Airborne pollen trends in Sierra de las Nieves National Park (southern Spain)

Abstract

Sierra de las Nieves (southern Spain) is a protected space recently declared National Park with emblematic high and mid-mountain species and relevant forest masses surrounded by unfavourable environmental conditions. In a global warming scenario, it is important to determine how climate change can affect these forest species to establish conservation guidelines. In this study, airborne pollen was sampled by means of a Hirst-type volumetric pollen trap installed in “Las Conejeras” recreational area, bordering the domains of the National Park. In this study, data from 2018 to 2023, both inclusive, were considered to calculate trends in the Main Pollen Season (MPS) parameters. The MPS was defined by fitting a logistic regression to the accumulated sum of pollen concentrations as well as the calculation of derivatives. Data were managed by means of the AeRobiology package, implemented in R software. Different responses to climate change were observed within the most abundant pollen types with forest interest. Pollen types such as Pinus and Cupressaceae did not show any significant trend while others, such as Olea, showed an incipient trend, and others, such as Castanea and Quercus presented clear significant trends to bring forward the start of their pollination period due to the increase in temperatures. According to these results, the responses to global warming showed diverse behaviours in this protected area, there being species whose conservation measures should be considered as a priority, given their greater sensitivity to temperature increases.