EurekaMag.com logo
+ Site Statistics
References:
53,869,633
Abstracts:
29,686,251
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Effect of shrubs on recruitment of Quercus douglasii and Quercus lobata in California



Effect of shrubs on recruitment of Quercus douglasii and Quercus lobata in California



Ecology (Washington D C) 73(6): 2118-2128



Biologically derived safe sites appear to strongly affect spatial and temporal patterns in terrestrial plant communities; however, few experimental field studies have been conducted to investigate the importance of such interactions or the mechanisms by which they operate. Quercus douglasii and Quercus lobata are winter-deciduous oaks endemic to California (USA). I examined associations between seedlings of these oaks and several species of shrubs and conducted field experiments that tested for facilitative effects of two shrubs, Salvia leucophylla and Artemisia californica, on seedling survival. Naturally occurring Q. douglasii seedlings were relatively common (280 seedlings/ha) and were strongly associated with shrub canopies. In two experimental plantings, 30% and 55% of O. douglasii seedlings that emerged under shrubs survived for gt 1 yr, whereas no seedlings in the open survived in either experiment. Survival of Q. douglasii where shrubs were removed was similar to survival in the open grassland, indicating that association between shrubs and oak seedlings was not due to shared microsite requirements. Q. douglasii seedling survival was not different between the two shrub species. Only three Q. lobata seedlings were found in 26 study plots, although reproductive adults were present. The seedlings were under shrub canopies. However, the survival of Q. lobata was not facilitated by shrub cover or shrub simulation and no other evidence was found for nurse-shrub interactions with this oak species. Artificial shade was critical to the survival of Q. douglasii seedlings in simulated shrub environments. When grown in artificial shade, photosynthetic capacities and root elongation rates of Q. douglasii seedlings were significantly higher than those of Q. lobata. These differences may partially explain why nurse-plant interactions exist between shrubs and Q. douglasii seedlings but not between the same shrubs and Q. lobata seedlings. Causes of acorn and seedling mortality differed between the shrub and open grassland habitats. Under shrubs, acorn predation was the primary cause of mortality, whereas mortality due to shoot herbivory was much more frequent in the open grassland. Thus, propagules under shrubs that avoided predation until shoot emergence benefitted from canopy shade and protection from herbivores. The shade tolerance and nurse-plant utilization of Q. douglasii seedlings have parallels with shade tolerance and late successional roles of other oak species in temperate deciduous forests, and, as in these forests, may affect the long-term spatial dynamics in California woodlands.

(PDF emailed within 0-6 h: $19.90)

Accession: 002604457

Download citation: RISBibTeXText

DOI: 10.2307/1941460



Related references

Native oaks and urban sprawl California, Quercus lobata, Quercus douglasii, Quercus wislizeni. Pacific horticultureng 43(1): 13-17, 1982

Limited hybridization between Quercus lobata and Quercus douglasii (Fagaceae) in a mixed stand in central coastal California. American Journal of Botany 89(11): 1792-1798, 2002

Historical recruitment of quercus douglasii blue oak in southern california usa. Bulletin of the Ecological Society of America 71(2 SUPPL): 183, 1990

Interactions of factors affecting seedling recruitment of blue oak Quercus douglasii in California. Ecology (Washington D C) 70.2: 389-404, 1989

Interactions of factors affecting seedling recruitment of blue oak quercus douglasii in california usa. Ecology (Washington D C) 70(2): 389-404, 1989

Historical review of Quercus lobata and Quercus agrifolia in southern California. USDA Forest Service general technical report PSW United States Pacific Southwest Forest and Range Experiment Station: (100) 440-443, 1987

The impact of European settlement on blue oak (Quercus douglasii) regeneration and recruitment in the Tehachapi Mountains, California. Madrono 39(1): 36-46, 1992

Heterogeneity in recruitment and habitat patterns of valley oak Quercus lobata N e at the site and landscape scale in the Santa Monica Mountains, California, USA. 2013

Oak d mortality in pennsylvania usa a 10 year study asterolecanium minus agrilus bilineatus quercus rubra d quercus prinus d quercus coccinea d quercus velutina d quercus alba d croesia semipurpurana. Journal of Forestry 66(9): 681-694, 1968

Fire related recruitment in stagnant quercus douglasii populations. Canadian Journal of Forest Research 19(5): 580-585, 1989

Growth trends of blue oak (Quercus douglasii) in California. Canadian Journal of Forest Research 23(8): 1720-1724, 1993

Thematic mapper analysis of blue oak (Quercus douglasii) in central California. General technical report PSW US Department of Agriculture Forest Service Pacific Southwest Forest and Range Experiment Station: 26) 198-201, 1991

Facilitation and interference of Quercus douglasii on understory productivity in central California. Ecology 72(4): 1484-1499, 1991

Species richness in quercus douglasii woodlands in central coastal california usa. Proceedings of the International Botanical Congress 13: 264, 1981