“…Moreover, nutrient availability is known to change along soil moisture gradients, with a maximum in mesic soils and minimum in very dry conditions (Araya, Gowing, & Dise, 2013;Saha, Sternberg, & Miralles-Wilhelm, 2009). Thus, the fine-scale hydrological gradient present in our study area can be also linked to N conditions (Gallardo & Merino, 1993;Martínez, Merino, Martín, García Martín, & Merino, 1998;Serrano, Calzada-Bujak, & Toja, 2003), which plant δ 15 N could reflect (Bedard-Haughn, van Groenigen, & van Kessel, 2003;Handley et al, 1999).…”