Area of Focus: Sections of Mt. Tam included in the scope of this ecological health analysis. 

Condition: Current state of a metric or of the indicator as whole, based on an average of the condition of its metrics. Conditions are good, caution, significant concern, or unknown (if insufficient information is available). Thresholds for changes in condition category are set on a case-by-case basis.

Condition Goal: The desired, measurable state for each metric against which monitoring data are compared.

Confidence: The amount of certainty with which the condition and trend are assessed.

• High: Measurements are based on recent, reliable, suitably comprehensive monitoring.
• Moderate: Monitoring data lack some aspect of being recent, reliable, or comprehensive; however, measurements are also based on recent expert or scientist observation.
• Low: Monitoring is not sufficiently recent, reliable, or comprehensive; but either some supporting data exists or measurements are also based on expert or scientific opinion.

Desired Condition(s): The qualitative goal for the overall indicator; the threshold or state it should be in to be considered healthy; often identified as a recovery target for rare/listed species.

Indicator: The species, community, or physical process (e.g., stream flow/water quantity) that provides an essential ecological function, or are indicative of essential habitat conditions, and are measured as an indication of health. Indicators are akin to human vital signs such as blood pressure and pulse: easily measured and strongly correlated with overall condition, sensitive to stressors, and an early warning of potential problems.

Metric: How an aspect of an indicator is assessed or measured.

One Tam Partners: One Tam is made up of four agencies and one nonprofit organization: California State Parks, Marin County Parks, Marin Water, the National Park Service (including Golden Gate National Recreation Area and Muir Woods National Monument), and the Golden Gate National Parks Conservancy (Parks Conservancy).

Overall Condition: The combined current state of the indicator based on the totality of its metrics.

Stressors: Elements that challenge the integrity of ecosystems and the quality of the environment; may be natural environmental factors or may result from the activities of humans. Some stressors exert a relatively local influence, while others are regional or global in scale.

Trend: The change in condition as determined by comparing current versus previous measures; the trend is independent of current condition (e.g., a resource may be “Declining” but still be in “Good” condition).

• Improving: The condition is getting better.
• No Change: The condition is unchanging.
• Declining: The condition is deteriorating/getting worse.
• Unknown: Not enough information is available to state a trend.