SEARCH

SEARCH BY CITATION

Keywords:

  • organic fertilization;
  • irrigation;
  • limestone quarry;
  • woody-grass competition;
  • semi-arid.

Abstract

Question

Is the response of woody plants to herbaceous competition affected by the level of irrigation and organic fertilization? Does the magnitude and the sign of this response depend on the successional status of woody species?

Location

A limestone quarry in a semi-arid Mediterranean area in SE Spain.

Methods

We studied seedling survival and growth of six woody species with contrasting ecological strategies (early-successional vs late-successional) and their associated herbaceous layer under different irrigation and organic fertilization levels

Results

Elevated water supply, but not organic fertilization, increased herbaceous cover. The response of woody seedlings and changes in herbaceous cover to a contrasting resource supply was species-specific. Seedling survival and growth of late-successional species increased at high levels of irrigation. Pioneer species showed the opposite trend, suggesting that increases in water availability may outweigh the deleterious effect of increased herbaceous competition in late-successional species but not in early-successional species.

Conclusions

Our study provides further insights into the role of techniques such as irrigation and organic fertilization, which are commonly used in conjunction with hydroseeding, in defining woody plant establishment and successional trajectories in semi-arid areas under restoration. Our results will contribute to improve restoration success by reconciling two major objectives of restoration: soil protection and secondary succession. We recommend a new approach for the restoration of limestone quarries. This approach comprises the planting of late-successional species on randomly distributed nutrient-rich patches of high availability of water and nutrients, and the use of pioneer species in the surrounding nutrient poor and drier matrix. This approach should promote optimal ecosystem functioning, including soil protection, while increasing biodiversity and fostering secondary succession.