Welcome to an overview of what Economic Botany has to offer.
It will be a distance learning course this spring 2000, so below are highlights of what I plan
to be doing in the TopClass format
LECTURE 8 HIGHLIGHTS FOR BIOLOGY 03074, ECONOMIC BOTANY: THE LAWN
Text: 2nd ed.: Ch. 12 (pp. 205-206); 1st ed.: Ch. 12 (pp. 191-192)
possible web site: http://www.ces.ncsu.edu/TurfFiles/
(North Carolina State University Cooperative Extension information on lawns)
lawn:"a usually closely mown plot or area of grass or similar plants." ref: Webster's II New Riverside University Dictionary
LAWN GRASSES
Grasses (Poaceae) Grass leaves have a sheathing base and extending leaf blades. Grasses form tough fibrous roots that anchor the plant into the ground. Mowing the lawn cuts off the blades, but the crown can produce more leaves. When lawn grasses aren't mowed, they can produce flowering stems (seeding).
Typical grasses used in lawns:
Kentucky bluegrass (Poa pratensis) does well in more humid settings, with a fine texture and beautiful color.
Fine or red fescue (Festuca rubra) is drought and shade tolerant, and has a fine leaf .
Bermuda grass (Cynodon dactylon) is more drought tolerant, but has a coarser texture.
Other grasses are marketed because of their characteristics, e.g., the"miracle" Zoysia grasses marketed in the Sunday paper ads have dense growth and need very little water. Love of lawns involves aesthetics, economics, psychology, and history. Lawns can be useful: serve as a firebreak, have recreational value, and can muzzle noise and heat as part of needed"green space." From an overall ecological point of view, though, the American lawn does pose challenges.
LAWN HISTORY
The lawn as we know it is not old--it really stems from 18th century France and especially England. Why England? England is a country of mild winters, high humidity, and temperate climate, all good for grass. Transporting the British lifestyle to New World included planting of grass. Lawns in early America were kept short by hand scythes or grazing. The modern lawn appeared with the creation of the American suburb in the mid-1800s. By 1870s, winding streets and continuous front lawns helped to define a still-typical suburb.
LAWN IMPACT: ECONOMY
How can a continent filled with very different patterns of vegetation all be covered with similar lawns? A lot of effort put into plant breeding, nutrition, irrigation, etc., all of which leads up to a major lawn care industry in the USA: $25 billion+/year. Basically, what this industry deals with is the adaptation of intensive agricultural monoculture practices to our doorstep. An"industrial" lawn (see below) costs more per acre to maintain than corn, rice, etc.
LAWN ENVIRONMENTAL IMPACT: BIODIVERSITY
An idealized"industrial lawn" consists of a major lawn grass (see above) grown in the following fashion:
1) grass species only
2) free of weeds and other pests
3) continuously green
4) regularly mowed to low, even height
Lawns replace native habitats, and so suburbs are less biodiverse than other areas. In contrast to the suburban ideal, many lawns contain"weedy" species: dandelions (Taraxacum), violets (Viola), clovers (Trifolium), etc., and are subjected only to the major influence of (occasional) mowing.
LAWN ENVIRONMENTAL IMPACT: CHEMICALS
A pesticide is a chemical that is designed to kill or inhibit the growth of an undesirable organism. Ideally, one would want to use a narrow-spectrum pesticide that killed only the pest and no beneficial organisms, would break down into nontoxic byproducts rapidly, and would stay only in the sprayed field and not spread. No one pesticide is perfect in all of these considerations.
LAWN ENVIRONMENTAL IMPACT: WATER USE
Grasses need water to grow, so in Southwest, lots of evaporation and so lots of watering in order to keep the grass green. Would it be more appropriate to grow native, drought-tolerant species in locations where our typical lawn grasses would not naturally grow?
|main page| |background| |03028: Physiology| |03048: Anatomy|
|03050: Invertebrate Zoology| |03051: Vertebrate Zoology| |03074: Economic Botany|
Please send comments and questions to: cronewil@hvcc.edu
Copyright 1999 by Wilson Crone
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This page updated on October 4, 1999