2 - Land Classification Flashcards
The first prescription element…
- Land classification (sets the stage and context of activities and yield projection)
Land Classification
- The process of generating and applying land strata that are sufficiently homogeneous with respect to physical, vegetative, and development attributes that the face validity of models and projections based on such strata is not threatened
- Classification of lands into homogeneous strata allows us to generalize results from observed or studied areas to similar by unstudied areas
- EX: G&Y of Loblolly Pine
Primary Purpose of Land Classification
- The primary function is to allow us to predict the outcome of our actions
· Yield table (site index and age define the stand type-yield is the prediction)
· Sediment yields
· Wildlife responses to treatments or schedules of activities
Secondary Purpose of Land Classification
- The secondary function is that it serves as a language to communicate
- EX: “This parcel is a good site on a steep, north-facing slope”
Stand type
- Homogenous land type, having the same (or sufficiently similar) combination of characteristics (physical, vegetative, or developmental)
- Synonyms: land type, site type, condition class, forest type, the analysis area
Stand
- Homogenous, geographic, contiguous parcel of land
· All of the same stand type
· Subset of a stand type
Management Unit
- Geographically contiguous parcel of land which contains one or more stand types
- Synonyms: heterogeneous planning unit, allocation and scheduling zone, administrative area
- Defined for management purposes by:
· Watersheds
· Ownerships
· Administrative boundaries (i.e. ranger district, opportunity area)
Methods for Developing a Land Classification System
- Determine Objectives
- Determine Attributes of Interest
- Map Attributes (to determine where attributes of interest occur on the ground)
- Overlay Attribute Maps
- Prediction of Yields/Outcomes
STEP 1 - Methods for Developing a Land Classification System
- Determine attributes of interest (many to choose from)
· Air temp
· Surface shape – slope, aspect, elevation
· Water – area, depth, flow rate
· Current vegetation – species composition, height, density, canopy/understory
· Potential vegetation – “climate” plant community
· Under surface – soil type, stability, soil depth
· Location – lat/lon, jurisdiction, ownership, easements
STEP 2 - Methods for Developing a Land Classification System
- Map attributes to determine where attributes of interest occur on the ground
· Use USGS quad sheets, air photos, satellite imagery, N.R.C.S. soils maps, cruise data, other inventories
· Like all other steps, what you do depends on the owner’s objectives
STEP 3 - Methods for Developing a Land Classification System
- Overlay attribute maps
· Purpose to identify areas that will respond in a homogenous manner to management treatments
· Overlaying required anytime that you have more than one attribute of interest - EX: See D&J page 32
STEP 4 - Methods for Developing a Land Classification System
- Prediction of Yields/Outcomes
· Sediment, timber, wildlife, water, recreation, etc…
Classification of Space Dependent Attributes
- Attributes can be defined as place-specific vs. place-independent
Place Specific
- Need to know where the parcel is located in order to determine attribute
- EX: ownership, watershed-cumulative effects, distance to stream, wildlife corridor?, visual sensitivity
Place Independent
- Could determine attribute from a relocated “plug”, without knowing where it came from
- EX: aspect, slope, elevation, soil, and vegetation
Importance of Space Dependent Attributes
- It is important to classify attributes as distance specific or distance independent
- Importance: Basic lack of data about any given parcel – must extrapolate from other areas – place specific becoming more important with ecosystems focus – often we want location specific analysis, but stuck with independent data
- EX: Some companies and the federal government use MAI (average annual growth over the life of the stand) to predict yields of red pine and several spruce species in harvest scheduling calculations
Classifications of Attributes
- Categorical vs. Continuous
Categorical Classification of Attributes
- Defined such that discrete labels are used to describe the characteristics
- EX: soil type, habitat type, cover type
Continuous Classification of Attributes
- Numerical attributes – the difference between any two values represents the difference in the magnitude of the attribute
- EX: elevation: 10,000’ – 7,000’ = 3,000’ elevation change
How many attributes can you handle?
- D&J Example: · 2 watersheds · 2 slope classes · 3 vegetation · 2 road access · 2 size - There are 48 possible combinations (stand types) - However, only 11 actually exist