Effect on Blue Oak (Quercus douglasii) of 2,4-D and 2,4,5-T Concentrates Applied to Cuts in Trunks

1956 ◽  
Vol 9 (1) ◽  
pp. 15 ◽  
Author(s):  
Oliver A. Leonard
Keyword(s):  
Quercus Douglasii ◽  
Blue Oak

scholarly journals Hotter Drought Escalates Tree Cover Declines in Blue Oak Woodlands of California

2021 ◽  
Vol 3 ◽  
Author(s):  
Francis K. Dwomoh ◽  
Jesslyn F. Brown ◽  
Heather J. Tollerud ◽  
Roger F. Auch
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Land Surface ◽  
Climatic Variability ◽  
Tree Cover ◽  
Quercus Douglasii ◽  
Oak Woodlands ◽  
Vegetation Communities ◽  
Blue Oak ◽  
Climate Risks

California has, in recent years, become a hotspot of interannual climatic variability, recording devastating climate-related disturbances with severe effects on tree resources. Understanding the patterns of tree cover change associated with these events is vital for developing strategies to sustain critical habitats of endemic and threatened vegetation communities. We assessed patterns of tree cover change, especially the effects of the 2012–2016 drought within the distribution range of blue oak (Quercus douglasii), an endemic tree species to California with a narrow geographic extent. We utilized multiple, annual land-cover and land-surface change products from the U.S. Geological Survey (USGS) Land Change Monitoring, Assessment and Projection (LCMAP) project along with climate and wildfire datasets to monitor changes in tree cover state and condition and examine their relationships with interannual climate variability between 1985 and 2016. Here, we refer to a change in tree cover class without a land-cover change to another class as “conditional change.” The unusual drought of 2012–2016, accompanied by anomalously high temperatures and vapor pressure deficit, was associated with exceptional spikes in the amount of both fire and non-fire induced tree cover loss and tree cover conditional change, especially in 2015 and 2016. Approximately 1,266 km2 of tree cover loss and 617 km2 of tree cover conditional change were recorded during that drought. Tree cover loss through medium to high severity fires was especially large in exceptionally dry and hot years. Our study demonstrates the usefulness of the LCMAP products for monitoring the effects of climatic extremes and disturbance events on both thematic and conditional land-cover change over a multi-decadal period. Our results signify that blue oak woodlands may be vulnerable to extreme climate events and changing wildfire regimes. Here, we present early evidence that frequent droughts associated with climate warming may continue to affect tree cover in this region, while drought interaction with wildfires and the resulting feedbacks may have substantial influence as well. Consequently, efforts to conserve the blue oak woodlands, and potentially other vegetation communities in the Western United States, may benefit from consideration of climate risks as well as the potential for climate-fire and vegetation feedbacks.

scholarly journals The Effects of Different Sizes of Tree Shelters on Blue Oak (Quercus douglasii) Growth

2001 ◽  
Vol 16 (4) ◽  
pp. 153-158 ◽  
Author(s):  
Douglas D. McCreary ◽  
Jerry Tecklin
Keyword(s):  
Field Performance ◽  
Height Growth ◽  
Average Height ◽  
Quercus Douglasii ◽  
Tree Shelters ◽  
Blue Oak ◽  
Promising Tool ◽  
Wide Range ◽  
Stock Types ◽  
Time Required

Abstract Tree shelters have been used effectively in many locations to establish a wide range of tree species including oaks. However, their efficacy in Mediterranean climates like the hardwood rangelands of California has not been thoroughly tested. This study evaluated the field performance of blue oak (Quercus douglasii)—a species that is reported to be regenerating poorly in many locations in the state—protected by several sizes of tree shelters and compared response of directly sown acorns to that of 4-month-old transplants. After five growing seasons, seedlings in all sizes of tree shelters are larger than their unprotected counterparts. Tree shelters have been especially effective in promoting rapid height growth. However, regardless of tree shelter size, when seedlings grew above the tops of the shelters, average height growth diminished and diameter growth increased. Differences among stock types were relatively small, although transplants tended to perform better than directly sown acorns. These results suggest that tree shelters can greatly reduce the time required by seedlings to grow to a size where they are less vulnerable to browsing. As such, they appear to be a promising tool in efforts to regenerate blue oak in California. West. J. Appl. For. 16(4):153-158.

Competition for soil water between annual plants and blue oak (Quercus douglasii) seedlings

Oecologia ◽  
1989 ◽  
Vol 79 (4) ◽  
pp. 533-541 ◽  
Author(s):  
D. R. Gordon ◽  
J. M. Menke ◽  
K. J. Rice
Keyword(s):  
Soil Water ◽  
Annual Plants ◽  
Quercus Douglasii ◽  
Blue Oak

Interactions of Factors Affecting Seedling Recruitment of Blue Oak (Quercus Douglasii) in California

Ecology ◽  
1989 ◽  
Vol 70 (2) ◽  
pp. 389-404 ◽  
Author(s):  
Mark I. Borchert ◽  
Frank W. Davis ◽  
Joel Michaelsen ◽  
Lyn Dee Oyler
Keyword(s):  
Seedling Recruitment ◽  
Quercus Douglasii ◽  
Factors Affecting ◽  
Blue Oak

scholarly journals Quality and Yield of Forage as Affected by Chemical Removal of Blue Oak (Quercus douglasii)

1964 ◽  
Vol 17 (3) ◽  
pp. 142 ◽  
Author(s):  
Alfred H. Murphy ◽  
Beecher Crampton
Keyword(s):  
Quercus Douglasii ◽  
Blue Oak

Augering and Fertilization Stimulate Growth of Blue Oak Seedlings Planted from Acorns but not from Containers

1995 ◽  
Vol 10 (4) ◽  
pp. 133-137 ◽  
Author(s):  
Douglas D. McCreary
Keyword(s):  
Slow Release ◽  
Field Performance ◽  
Quercus Douglasii ◽  
Artificial Regeneration ◽  
Container Seedlings ◽  
Blue Oak ◽  
Field Response ◽  
Direct Seeded ◽  
Positive Effect ◽  
Better Than

Abstract Blue oak (Quercus douglasii), a widely distributed species in California, is reported to be regenerating poorly in portions of the state. To ensure this species can sustain itself, successful artificial regeneration strategies are needed. Two separate studies evaluated the effects of augering and fertilization on the field performance of direct seeded acorns and P+0 container seedlings. In each study, 30 planting spots were established for each of the 8 combinations of fertilization (none and a 21 g slow release tablet) and augering (0, 30, 60, and 90 cm). Field response was evaluated for 4 yr. Fertilization significantly increased the growth of direct seeded acorns, but not of transplanted seedlings. Augering had a similar, but less pronounced positive effect—but again, only for the acorns. For all treatments, acorns tended to grow better than transplants. These results suggest that blue oak can be successfully established by planting acorns, and that both augering and fertilization can enhance field performance. West. J. Appl. For. 10(4):133-137.

Factors affecting the relationship between carbon isotope discrimination and transpiration efficiency in blue oak (Quercus douglasii)

2001 ◽  
Vol 28 (1) ◽  
pp. 49 ◽  
Author(s):  
Steven L. Matzner ◽  
Kevin J. Rice ◽  
James H. Richards
Keyword(s):  
Carbon Isotope ◽  
Carbon Isotope Discrimination ◽  
Population Level ◽  
Plant Size ◽  
Relative Effect ◽  
Population Variation ◽  
Transpiration Efficiency ◽  
Quercus Douglasii ◽  
Isotope Discrimination ◽  
Blue Oak

In a greenhouse study, variation in plant and leaf transpiration efficiency(W, A/E)and carbon isotope discrimination (D) were assessed forQuercus douglasii Hook & Arn. (blue oak) from a‘wet’ (930 mm) and a ‘dry’ (500 mm) site. Plants weregrown at 75–100% (wet) and 50–75% (dry) of fieldcapacity. Family variation masked population level differences, and twocontrasting patterns emerged. The expected pattern was observed with drytreatment plants having lower leaf internal CO 2concentration (c i ) and D, andhigher W andA/E. For families with verylarge increases in plant size from dry to wet treatments, however, wettreatment plants had lower c i andD, and higher W andA/E, reflecting a greaterinfluence of the maximum assimilation rate (Amax ) compared with stomatal conductance(g s ) on ci . In addition, large within-population variation inplant size appears to have affected both n (the vapor pressure deficit) andø c (a measure of respiredcarbon). Lower n for large plants may be due to the higher rates of stomatalconductance and greater leaf cooling. Values of øc appear to have increased for plants below 2.5 g (drymatter, DM). Variation in these factors would directly affect the relationshipbetween W and D. This study illustrates a case where significant within-population variation can occur in the relative effect ofg s and Amax on c i .In addition this study indicates that øc may not be a constant for a species.

Sign in / Sign up

Export Citation Format

Share Document