Marshland Vegetation: Sodium Tolerance + Natives - Jordan John
Above: the first section of the effluent wetland/marshland, complete and ready for use.
In my research for this class, I hone in on choice native specimen of wetland, marshland, and marine habitats whose inclusion in our landscaping for the compost “pee pee” toilet should serve us well as we landscape a urine detention site / sink. Specifically, I include plants that collectively comprise a full micro-ecosystem in terms of ground-level, prairie (1-3 ft), shrub, and canopy level. It also includes nitrogen fixers, a vital component of most any plant community.
I was ecstatic to find there is a sufficiently wide selection of such sodium-tolerant plants that occur in . Common grass genera that exist in such conditions include Carex spp (Sedge), Juncus spp (Rush), and a particularly salt-tolerant, low-lying grass Distichilis spicata (saltgrass) that would be great groundcover and can take a real blow of salt. Additionally, apparently it is even choice larval host for several butterfly species (all animals need their sodium, I guess!) Additionally, for shrubs, there is the Pacific Wax Myrtle shrub that actually fixes nitrogen while growing to shy of 20 ft tall. This plant would be a great space filler as well as a mediator in its nitrogen fixation, hydrogenating and making solid nitrogen gases that might accrue resulting from the urine. Also, there is coastal sagewort, Artemisia pycnocephala, that is an extremely hardy, Bay Area coast/shore native, elegant shrub with pale, blue-gray foliage with seasonal erect shows of minute, inward-faced yellow flowers that are subtly fragrant. Speaking of such, for flowers, there is the hardy, mostly year-round flowering seaside daisy (Erigeron glaucus) that could be great for adding consistent color and fragrance to border spaces. For trees, we have a wide selection of any Salix (Willow) or Populus (cottonwood, poplar, quaking aspen) species which are large, elegant, beautiful deciduous trees that can anchor the ecosystem if we plant anywhere from 1 to several throughout the detention site. Most or all of this is sold at Watershed Nursery in Richmond CA for bargain prices, just a few dollars per plug or several for a 1 gallon pot, as well as other native nurseries in the area.
In attempting to more specifically lay out a possible design plan with these plans, I came across some really interesting biochemistry in looking at exactly how sodium works in soil -- relative to urine concentrations. I found that the milliequivalents of sodium in the average human urine, 60-120/L, is highly manageable given a typical soil's total cation exchange capacity is 1000+/L (mineral content, basically) and typical soils contain up to 5% sodium before any issue is noticed in plant growth. Salt-tolerant plants are fully capable of handling even higher levels, probably into the range of 10%. And it is not that the sodium will concentrate; it would disperse, finely, across the hundreds of cubic meters of soil packed right around the urine wetland site. Meanwhile, the plants will indulge in the abundant nutrients of the urine, building microbial populations as well.
Overall, this has been an eye-opening research project in which worlds have been opened. Plants can harbor comprehensive ecosystems on or off of the floodplain, fully salt-hardy, and anyway, urine salt concentrations are relatively negligible! All is well in Mother Nature and Gaia!
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