Woody plant

From ArticleWorld

Woody plants are important and the foundation to the landscape. They are characterized by form , and are either trees, shrubs or lianas. Woody plants control the vegetation whenever conditions are favorable for plant growth. The reason why is because they have large, permanent stems and stable root systems that places their leaves where it captures the most incoming light.

Biologically

Woody plants produce vascular cambium which accounts for growth in diameter of stems and trunks and cork cambium that produces bark for woody plants.

Classification

• Deciduous is a plant that loses its leaves annually at the end of its growing season. It refers to trees, shrubs or lianas.
• Evergreen is a plant that has foliage throughout the year. An evergreen plant does drop its older leaves each year. This occur over a long period of time and at any season. Foliage may need needles, scales or broad leaves.
• Trees are plants that have a dominant vertical trunk and reaches of heights of fifteen feet or more.
• Shrubs is a plant that is smaller than a tree and generally has multiple branches origination at or near the ground.
• Liana is a vine like plant with flexible stems and may be classified by growth habit as:

1. climbing-lianas that require support like tendrils may be produced which aid attachment to structures.
2. Ground cover- lianas that are similar to climbers with the exception of a prostate growing habit.

Environmental problems

The five most common temperatures and moisture related problems in woody plants are:

1. Sunscald which occurs during cold, bright days in midwinter. When direct sun rays heat south-facing branches and southwest sides of tree trunks the bark temperature raises freezing and causing some cells to become active. Sunscald occurs most frequently on thin-barked trees such as aspen, birch, cottonwood, fruit trees, honeylocust, mountain ash, maple and willow.
2. Drought injury is a dehydration of a leaf or branch tissue that occurs when more water is lost through leaves that can be replaced through roots. Environmental factors that contribute are prolonged hot, dry summer weather, dry winters, low relative humidity, wind, soil with high salt concentrations, and restricted root growth from too much water and compacted soil. Drought occurs mostly in the summer months.
3. Drowning of roots.
4. Over watering in woody plants are common problem in irrigated turf grass areas. The most common symptom in broad-leave trees is that the leafs fall in midsummer with some interveinal discoloration of the leaves. Ash, aspen, honeylocust, birch, and maples are the most susceptible to drowning or wet soil conditions.
5. Frost injury for many woody plants are damaged by early fall and late spring frosts. Frost injury is characterized by blackening or browning of foliage or newly emerged shoots and flowers all over the plant. In parts where frost pockets develop, only the lower plant parts are affected. Once frost injury has happened nothing can be done, but frost damage can be prevented.