Dataset for: "Climate adaptation for freshwater biodiversity requires wetland protection: evidence from Turkish aquatic insects"

Freshwater biodiversity faces compounding threats from climate change and wetland loss, yet assessments typically address these drivers separately. A dual-method framework partitioned direct climate effects from wetland loss contributions to range declines across 1,191 aquatic insect species (Ephemeroptera, Plecoptera, Trichoptera, aquatic Coleoptera) across Turkey, a Mediterranean biodiversity hotspot projected to experience severe water scarcity. Endemism analysis identified 351 endemic species (29.5%), with lotic specialists exhibiting 3.7-fold higher endemism than lentic generalists (35.5% vs. 12.9%). Under SSP5-8.5 by 2090, climate-only projections indicated 25% mean range loss, but incorporating wetland decline increased this to 74%, representing a threefold amplification. Wetland loss contributed 49% of projected extinction risk beyond climate effects, shifting 83% of species into high-risk categories versus 3% under climate-only scenarios. Range centroids shifted 74.7 km on average, predominantly northward and upward. Climate adaptation strategies focusing solely on thermal refugia substantially underestimate biodiversity loss in water-limited regions. Effective conservation requires integrating wetland protection into climate planning, prioritizing areas where high endemism intersects with projected hydrological stress.