Proper Functioning Condition - PFC
PFC is intended to be a rapid assessment and the qualitative PFC checklist should work for most sites if the procedure is followed and the definitions are understood.  

REFERENCE:
Prichard, D., H. Barrett, J. Cagney, R. Clark, J. Fogg, K. Gebhardt, P.L. Hansen, B. Mitchell, and D. Tippy. 1998a. Riparian area management: Process for assessing proper functioning condition. Technical Reference 1737-9, BLM/SC/ST-9/003+1737+REV95+REV98. Bureau of Land Management, Denver, CO.

METHODS:
PFC uses the Ecological Site Inventory (ESI) data as a basis for assessing condition. The “BLM Riparian and Wetland Classification Review” reviewed classifications that can potentially be used to classify riparian-wetlands areas for the ESI and PFC methods. BLM developed several methods to assess and manage riparian areas. At least 22 documents provide guidance relative to various aspects of riparian area management including inventory and monitoring, classification, grazing management, ecological inventory, vegetation resources, and assessing proper functioning condition of lentic and lotic systems (refer to http://www.blm.gov/nstc/library/techref.htm). A separate review is included in this database for “Using Aerials to Assess Proper Functioning Condition.” “Montana Natural Heritage Wetland Assessment” used the site-based functional assessment approach for lentic riparian areas in PFC. “Washington Aquatic Habitat Design Guidelines” suggests using PFC to characterize habitat.  

PURPOSE:
To assess whether a riparian-wetland area is functioning properly based on the interaction of vegetation, landform/soils, and hydrology. The 1991 Riparian-Wetland Initiative for the 1990's established national goals and objectives for BLM management of riparian-wetland resources on public lands. One of the primary goals of this initiative was to restore and maintain riparian-wetland areas so that 75 percent or more were in proper functioning condition (PFC) by 1997. This document outlines the process for assessing PFC.  

METHOD CLASSIFICATION SCHEME:
Soil and vegetation types as determined for the specific inventory. May use classification scheme such as Hydrogeomorphic (HGM) Classification (Brinson 1993) to delineate types.  

METHOD DESCRIPTION:
There are three steps in assessing PFC:

1) Review existing documents that provide the basis for assessing PFC - These include “BLM Riparian and Wetland Classification Review” (Gebhardt et al. 1990)(see review in database), “The use of aerial photography to inventory and monitor riparian areas” (Batson et al. 1987), “Inventory and monitoring of riparian areas” (Meyers 1989), and “Procedures for ecological site inventory – with special reference to riparian-wetland sites” (Leonard et al. 1992). See later reference list for additional documents.

2) Analyze the definition of PFC for riparian-wetlands - Determine when there is adequate structure present to provide the benefits applicable to a particular area.

3) Assess functionality - (a) Identify the attributes and processes for the area being evaluated (e.g., temperature may be an attribute of the Water Quality process), (b) Assess the capability and potential using – e.g., use historic photos and species lists; examine soils, hydrology, and existing vegetation, and, (c) Determine functioning condition. Analysis must be based on the riparian-wetland’s “capability” and “potential.” Note that one of the initial steps in assessing functionality is to stratify sample units based on terrestrial (USFS 1994) or aquatic (Maxwell et al. 1995) ecological units in order to minimize natural variability among sample sites

The functional status of riparian-wetland areas is then characterized as one of four different categories: Proper functioning condition, Functional-at risk, Nonfunctional, and Unknown (see definitions below). Trend for Functional-at Risk is also rated as upward, downward, or not apparent.

Although authors acknowledge the qualitative nature of PFC, they recommend using quantitative sampling techniques in conjunction with the PFC checklist when individual calibration is needed, answers are uncertain, or if the experience of the field survey team is limited. The checklist for lotic riparian-wetland areas itself consists of a series of Yes/No (or N/A) questions for 17 variables that address hydrology, vegetation, and erosion/deposition in riparian-wetland areas (Prichard et al. 1998b - Table 1). Prichard et al. (1998b) provide background and rationale for each variable in the PFC checklist, provide examples of various characterizations for many of these variables (e.g., PFC, functional at-risk, or nonfunctional), and also suggest specific methods to quantitatively assess each variable. These quantitative methods are further described in Leonard et al. (1992).

A final determination of the functional rating of a riparian-wetland is a subjective exercise based on a review of the Yes/No answers from the checklist. There is no point score associated with these answers, and PFC, functional at risk, or nonfunctional is determined based on the collective opinion of the field survey team.

PFC assessment is used to develop management plans using the following process:

1) Determine existing conditions,
2) Determine potential conditions (PNC),
3) Determine the minimum conditions necessary for PFC,
4) Determine existing and potential resource values,
5) Negotiate specific objectives to reach management goals,
6) Design management actions,
7) Design appropriate monitoring strategies, and
8) Maintain management flexibility.

Appendices include reporting tables (data sheets), examples of channel evolution patterns, riparian-wetland functional checklist, and photographs and descriptions of riparian-wetlands in various conditions.

PFC related BLM Technical References can be obtained from: http://www.blm.gov/nstc/library/techref.htm  

KEY TERMS:  

Capability:
the highest ecological status an area can attain given political, social, or economical constraints, which are often referred to as limiting factors.

Functional-at risk:
riparian-wetland areas that are in functional condition, but an existing soil, water, or vegetation attribute makes them susceptible to degradation.

Nonfunctional:
riparian-wetland areas that clearly are not providing adequate vegetation, landform, or large woody debris to dissipate stream energy associated with high flows, and thus are not reducing erosion, improving water quality, etc.

Potential:
the highest ecological status a riparian-wetland area can attain given no political, social, or economical constraints, and is often referred to as the potential natural community (PNC).

Potential natural community (PNC):
the biotic community that would become established if all successional sequences were completed without interferences under the present environmental conditions.

Potential plant community (PPC):
represents the seral stage the botanical community would achieve if all successional sequences were completed without human interference under the present environmental conditions.

Proper functioning condition (PFC):
areas are functioning properly when adequate vegetation, landform, or large woody debris is present to dissipate stream energy associated w/ high waterflows, thereby reducing erosion & improving water quality; filter sediment, capture bedload, & aid floodplain development; improve flood-water retention & ground-water recharge; develop root masses that stabilize streambanks against cutting action; develop diverse ponding & channel characteristics to provide habitat & water depth, duration, & temp. necessary for fish production, waterfowl breeding, & other uses; & support greater biodiversity.

Unknown:
riparian-wetland areas that managers lack sufficient information on to make any form of determination.  

EXPERTISE TO PERFORM PFC EVALUATION:
Practitioners should be familiar with normal (natural) variation among stream and riparian wetland features in a given region. Prichard et al. (1998b) stress that different riparian-wetland areas (e.g., different stream types, different watershed settings) “can and do function quite differently,” and as a result need to be assessed “against their own capability and potential.” Understanding channel evolution and riparian vegetation successional sequences is also important.  

GENERAL INFORMATION ABOUT OUTPUT:

• Method attempts to identify stressor/disturbance factors that cause departure from reference.
• Method can be characterized as “repeatable” among different users. This assumes that the user possesses the requisite level of expertise/training to employ the method.
• Method provides a set list of metrics/indicators that should be measured/estimated. This is in contrast to methods that provide a list of considerations that may or may not be used in assessing condition.
• Method uses clearly defined metrics/indicators that are easily measured/estimated and distinguished (e.g., percent vegetation cover, percent impervious surface, soil type, seasonally flooded). This is in contrast to methods that provide loosely defined metrics (e.g., aquatic diversity is sufficient to utilize nutrients).
• Provides explicit definition of reference and uses reference sites (e.g., based on literature or field data).This is in contrast to being based on best professional judgment.