Analysis of the Probabilities of the Classification of Small Headwater Streams as Primary Headwater Habitat (PHWH) and Warmwater Habitat (WWH) in Southwest Ohio
As part of a series of analyses of the attainability of aquatic life uses in small headwater streams in Ohio, MBI analyzed a regional dataset based on recent assessments in southwestern Ohio watersheds. Specifically this analysis focuses on small headwater streams that are at the “boundary” of watershed sizes between Primary Headwater Habitat (PHWH) and Warmwater Habitat (WWH) streams as each is defined and designated by Ohio EPA. Ohio EPA developed the PHWH methodology as a technique for evaluating and classifying the existing uses of small headwater streams that do not harbor fish assemblages capable of meeting the biocriteria for the WWH use designation as codified in the Ohio WQS (Ohio EPA 2002a). While there is no watershed size threshold that can accurately predict whether a stream will be capable of supporting either PHWH or WWH, “rules-of-thumb” have emerged and generally include a 1.0 mi.2 threshold for screening purposes. Some of these thresholds are being considered for routine use in regulatory applications such as 404 Nationwide Permits and without the benefit of vetting with actual site-specific monitoring data. One major problem is that biological and habitat data sufficient to determine the difference between PHWH and WWH (or any of the other Ohio aquatic life use tiers) is generally not collected in streams of this size thus leaving a significant knowledge gap to determine whether or not such rules-of-thumb are accurate or appropriate.
As part of intensive watershed monitoring conducted in the greater Hamilton County area of southwest Ohio, MBI routinely includes sufficient biological and habitat data collection in small headwater streams with some sites <0.5 mi.2 in drainage area. Furthermore, data was collected in a manner that allowed for a determination of whether a stream had the potential to attain one of the WWH aquatic life use tiers or if the existing use is more appropriately PHWH. This was performed at any stream site of <2.5 mi.2 based on the early Ohio EPA studies that resulted in the development of the PWHW classification scheme (Ohio EPA 2002b). Since 2011 a total of 96 stream sites of <0.5-2.5 mi.2 were sampled following this approach in the Mill Creek, Little Miami River, and Great Miami River study areas (Table 1). A fourth study area that includes similarly sized tributaries to the Ohio River mainstem were sampled in 2014, but those results have not yet been analyzed. The determination of the appropriate and attainable use designation was performed by Level 3 Qualified Data Collectors under project study plans approved by Ohio EPA. The techniques of data analysis and assignments of aquatic life use designations are the same as that practiced by Ohio EPA1 . Table 1 summarizes the results of this analysis.
Because it doesn’t produce its own food supply, Squawroot is a true parasitic plant. It is parasitic exclusively with oak trees and feeds off of their roots. At the point where the Squawroot attaches to the oak root a nodule or lump often forms leading to one of its common names -“cancer-root”. Unlike a lot of parasites, it does not do any apparent damage to the oak tree host and appears to live in harmony and balance with its food supply.
Because it blooms early in the spring, it is also reputed to be a favorite food of bears just coming out of hibernation. This is the apparent source of another of its common names – “bear corn”. Squawroot apparently does have some astringent medicinal properties. Reputedly it has also been used in tea or concentrated form for relief of headaches and pain.
The genome of the Squawroot has been sequenced. Interestingly, the genes related to photosynthesis are missing while the rest of the genome is largely similar and consistent with other vascular, seed-bearing flowering plants. This leads some to the conclusion that there was a genetic mutation responsible for the current dramatic nature of the plant.
While there are no flowers apparent on the pictured plants, Squawroot is a flowering plant. It produces seeds that work their way into the ground looking for oak roots rather than growing toward the sunlight. If you’re lucky enough to encounter the Squaw root stop and take a close look. It is a remarkable plant.