Abstract

Environmental DNA (eDNA) has become a powerful tool for non-invasive biodiversity monitoring, offering real-time insights into organismal presence and ecosystem dynamics. This study investigates how temporal oscillations in eDNA profiles can function as biomarkers for climate-induced changes in ecosystem structure and function. Focusing on freshwater lakes, forest soils, and coastal marine habitats across Saudi Arabia, we conducted multi-seasonal eDNA sampling and metabarcoding targeting 16S rRNA, COI, and ITS markers. These data were integrated with satellite-derived and on-site environmental parameters, including temperature, rainfall, and atmospheric CO2 levels. Our findings reveal that eDNA signatures fluctuate in synchrony with seasonal and extreme climatic events. Notably, microbial richness in forest soils peaked during wet periods, while declines in coral-associated eDNA correlated with elevated sea surface temperatures. Indicator species analyses identified sentinel taxa responsive to heat, humidity, and rainfall variability. These patterns suggest that eDNA oscillations can serve as sensitive, real-time indicators of ecosystem stress, offering a dynamic framework for climate-resilient biodiversity monitoring.

Key words: Environmental DNA (eDNA), Climate change, Temporal biodiversity monitoring, eDNA oscillations, Sentinel species, Metabarcoding, Ecosystem response