Giuseppe et al. (2026) Climate in a Mediterranean nature reserve: patterns and trends in the Castelporziano Presidential Estate (Italy)

Identification

• Journal: RENDICONTI LINCEI
• Year: 2026
• Date: 2026-03-18
• Authors: Edmondo Di Giuseppe, Sara Quaresima, Giorgio Matteucci, Carlotta Ferrara, Tiziano Sorgi, Valerio Moretti, Piermaria Corona, Massimiliano Pasqui
• DOI: 10.1007/s12210-025-01368-8

Research Groups

• Institute of BioEconomy, CNR, Rome, Italy
• Research Centre for Forestry and Wood, CREA, Rome, Italy

Short Summary

This study analyzes seasonal and annual patterns and trends of temperature and precipitation, including extreme events, in the Castelporziano Nature Reserve (Italy) from 1980, revealing a significant warming trend, particularly for maximum temperatures and extreme heat indices, influenced by coastal proximity, while precipitation shows no significant trend.

Objective

• To analyze the seasonal and annual patterns and trends of temperature and precipitation, including extreme events and a combined precipitation-evapotranspiration index, in the Castelporziano Nature Reserve (Italy) from 1980, and compare these findings with surrounding urban areas to understand potential drivers of ecosystem decline.

Study Configuration

• Spatial Scale: Castelporziano Presidential Estate (CPE), a 60 km² protected area along the Tyrrhenian coast, near Rome, Italy. Comparison with urbanized areas of Rome.
• Temporal Scale: Data analyzed from 1980 to 2023 (some station data from 1995 or 1999, ERA5-Land from 1950). Trend analysis period: 1995–2023 (29 years). Climate normal reference: 1981–2010.

Methodology and Data

• Models used:
  • Inverse Distance Weighting (IDW) for spatial interpolation.
  • Mann-Kendall trend test (nonparametric, corrected for autocorrelation).
  • β-Sen methodology for trend magnitude.
  • Standardized Precipitation Evapotranspiration Index (SPEI) calculated using the Hargreaves equation for potential evapotranspiration (PET).
  • Expert Team on Climate Change Detection and Indices (ETCCDI) for 4 temperature and 9 precipitation extreme indices.
  • R packages: mice (for imputation), zyp (for trend), SPEI (for SPEI/PET), ClimInd (for ETCCDI).
• Data sources:
  • Castelporziano Presidential Estate (CPE) Monitoring Network (5-12 weather stations, operational since 1995).
  • Italian Air Force Meteorological Service (AM) (2 stations: Roma Fiumicino, Pratica di Mare, 44-year daily time series from 1980–2023).
  • ERA5-Land gridded reanalysis (15 grid cells, 0.1° × 0.1° resolution, hourly data from 1950 to present, aggregated to daily).
  • Data imputation using Fully Conditional Specification (FCS) / Multivariate Imputation by Chained Equations (MICE) after outlier detection (Tukey boxplot, Hampel filter).

Main Results

• A clear thermal gradient exists within the CPE, with coastal areas being cooler and inland areas warmer, particularly for maximum temperatures.
• A consistent upward trend in temperature was observed from 1995 to 2023. Yearly maximum temperatures (Tmax) increased by +1.2 to +1.5 °C, while minimum temperatures (Tmin) showed a statistically significant increase of +1.5 to +1.7 °C in winter. Summer and autumn experienced the highest warming, with increases up to +3.2 °C.
• The urbanized area of Rome exhibited significantly higher positive thermal anomalies during summer compared to the CPE, indicating an urban heat island effect.
• No statistically significant trend was found for precipitation, although winter and autumn are the wettest seasons, and inland areas generally receive more rainfall.
• A joint analysis of temperature and precipitation anomalies revealed that the most recent years (2014–2023) were predominantly characterized as either "hottest and driest" or "hottest and most humid."
• Several drought episodes were identified using the SPEI12 index, with spatial and temporal variations across the reserve (e.g., 2000–2003, 2007–2008, 2022–2023).
• Analysis of extreme climate indices showed a significant increase in tropical nights (Tmin > 20 °C), with Castello experiencing an increase of 21 nights from 1995 to 2023.
• The duration of warm spells for maximum temperatures (WSDI-TX) significantly increased, with Tor Paterno showing an increase of +34.6 days since 1999.
• The number of days with maximum temperatures exceeding 25 °C (SU) increased by +32.8 days at Tor Paterno since 1999.
• Heat waves based on minimum temperature (WSDI-TN) also showed significant increases in duration at Castello (+27.6 days) and Tor Paterno (+28.6 days).
• Precipitation extreme indices generally showed no statistically significant trends, except for an increase of 5 days in consecutive wet days (CWD) at Castello since 1995, particularly in winter.

Contributions

• Provides a comprehensive, multi-source climate analysis of the Castelporziano Presidential Estate, a critical Mediterranean nature reserve, highlighting its vulnerability to climate change.
• Identifies and quantifies fine-scale spatial climate variability within the reserve, demonstrating the influence of coastal proximity on temperature and precipitation patterns.
• Robustly establishes significant warming trends and increases in temperature-related extreme events (e.g., tropical nights, warm spells) using long-term observational and reanalysis data.
• Offers a valuable comparison of climate trends between a protected natural area and adjacent urbanized regions, underscoring the amplified warming in urban environments.
• Emphasizes the critical importance of long-term environmental monitoring for understanding and addressing climate change impacts on ecosystems.

Funding

• Scientific Council of Castelporziano Presidential Estate
• Segretariato Generale della Presidenza della Repubblica (Presidential Decree n.69/N/2020 and subsequent amendments and supplements)

Citation

@article{Giuseppe2026Climate,
  author = {Giuseppe, Edmondo Di and Quaresima, Sara and Matteucci, Giorgio and Ferrara, Carlotta and Sorgi, Tiziano and Moretti, Valerio and Corona, Piermaria and Pasqui, Massimiliano},
  title = {Climate in a Mediterranean nature reserve: patterns and trends in the Castelporziano Presidential Estate (Italy)},
  journal = {RENDICONTI LINCEI},
  year = {2026},
  doi = {10.1007/s12210-025-01368-8},
  url = {https://doi.org/10.1007/s12210-025-01368-8}
}