Foliar respiration is related to photosynthetic, growth and carbohydrate response to experimental drought and elevated temperature

• Published in: Plant, cell and environment cell and environment, 2021-12, Vol.44 (12), p.3623-3635
• Main Authors: Collins, Adam D., Ryan, Michael G., Adams, Henry D., Dickman, Lee Turin, Garcia‐Forner, Núria, Grossiord, Charlotte, Powers, Heath H., Sevanto, Sanna, McDowell, Nate G.
• Format: Article
• Language: English
• Subjects: Acclimation; Acclimatization; anisohydry; Availability; BASIC BIOLOGICAL SCIENCES; Carbohydrate Metabolism; Carbohydrates; Drought; Droughts; Foliage; High temperature; Hot Temperature; isohydry; Juniperus - growth & development; Juniperus - physiology; Leaves; nonstructural carbohydrates; Photosynthesis; Pinus - growth & development; Pinus - physiology; Plant Leaves - growth & development; Plant Leaves - physiology; Precipitation; Respiration; Species; Stomata; stomatal control; Substrates; Temperature; thermal acclimation; tree; tree mortality; Water potential
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.14183

Short‐term plant respiration (R) increases exponentially with rising temperature, but drought could reduce respiration by reducing growth and metabolism. Acclimation may alter these responses. We examined if species with different drought responses would differ in foliar R response to +4.8°C temperature and −45% precipitation in a field experiment with mature piñon and juniper trees, and if any differences between species were related to differences in photosynthesis rates, shoot growth and nonstructural carbohydrates (NSCs). Short‐term foliar R had a Q10 of 1.6 for piñon and 2.6 for juniper. Piñon foliar R did not respond to the +4.8°C temperatures, but R increased 1.4× for juniper. Across treatments, piñon foliage had higher growth, lower NSC content, 29% lower photosynthesis rates, and 44% lower R than juniper. Removing 45% precipitation had little impact on R for either species. Species differences in the response of R under elevated temperature were related to substrate availability and stomatal response to leaf water potential. Despite not acclimating to the higher temperature and having higher R than piñon, greater substrate availability in juniper suggests it could supply respiratory demand for much longer than piñon. Species responses will be critical in ecosystem response to a warmer climate. In a field experiment, piñon foliar R did not respond to the +4.8°C temperatures, but R increased 1.4× for juniper showing no thermal acclimation. Across treatments, piñon foliage had higher growth, lower NSC content, 29% lower photosynthesis rates and 44% lower R than juniper. Removing 45% precipitation had little impact on R for either species. Species differences in the response of R under elevated temperature were related to substrate availability and stomatal response to leaf water potential. Despite not acclimating to the higher temperature and having higher R than piñon, greater substrate availability in juniper suggests it could supply respiratory demand for much longer than piñon. Species responses will be critical in ecosystem response to a warmer climate.