J Plant Ecol ›› 2016, Vol. 9 ›› Issue (1): 61-68 .DOI: 10.1093/jpe/rtv045

• Research Articles • Previous Articles     Next Articles

UV-B has larger negative impacts on invasive populations of Triadica sebifera but ozone impacts do not vary

Hong Wang1,2, Xiaochi Ma1, Ling Zhang3, Evan Siemann1,2 and Jianwen Zou1,*   

  1. 1 College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; 2 Department of Biosciences, Rice University, Houston, TX 77005, USA; 3 College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China
  • Received:2015-02-01 Accepted:2015-05-15 Published:2016-01-27
  • Contact: Siemann, Evan

UV-B has larger negative impacts on invasive populations of Triadica sebifera but ozone impacts do not vary

Abstract: Aims Abiotic stresses may interact with each other to determine impacts on plants so that their combined impact is less than or more than additive. Increasing UV-B radiation and surface ozone (O 3) are two major components of global change that may have such interactive impacts. Moreover, invasive and native populations of plants may respond differently to stresses as they can vary in primary and secondary metabolism.
Methods Here, we conducted a factorial field experiment with open-top chambers assigned to an ozone treatment (ambient, 100 ppb, or 150 ppb) and UV-B treatment (ambient or increased 20%). We grew seedlings of native and invasive populations of Triadica sebifera in these chambers for one growing season.
Important findings Invasive plants grew faster than native plants in ambient UV-B but they did not differ significantly in elevated UV-B. Litter production of invasive plants was especially sensitive to UV-B in a way that increased with UV-B for native plants but decreased for invasive plants which may be important for nutrient cycling. In ambient UV-B, total mass decreased as ozone increased. Total mass was lower with elevated UV-B but there was no additional impact of increasing ozone. Leaf area did not decrease with UV-B so SLA and LAR were lowest at ambient ozone levels. These results suggest that the effects of ozone will depend on UV-B conditions perhaps due to changes in foliar traits. The traits that allow invasive populations of plants to be successful invaders may make them especially sensitive to UV-B which may reduce their success in future climatic conditions.

Key words: invasive, UV-B, O3, cross-tolerance, litter

摘要:
Aims Abiotic stresses may interact with each other to determine impacts on plants so that their combined impact is less than or more than additive. Increasing UV-B radiation and surface ozone (O 3) are two major components of global change that may have such interactive impacts. Moreover, invasive and native populations of plants may respond differently to stresses as they can vary in primary and secondary metabolism.
Methods Here, we conducted a factorial field experiment with open-top chambers assigned to an ozone treatment (ambient, 100 ppb, or 150 ppb) and UV-B treatment (ambient or increased 20%). We grew seedlings of native and invasive populations of Triadica sebifera in these chambers for one growing season.
Important findings Invasive plants grew faster than native plants in ambient UV-B but they did not differ significantly in elevated UV-B. Litter production of invasive plants was especially sensitive to UV-B in a way that increased with UV-B for native plants but decreased for invasive plants which may be important for nutrient cycling. In ambient UV-B, total mass decreased as ozone increased. Total mass was lower with elevated UV-B but there was no additional impact of increasing ozone. Leaf area did not decrease with UV-B so SLA and LAR were lowest at ambient ozone levels. These results suggest that the effects of ozone will depend on UV-B conditions perhaps due to changes in foliar traits. The traits that allow invasive populations of plants to be successful invaders may make them especially sensitive to UV-B which may reduce their success in future climatic conditions.