### substance | wood:

Oak
* All oaks are good wildlife trees
  - plants
  - can resprout from stems when top-killed by fire
  - have natural open spaces in the wood
* Most oak contains oak
  - white oak
* Most oak has bitter acorns
  - edible acorns
  - lives for years
  - produces pollen
  - oaks have a deeply penetrating taproot
* Some oak grows in zones
  - has rays
* Some oaks are maples
  - never become taller than small shrubs
* also provide valuable habitat and food source for wildlife.
* are a valuable timber and wildlife resource.
* are also among the dominant trees of the Chaparral region of California
  - hosts to mistletoe clumps that produce berries which entice still other birds
  - important for wildlife, providing plenty of acorns for animals to eat
* are among most preferred host species
  - the most impressive of all trees
  - an important source of lumber
  - beautiful, their wood valuable, and their fruit a source of food for animals
  - classified as being monoecious, which means they produce both male and female flowers
  - common in woodlands throughout Ohio
  - critical food for many species of wildlife
  - either deciduous with lobed leaves or evergreen with leathery leaves
  - excurrent trees that have a central leader
  - extremely abundant in the SE and of immense value economically and environmentally
* are generally more stately and commanding than maples
  - pest free
  - highly resilient trees, but they are also host to many plant pathogens and insect pests
  - host to majority of galls but other trees and shrubs affected as well
  - important to wildlife species for both cover and food
  - in flower, with tiny leaves emerging
  - magnificent shade trees
  - more likely to be damaged by fall fire than earlier fires
  - native to nearly all states and many species have traditionally been used as human food
* are often the most commonly affected deciduous native species for Oklahoma
  - very tall trees that can obtain heights up to ninety feet
  - overwhelmingly dominant in dry forests
  - some of the largest trees in the forest
* are subject to many pests, depending on the species
  - root rot and various insect pests
* are susceptible to canker, anthracnose, rust, leaf spot, gall and borer
  - many insect pests, fungi, cankers, and wilts
  - the major shade trees of Texas
* are the most commonly attacked plants
  - reliable wood for producing mushrooms
  - trees with leaves that turn brown but hang on through the winter
  - used to make timber, stairs, parks, furniture, casks and railway sleepers
  - valuable as shade trees, specimens and street trees
* are very beneficial trees for wildlife
  - vitally important to North Bay wildlife
  - wind-pollinated
* can have numerous types of galls
  - photosynthesize at high temperatures , but they are being wiped out by grazing and farming
* generally survive low-intensity, fast fires.
* grow slowly
  - well in the open sun, but maples prefer the shade
* grown from nursery stock have better survival rate.
* has acorns
  - sweet acorns
* have a darkly colored protection wood called heartwood
  - heavy crop of acorns, but only about every fourth year
  - softer rustling
  - thick bark which greatly increases survival for the core trunk
  - very strong root system
  - alternate leaves
  - deep, well-behaved roots
  - leaf surface hairs that reduce air movement across leaves
* occur in a wide variety of habitats
  - sporadically in groves along the river
* often turn brown, but sometimes a deep red.
* outrank any other group of trees in Missouri forests in number of species.
* produce acorns for food, and conifers are especially good for nesting sites
  - purplish red leaves during the fall
* provide shelter for hedgehogs, adders, mice and other mammals
  - wildlife habitat and are valuable to the Ohio forest products industry
* require moderate light intensities to reproduce in a forest.
* take dozens of years to reach maturity.
* tend to hybridize easily with each other.
* thrive best in acid soils.
* thrive in acid soils produced by their fallen leaves
  - forests throughout the continental United States except for Alaska
* usually change later, after the first frost.
* vary greatly in susceptibility
  - widely in size and in the way they grow