Soil micro-organisms and competitive ability of a tussock grass species in a dry ecosystem

Yudi M. Lozano, Sara Hortal, Cristina Armas, Francisco I. Pugnaire

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

Drylands are among the most threatened ecosystems in the world because of the effects of global change and because they are not particularly resilient. Regeneration after disturbance is quite slow and secondary succession can be delayed to the point of nearly stop. This is exacerbated when the community is strongly dominated by a single species able to quickly respond after disturbance. One example of such monospecific dominance is the colonization of abandoned fields in SE Spain by an early successional and native tussock grass, Lygeum spartum, that seems to halt succession. Here we tested the competitive ability of Lygeum against Salsola oppositifolia, a shrub species that can be found interspersed with Lygeum in mid-successional stages, and assessed how plant–soil interactions mediate the outcome of plant–plant competition. To do so, we sowed seeds and grew plants of Lygeum and Salsola in either intra- or interspecific competition under controlled conditions using sterile field soils inoculated with either live (i.e., with micro-organisms) or sterile soil extracts from the understories of either Lygeum or Salsola. Soil nutrient content, seed germination rate, and shoot mass growth were determined after 5 months, and soil bacterial communities were characterized by sequencing. Lygeum soil micro-organisms and soil properties, such as the high content of N and organic matter, enhanced seed germination rate of Lygeum individuals. By contrast, Salsola adults outperformed Lygeum when growing in interspecific competition. Synthesis. The enhanced competitive ability of Lygeum, which was mediated by soil micro-organisms, may lead to complete dominance of Lygeum in the plant community right after abandonment of agricultural fields. However, when the plant community is already developed, Lygeum would be unable to enforce such dominance. We conclude that positive plant–soil feedbacks combined with certain plant traits such as clonal growth support the strong resilience of Lygeum and allow for its dominance in extreme habitats.
Original languageEnglish
Pages (from-to)1215-1225
Number of pages11
JournalJournal of Ecology
Volume107
Issue number3
DOIs
Publication statusPublished - 2019

Keywords

  • arid regions
  • bacteria
  • bunchgrasses
  • soil microbiology
  • soils

Fingerprint

Dive into the research topics of 'Soil micro-organisms and competitive ability of a tussock grass species in a dry ecosystem'. Together they form a unique fingerprint.

Cite this