[APWG] Ecosystem Restoration Riparian CA Southern region Re: NEWS: Norco riders reject arundo removal

[Wayne Tyson]

APWG:

It is unfortunate that the equestrian folks were not involved in project planning. Perhaps they were, and perhaps the COE representative was misquoted when he said that restoration would take place if natural colonization had not taken place in a couple of years. I may have thought much the same way many years ago (so hereby hope to correct the error), but experience has taught me that a quick intervention, if well-thought-out, is ESSENTIAL if satisfactory results (highly diverse riparian gallery forest resembling a "climax" association) are to be realized economically. I have briefly stated the reasons along with the basic approach (yes, the devil is sometimes in the details) for successful riparian ecosystem restoration below. Natural colonization can be a PART of a sound ecosystem restoration project, and always should be, but in cases like this it is asking for big trouble. 

Since Arundo donax apparently does not reproduce by seed, or if so, very rarely in North America, once it is eradicated, a modest but regular maintenance effort should minimize reinvasion, particularly if eradication starts at the top of the watershed. 

Restoration by natural colonization is feasible, but probably not advisable, as the most prolific indigenous species are likely to form almost "pure" stands of one or a few "pioneer" species (e.g. Salix lasiolepis in Southern California). To ensure a highly diverse stand as quickly as possible, the site should be planted with a mix of species indigenous to riparian sites in the bioclimatic region of the project starting with those least common (e.g. Salix gooddingii). To avoid excessive colonization by Salix lasiolepis (don't worry, they will colonize anyway, both vegetatively and sexually, as will other pioneer species), project grading should be done when they are not dispersing seeds. Unlike more xeric sites, true riparian areas can be planted, at least in part at other times, but the fall and winter seasons are most likely to be the best (although the actual timing should be based on a carefully worked out set of project requirements). Pole cuttings, rooted and unrooted or callused, can be planted deeply to provide large trees more quickly at low cost, but bare-root stock can be grown or purchased for species more difficult to establish in this way (e.g. Platanus racemosa). 

Southern California riparian systems can be highly variable, particularly with respect to soil profile and groundwater, so specific data needs to be collected to optimize results (this is far cheaper than even spotty failures). Irrigation should not normally be used, except as a supplement to rainfall and flooding events that do not materialize according to the plan. However, irrigation of true riparian restoration sites is only justified to save a significant proportion of the "investment." Any restoration program must contain reasonably well-founded attrition factor(s). 

Restoration should proceed immediately following vegetation removal, before colonization by unwanted vegetation. Any delay in establishing desirable vegetation will make restoration more difficult, costly, and risk much greater chances of reduced performance or failure. 

You can see a project that was done this way* along the northerly side of the Temecula Creek channel in southwestern Riverside County. The project consisted of a 2 1/2 mile reach between Avenidas De Missions [sic] and Butterfield Stage Road. You can see it from Redhawk Parkway too, and on Google Maps/Earth, about 2 miles easterly of Interstate 15, just south of California State Route 79, southeasterly of the town of Temecula. Originally it was a 100-foot strip on the north side of the channel. 

WT

*As is the case with all restoration projects, this one was not completed entirely in accordance with specifications, but it is about as good a case of real-world results as can be expected. One unexpected result: Theft of nearly all of the few California sycamores that were planted. 

----- Original Message ----- 
From: "Olivia Kwong" <plant at plantconservation.org>
To: <apwg at lists.plantconservation.org>
Sent: Friday, August 06, 2010 5:29 AM
Subject: [APWG] NEWS: Norco riders reject arundo removal


> http://www.pe.com/localnews/corona/stories/PE_News_Local_D_wtrails06.326c6cc.html
> 
> Norco riders reject arundo removal
> 10:00 PM PDT on Thursday, August 5, 2010
> 
> By LESLIE PARRILLA
> The Press-Enterprise
> 
> Temperatures dropped as Bobbie Pope rode a quarter horse through lush 
> bamboo-like tunnels to escape the blazing Norco heat this week, something 
> she won't be able to do next month when clearing of the well-known trails 
> starts.
> 
> See the link above for the full article text and story podcast.
> 
> 
> 
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> 
> Disclaimer
> Any requests, advice or opinions posted to this list reflect ONLY the opinion of the individual posting the message.


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