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dominated by white pine and oak, with other trees as well.=C2=A0< This is a multi-part message in MIME format. ------=_NextPart_000_25E4_01CF7513.4AD78360 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Randy & All, I had imagined these dunes to be bare sand. With tree cover on the = peaks and presumably none on the slacks there is another effect that = will increase effective ppt in the slacks; sublimation on the tree = canopy in calm weather and selective snow accumulation in treeless areas = (roads, glades, etc) in windy weather due to less turbulence and less = speed over glades.. Yt, DW ----- Original Message -----=20 From: Randy Lauff=20 To: NatureNS=20 Sent: Wednesday, May 21, 2014 9:57 AM Subject: Re: [NatureNS] slacks - when do they refill? 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.=20 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.=20 Have you been there in winter and if so does any of this = register ? Yt, Dave Webster, Kentville=20 ----- Original Message -----=20 From: Randy Lauff=20 To: NatureNS=20 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.=20 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 No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4577 / Virus Database: 3950/7529 - Release Date: = 05/20/14 ------=_NextPart_000_25E4_01CF7513.4AD78360 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML>