FRST 211- lecture 14 Floristics and Plant Associations

International Vegetation Classification (IVC)(

• Classify existing natural vegetation

• Basedd on physiognomy and floristics

• Hierarchical classification

8 hierrchy Level for Natural Vegetation

Physiognomy

• Dominant and diagnostic growth forms

Floristics

• Diagnostic species, usually form multiple growth forms and/or strata

8 hierarchy levels for Natural Vegetation

Vegetation types:

Formation Class (Upper level) - Physiognomy

Formation Subclass (Upper level) - -Physiognomy

Formation (Upper level)- Physiognomy

Division(Middle level)-Physiognomy, Floristics

Macrogroup (Middle) - Physiognomy, Floristics

Group (Middle)- Physiognomy, Floristics

Alliance (Lower level) - Floristics

Association (Lower Level) -Floristics

what do formation class vegetation type

• Temperature (Temperature and Moisture)

Formation subclasss

• Latitude and continentality

Association

• Local climate, site, disturbance

What is hierarchy based on in vegetation hierarchy levels?

• “Diagnostic” growth forms and species and compositional similarity

• Species and growth forms that exhibit patterns of fidelity, constancy, or dominance that differentiate one type from another

Diagnostic Growth Form

• Any growth form or group of growth forms whose relative constancy or abundance differentiates one vegetation type from another. Diagnostic growth forms include dominant Growth Form and Indicator Growth Form.

Dominant Growth Form

• A growth form with a high percent cover, usually in the uppermost canopy layer

Indicator Growth Form

• Growth form whose presence, abundance, or vigor is considered to indicate certain climatic and site conditions

Dominant Species

• Species with the highest percent of cover (or biomass or density or height, usually in the uppermost or dominant vegetation layer

Diagnostic Species

• A plant species that is distinctly more widespread or successful in one of a pair of group of plant communities than int he other(s), although it may be still more successful in other communities not under discussion

Character species

• As species that shows a distinct maximum concentration, quantitatively and by constancy, in one well-defined vegetation type; sometimes recognized at local, regional, and general geographic scales

Constant species

• Species that are present in present in a high percentage of the plots that define a type, often defined as those species with at least 60% constancy

Which are the diagnostic species?

• Community A

• Community B: Hoary puccoon

Which is the dominant species?

• Sage brush

Level 1-3 - CLimate

• General similarities iin vegetation physiognomy at coarse scales

Level 8 - ORPT

• Local-scale factor cause variation among sites in floristics at fine scales

Completely Random

• Statically unbiased

• All samples independent

• The location of one sample is not related to the locations of the other samples

Stratified Random

• Subdivide the area into homogenous units

• To account for known differences in factors like soil or aspect

• Randomly sample within units

Stratified Random Systematic

• Subdivide the area into homogeneous units

• Randomly select first sample

• Starting from first sample, systematically sample along transects

• Not statiscally optimal but allows for greater sample size in limited time

Collecting Fine-Scale Floristic Data

1. Stand selection and plot design

2. Species composition (floristics) of the plot

3. Vertical structure and physiognomy of the plot

4. Physical data of the plot

5. Geographic and metadata

What to do with vegetation plot data

• A. Develop a new classification system

• B. Determining Plant Association Using An Existing Classification System

• C. Use Vegetation Plots to Verify Classification Maps