Valley Oak (Quercus lobata) Distribution map for Valley Oak: • Endemic to valley habitats of California (in fertile lowlands in deep rich soils between the Sierra Nevada and the coast) • May be the largest N. American oak • Can live to 400-600 years • Massive trunks (over 2 meters in diameter) One meter diameter trees may be “only” 150-250 years old • Can grow to 30 meters tall • Grows very rapidly in mesic sites where roots can * 501 Oak Ave Quercus lobata DBH = 6’5”! On the City of Davis Landmark Trees List According to the City of Davis Master Tree List: valley oaks make good street and parking lot trees and have a moderate growth rate. Landmark Trees may be so designated because they are unique in being: • An outstanding specimen of a desirable species • One of the largest or oldest trees in Davis • Of historical interest • Of distinctive form Using the Trunk Formula Method of Tree Appraisal by the CTLA (Council of Tree and Landscape Appraisers), and species ratings by Regional Groups The Appraised Value for the Valley Oak at: 501 Oak Ave Davis, Ca = $97,400 (from a whopping $193,300 prior to personal speculation on tree location, placement and health!). *According to the “Street Tree Planting Guide” provided by the City of Sacramento Urban Forest Services Division (of the City of Sacramento Department of Parks and Recreation): • Valley Oaks average 50-70’ height and canopy spread • Are rounded in shape • Deciduous • Drought tolerant •Are ‘fair’ in terms of root suitability to confined spaces •Are poorly suited to canopies in confined spaces or in conflict withoverhead wires • Are the largest valley native. • And, should not be planted in turf areas. According to USDA (United States Department of Agriculture) NRCS (Natural Resources Conservation Service) Plants Database: http://plants.usda.gov/ Classification: Quercus lobata Née (also called California White Oak) KingdomPlantae ‒Plants SubkingdomTracheobionta ‒ Vascular plants SuperdivisionSpermatophyta ‒ Seed plants DivisionMagnoliophyta ‒ Flowering plants ClassMagnoliopsida ‒ Dicotyledons SubclassHamamelididae OrderFagales FamilyFagaceae ‒ Beech family GenusQuercus L.‒oak SpeciesQuercus lobata Née ‒ valley oak Related Taxa: 6 genera in Fagaceae, 206 species in Quercus Morphology/Physiology: Reproduction: Active Growth Period: Spring and Summer Bloom Period: Early Spring Growth Form: Single Crown (flowers monoecious, wind-pollinated Shape and Orientation: Rounded Fruit/Seed Period Begin: Summer Habit: deciduous tree Fruit/Seed Period End: Fall Growth Rate: Rapid (Seed ripens in the first year, good crops every 2-3 yrs.) Height at 20 Years, Maximum (feet): 35 Height, Mature (feet): 100.00 Resprout Ability: Yes Growth Requirements: Suitability/Use: Adapted to Coarse Textured Soils: Yes Berry/Nut/Seed Product: No Adapted to Fine Textured Soils: No Christmas Tree Product: No Adapted to Medium Textured Soils: Yes Fodder Product: No (Prefers medium loamy and heavy clay) Fuelwood Product: High Anaerobic Tolerance: None Lumber Product: No Drought Tolerance: Medium Naval Store Product: No Fertility Requirement: Medium Nursery Stock Product: Yes Fire Tolerance: Low Palatable Browse Animal: Low Frost Free Days, Minimum: 200 Palatable Graze Animal Palatable Human: No Moisture Use: Medium Post Product: No pH: 4.50 ‒ 7.50 (most any pH) Protein Potential: Low Precipitation, Minimum: 16 Pulpwood Product: No Precipitation, Maximum: 40 Veneer Product: No Root Depth, Minimum (inches): 42 (Plants produce a deep taproot and need to be planted out into their permanent positions as soon as possible, in fact seed sown in situ will produce the best trees. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.) Salinity Tolerance: None Wind Tolerance: High Shade Tolerance: Intolerant Temperature, Minimum (°F): 7 (hardy to zone 7) Hookers Valley Oak *FORMORLLY A DOMINANT SPECIES IN THE CENTRAL VALLEY: • Used to occur in extensive park-like groves • OAK APPLES caused by CYNIPID WASP (Andricus • Common riparian species californicus) • Extensive forests largely eliminated during agricultural •Galls are formed when adult wasps deposit development their eggs into plant tissue in the summer • Habitat destruction is the primary problem • Larval secretions cause the galls to form as • The favorite oak species for larvae feed within. ecological restoration • Form ectomycorrhizal •When mature, the wasp chews a hole in the relationships gall and flies off (usually in late spring) • Acorns provide food for many small animals and are adapted to survival in our harsh summer drought climate .