EOO seems great, 1900.000 km2, but relatively few sites inside and few AOO circa 400.
Lactarius mediterraneensis has a large EOO (1900.000 km2). It belongs to a well known genus and produces conspicuous basidiomata, nevertheless the observations of the species are rare, considering that the habitat of evergreen oakwoods is very common inside the EOO. Its presence is predominantly concentrated in two main areas: Eastern Spain and Tuscany. Maybe more studies on microhabitat preference of the species are needed to clearly understand its ecology. It seems more linked to “humid” areas (in mediterranean meaning) and calcareous soils. It was not observed in dry evergreen oakwoods in Greece, even after years of study (Polemis et al. 2012a,b). It is estimated that there are many more sites where the species occurs in central-western Mediterranean region, however it seems to be absent in Western Spain and Portugal, rare in Sardinia and Sicily, even though both are well studied Islands, and it is very rare in Greece. In Tuscany some sites no longer exist. The conservation status of the main habitat of the species (mediterranean Quercus ilex forests) is assessed as poor (https://biodiversity.europa.eu/habitats/9340). Thus we assume a population decline, due to habitat and habitat quality decline, of about 15% over the past 50 years (approximately three generations). This decline in habitat/ habitat quality is ongoing, caused by increase of fires and/or overgrazing, changes in land use and urbanization and is not expected to stop over the next 50 years. Therefore the species is assessed as NT (A2c+3c+4c).
Lactarius mediterraneensis Llistos. & Bellù is characterised by the white latex that is slowly changing to yellow, the zonate, sticky surface of the pileus and the presence of scrobicules on both the pileus and stipe. Other similar species that belong also in section Zonarii (subgenus Piperites) are Lactarius acerrimus (characterized by bigger basidiospores and two-spored basidia), Lactarius zonarius (differentiated by smaller basidiospores and presence in deciduous Quercus forests) and Lactarius zonarioides (occurring in Abies or Picea forests) (Basso 1999).
Lactarius mediterraneensis Llistos. & Bellù is a European species, distributed mainly in the Mediterranean area of southern Europe, recently recorded from Greece (Kaounas et al. 2016, Triantafyllou unpublished data), Algeria (Benfriha et al. 2020) and Turkey (Doğan et al. 2021) as well. Considered rare or infrequent in Greece, Italy, Algeria.
Lactarius mediterraneensis exhibits a distribution encompassing the Mediterranean Region, specifically Spain, Italy, and France. Notably, recent observations have extended its range to include Algeria (Benfriha et al. 2020) and the eastern reaches of the region, in particular Greece (Kaounas et al. 2016, Triantafyllou unpublished data) and Turkey (Doğan et al. 2021). It is noteworthy that the main distribution area of this species appears to be the Iberian Peninsula.
Lactarius is a well-known and extensively studied genus. Lactarius mediterraneensis is an ectomycorrhizall species described about 30 years ago. It forms conspicuous basidiomata in the presence of the genus Quercus, especially under Quercus ilex or more rarely under Quercus coccifera in the Eastern Mediterranean. The distribution of the host (sclerophyllous species of genus Quercus) in the Mediterranean region is significantly wider than the occurrence of Lactarius mediterraneensis. However, it’s important to clarify that we do not consider this difference an underestimation. This perspective is supported by the fact that in numerous sclerophyllous Quercus ecosystems subjected to mycological diversity studies, Lactarius mediterraneensis has only been infrequently reported. This species appears to be relatively rare, with a mere 136 recorded instances, drawing data from sources like GBIF, bibliographic records, and unpublished materials. Its presence is predominantly concentrated in two main areas: Eastern Spain and Tuscany. However, even in these regions, there is uncertainty regarding its occurrence as some studies do not confirm its presence (Ponce pers. comm. 2023) or report it as rare (Clericuzio et al., 2022). The conservation status of the main habitat of the species (mediterranean Quercus ilex forests) is assessed as poor (https://biodiversity.europa.eu/habitats/9340). Therefore a population reduction can be suspected for this rare species due to decline in habitat quality and maybe also decline in AOO because of increasing fires in mediterranean region.
Lactarius mediterraneensis is an ectomycorrhizal species growing in association mostly with Quercus ilex in the main range of its distribution, namely Spain, France and Italy (Basso 1999, Vila et al. 1996). In Algeria the species was found in a mixed Quercus ilex and Q. fagenia forest (Benfriha et al. 2020). In Greece Lactarius mediterraneensis was found to occur in association with Quercus coccifera (Kaounas et al. 2016, Triantafyllou unpublished data) which is much more common and widely distributed in the eastern Mediterranean region than Q. ilex. The same pattern is followed by Lactarius atlanticus, another mediterranean species growing in association with sclerophyllous Quercus species (Triantafyllou et al. 2015).
The Mediterranean evergreen Quercus woodland is characterized by its evergreen oaks and accompanied by broadleaved sclerophyllous and lauriphyllous evergreen trees and shrubs adapted to the summer drought typical of the thermo-mediterranean climate. According to the European Red List of habitats reports, this habitat is classified as “Least Concern.” However, the same assessment highlights concerning decreases in the populations of Quercus spp. in mainland Italy, Sardinia, and Sicily over the past 50 years, whereas in mainland Spain, the populations have remained relatively stable.
It’s essential to note that the habitat type of Quercus ilex and Quercus rotundifolia forests, categorized under the Habitats Directive Annex I code 9340, is facing challenges in Spain. This habitat type, in Mediterranean region, has received an assessment of “Unfavourable – Inadequate.” This unfavorable assessment is attributed to specific structural and functional issues within this habitat. Additionally, it’s worth mentioning that the distribution of this specific habitat largely overlaps with the presence of Lactarius mediterraneensis in Spain, underscoring the potential impact of habitat conservation efforts on this species.
The main known threat to this species is habitat degradation and loss due to fires (for many different reasons e.g. not good forest management and controll of “anti fire zones”), overgrazing, the combination of fire followed up by overgrazing, changes in land use and other human activities such as new wind turbin areas and new traffic connections and to a lesser extent, logging.