Cantharellus eccentricus is endemic to New Caledonia. Its poptential host plants (Nothofagus balansae and Arillastrum gummiferum) are both also endemic to New Caledonia, and are both considered to be in decline due to threats including logging and mining. Therefore, it is suspected that C. eccentricus is also in decline. An overall population size of 2,000-20,000 mature individuals is estimated, but further work is required. Overall, therefore, the population could potentially qualify for a threatened category, but there is a high degree of uncertainty, and if the species were to be shown to be stable then it could even qualify as Least Concern. A tentative assessment of Near Threatened under criterion C2a(ii) is given here, but further survey work is encouraged.
Cantharellus eccentricus has only been collected from New Caledonia, and two potential host plants that is has been collected under (Nothofagus balansae and Arillastrum gummiferum) are both endemic to New Caledonia (see Buyck 2014, Baldwin 2018, Amice et al. 2020). Taking into account the range of its potential hosts, then the species could occur across Grand Terre at least.
It is difficult to accurately assess the population size and trend of this species. Both potential host species have been assessed as being in decline (Baldwin 2018, Amice et al. 2020), and so it is tentatively suspected that this species may be in decline too. However, Nothofagus balansae was assessed as Least Concern, while Arillastrum gummiferum was assessed as Vulnerable under criterion A. However, the three generation time period for A. gummiferum is 210 years, which is considerably greater than would be used for an ectomycorrhizal fungus (see Dahlberg and Mueller 2011). Therefore, it is likely that even if the species is in decline, that rates would not be great enough to approach the thresholds for listing as threatened.
Although the species is known from only a small number of specimens (see Buyck 2014), given the distribution of its potential hosts, it could be quite numerous. If each site is tentatively treated as one functional individual, then each site could be said to contain 10 mature individuals (based on the species’ ecology; see Dahlberg and Mueller 2011). Based on the distribution of the potential hosts, then it is possible that there are 100-1,000x as many potential sites for the species, which could give an overall population size of 2,000-20,000 mature individuals, which would be assumed to be in one subpopulation.
Population Trend: Decreasing
This species has been collected on the ground, from ultramafic soil, under Nothofagus balansae and Arillastrum gummiferum (Buyck 2014).
Key threats to its habitat in New Caledonia are posed by ongoing mining activities and logging of the host plants. However, it is not known whether such activities are specifically impacting sites where the species occurs.
Further research is needed to get a clearer idea of the full distribution of the species on Grand Terre, and so would allow for a clearer assessment of the threats the species may face.