Trend analysis on eco-hydrological indicators as management tools in Mediterranean Environmental Protected Areas: The case study of Sierras Subbéticas Natural Park (Spain)

Mountain areas constitute the headwaters of river basins, biodiversity hot-spots, and have a high value as ecosystem resources provision zones. Within the context of climate change, their meteorological trends and projections of future climate scenarios show a high resource vulnerability, highlighting the need to reduce the uncertainty associated with the dynamics of ecological-hydrological-meteorological processes. In these semiarid regions, there is a generalised increase in temperature, especially in summer, a decrease in average annual precipitation with an increase in torrentiality, and a decrease in snow's frequency and persistence. These can change the vegetation's phenological cycle, behaviour, and distribution. In addition, the socio-economic activities linked to these rural Mediterranean systems would be affected.

 

This study aims to establish a bridge between the different sources of available ecological-hydrological-meteorological information  and the local information that the final user needs, defining eco-hydrological indicators. Our long-term goal is to improve the management and conservation of Mediterranean mountains in the framework of climate change adaptation. 

 

For this purpose, we carried out a spatiotemporal analysis of precipitation and temperature historical trends (1960-2022, with nonparametric Mann-Kendall (MK) statistical test) as basic eco-hydrological indicators in the pilot area of the Sierras Subbéticas Natural Park (1570 m.a.s.l.) a  representative Mediterranean Mountain Range (Southern, Spain). This analysis constitutes the basis for the definition of targeted eco-hydrological management indicators. Among the different management challenges identified (e.g., sustainable olive tree production, preservation of autochthonous forest formations, water availability in groundwater reservoirs), we focus on the conservation of natural holm oak forest. Therefore, we selected as a targeted eco-hydrological indicator the occurrence of extreme drought periods in spring (3-months SPI in June), which is considered a primary meteorological factor influencing leaf development.

 

The trends analysis’ results reflect a significant increase in average annual mean temperatures, especially in the central and lowest areas of the mountain range. Regarding annual precipitation, there is great variability between dry and wet years, with a decreasing trend (-0,821 mm/year) without statistical significance. In the same way, the selected eco-hydrological indicator shows a non statistically significant trend.  This index directly influences the maintenance and regeneration of the Natural Park forest masses, which are of particular interest for managing its ecosystem services. In addition, this indicator constitutes an example of how these specific indicators allow us to use climatic-hydrological data sources in a practical application, with the future goal of integrating meteorological forecasts into the pipeline.

Acknowledgment: This work has been funded by project MONADA - "Hydrometeorological trends in mountainous protected areas in Andalusia: examples of co-development of climatic services for strategies of adaptation to climatic change", with the economic collaboration of the European Funding for Rural Development (FEDER) and the Andalusian Office of Economic Transformation, Industry, Knowledge and Universities. R+D+i project 2020.