J Plant Ecol ›› 2022, Vol. 15 ›› Issue (3): 494-508 .DOI: 10.1093/jpe/rtac001

• Research Articles • Previous Articles     Next Articles

Drought may be beneficial to the competitive advantage of Amaranthus spinosus

Youli Yu1, Huiyuan Cheng1, Shu Wang1, Mei Wei1, Congyan Wang1,2,3, *, and Daolin Du1,2, *   

  1. 1 Department of Environmental Science, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China, 2 Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China, 3 State Key Laboratory of Tree Genetics and Breeding, School of Forestry, Northeast Forestry University, Harbin 150040, China

    *Corresponding author. E-mail: liuyuexue623@ujs.edu.cn (C.W.); ddl@ujs.edu.cn (D.D.)
  • Received:2021-03-31 Revised:2021-05-21 Accepted:2021-11-09 Online:2022-01-09 Published:2022-06-01


Drought can affect the growth and soil enzyme activities of invasive alien plants (IAPs). It is imperative to evaluate the competitive advantage of IAPs compared with that of the native species and the activities of soil enzymes under drought. This study aimed to evaluate the competitive advantage of the IAP Amaranthus spinosus that originated from tropical America compared with the native Chinese species A. tricolor and the activities of soil enzymes under drought. A competitive co-culture of A. spinosus and A. tricolor was established using a planting basin experiment. The two species were treated with different levels of drought, i.e. (i) the control; (ii) a light level of drought and (iii) a heavy level of drought. The functional traits, osmotic adjustment and the activities of antioxidant enzymes of the two species, as well as soil pH and electrical conductivity, contents of soil microbial biomass carbon and the activities of soil enzymes were determined. The relative competition intensity and relative dominance of A. spinosus were greater than those of A. tricolor under drought. Drought may provide an advantage to the competitive advantage of A. spinosus. Soil water-soluble salt content and sucrose hydrolytic power of A. spinosus were greater than those of A. tricolor under drought. The ability of A. spinosus to grow in soil with higher levels of water-soluble salt contents and sucrose hydrolytic power under drought may aid in its acquisition and utilization of nutrients.

Key words: biomass stability, invasive alien plants, relative competition intensity, relative dominance, stress intensity

干旱可以影响入侵植物的生长和土壤酶活性。因此,非常有必要评估干旱背景下入侵植物的竞争优势以及入侵植物和干旱对土壤酶活性的影响。本研究旨在分析干旱背景下起源于热带美洲的入侵植物刺苋(Amaranthus spinosus)与本地植物苋菜(Amaranthus tricolor)共存时的竞争优势和土壤酶活性。通过栽植实验进行刺苋与苋菜的竞争共栽培,并进行不同水平的干旱处理,即:(i)对照;(ii)轻度干旱;(iii)重度干旱。实验结束后测定两种苋属植物的功能性状、渗透调节、抗氧化酶活性以及土壤pH、电导率、土壤微生物生物量碳含量和土壤酶活性。干旱背景下,刺苋的相对竞争强度和相对优势度均高于苋菜。因此,干旱利于刺苋的竞争优势。干旱背景下,刺苋的土壤水溶性盐含量和蔗糖水解能力均大于苋菜。而较高的土壤水溶性盐含量和蔗糖水解能力利于刺苋对养分的获取和利用。

关键词: 生物量稳定性, 入侵植物, 相对竞争强度, 相对优势度, 胁迫强度