Physical Analysis - 39% Flashcards
exist. vegetation + plant communities questions
- what is the predominant habitat of region?
- what are existing veg communities on site?
- what are primary invasive species in regin, on site, or on neighboring properties
exist. vegetation context/geography questions
- how are the habitats connected on/near site?
- what is precipitation, hardiness, or heat zone?
exist. vegetation cultural conditions + built context
- how will users interact with the veg?
- from where will veg. be seen?
- what service is the veg. exptected to provide?
habitat design questions re wildlife
- regional corridors and habitat patches adjacent + crossing
- wildlife species in existing/enhanced corridors and patches
- explore habitat conditions and compare against potential
- evaluate the probability of improving corridor to attract desired species
- compare corridor and patch potential against habitat needs of desire species
Firewise program
= segment property around a structure into 4 zones
1- w/i 30’ - well irrigated or very low flammability buffer
2- 30-100’ - low flammability, low growing, and if nec irrig w/ few trees
3- 100-200’ - low-growing plants and well-spaced trees
4- 200+’ - potentially well-vegetated natural area but pruned to remove highly flammable dead material
what’s needed for ecological restoration?
- describe ecosystem to be restored
- identify a reference ecosystem
- identify historic ecological processes to reestablish
- perform ecol site assessment to understand drivers
- identify limiting site conditions
- identify biota - plant species and keystone species
- id ecol feedback loops
- id propagule sources
- id nec mgmt efforts
- id restoration endpoints
what is a site assessment
the evaluation of environmental limitations and opportunties in the context of the intended function of the site
soils questions in site assessment
- type and quantity
- where disturbed and in what way?
- where are soils that can be restored or made healthy?
- are there areas where soil is absent, or where soils are contaminated?
how to tell if healthy soil is present
- soil horizons are similar to reference soil
- both topsoil and subsoils are uncompacted
- organic matter content is equal to or exceeds that of reference soil
- soils don’t have compounds toxic to anticipated plants
- existing veg is representative of native plant communities
minimal soil disturbance
= soils that are very minimally graded or only somewhat compacted - may exceed MADB (Maximum Allowable Bulk Densities per SITES) in surface horizons but not covered with impervious and do not have sig subsoil compaction or disturbance
moderate soil disturbance
common around buildings
topsoil is absent, and subsoil has been graded; if topsoil is present it likely exceeds MABD (Max Allowable Bulk Densities). Subsoils will have been altered, compacted, or mixed
severe soil disturbance
e.g., soil beneath existing asphalt or buildings, or brownfields
combines characteristics of moderately disturbed soils (topsoil is absent, and subsoil has been graded; if topsoil is present it likely exceeds MABD (Max Allowable Bulk Densities). Subsoils will have been altered, compacted, or mixed) but are also paved over or contaminated
ecological restoration definition
per Society for Ecological Restoration International (SER): the process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed
Soils - qualities of disturbed soils compared to original
may still be present: soil chemistry and texture
may be altered beyond recognition: drainage, pH content, soil structure, soil horizons
5 contexts for ecological restoration
- recovery of degraded/damaged ecosystem
- replacement of destroyed ecosystem with same kind
- transformation from one type to another when historical type is no longer viable (e.g., overgrazed)
- substitution of “novel” landscape when historical type can no longer be supported - derived from historical but a new assemblage to suit site
what are feedback loops?
= processes within an ecosystem that direct change or maintain a system
big picture soil assessment
- observe/research land use history = what occurred here in the past - use historical aerials and maps
- what are the major soil areas and challenges within the site? (to protecting ecosystem services)
- what are the regulatory concerns?
biomass density index
BDI
total percent of the total area of the site covered by various veg types, x cover category value based on leaf area
trees - which strip more airborne pollutants?
greater foliage density, such as evergreen
soils - correlations with existing vegetation + landscapes
nutrient deficiences = altered soil chemistry
decline of large tree = root disturbance up to 20 yrs earlier
poor tree vigor = poor soil quality or compromised conditions or disturbance
healthy/valuable specimens = healthy soils, protection warranted
invasives = disturbance
indicator species = distrubance, wet soils, thin soils, high - or low-quality soils
witch’s from, branch dieback, leaf scorching = salt exposure
soils - correlations with hydrology/topography
erosion = could show altered chemistry/nutrient deficiencies
original topo = soil char will shift
impervious/runoff routes = soils vulnerable to erosion
ponding, slow drainage = with less disturbed sites, special soils/conditions; with more disturbed sites, compaction and/or poor internal drainage
soils - mapping
- historical changes
- differences in type incl imported
- diff in maint/mgmt
- areas of vehicular and ped traffic
- location/differences in plant growth/type
- areas near sidewalks, parking lots, and buildings
- areas treated with deicing salts
- eroded/noneroded
- diff in slope
- wet/dry areas
- rock outcrops/ledges
- watersheds
soils - categories for classification
healthy
min disturbed
mod disturbed
severely disturbed
no soils
n/a
soils - where/how to sample
-where site analyses show potential differences in the soil, preference given to areas needing remediation or preservation
-representative of area, not composite
soil - impacts of texture
- drainage
- water-holding capacity
- compactability/porosity
- fertility
- which plants will grow successfully
- interpretation of compaction tests
- calculations fro modifying soil ph and remediating compacted soils
soil - test for texture
texture by feel method - ribbon analysis
good for prelim site assessment and interp of past disturbance
other methods: mason jar
best: send to lab
soil - clay - qualities of texture
- greater surface area, so retain more moisture
- negatively changed, so have binding properties promoting soil structure formatoin and carbon retention
soil - organic matter - testing for
visual inspection
Munsell Soil Color Chart supports
lab test is most accurate
LOI - Loss on Ignition lab test - may overstate in clay or be less reliable at low carbon levels
Walkley-Black Procedure
<3-5% indicates issues
soil - pore structure
macropore - air and water infiltration
micropore - water retention
soil - compaction testing
- eval density of dry soil for a given volume = soil bulk density (best method) or soil dry bulk density > Undisturbed Core Method (dry in oven and measure dry weight, then perform calcs) - standard but not instantaneous
- eval soil strength, or resistance to penetration - amt of force to insert a metal rod in the soil > cone penetrometer - quick but soil must be moist - measures depth of usable soil
soil - volume requirements
at least 3m3 of soil per 5m2 of ultimately canopy projection
soil - perc test
the speed at which water moves through the soil measured in cm or in. per hr.
<1in/hr = extremely poor drainage
<1-4in/hr = poor drainage
4-8in/hr = good drainage
8+in/hr = excessive drainage
soil - cation exchange capacity
CEC - capacity of the soil to retain positively charged ions (cations), which include many plant nutrients - and also lead
sandy and silty soils have low CEC
maps - infrared color correspondences
waterbodies - blue
dense veg - red
less dense veg + urbanized - lt red
unhealthy veg - greens
bare soils - white/blue/green - more moisture means bluer
maps - USGS aerials - area of representation
center on a quarter section of a 7.5’ USGS quadrangle, which is about 5.5mi x 5.5mi area
maps - USGS - DOQs
= Digital Ortho Quadrangles
- rectified and projected aerial, grayscale/natural/color infrared with 1m resolution, cover 7.5’ longitude by 7.5’ latittude
maps - USGS topo map scales
1:24,000 1:25,000 and 1:63,360
7.5’ x 7.5’
maps - USGS - DRG
= digital raster graphics - scanned image of a USGS topographic map - 1995-1998
large scale - 20,000, 24,000, 25,000,
medium scale - 100,000
small scale - 2,000,000
maps - cadastral definition
= maps and recoreds showing boundaries, ownership, and attributes of real property
used for taxation planning, zoning, assessment, and permit granting
integrated database of land description, value, ownership, and socioeconomic data
Bureau of Land Mgmt (BLM) - public lands
IAAO - Int’l Assoc of Assessing Officers
maps - metes and bounds
limits or boundaries as identified by natural landmarks such as rivers, or man-made structures like roads, stakes, or other markers
land uses - color coding
yellow - residential
brown - multi-familyl
red- retail/commercial
purple - industrial
blues - institutional/public
greens - recreational
grays - industrial
