midterm Flashcards
landscape
consists of a mosaic of two or more ecosystems that exchange organisms, energy, water, and nutrients
ecosystem
plants, animals, microorganisms within a given area, the environment that sustains it (abiotic factors), and their interactions
habitat
dwelling place of an organisms or community that provides the requisite conditions for its life processes; smaller than ecosystem; (pond, greenway, woods, prairie)
population
a group of organisms belonging to the same species that live in the same area and interact with one another
community
all of the populations of different species that live in the same area and interact with one another
layers of tree (outside to inside)
outer bark, inner bark (phloem), cambium, sapwood (xylem), heartwood
starter plants (plugs, starts, transplants, seedlings)
plants that are several weeks old; alternative to starting from seed
seed tray
container with individual cells for starting seeds
seed flat
container with one giant cell for starting seeds
carrying capacity
a species’ average population size in a particular habitat; size is limited by environmental factors like adequate food, shelter, water, and mates
functional groups
assemblages of organisms that can be recognized by their functional roles in the ecosystem (primary producers, herbivores, carnivores, decomposers, nitrogen fixers, pollinators)
sustainable cultural practices
traditional human land uses that maintain biodiversity and productivity
degradation
gradual or subtle changes that reduce ecological health
damage
acute and obvious changes in an ecosystem
transformation
conversion of an ecosystem to a different kind of ecosystem or land use type
reference ecosystem
ecosystems that can serve as the model for planning an ecological restoration project, and later serve in the evaluation of that project
ecological trajectory
developmental pathway of an ecosystem through time; trajectory begins with an unrestored ecosystem and progresses towards desired state of recovery
genetic fitness
gene pool contains a diversity of alleles (two or more alternative forms of a gene that arise by mutation) that may be selected in response to an environmental change
species richness
simplest measure of species diversity and is either a count of the number or list of species in a community
community structure
combination of species richness and species diversity
allelopathy
biochemical production of a plant; beneficial or harmful effects of one plant on another plant, from the release of biochemicals, known as allelochemicals, from plant parts; juglone from black walnut is an example
forbs
flowering herbaceous plants that aren’t grasses
attributes of restored ecosystem
- contains characteristic assemblage of the species that occur in the reference ecosystem
- Restored species provide appropriate and similar community structure
- native plants
- functional groups necessary for stability of environment
- physical environment capable of sustaining reproducing populations of the species and function without human input
- Potential threats to health and integrity of restored ecosystem have been eliminated or reduced
- Restored ecosystem is resilient to endure stress events
- self sustaining
eoczone (biogeographical realms)
broadest biogeographic division of Earth’s land surface, based on distributional patterns of terrestrial organisms
ecoregions
large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions
biomes
major global plant communities defined by climate; aquatic, grassland, forest, desert, tundra (arctic and tundra)
plant communities
collection of plant species within a geographic unit, which forms a relatively uniform patch, distinguishable from neighboring patches; group of plants sharing a common environment that interacts with eachother
ecotones
mixture and blending of plant communities
plant community distribution
environmental drivers- climate, water availability, elevation, soil characteristics, competition; anthropogenic drivers- land use disturbance, invasive plants
terrestrial plant communities
forests, woodlands, shrublands, herbaceous openings
palustrine plant communities
include any inland, nontidal wetlands that lack running water and have trees, shrubs, and herbs; palustrine forests, palustrine woodlands, palustrine shrublands, palustrine herbaceous openings
forests / palustrine forests
trees over 15 feet high that dominate community; canopy is nearly closed; 60%-100% canopy cover; coniferous, broadleaf-coniferous, broadleaf
woodlands/ palustrine woodlands
trees over 15 feet high dominate dominate; tree canopy cover is sparse, between 10%-60%; coniferous, broadleaf-coniferous, broadleaf
shrublands/palustrine shrublands
shrubs and small trees dominate; trees over 15 feet make up no more than 5%; herbaceous plants may be present at any cover level; coniferous shrublands, broadleaf-coniferous shrublands, broadleaf shrublands
herbaceous openings
community dominated by herbaceous plants
palustrine herbaceous openings
dominated by herbaceous plants; includes swamps, marshes, bogs, fens, tundra, floodplains
tundra
type of palustrine herbaceous opening that is flat, cold, dry, and treeless
floodplain
area of land adjacent to stream or river, which experiences flooding
stream/creek
natural flow of water that follows a more temporary path
native species
occur naturally in an area without direct or indirect human intervention and have lived in said area prior to european settlement
process of invasion
- many new immigrant species die upon arrival or during travel
- some survive to reproduce, but often offspring die after a few generations; small fraction of offspring will persist
- among species that persist, a few will become invasive
accidental introductions from humans
most microorganisms, most insects, most marine invertebrates, some vertebrates, and few plants
deliberate introductions from humans
some insects, some marine invertebrates, some vertebrates, most plants
lag forces/factors
number and arrangement of infestation, limits on detection of population growth, natural selection that produces novel genetic types, habitat alteration, environmental forces
vacant niche hypothesis
suggests communities have low numbers of native species; cannot provide “biological resistance” to newcomers
escape from biotic constraints
many immigrants arrive in new locales as seeds, spores, eggs, without their native associates, including their usual predators; most straightforward hypothesis to explain success of an invader and also provides motivation for researchers to search for biological control agents among its enemies in its native range
community species richness
resistance to invasions increases in proportion to number of species in the community (its species richness); communities are more stable if they are species rich; less likely to have vacant niches if there are many species; on land however, resistant to plant invasion may correlate more sternly to structure of plant community, rather than actual number of species within the community
disturbance before or upon immigration
human or environment changes may encourage invasions by causing sudden, radical disturbances in the environment landscape; if native species cannot adapt to new environment, the arrival of the new immigrants can lead to invasions
economic consequences of invasive species
- affect the economy, such as losses in crops, forests, fisheries, and grazing capacities
- direct cost of combating invasions
prevention for invasions
- prevent opportunity for invasions by prohibiting the entry of nonnative species
- curb the spread and impact of nonnative species
control for invasions
- use of quarantine to prohibit organisms from entering a new range
- eradication attempts to remove species which is most feasible early on
- maintenance control is used if eradication fails, using chemical, biological, or mechanical control
information gap in invasive species
- too much data remains anecdotal
- need better understanding of the epidemiology of invasions
- more cost benefit analysis
- need better assessments of on going invasions
- need greater public and governmental awareness of chronic and global effects of invaders
ecological succession
series of progressive changes in the species that make up a community; changes in plant composition over time and space
predictable ecological succession
proposed concept of a climax state for communities representing the final or permanent end stage of succession; climax communities are assemblage of characteristic plants that define an ecosystem; all species work together to maintain a stable composition
individualistic ecological succession
argued that communities were individualistic; no such thing as a climax community; communities are random assembly of species; community changes aren’t that predictable
primary succession
new rock is formed/exposed; weathering breaks down rocks; hardy plants, mosses, and lichens establish; plants further break down rock into soil; new plans grow on exposed soil; plants grow and die leaving organic matter and contribute to soil formation
secondary succession
an area that was previously occupied by living things is disturbed, then recolonized; new pioneer species grow after disturbance and over time large woody plants and trees begin to establish
climax state
climax communities are stable and can vary depending on region; final biological matrix of plants and animals
early successional systems
smaller plant biomass, shorter plant longevity, faster rates of soil nutrient consumption, reduced role for decomposers, higher rates of net primary productivity, lower stability, lower diversity
facilitation in succession
when one species or group of species colonizes a disturbed area, and subsequently alters the environment of that area, making it more habitable for later successional species
engine of succession
impact that each species has on their environment, changed conditions of the environment
stages of succession
roc, soil, herbaceous, shrubland, young forest, mid age forest, mature forest
large intensity disturbance
results in very slow succession with a huge impact, caused by volcanoes or glaciers
large low intensity disturbance
results in moderate successional response and can recolonize quickly, as caused by fire, storms, agriculture
resource ratio hypothesis
models successional shifts in plant communities based on assumption that succession is driven by a tradeoff in competition for nutrients in early succession and for light in late succession
how to manipulate mechanisms of succession
increase seed availability, reduce competition, and amend soil to better match late succession conditions
three models of plant establishment
facilitation, tolerance, inhibition
facilitation
traditional successional theory process of plant establishment based in part on the plants that existed before them; when one species or group of species colonizes a disturbed area, and subsequently alters the environment of that area, making it more habitable for later successional species
tolerance
vegetation change favors species that are most efficient at exploiting the available resources; most superior and able plant wins
inhibition
no sequence of species establishment but rather a chance coincidence by which the species colonizes and occupies its space
how to manage succession
seed availability, soil conditions, and disturbance regimes
methods for managing succession
mechanical methods and chemical methods
mechanical methods for managing succession
any physical activity that promotes or inhibits plant growth and vegetative change; physical methods like cutting, mowing, planting, mulching, tilling, pulling, soil solarization, herbivory, biocontrol
chemical methods for managing succession
any chemical or synthetic activity that promotes or inhibits plant growth; pesticides and fertilizers
herbicides
chemicals that control/kill weeds; proper rate and timing of application is important; each herbicide controls certain weeds
systemic herbicides
absorbed and moved through plant
direct herbicides
direct contact with plant tissues
methods for applying herbicide
backpack sprayer, pump sprayer, boom sprayer, cut stump treatment, hack and squirt
fertilizers
any material of synthetic or natural origin that is applied to soil or plant tissues to supply a plant nutrient for plant growth; either supplies a nutrients or enhances effectiveness of soil by modifying its soil retention and aeration
managing succession with seed availability
add seed, remove seed, or release seed
managing succession with competition
add plants or remove plants
managing succession with site conditions
altering soil and altering light availability
managing succession with disturbance regimes
increase/maintain or reduce
