Predicting past, current and future suitable habitat for endemic Hyrcanian species Populus caspica Bornm.

The Hyrcanian Forests in Northern Iran, listed as a UNESCO's World Heritage Site, contains the last remnants of an ancient, widespread Tertiary broad-leaved forest. Little research, however, has examined the consequences of climate change on the distribution patterns of the rich endemic flora of this ecoregion. Climate change can be a major, and undesirable, threat to the various species of the Hyrcanian Forests ecoregion. Therefore, determining suitable habitats for the endemic species from this ecoregion is crucial for their conservation. Populus caspica Bornm, for example, is one of the endemic species of this area. We used the current locations of natural populations of P. caspica to predict the potential habitat range of this species by applying MAXENT algorithm for the present, past (Last Glacial Maximum-Holocene Optimum), and future (2070s) climatic conditions. Our results suggest that the range of the natural habitat of P. caspica expanded during the Holocene, and the present range is wider than that of the past (about 6 ka BP) ages. Climate changes, however, will negatively impact the future habitat range of this species, reducing suitable range by up to 63.46% in the Hyrcanian forests, and only 36.54% of the stable habitats will be retained. These findings can be used to develop an effective conservation strategy for the future. Our models suggest a common priority area in the Eastern part of the Hyrcanian Forests, where the populations of P. caspica are at high risk and should be taken under special protection.

Automated summary

The Hyrcanian Forests in Northern Iran, a UNESCO World Heritage Site, contain the last remnants of an ancient broad-leaved forest. Little research has examined the consequences of climate change on the rich endemic flora of this region. Climate change poses a major threat to the various species in the Hyrcanian Forests, making it crucial to determine suitable habitats for their conservation.