The wild relatives of agricultural crops and other socio-economically valuable plant species are inextricably linked with human history. Among them are wild pears (genus Pyrus L.), a valuable gene pool of conservation concern. The centres of diversity for Pyrus are in the mountainous regions of East Asia, the Mediterranean and Southwest Asia, including the Caucasus. Estimates of species numbers in Pyrus range from 20 to 80 (Korotkova et al., Reference Korotkova, Parolly, Khachatryan, Ghulikyan, Sargsyan and Akopian2018). Armenia, in the Caucasus Ecoregion, is notable for its wild pear diversity, with 32 species, 12 of which are endemic to the country (Akopian, Reference Akopian2007) and 10 of which are globally threatened (IUCN, 2023). Their habitats are arid open woodlands and deciduous forests, roadsides, hay meadows, field edges and abandoned orchards at 800–2,300 m altitude. In the south of Armenia at the lower forest border there are sparse woodlands comprising wild fruit trees such as apples Malus orientalis, hawthorns (Crataegus spp.), plums Prunus divaricata and pears. These habitats originated as a result of selective logging in which fruit trees were spared because of their economic value. There are also sites above the forest where sparse pear communities have formed as a result of natural reproduction by seed, distributed by wild animals, primarily the brown bear Ursus arctos.

The wild pears of Armenia are generally either mesophilic or xerophilic, although some species have intermediate features, probably a result of hybridization (Asatryan, Reference Asatryan2019). The mesophilic Pyrus daralagezi Mulk., a tree up to 12 m tall occurring in broadleaved forests at 1,700–2,200 m, is categorized as Endangered on the IUCN Red List (Oganesyan, Reference Oganesyan2014); the xerophilic Pyrus hajastana Mulk., a thorny tree up to 5 m tall occurring in open, dry, stony habitats in sparse woodlands at 1,800–2,100 m, is categorized as Endangered (Nersesyan, Reference Nersesyan2014); and the intermediate Pyrus gergerana Gladkova, a thorny tree up to 13 m tall occurring on roadsides and beside fields and hay meadows at 1,600–2,100 m, is categorized as Critically Endangered (Fayvush, Reference Fayvush2014). All three are endemic to Armenia (Plate 1), occurring only in the province of Vayots Dzor (Akopian, Reference Akopian2022), which includes three of the six pear diversity hotspots in Armenia (Asatryan, Reference Asatryan2019).

Plate 1 (a) Pyrus hajastana and (b) its population in the Yeghegis area, (c) Pyrus daralagezi in Herher open woodland state sanctuary, and (d) Pyrus gergerana by the road to the village of Herher.

These three species were previously known from only a few localities, with little data on their population size or area of occupancy. I collected data on the distribution of all three species during 2016–2018 in the framework of scoping projects with funding from Fauna & Flora International and The Global Trees Campaign (Asatryan, Reference Asatryan2018, Reference Asatryan2019). My field surveys, targeting these three species and also Pyrus tamamschianae Fed. and Pyrus sosnovskyi Fed., continued during 2020–2021 as part of a project on conservation translocations of threatened pear species (Asatryan, Reference Asatryan2024). One of the aims was to find mature trees as sources of seeds for reproduction in nurseries. My field observations and data collected from the literature and from the herbarium of the Takhtajyan Institute of Botany of the National Academy of Sciences of the Republic of Armenia (herbarium code ERE) indicated that the five species were most likely to occur in the Yeghegis River gorge, areas around the village of Artavan, the Herher open woodland state sanctuary, and the areas along the road to the village of Herher (Fig. 1). During September–October 2020 and 2021, I searched these sites, identifying and inventorying individual trees.

Fig. 1 The three study areas of Yeghegis, Herher and Artavan in Vayots Dzor province, Armenia.

I was unable to locate P. tamamschianae or P. sosnovskyi, but recorded five new individuals of P. daralagezi in the oak forest in Herher open woodland state sanctuary, adding to the four already known from this area (Table 1). I rediscovered a small population of P. hajastana in the species’ locus classicus, the site from which it was collected in 1968 and described in 1969 (Akopian, Reference Akopian2022). I also found a new locality for P. gergerana in the Artavan area, with five mature trees in hay meadows and beside unmade roads, a few km from each other, bringing the total number of known individuals in the study area to seven. Two are remarkable for their large size and attractive shape, and both produce a large amount of fruit. Geographical coordinates were recorded for all individual trees, for monitoring and seed collection.

Table 1 Recorded individuals of the three pear Pyrus species recorded in the province of Vayots Dzor, Armenia (Fig. 1), with localities, height, number of trunks and girth (measured at a height of 1.5 m above ground level).

My observations indicate that two principal causes are limiting the natural reproduction and expansion of P. daralagezi: low seed viability, and fruit structure. Trees bear low numbers of fruits and c. 50% of the seeds were empty and infested, and only half of the healthy seeds germinated in later propagation at Yerevan Botanical Garden. The fruits have little flesh and are hard, containing a large number of stone cells (sklereids), making them unattractive to animals and thus limiting seed dispersal and germination. In comparison, the widespread species P. pseudosyriaca Gladkova, which co-occurs with P. daralagezi in the Herher area, reproduces well and is more common; trees bear relatively large and juicy fruits that are favoured by bears.

The rediscovered population of P. hajastana comprises 28 mature individuals and a large number of young trees, germinated naturally from seed, with c. 1,200 in an area of c. 250 m². I observed almost no variability in morphological features between trees. This is unusual amongst Armenia’s endemic pears, which usually demonstrate some variability between individuals and occur as single trees or small groups of trees rather than forming groves. The successful germination of P. hajastana in this population is most likely a result of dispersal by animals: I observed a large number of vole (Microtus sp.) holes and bear excrement containing P. hajastana fruit remains. The comparatively sparse grass cover in this stony habitat does not hinder the development of tree seedlings, in contrast to the surrounding meadow grass that is probably a barrier to further expansion of this pear grove. I found both P. hajastana and P. gergerana close to settlements, on roadsides, and by arable lands and hay meadows, which makes them vulnerable to habitat destruction.

The mountainous landscape, general absence of roads and often impenetrable vegetation in wild pear habitats is a challenge to fieldwork. These conditions, along with the difficult taxonomy of Pyrus species (Asatryan, Reference Asatryan2019), explain the lack of comprehensive data on the distribution of threatened pear species. Because of polymorphism in the populations and variability of the main diagnostic features (e.g. fruit and leaf shape, colour, size, pubescence), I recommend that botanists work as far as possible with fresh material, prioritizing on-site identification. The first half of autumn, when pear fruits are ripe but leaves have not fallen, is the best time for fieldwork.

Threatened wild pear species occur in Important Plant Areas and Key Biodiversity Areas such as the Deciduous Open Forest of Herher Important Plant Area (Asatryan, Fayvush, Reference Asatryan and Fayvush2013) and Jermuk–Eghegis Key Biodiversity Area (Zazanashvili et al., Reference Zazanashvili, Sanadiradze, Garforth, Bitsadze, Manvelyan and Askerov2020) within this area, and their study and conservation helps fulfil the aims of the Global Strategy for Plant Conservation (CBD, 2023) and the Kunming–Montreal Global Biodiversity Framework (CBD, 2022). Conservation of individual trees in their habitat will not only contribute to protection of wild pear genetic diversity and their habitats, but will also ensure continuation of the natural process of speciation.

Wild pear fruits are an important food source not only for wildlife; they are widely used by local communities (Asatryan, Reference Asatryan2019). The gene pool of wild pears is a valuable source for selection. There is a need for long-term science-based conservation programmes, to increase the number of individuals in the populations and to create new localities for threatened pear species within their natural range. Further studies on the distribution and population size of threatened pear species are required to support reassessment of their conservation status, and investigations of interactions with pollinators and seed dispersers are needed for an improved understanding of reproduction mechanisms.