Ecology Lab 2 Flashcards
Habitat
the location an organism inhabits. Its study usually involves a description of the biotic and abiotic structure of the environment
Growth form
the physical structure of an organism; e.g. tree, shrub, vine, herb
Life History
refers to the reproduction, growth, longevity, and seasonal or age-specific behavior of organisms
Annual
Plant lives less than one year, and tends to put most of its resources into seed production
Winter annual
an annual which germinates in the late fall, grows during warm spells in the winter and early spring, blooms in the early spring, sets seed, and then dies
Summer annual
an annual that germinates in the spring or summer, and blooms in or before fall. Many agricultural weeds fall into this category.
Seed Bank
All viable seed that remain in the soil. Many annual species have a long-lived seed bank.
Biennial
the plant that lives two years; a seed germinates, the plant devotes its first year to vegetative growth, the second year to reproduction; it then dies.
Perennial
the plant lives more than two years. Some perennials reproduce all at once and then die, while others spread their reproduction, it then dies
Ruderal
refers to a plant, usually an annual or biennial, which requires disturbed soil. Ruderals are often informally referred to as weeds.
Deciduous
leaves fall off at the end of the growing season (in Texas, the growing season is the warm period of the year- in many tropical regions, the growing season corresponds with the rainy season)
Evergreen
leaves are retained throughout the year and may last several years. For many evergreen species (especially conifers), leaves are needles or scales
Herb
A plant with no woody stem above the ground
Graminoid
an herb that is or resembles a grass; includes grasses, sedges, and rushes
Forb
a non-graminoid herb; includes most wildflowers. Although some consider forms to be weeds, they are very important in grasslands and forests.
Shrub
A woody perennial, smaller than a tree, usually without a dominant trunk
tree
perennial woody plant with an evident trunk
vine
a plant that climbs on other plants by means of tendrils or other structures
Liana
a perennial and woody vine
self-pollination
pollen is transferred from anther to stigma of the same flower (or less commonly, another flower on the same plants), often by direct contact
apomixis
seed is produced without pollination (similar to parthenogenesis in animals)
outcrossing
pollination with pollen from a different individual (and therefore with a different genotype) of the same species
animal pollination
animals transfer pollen; flowers are often “showy” (brightly colored, scented, etc.). Plants usually provide rewards for the animal such as nectar or extra pollen.
Wind Pollination
wind transfers pollen; flowers are often “reduced” (lacking showy parts such as petals or sepals)
water pollination
(rare) pollen floats on water between flowers in some aquatic plants
perfect flowers
both male and female parts are present within the same flower (examples: mesquite, cactus, most grasses, most wildflowers, most ruderals/weeds)
Monoecious
individual flowers are either male or female, but both are present on the same plant (examples: oak, pecan, ragweed, corn)
dioecious
male and female flowers are on different plants. Thus dioecious species, we can speak of male plants and female plants (examples: junipers, willow, cottonwood)
stolons (runners)
specialized above ground stems that spread from parent plant and root at the nodes
Rhizomes
specialized below-ground stems that spread from the parent plants and send up shoots
Fragmentation
Establishment of new plants from bits broken off of a parent; common in aquatic plants, cacti, grasses, and many rhizomatous (rhizome-possessing) plants.
Wind dispersal
seeds are winged, tufted, or very tiny
animal dispersal
either external or internal. Externally dispersed seeds stick to animals by means of hooks, prickles, or mucilage (sticky substance), or they may be intentionally carried (e.g. nuts by squirrels). Internally dispersed seeds pass unharmed through the gastrointestinal tract; these are usually enclosed in an edible fruit
water dispersal
seeds float about on water most plant species are capable of this, but some shoreline and aquatic species are especially adapted to this mode of dispersal.
Indigenous
native to the area; having arrived and become established without human assistance
naturalized
growing and reproducing without human assistance after being introduced to the area by humans; includes many weeds, escaped crops, and ornamentals
exotic (introduced)
species not indigenous to the area; may or may not be naturalized
ornamental
cultivated for esthetic purposes in a specific place; includes both indigenous and exotic species
C3
this is the most common kind of photosynthesis. The carbon (from carbon dioxide) is immediately “fixed” into a 3-carbon compound. Almost any plants active during the winter will belong to a C3 species. C3 grasses are called “cool season grasses.” However, C3 species can also be active in the summer. Most woody plants in Texas (unless you consider cactus to be “woody”) are C3 species).
C4
C4 photosynthesis puts carbon from CO2 directly into a 4-carbon compound. The enzyme that does this is quite efficient; therefore, not much CO2 needs to be around for it to work. The advantage of this is that C4 plants do not need to open their stomata (holes under leaves) very far to let in the CO2 molecules. Since they do not open their stomata far, water loss is minimal. C4 plants are adapted to dry climates and are most active during the summer. Almost all C4 species are grasses, including big bluestem, little bluestem, Johnson grass, and Bermuda grass. C4 grasses are the “warm season grasses.”
CAM
Succulent species such as cactus utilize CRASSULACEAN ACID METABOLISM (CAM). CAM species open their stomata only at night, when evaporation is low, and store the carbon in the form of acids. During the day, these acids release the carbon within the leaf. This carbon is then utilized in normal C3 photosynthesis. CAM plants are most common in extremely dry climates such as deserts.
