Intense solar radiation constrains plant species richness in global grasslands

• Autores: Spohn, Marie; Arnillas, Carlos Alberto; Bakker, Jonathan D.; Borer, Elizabeth T.; Bråthen, Kari Anne.; Cadotte, Marc W.; Carbutt, Clinton; Catfordi, Jane A.; DuPre, Mary E.; Dwyerm, Ciara; Peri, Pablo Luis; Zhang, Pengfei
• Año de publicación: 2026
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: PNAS 123 (6) : e2527128123 (February 2026)
• Materia: Pastures; Solar Radiation; Photosynthetically Active Radiation; Biomass; Grasslands; Pastizales; Radiación Solar; Radiación Fotosintéticamente Activa; Biomasa; Praderas; Plant Species Richness; Plant Diversity; Environmental Filters; Climate Variables; Riqueza de Especies Vegetales; Diversidad Vegetal; Filtros Ambientales; Variables Climáticas
• Institución: Instituto Nacional de Tecnología Agropecuaria

The search for predictors of plant diversity has challenged scientists for decades. Here we identify intense photosynthetically active radiation (PAR) as a major factor constraining plant species richness in global grasslands. We show that the strength of the negative relationship between species richness and PAR increases with increasing elevation and that species richness is more strongly correlated with intense PAR than with UV-B radiation, climate variables, and atmospheric nitrogen deposition. In addition to species richness, plant biomass was also negatively correlated with PAR at higher elevations, indicating that intense PAR also constrains plant biomass in montane grasslands. Furthermore, we show that the decrease in plant species richness with increasing PAR is mainly caused by a decrease in species richness of forbs, sedges, and rushes. In contrast, species richness of grasses was only negatively correlated with PAR at high elevations, and species richness of legumes was not significantly correlated with PAR. Our results suggest that PAR constrains plant species richness in global grasslands and limits the extent to which plant species of specific functional groups can migrate uphill in response to climate warming.
EEA Santa Cruz
Fil: Spohn, Marie. University of Bayreuth. Department of Soil Ecology, Bayreuth Center of Ecology and Environmental Research (BayCEER); Alemania
Fil: Spohn, Marie. Swedish University of Agricultural Sciences (SLU). Department of Soil and Environment; Suecia
Fil: Arnillas, Carlos Alberto. University of Toronto. Department of Physical and Environmental Sciences; Canada.
Fil: Bakker, Jonathan D. University of Washington. School of Environmental and Forest Sciences; Estados Unidos
Fil: Borer, Elizabeth T. University of Minnesota. Department of Ecology, Evolution & Behavior; Estados Unidos
Fil: Bråthen, Kari Anne. Arctic University of Norway. Department of Arctic and Marine Biology; Noruega
Fil: Cadotte, Marc W. University of Toronto Scarborough. Department of Biological Sciences Canadá.
Fil: Carbutt, Clinton. Ezemvelo KZN Wildlife. Scientific Services; Sudáfrica.
Fil: Carbutt, Clinton. University of KwaZulu-Natal-Scottsville. School of Agriculture and Science; Sudáfrica.
Fil: Catfordi, Jane A. University of Melbourne. School of Agriculture, Food & Ecosystem Sciences; Autralia.
Fil: Catfordi, Jane A. The Australian National University. Fenner School of Environment & Society; Australia.
Fil: DuPre, Mary E. MPG Ranch. Missoula; Estados Unidos.
Fil: Dwyerm, Ciara. Lund University. Centre for Environmental and Climate Science; Suecia
Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.
Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.
Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.
Fil: Zhang, Pengfei. Lanzhou University. College of Ecology. State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems. Lanzhou; China.
Fil: Zhang, Pengfei. University of Minnesota. Department of Ecology, Evolution, and Behavior; Estados Unidos