure the species should consider holding tissue-cultures. Consideration should be given to cultivating the species outside the global distribution of Austropuccinia, to see if at those sites the species can be secured in Botanic Gardens and other threatened plant collections.

Research into finding a cure for Austropuccinia is a global issue and many organisations are working in this area. Like all research however, those investigations are subject to funding issues and political whim. Austropuccinia is a global problem, a global response is needed – only time will tell if humanity understands the consequences of the loss of the Myrtaceae on world ecosystems and takes the right steps to find solutions to help manage this rust.

The other key threat to the species is fallow deer (Dama dama) which occur in large numbers throughout Woodhill forest – an area where there are still large tracts of Kunzea amathicola dominated forest. Fallow deer numbers are not being controlled and in places they are now causing canopy collapse. Deer could be controlled here, if the landowners understand the problem, education is needed.

It was assessed as ‘Threatened / Nationally Vulnerable’ qualified ‘De’ [Designated], ‘DP’ [Data Poor] by de Lange et al. (2018).