Abeka 7th Grade Science, Chapter 12 Review

taproot

root system in which the primary root grows straight down and remains larger than the secondary roots that branch out from it

spreading roots

root system that consists of several equally sized roots that spread out near the surface

bark

rough outer covering of a tree

vascular cambium

ring of growth cells within a tree trunk that separates the bark from the wood and is responsible for secondary growth

pith

central core of a young woody stem

heartwood

hard, inactive dead wood in the center of a stem

sapwood

functioning wood surrounding the heartwood of a tree

competition

struggle against other organisms for needed resources

terminal bud

bud found at the end of a twig that allows the stem to grow in length

bud scale

any of the scales that cover and protect a terminal bud during winter dormancy

lateral bud

bud found on the side of a twig that allows the stem to form branches

primary growth

growth of a root or stem in length

secondary growth

growth of a root or stem in diameter

leaf scar

scar that remains on a stem after a leaf falls off

forest management

manipulating trees to meet the landowner's current objectives for tree regrowth and production or yield

forestry engineering

branch of forestry concerned with the solution of long-term ecological and environmental effects forest use may cause

carbon sink

system or object that absorbs cardon dioxide from the environment

carbon source

system or object that produces carbon dioxide

slash

branches and other logging debris

sustained yield management

intensive forest management system that, when applied, causes the forest to grow more high-quality trees that mature faster than they normally would

prescribed burn

forestry technique of deliberately starting a controlled forest fire to encourage forest health

conifer

evergreen, cone-bearing tree

three functions of tree roots

absorbing water and minerals, anchoring the tree firmly in the soil, storing food

Buds

plant structure containing undeveloped tissue that can produce new stems and leaves

Cuticle

A waxy covering on the surface of stems and leaves

An old-growth forest

shows no significant signs of major disturbances; at least 150 years old; has fallen, dead trees in various stages of decay; has trees of many different ages

Five methods of tree harvesting

clear-cutting, block cutting, seed-tree method, selection cutting, shelterwood

Shrub

woody plants with several equally large stems instead of a single main stem; usually shorter than 4 to 5 meters

Deciduous trees

Deciduous trees lose their leaves in the fall and stay bare in winter

Sun leaf

Thicker, more cell layers, more chloroplasts

Shade leaf

less light, larger, thinner

the role of forests in the carbon-oxygen cycle

Trees undergo photosynthesis to give off oxygen and take in carbon dioxide.

Canopy

Dense covering formed by the leafy tops of tall rain forest trees

Theodore Roosevelt

President who created the national forest service

Xylem

vascular tissue that carries water upward from the roots to every part of a plant

Phloem

type of vascular tissue that carries nutrients and food from place to place inside the cell