Sun, 05/03/2015 – 00:10 — erica braun
Horses do control tules by trampling the growing edges, disrupting the underwater tubers, and eating some of the new growth. The horses did a good job of maintaining habitat as well along the pond verge for the amphibians – much better than cattle would have done. It worked pretty well for years to have the horses keep the tules somewhat in check and the verge of the pond open but not barren, maintaining an adequate balance. My understanding from my EBMUD contacts is that they would be VERY happy if we were to re-open the pond fence to let the horses return to the job – much preferred to any mechanical solution that will be temporarily quite destructive of habitat. That EBMUD is letting us decide what is best for the horses by not requiring us to control the tules with them, is different from saying that the horses would not control them.
Pond Fence
Fri, 03/27/2015 – 17:07 — hpineda
I am in favor of removing the fence around the pond. I disagree with the statement in one of the documents that the horses do not eat the tules, as I have seen horses doing so. As shown by the increase in the amount of reeds since the pond was fenced (and the lack of other variables affecting reed growth), it is clear that the horses having access to the pond helps control the reed growth. I will be interested to hear EBMUD’s perspective on the fence, as in the past they preferred that we not fence the pond.
Heather
Some history from Linda F.
Wed, 04/01/2015 – 15:33 — ereiter
The history of EBMUD management of the tules has differed. When they first saw them we were told not to touch them—–they wanted them to grow in the pond for wildlife habitat and they were worried that the horses would eat them. At that time Marcie and I told them that they would eventually take over the pond. She and I still laugh about how worried they were about them.
Re-Opening the Pond
Mon, 04/20/2015 – 21:43 — jedixo
Having spent a LOT of time researching creative ways to destroy our tules, I don’t think that allowing horses back into the pond area is going to fix that problem. If that’s what this is about – controlling the tule population and saving the pond instead of letting it get grown over – we are beyond most horse-powered solutions. Here’s what I know:
– You CAN cut tule, but it’s really hard to cut it below the water. It will grow back within about 6 months in our climate. There are special, machine-powered, expensive tools that can do this, usually in water up to 6 feet deep. Tule gets most of its oxygen above water. There are some reports online that say if you can cut 2-3 times through spring and summer you’ll see a reduction in the overall growth the following year.
– Another option is to reduce the amount of water in the pond during spring and summer, but I don’t think this would work for us.
– The only sure way to remove tule is to remove the tubers.
– The tubers are between 6-12″ under ground. In most cases, this ground is under water. So, truly getting rid of them manually requires a near-maniacal devotion to mud, a rebreathing apparatus, and some real muscle power, or (more realistically) a backhoe.
Can we get confirmation as to whether we are trying to get rid of tule, or just discuss whether to allow pond access?
Thanks,
Julie
Mon, 05/11/2015 – 02:40 — wakean
I think we should re-open the pond -with an option for those who want to keep their horse in another pasture away from the pond. Though it could be one possible source of EPM it seems too paranoid to close it off-it was a beautiful part of an ecology shared by grazing animals. I think the hoof action and browsing on tules was helpful in keeping the pond open for years -we can help by cutting/digging and maybe getting EBMUD to use mechanical means also if needed.
Other possible EPM sources at OHA include all the other water sources, the stored feed, any of the structures & hay storage, or even just the ground. Or sources from off OHA, like feed .We have not tried the recommended strategy of trapping, testing and removing possums– which would seem the most direct action to take.
EPM is very tricky to diagnose due to imperfect testing and hard to define symptoms. According to my notes from UC Davis Dr Pusterla’s talk to OHA: 30-50% of CA horses test positive for EPM antibodies, and less than 1% of horses exposed to EPM will develop it. Some other risk factors for EPM to develop include age (young more
likely), season (spring/summer/fall more likely), stress (poor
nutrition, horses w/ existing health problems), use (transport .racing, eventing).
To my best knowledge there are 2, maybe 3 horses at OHA in the last 10 years that MAY have contracted EPM at OHA (not 4 in 1 year from OHA) -these 2 or 3 were not continually at OHA-the fact that the 2 or 3 all shared the same off-OHA travel to Petaluma does seem much more statistically significant than that they shared OHA pasture, though there is no conclusion. Not sure OHA should have been called a “hot spot”.
Probably most vets would be safe and recommend avoiding as much risk as possible (open pond) but this may not be practical or desirable with our herd situation. I would be for trapping possums, practice all the other housekeeping habits recommended, and open the pond to those willing .
Wakean
Sat, 03/28/2015 – 04:30 — paintedrider
I think that the horses may eat the tules, but more so they have always trampled the tules down. Also, if we are so worried about EPM then every water source in the pasture that the horses drink from need to be fenced off. I believe that what I have heard is that EBMUD does not want the fence up. Perhaps Sally as liason should ask them.
Heidi
Tue, 04/21/2015 – 04:36 — erica braun
I agree that the horses probably eat the new growth tules, but most importantly, they trample new tuber growth along the edges under water – perhaps the most effective control.
I have much respect for Julie’s experience working hard to do hand control, and others – several of whom are in my family and our friends – have also worked hard, and will back her up. Disrupting tuber growth under water, however, is almost surely why the horses were effective for so many years at controlling tule growth.
Dredging the pond with machines is one way to disrupt tuber growth, but it is terribly destructive of habitat. The horses are not so destructive and are in the pond at a time when EPM danger is low and habitat destruction is minimal – July.
I’m in favor of voluntary grazing in the Pond Pasture with the pond exclosure open for a week or so in July. If we can avoid dredging and protect horses who are at particular risk for further EPM exposure, this is an easy choice.
Erica