Temporal dynamics of herbivory and water availability interactively modulate the outcome of a grass-shrub interaction in a semi-arid ecosystem

The study of plant—plant interactions along grazing and abiotic stress gradients is a major research topic in plant ecology, but the joint effects of both stressors on the outcome of plant—plant interactions remains poorly understood. We used two different factorial experiments conducted in a semi-a...

Full description

Saved in:
Bibliographic Details
Published in:Oikos 2011-05, Vol.120 (5), p.710-719
Main Authors: Soliveres, Santiago, García-Palacios, Pablo, Castillo-Monroy, Andrea P., Maestre, Fernando T., Escudero, Adrián, Valladares, Fernando
Format: Article
Language:English
Subjects:
Animal and plant ecology
Animal, plant and microbial ecology
Biological and medical sciences
Drought
Flood damage
Fundamental and applied biological sciences. Psychology
General aspects
Herbivores
Nurses
Plant ecology
Plant interaction
Plants
Rabbits
Retama
Retama sphaerocarpa
Seedlings
Soil water
Stipa
Synecology
Terrestrial ecosystems
Water resources
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The study of plant—plant interactions along grazing and abiotic stress gradients is a major research topic in plant ecology, but the joint effects of both stressors on the outcome of plant—plant interactions remains poorly understood. We used two different factorial experiments conducted in a semi-arid Mediterranean steppe to assess: 1) the role of the perennial grass Stipa tenacissima, a low-palatability species, providing protection from rabbit herbivory to the shrub Retama sphaerocarpa (experiment 1), and 2) the effects of environmental amelioration provided by Stipa on the recovery of Retama after rabbit damage under two contrasted levels of water availability (experiment 2). In the experiment 1, water stress worked as an indirect modulator of herbivore protection by Stipa. This species protected Retama seedlings from rabbit herbivory during the wetter conditions of spring and winter, but this effect dissapeared when rabbit pressure on Retama increased during summer drought due to the decrease in alternative food resources. In the experiment 2, Stipa exerted a negative effect on the survival of Retama seedlings during the three years of the experiment, regardless of inter-annual differences in rainfall or the watering level applied. This negative effect was mainly due to excessive shading. However, Stipa increased Retama recovery after initial rabbit impact, overriding in part this negative shade effect. Conversely, Stipa impact on the Fv/Fm of Retama seedlings depended on the intra-annual water dynamics and its experimental manipulation, overall contradicting predictions from the stress—gradient hypothesis. The complex interactions found between herbivory, microclimatic amelioration from Stipa, and water availability as drivers of Retama performance illustrate the importance of considering the temporal dynamics of both biotic and abiotic stressors to fully understand the outcome of plant—plant interactions.
ISSN:0030-1299
1600-0706
DOI:10.1111/j.1600-0706.2010.18993.x