Resumen:
<p style="border:0px; display:block; height:0px; left:-9999px; margin-bottom:0px; margin-left:0px; margin-right:0px; margin-top:0px; opacity:0; overflow:hidden; padding:0px; position:absolute; top:0px; width:0px"> Children today spend less time outdoors than previous generations, with potential consequences for health, learning and pro-environmental attitudes. We assessed children's connection with and exposure to nature in a Mediterranean setting using the Nature Connection and Experience Index (NCEI), a composite measure that integrates an affective-cognitive connection-to-nature module with indicators of everyday nature experiences. A school-based cross-sectional survey (4 March-4 April 2022) was conducted in 50 randomly selected public schools in the Region of Murcia (Spain). The questionnaire (26 items) was completed by 3395 pupils aged 7-17 years (overall response 67.2%). Psychometric checks supported the CN block. Only about one in four pupils reported daily or near-daily contact with nature across the year; approximately three in four met criteria for Nature Experience Deficit (<1 h/day, annual measure). NCEI scores declined with age and were higher in girls than boys. Lower scores were observed in more urban and socio-economically unequal municipalities, whereas participation in outdoor lessons was positively associated with NCEI. These findings point to a substantial nature-experience gap in childhood and adolescence. Embedding regular outdoor learning into timetables and improving access to nearby green and blue spaces-particularly in urban and disadvantaged areas-could strengthen children's everyday relationship with nature, with co-benefits for health, learning and sustainability. The NCEI offers a practical tool for monitoring and programme design in schools. <p style="border:0px; display:block; height:0px; left:-9999px; margin-bottom:0px; margin-left:0px; margin-right:0px; margin-top:0px; opacity:0; overflow:hidden; padding:0px; position:absolute; top:0px; width:0px">