DRAFT 5/14/2015

Northwest Forest Plan Interagency Regional Monitoring, 

20-Year Report 

Status and Trend of Watershed Condition 

Aquatic and Riparian Effectiveness Monitoring Program (AREMP) 

Stephanie Miller, Module Lead 

Objective 

The Aquatic and Riparian Effectiveness 

Monitoring Program (AREMP) evaluates 

whether the Northwest Forest Plan 

(NWFP) aquatic conservation strategy 

(ACS) is achieving the goal of maintaining 

and restoring the condition of watersheds. 

Methods 

AREMP determines the status and trend of 

stream, and upslope/riparian watershed 

condition for sixth-field watersheds within 

the Northwest Forest Plan (NWFP) area. 

Upslope and riparian condition was based 

on mapped data (e.g. road density, vegetation) representing the years 1993 and 2012 

for all watersheds with ≥5% federal ownership. Stream condition uses yearly physical 

stream data (e.g. substrate, wood, pools, 

temperature, and macroinvertebrates) collected under a sampling program that visits 

watersheds with 25% or more federal ownership in repeating eight year rotations. 

The first rotation (2002-2009) is complete 

and we are currently halfway through the 

second rotation (2010-2017). Watersheds 

were scored from 0 to 100 for stream condition and upslope/riparian condition, separately. Scores closer to zero signify a watershed has adversely deviated from expectation; 100 denotes above expectation. 

What’s new this time? 

Models for upslope/riparian and stream 

condition, were standardized across aquatic provinces for more consistent and comparable assessment. A more empirical approach was used for evaluation based on 

the distribution of values found in minimally 

disturbed sites for each vegetation zone 

and physical stream habitat metrics. Environmental variability was directly incorporated into the models by including information such as geology, landforms, and 

precipitation. 

 Key Results: 

Upslope and Riparian

 At the plan scale, we did 

not detect a trend in mean 

condition score between 

1993 and 2012. 

 However, at the watershed scale, score increases outnumbered declines 

by 2:1 (16% versus 7%). 

 Overall, sharp declines in 

score were mainly driven 

by large fires, and were 

offset by moderate, broad

-scale improvements in 

vegetation and focused 

improvements from road 

decommissioning. 

 Fires often impacted reserve areas, such as with 

the Biscuit fire in SW Oregon, the B&B complex in 

the central Oregon Cascades, and numerous fires 

along the eastern edge of 

the North Cascades in 

Washington. 

 The majority of the positive changes occurred in 

areas that had previously 

been the most heavily 

managed, including the 

Oregon Coast range and 

western flank of the Cascade Range. 

Figure 1—Trend in upslope  &

riparian scores represented by

the change in scores from

NWFP incepƟon 1993 to 2012.  
DRAFT 5/14/2015

Management Considerations and Next Steps

Upslope and riparian scores reflect negative impacts of roads to sediment delivery into streams 

and fish passage. As such, decommissioning 

roads improved model scores but other fish passage improvement work is not tracked well by 

agencies at the regional level. 

Forest growth led to broad-scale moderate increases in scores, particularly on matrix land. 

These are realized through cumulative small 

increases in vegetation growth across the landscape. Vegetation scores in reserves declined 

slightly owing to wildfires. Effects of wildfire on 

aquatic systems can be positive and negative. 

Improvements in macroinvertebrates and water 

temperature stream condition may suggest increased growth of riparian vegetation has positively affected streams. Declining pool tail fine 

scores may indicate a negative effect of roads, 

fire, or even climate change. However, increasing overall substrate scores offset this decline. 

We will continue to work towards understanding 

the causal relationships between upslope management actions and stream response at varying spatial scales. We are also further working 

toward better understanding and evaluation of 

the multiple effects of wildfires. 

Response to Local & Regional Needs

AREMP has made several program adjustments 

in response to needs presented by the region 

and the local units. 

 We are able to provide scaled down customized reports for local units and districts. 

 The empirical approach that we now use is

more consistent with regional and national 

programs in both the Forest Service and 

BLM allowing us to feed into reporting at 

even larger scales. 

 We have coordinated a multi-agency project

and created a consistently defined reference 

networks allowing agencies operating in the 

NWFP area to draw upon these data to inform stream condition benchmarks. 

 Evaluation tools developed by AREMP can

be used by any agencies working on NWFP 

federal lands. 

 We continue to explore ways to better integrate regional scale monitoring with management unit planning and national landscape level initiatives. 

 AREMP has substantial baseline data, and

the tools necessary to assess change for 

evolving management across the landscape.

(2010-2013)

POOL TAIL FINES 

WATERSHED FREQUENCY 

SUBSTRATE 

Key Results: Stream Condition

Consistent with FEMAT and ACS expectations, stream condition yearly status scores indicate that no trend in overall 

physical habitat was detected (fig 2). 

 Trends in physical habitat were not expected for several

decades. Overall trends in physical habitat were not 

detected but this does not imply that no trend exists. 

 Individual components of the physical habitat score

components show a decline in pool tail fines and improvements in substrate (fig 3). 

 Improving status trends were detected for both

macroinvertebrate diversity and water temperature.

Figure 3—Trend in individual habitat metrics between rotaƟons.

Arrows represent the direcƟon of change in each component.

2002-2009

Rotation 2

Rotation 1

PHYSICAL HABITAT 

Figure 2—Trend in Stream CondiƟon between rotaƟons.