Publication Date:
2017-05-14
Description:
Questions Can shrubs ( Cytisus multiflorus ) and large herbivore exclusion (fence) facilitate seedling survival and growth of marcescent and sclerophyllous oaks ( Quercus pyrenaica vs Q. ilex subsp. ballota ) under a bioclimatic limit in Mediterranean grazed areas? Location Open oak woodlands in central-western Spain (41º13’ N, 6º24’ W). Methods A two-year field experiment was conducted by planting 200 seedlings of each Quercus species under four different treatments combining the influence of nurse shrubs and fencing on Quercus seedling survival and growth. Results C. multiflorus enhanced the poor Quercus seedling survival found in the study area, at least during the first two years after planting and particularly during the first dry season. The improvement in soil organic matter under shrub canopy may have contributed to this positive effect, which was more pronounced on Q. pyrenaica seedlings. Seedling herbivory did not seem to be a limitation to survival. Increase seedling growth in both species was also very low and no growth was recorded two years after planting without shrubs. The positive shrub effect on seedling growth, especially marked in fenced areas, was more important in Q. pyrenaica in the first growing period and in Q. ilex in the second; two years after planting no different shrub effect on growth was found in either Quercus species. Seedling herbivory was a limitation to seedling growth in areas without shrubs, mainly in the case of Q. pyrenaica . Conclusions In Mediterranean grazed areas with important summer drougth and very sandy soils, shrubby Cytisus multiflorus plants have a clear facilitative effect on seedlings of ecologically-contrasted Quercus species. The facilitative effect was found in both marcescent and sclerophyllous oak seedlings, but to a different degree depending on the species considered and the variable measured (survival or growth). In terms of survival, the marcescent species was more favored by shrub cover than the sclerophyllous one, and this effect was accentuated throughout time. However, in terms of growth, although Q. pyrenaica was initially more favored by shrubs, differences between both species were attenuated after two years. Therefore, C. multiflorus can have a key role in the restoration of these oak degraded environments. This article is protected by copyright. All rights reserved.
Print ISSN:
1100-9233
Electronic ISSN:
1654-1103
Topics:
Biology
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