Martha Creek NEON / MART

Martha Creek (MART) is an aquatic NEON field site located just north of the Columbia River Gorge in Gifford Pinchot National Forest. Martha Creek is a third-order wadeable stream that drains a 6.34 km² (1570 acre) watershed and is a tributary of Trout Creek. The land is managed by the U.S. Forest Service. The watershed is dominated by old-growth coniferous forest and is designated a Tier I Key Watershed in the Northwest Forest Plan due to its importance in supporting threatened native fish populations. The 2012 removal of a dam to improve fish passage in the creek allows for the study of aquatic habitat restoration. MART is located in NEON's Pacific Northwest Domain (D16), which is bounded by the Pacific on the west and Canada on the north. It includes the eastern halves of Washington and Oregon and parts of northern California. The Domain hosts three other field sites: one additional aquatic and two terrestrial. MART is near the WREF terrestrial site. [1] [2]

Martha Creek’s climate is largely determined by its proximity to the Pacific Ocean and the Columbia River Gorge, with secondary orographic lifting effects from the Cascade Range. The area experiences strong winds in any season, and cold air draining into the valley can bring frosts almost any time of year. Warm and dry conditions dominate the summer months, whereas winters are characterized by cool, wet weather. Precipitation occurs as rain or snow during fall, winter, and spring, with annual accumulation averaging about 2328 mm (91.7 in.). The average annual temperature is 9.6°C (49°F). Interannual variation plays a major role in yearly precipitation levels; the El Niño Southern Oscillation is a driving force behind warmer, drier years, which leads to an increased chance of drought and wildfires. [3] [8] [9]

Martha Creek’s geology is primarily volcanic, featuring basalt and andesite bedrock with colluvial and glacial till. [3] [4]

The substrate in Martha Creek is dominated by cobbles, including riffles and pool habitats. [1]

Martha Creek’s drainage is largely in the “rain-on-snow” elevation zone, where alternating periods of snow accumulation and snowmelt are common throughout the winter. As a result, streamflow in Martha Creek typically peaks in response to these events in the late fall, winter, and spring, and decreases to annual lows during the summer dry season. [1] [2]

The mild, wet climate of lowland valleys in the Western Cascades promotes the growth of dense western hemlock-Douglas fir forests which give way to mountain hemlock, noble fir and Pacific silver fir at higher elevations. The riparian area at Martha Creek consists of mixed deciduous forest of red alder (Alnus rubra), Pacific dogwood (Cornus nuttallii), and large conifers including Western hemlock (Tsuga heterophylla) and Pacific silver fir (Abies amabilis). Some areas of the stream bank have dense growth of understory shrubs and devil’s club (Oplopanax horridus). [1] [5]

The old growth forests surrounding Martha Creek host many species that serve as indicators of forest health including the threatened northern spotted owl (Strix occidentalis caurina). The creek itself is home to frogs, mollusks, and salamanders and provides critical habitat for anadromous fish, particularly the Lower Columbia River steelhead (Oncorhynchus mykiss). [2]

Martha Creek and the adjacent Wind River Experimental Forest (WREF) share a rich history dating back to 1909, when water from the creek was diverted to irrigate the experimental site’s initial nurseries. The continued expansion of the nurseries and support facilities at Wind River prompted calls for improvements to the existing irrigation, and in 1924 a 12 m (40 ft.) concrete dam was built across the creek that could provide water even during dry summer months. Martha Creek continued providing water for the site until it was replaced by a new water system on Trout Creek in 1933; however, Martha Creek water continued to supply the administrative buildings with water until a well was constructed in 1948. By the 1950’s, the dam was abandoned, and by the end of the century, coarse sediment had filled many of the channels upstream of the dam. In 2012, as part of a series of dam removals in the Wind River watershed, Martha Creek’s dam was removed, allowing the creek to run unimpeded for the first time in 88 years. [2] [6]

Together with Wind River Experimental Forest (WREF), Martha Creek serves as a major center for ecological research in Pacific Northwest forests, and accommodates a variety of long term ecological studies. Managed by the U.S. Forest Service as part of its Pacific Northwest Research Station, the site hosts collaborators including the U.S. Department of Energy, the Environmental Protection Agency, Smithsonian Institution, and universities across the western United States. Research at Martha Creek focuses on pollutant monitoring, nutrient cycling, biological diversity, ecosystem function, and the testing of remote sensing equipment. Martha Creek continues to provide valuable data about aquatic habitat protection and restoration in the wake of its dam removal. [7]

MART’s site characterization began in February 2017, and was completed by early November. By February 2018, the site’s aquatic instrument system (AIS) began streaming data, and by June 2018 the aquatic observation system commenced sampling.