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BR></BLOCKQUOTE><BR></DIV>* I had the same thou --001a11c2e886e5b07d04f9e88c5a Content-Type: text/plain; charset=UTF-8 Thanks folks, I haven't been there in winter, despite my being in NS now for over 20 years. Here's the landscape picture though. Picture an accordion, partly open lying on its back. The bellows represent the dune system at Pomquet, there are peaks and troughs (slacks), and precious little other elevations going on. At the slack in question, the surrounding peaks of the dunes are dominated by white pine and oak, with other trees as well. Fred asked, if the dunes are sandy, how are they holding water in the first place? Basically, I think there is leaf litter which may be accumulating in the slack to slow the water seepage. Further to Anne's email, the slack in question is well back from the salt water, I suspect there is no salt to speak of in that water. Mosquitoes are there in the billions, peepers are deafening, both suggesting fresh water (though I realize a few mosquitoes can tolerate brackish water). Randy _________________________________ RF Lauff Way in the boonies of Antigonish County, NS. On 20 May 2014 18:24, David & Alison Webster <dwebster@glinx.com> wrote: > Hi Randy & All, May 20, 2014 > I don't have a clear picture of the topography, either dune or inland, > but one possible source of water in the slacks is drifting of snow into > pools. > > In woods south of Kentville, where I used to walk in winter, pools in > woodland cradlehollows of swampy sites never froze. With 2'-3' of snow on > the ground, the air cone was typically about ~1' across at snow level and > 4" across at water level. Even at -20o C, with heavy snowfall, 60 mph winds > and drifting snow there would be no hint of ice. From the viewpoint of ppt > per unit area these cones act as black holes; snow blows into them > but, soon being water, can not escape. These air cones were absent when > snow was not deep enough to act as a good insulator. With sufficient snow > cover drifted ~level over the swamp, the soil at the base of cradlehollows > would warm sufficiently by ground heat from below to melt overlying snow > and eventually generate one of these air cones. > > If these pools were sufficiently above the water table then they would > tend to be transient but, in most soils (given sufficient iron and > decomposable organic matter), infiltration rate at constant head will > gradually slow due to formation of a local iron pan over decades or > centuries. This effect interested me because ortstein is sometimes very > scattered; patches 3-4' wide and 10-15' apart and these pools that collect > below air cones could account for this. Also prolonged wetting will slake > any soil aggregates and decrease infiltration rate. > > Getting back to dunes, in the idealized case of parallel linear dunes > and linear slacks and in deep snow conditions I would expect linear narrow > pools at the base of linear narrow trenches in the snow; V-shaped deposits > of ortstein if dunes are stable and not advancing. > > Have you been there in winter and if so does any of this register ? > Yt, Dave Webster, Kentville > > ----- Original Message ----- > *From:* Randy Lauff <randy.lauff@gmail.com> > *To:* NatureNS <naturens@chebucto.ns.ca> > *Sent:* Tuesday, May 20, 2014 4:20 PM > *Subject:* Re: [NatureNS] slacks - when do they refill? > > Thanks Fred, but in a dune system, wouldn't that mean that the slacks > would be less than half full with water? These are sand dunes...very > porous, so I'm suspecting water leaching in from the hills of the dunes > into the slacks just couldn't fill them. This is unlike the condition in > vernal pools where there can be ample elevation around from which water > could leach in to the pool area. I'm thinking there has to be a significant > rain or snow fall to fill them. > > Randy > > _________________________________ > RF Lauff > Way in the boonies of > Antigonish County, NS. > > > On 20 May 2014 15:30, Fred Schueler <bckcdb@istar.ca> wrote: > >> On 5/20/2014 2:18 PM, Randy Lauff wrote: >> >> Between several of the dunes at Pomquet Beach, Ant. Co., the slacks (the >>> troughs between dune crests) fill with water, but by summer are dry. I >>> guess I've just never been there at the right time to see when they fill >>> again...it can't be just from winter melt water, since the slacks are >>> almost full (and snow melts to about 10% its volume as water). Do the >>> autumn rains fill them again, or the spring rains? Or is it a >>> case-by-case scenario, which I'd just have to monitor? >>> >> >> * I had the same thought about vernal pools at the CARCNET meeting at >> Quebec City in 1999, during a presentation on Marbled Salamanders, which >> come down into the vernal pools to lay their eggs on the dry pondbed in the >> fall, and stay with them all winter. It turns out that the vernal pools >> fill from the water table, as one would think sandy dunes would. And yes, >> I've been monitoring water level in our local Wood Frog ponds, fall and >> late winter, ever since then. >> >> fred. >> ------------------------------------------------------------ >> Frederick W. Schueler & Aleta Karstad >> Daily Paintings - http://karstaddailypaintings.blogspot.com/ >> Vulnerable Watersheds - http://vulnerablewaters.blogspot.ca/ >> study our books - http://pinicola.ca/books/index.htm >> RR#2 Bishops Mills, Ontario, Canada K0G 1T0 >> on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W >> (613)258-3107 <bckcdb at istar.ca> http://pinicola.ca/ >> ------------------------------------------------------------ >> > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4577 / Virus Database: 3950/7502 - Release Date: 05/15/14 > > --001a11c2e886e5b07d04f9e88c5a Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">Thanks folks,<div><br></div><div>I haven't been there = in winter, despite my being in NS now for over 20 years.</div><div><br></di= v><div>Here's the landscape picture though. Picture an accordion, partl= y open lying on its back. The bellows represent the dune system at Pomquet,= there are peaks and troughs (slacks), and precious little other elevations= going on. At the slack in question, the surrounding peaks of the dunes are= dominated by white pine and oak, with other trees as well.=C2=A0<