Abstract
Monitoring Components:

• Glaciers and Permanent Snowfields
• Watersheds and Landforms
• Geomorphic Features
• Soils

Abstract

Outstanding geologic and hydrologic resources at North Cascades NPS Complex are key abiotic elements in the North Cascades ecosystem. Resources addressed in this abstract include glaciers and snowfields, geomorphic features (watersheds, landforms), soils, and paleoecological deposits. These are sensitive and dynamic features in the rugged terrain of the North Cascades Mountains. Glaciers, snowfields, and some watersheds, landforms and soils are particularly sensitive to air pollution and climatic change because they are located within high-elevation zones that receive heavy precipitation. Adding to the sensitivity of these resources are strong climatic gradients and inter-annual (ENSO), decadal (PDO), and century scale (Little Ice Age) climatic fluctuations.

Inventory of these features is important because of their widespread distribution and strong influence on the ecology of the park complex. They also strongly influence the formation and stability of habitat in terrestrial and aquatic environments. Inventory, research and monitoring of these features provides valuable information on the locations, magnitudes, and frequencies of disturbance events. Monitoring also provides information on directions and rates of change at a number of spatial and temporal scales, which can help establish normal limits of resource variation.

Monitoring of the ecological health in mountain landscapes is difficult. Spatial and temporal variation in climate, hydrology, geology, and disturbance events makes identification of status and trends in the health of biotic communities challenging. To control for some of the natural variability of climate and geology in the park complex, a system for monitoring key abiotic and biotic components at a range of scales is needed. This system must include monitoring of key functional components of the landscape, including watersheds, landforms, and evidence of disturbances that influence habitat and the health and distribution of biotic communities.

We believe that Watershed Analysis provides the best system for organizing long-term ecological monitoring of terrestrial and aquatic systems in mountain parks. Watersheds are important for several reasons. First, they define the ranges of plants and animals. They also are systems that integrate climatic, geologic, hydrologic, and biotic components in the creation and destruction of habitat as they move vast quantities of water and sediment from source areas in high mountains to low-elevation valley floors. Watershed analysis methods developed by Rosgen (1994), Montgomery and Buffington (1993), and NOCA staff provide a framework for understanding ecological processes at a range of scales, from the watershed down to a sampling site. We have selected Chilliwack, Thunder Creek, and Bridge Creek as "target watersheds" for our long-term monitoring program. These watersheds represent a range in conditions from marine west slope to arid east slope, a range in bedrock types, and a range in amount of glacial cover.

Landforms are key components of watersheds, and provide information on geologic processes, geologic hazards, ecological disturbance, and are an initial mapping unit for a soils map. In the absence of detailed soils maps for North Cascades NPS Complex, landforms represent the next-best feature to inventory. Further, landforms can be mapped far more quickly, accurately, and at lower cost than soils, which often require laboratory analyses to support taxonomic determinations. Knowledge of landform types and distribution is also valuable because landforms record the history of landscape change. When viewed from a watershed scale, landform maps provide key background information for other long term ecological monitoring programs. Mapping landforms at a watershed scale is a key component of the Aquatic Habitat component of this conceptual plan.

Geologic processes such as earthquakes, landslides, snow avalanches, floods, and volcanic eruptions are important disturbance events. Magnitude and frequency of geologic disturbance events are generally recorded in landforms. Ecosystem nutrient cycling, fire behavior, erosion sensitivity, and aquatic and terrestrial habitat models are also dependent on landform and soil data. Certain landforms such as fluvial terraces, lake beds and glacial moraines contain pollen, volcanic ash, and other information useful in paleoecological analysis.

Soils are the fundamental source of productivity in ecosystems, with biogeochemical dynamics and energy flow largely mediated by water movement. Taxonomic description of soils and physical-chemical quantification of soil properties are typically rare in wildland areas because of the logistic and analytical difficulties associated with data collection. While high-resolution soil inventory and classification have been completed for most agricultural areas in the United States, relatively few soil maps are available in mountainous regions such as North Cascades NP.

Accurate information on soils is needed to estimate hydrologic function, erosion potential, ecosystem productivity, and nutrient cycling. Much of North Cascades NP is located at high altitudes with cold temperatures and high precipitation (especially snowfall) – conditions conducive to the retention of carbon. Recent data have shown that the subalpine soils of the Cascade and Olympic Mountains store large amounts of carbon throughout the soil profile and represent a significant carbon sink in mountain ecosystems. There is very little known about carbon storage and dynamics in soils and ecosystems of North Cascades NP. Soils information is also critical for evaluating local impacts caused by human activities such as grazing, mining, and recreational activities. Basic physical and chemical data are needed to document past impacts and ongoing changes, and to evaluate proposed activities and restoration efforts.

Approximately half of all the glaciers in the conterminous states are within the park complex. These 318glaciers are a vital component of hydrologic systems and aquatic ecosystems, and are potentially important as accumulators of air pollutants such as organochlorides. They influence soil development, stream channel patterns, lake chemistry, distribution of vegetation, and are unique indicators of climatic change. Glaciers deliver vast amounts of water that buffers seasonal and annual low flows in lakes, streams and wetlands. Regional salmon and steelhead populations are especially sensitive to drought because major parts of their life cycles occur in Pacific Northwest rivers during summer. Any analysis of aquatic ecosystems must consider that streamflow has been supplemented in the 20th century by a greater contribution of water from melting glaciers

In addition to their importance to hydrology, aquatic ecosystems, and vegetation, glaciers are valuable indicators of climatic variability. Annual variability of temperature and precipitation makes identification of directional changes in climate difficult. Glaciers integrate these variations as they respond continually to variation in temperature and precipitation. Since the end of the Little Ice Age in the mid-19th century, glaciers have retreated throughout the North Cascades. It is likely that several dozen glaciers have disappeared from North Cascades NPS Complex during the past 100 years. Continued shrinkage and disappearance of glaciers in the North Cascades means that the park's hydrology, aquatic ecosystems and vegetation are changing as well.

The NPS has monitored four glaciers in the park for the past six years. Data collected through this effort have given managers and researchers previously unavailable information on spatial and temporal variation in climate, and on the rate and magnitude of glacial melting. Extending this monitoring effort to correlate glacial change with remotely collected meteorological data and sampling during climatic extremes (e.g., strong El Niņo and La Niņa years) will facilitate development of an energy-balance model for monitoring a larger number of glaciers within the park.

This component of the North Cascades LTEM program focuses on three objectives within the target watersheds and across the park complex. The first objective is to inventory geologic and hydrologic resources including glaciers, snowfields, rivers, and lakes. Landforms and soils will be initially inventoried for the three target watersheds. Inventories provide information on landscape stability by identifying the locations and ages of geologic disturbance events. This objective overlaps with the aquatic habitat component. The second objective is to monitor glaciers, snowfields, rivers and geologic disturbance events to establish limits of natural variation, assess trends in resource conditions and to provide information on landscape change for other monitoring efforts. Surface mass balance of four index glaciers will be monitored annually by established protocols. Physical and chemical attributes of winter snowpack, and the rate and timing of accumulation and melting will also be monitored at selected sites. Monitoring of streamflow and lake levels is addressed in the aquatic habitat section. Landforms, soils, and other geologic disturbances will be monitored primarily by aerial photographs. The final objective is to link monitoring of geologic resources with monitoring of other resources. This will be accomplished by a Watershed Analysis approach, which will provide a framework for linking abiotic processes and features with the distribution, abundance, diversity and range of aquatic and terrestrial resources.

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Monitoring Component:  Glaciers and Permanent Snow Fields

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Monitoring Component: Watersheds and Landforms

Potential Partners: USGS-Geologic Division, USDA Forest Service, University of Washington, Western Washington University.

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Monitoring Component: Geomorphic Features

Potential Partners:  USGS-Geologic Division, USDA Forest Service, University of Washington, Western Washington University.

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Monitoring Component: Soils

Potential Partners:  USDA - Natural Resources Conservation Service, USGS–Geologic Division, NPS – Geologic Resources Division, and USDA – Forest Service.

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