Study Guide Ch. 5 Biotic Systems

Question 1

Characteristics of existing vegetation that should be documented during the site inventory process and included as part of the site analysis

Answer 1

location
health
character
type

Question 2

What have the greatest impact on the type of vegetation that is found on an undisturbed site

Answer 2

available moisture and temperature extremes

Question 3

What generally possess greater biodiversity than the communities that they separate

Answer 3

transitional areas between ecological communities (“ecotones”)

Question 4

Carrying capacity

Answer 4

is a term from the ecological sciences and is a measure of the type and density of development that can be supported without detrimental effects to society, the economy, or the environment and without decreasing the capacity of the environment to sustain these uses into the future.

Question 5

Ecological footprint

Answer 5

is the impact of a person/community or use on the environment, expressed as the amount of land required to sustain their use of natural resources.

Question 6

Within the field of landscape architecture, plant selection plays a critical role in reducing on-site resource use, specifically the use of water. Plants can be classified according to their water needs, and these categories are as follows

Answer 6

Xerophytes
Mesophytes
Hydrophytes

Question 7

Xerophytes
Xeric plants

Answer 7

plants that require little moisture to survive and are often referred to as “drought tolerant.”

Question 8

Mesophytes

Answer 8

plants that are adapted to neither dry nor wet environments and grow best with a moderate use of water.

Question 9

Hydrophytes

Answer 9

plants that are adapted to living in aquatic or in wetland conditions with a surplus of available water.

Question 10

Xeriscaping

Answer 10

entails the use of drought-tolerant plants in a landscape design and emerged in the Western United States as a way to reduce water use in the landscape while still providing site users with all of the benefits that plant material brings (e.g. flowers, pollinators, sound, scent, screening, etc.).

may result in lower planting density, xeriscaping does not mean avoiding the use of plant material altogether

Many plants used in xeriscaping are native plants, however, many are not (e.g. exotic cacti and succulents may be suitable for a xeriscape, whereas a native wetland grass might not). Remember this distinction.

Question 11

native plants are typically considered desirable because they are pre-adapted to their respective climate and are often (but not always) less resource intensive to grow than exotic plants. They also tend to provide outstanding wildlife benefit and can provide a greater sense of place than non-native plants.

Question 12

Wetlands

Answer 12

are a specific point of emphasis throughout the LARE Section 2 and 3 exams, and they should be regarded as important site assets worthy of protection.

are fragile ecosystems, and unnecessary excavation and grading can disrupt groundwater flows that feed into them, causing irreparable harm.
Are heavily reliant on watershed management and are exceptionally sensitive to “upstream” changes in a hydrological system.
For the purposes of the LARE exam, no construction should ever occur inside wetlands (or—if forced to choose—the proposed use should be the least disruptive) and stormwater should not be drained into wetlands without being sufficiently treated for quantity/volume and quality.

Question 13

Although there are numerous types of wetlands, one can generally assume that a wetland will confer the following benefits to a site and its users

Answer 13

Groundwater recharge and discharge
Sediment stabilization
Flood attenuation
Water quality maintenance
Wildlife habitat
Climate moderation
Shoreline protection

Question 14

Wetlands are defined by their

Answer 14

hydrology
soils
the presence of specific vegetation (namely, hydrophytes).

Question 15

The US Fish and Wildlife Wetland Classification System defines five major wetland types, and they are as follows

Answer 15

Marine (open ocean and its associated coastline)

Estuarine (tidal waters of coastal rivers, salty tidal marshes, mangrove swamps, and tidal flats)

Riverine (rivers and streams)

Lacustrine (lakes, reservoirs, and large ponds)

Palustrine (marshes, wet meadows, fens, bogs, swamps)

Question 16

The majority of wetlands in the United States fall under the

Answer 16

palustrine” system

and "estuarine" is the second most prevalent wetland type

Question 17

Note that salt marshes are generally considered to be the most important, productive and diverse of all ecosystem types

Answer 17

Situated at the interface between land and sea, and salt and freshwater ecosystems, salt marshes offer habitat and food to a wide variety of terrestrial and aquatic life.

Question 18

Bog

Answer 18

a type of wetland found in northern climates that is characterized by acidic soils, rich deposits of organic material (such as peat) and a diversity of vegetation types.
Note that bogs and fens are identical with the exception that bogs are fed by rainwater, whereas fens are fed by groundwater.

Question 19

Estuary

Answer 19

a semi-enclosed coastal body of water connected with the open sea.

Estuaries are strongly affected by tidal action and contain brackish water (seawater is mixed with fresh water from land drainage).

Question 20

Marsh

Answer 20

a type of wetland characterized by herbaceous vegetation no taller than 6’.

Question 21

Swamp

Answer 21

a wetland dominated by woody vegetation

Question 22

Specimen trees

Answer 22

a considerable site asset that cannot be replaced, and they can lend exceptional character to a project site.

Question 23

Given the importance of trees/tree canopy in general and specimen trees in specific, an arborist will often be hired to conduct a tree survey, and they will document:

Answer 23

Tree location and size

Tree species (hardy, well-adapted species are considered the most desirable)

Tree condition, health and/or tolerance to potential disturbance

Question 24

Black spot

Answer 24

is a fungal disease that causes black, round spots that form on the upper sides of leaves, particularly on roses (as well as other highly ornamental plants).
Black spot is a problem during extended periods of wet weather or when leaves are wet for 6 hours or more.

Question 25

Canker

Answer 25

is often identified by an open wound that has been infected by fungal or bacterial pathogens.
Canker occurs primarily on woody landscape plants and trees.

Question 26

Chlorosis

Answer 26

is a condition typically caused by iron deficiency and is manifested by yellowed leaves with green veins. This iron deficiency can be produced by overly alkaline soils (high pH), overwatering and a lack of soil aeration.

Question 27

Fasciation

Answer 27

is a genetic mutation of a plant's growing tip, and it affects the stem, flowers, or fruits by inducing malformed growth.

Question 28

Powdery mildew

Answer 28

is a fungal disease in which infected plants will display a white powdery substance that is most visible on upper leaf surfaces. This fungus thrives during low soil moisture conditions combined with high humidity levels on the upper parts of the plant surface.

Question 29

Invasive species

Answer 29

States, counties and municipalities will often maintain a list of highly invasive plant species in that area, and—if found on site—these plants should be removed if at all possible.

Examples of highly invasive plants vary by region and include kudzu (Southern US) and purple loosestrife (Northeastern US and Midwest).

Proximity to urban development and site disturbance can result in the introduction of invasive species.

In sites with significant natural resources, consideration should be given to mapping the distributions of invasive species because this information can be used to develop a targeted plan for eradicating invasive exotic species and restoring degraded native plant communities.

Question 30

Wildfire

Answer 30

Climate change is resulting in longer fire seasons in the Western US (where fire has always been part of ecosystems), and fire dangers are spreading into areas where they have historically not been a consideration

Question 31

In locations with a high risk of wildfires,

Answer 31

Areas within 30’ of a structure should be either completely free of vegetation or be planted with plants that have low flammability.

Fire departments will often provide a list of plants suitable to be planted within this “defensible space.”

Areas surrounding structures should also be kept free of any extraneous flammable material and be regularly maintained to reduce the available fuel load in this same area.

Question 32

Note that most fire departments advise against planting trees adjacent to houses in areas with a high-risk of wildfires because trees can create a “fuel ladder” effect

Answer 32

in which fire climbs up the tree (from the ground) and can be transferred from the tree onto a building.

Question 33

“urban-wildland interface”

Answer 33

is generally considered to be the location with the highest fire danger within the built environment because urban uses introduce a variety of fire catalysts (e.g. cigarettes, grills, etc.) into areas with a high fuel load, as well as exposing the built environment to any baseline fire danger in “wild” areas.

Question 34

most important to know the three primary determinants of fire danger in the landscape, and they are as follows

Answer 34

Existing fuel load (the amount of flammable organic material in an ecosystem)

Weather

Topography

Question 35

When considering the importance of wildlife, site inventory and analysis is generally most concerned with identifying critical habitat and establishing the presence (or lack thereof) of threatened/endangered species.

Answer 35

The presence of threatened/endangered species on a site often triggers a variety of regulatory constraints and can significantly alter the potential for site development or preclude development altogether.

Question 36

Due to extensive habitat fragmentation occurring over the 20th century and into the present day, sustainable site planning should look to protect and/or strengthen natural corridors in the landscape that facilitate the movement of wildlife between habitats.

Answer 36

Identifying gaps in these corridors is also important because habitat restoration will be particular impactful in these locations.
Large, contiguous natural areas (especially those along riparian corridors and containing wetlands) should be given the highest priority for protection from development.