From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 23-FEB-1996 11:51:15.31 To: Multiple recipients of list QUATERNARY CC: Subj: Removing organic from pollen samples Greetings everyone, I'm working on woody peat samples from a forest hollow for pollen analysis. After standard preparation treatment (including hot 10% KOH for 15 min and acetolysis for 2.5 min), there are still very abundant organic particles about pollen size in the samples. Counting these samples are much more time-consuming, and the results could be unreliable because organic particles may obscure pollen grains, especially small grains. I wonder if someone out there has experiences with the methods which remove/reduce other organic particles without damaging pollen grains. Any lab trials on different combinations of timing, temperature and concentrations with KOH treatment? I heard that the New Zealand bleach method may damage pollen grains as well. Any suggestions and references would be greatly appreciated. I post this request to POLPAL-L and Quaternary lists. I apologize to everyone who receives duplicated copies. Cheers, Zicheng ____________________________________________________________________ Zicheng Yu, Botany Dept., Royal Ontario Museum, Toronto, ON M5S-2C6; Phone:(416)586-5609; Fax:(416)586-5516; E-mail:yuzi@utcc.utoronto.ca ____________________________________________________________________ From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 24-FEB-1996 17:38:39.58 To: Multiple recipients of list QUATERNARY CC: Subj: Pollen preparation techniques Greetings to all from tropical north Queensland. Zicheng Yu wrote recently with a problem in removing organic matter from pollen preparations. I have found that a judicious use of Schulz solution is a very effective way of shifting those persistent organic left overs in pollen preps from mangroves, coals and peats. Schulz solution is KClO3 dissolved in HNO3 - you can manipulate the vigour of action by selecting an appropriate concentration of the acid. I usually use 8 gm KCLO3 dissolved in 80 ml of 35% HNO3. Mix thoroughly with the sample and allow to stand for 50 - 60 minutes. Wash out he Schulz solution and follow up with an ammonia / ammonium hydroxide step (5 percent for 5 - 10 minutes) and the job is done. You can follow this with an acetolysis step if you are really serious about clearing your samples up. I hope this info is of use. I also have a question about pollen preservation and extraction. I have recently been working an material from a series of swamp forests growing on mounded peats in the wet and dry tropics of the Northern Territory (Australia). The material looks superb - nice peaty organic stuff - but seems to be utterly devoid of pollen! I hve given them the Schulz treatment as well as the standard regime of KOH - acetolysis to no avail. Can anybody point ot some literature which might help me explain this extremely irritating phenomenon? Cheers, Jon Luly the sample and allow to stand for 50 - 60 mins. From: PO3::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 25-FEB-1996 17:11:49.77 To: Multiple recipients of list QUATERNARY CC: Subj: A caution about Schultz Hi all! I agree with John Luly about the effectiveness of using the schultz solution to reduce unwanted organics. However a word of caution if you are expecting pollen grains less than about 8 microns in size - they disappear or at least are severely reduced in number if you Schultz your samples! I compared the results of both standard pollen prep and that using Schultz on samples from a core extracted from a lake in rainforest in western Tasmania (which includes a number of taxa which produce pollen less than about 8 microns. eg. Eucryphia (3-6 microns) and Leptospermum (6-9 microns). I found that in samples in which I did not use Schultz Eucryphia and Leptospermum were highly abundant (in the case of Eucryphia up to 50%). However, when I Schultzed samples from the same depth both these taxa were severely reduced in representation and in the case of Eucryphia, often absent! I believe that these smaller grains were being lost in suspension rather than being destroyed. Extending the centrifuging time to 15 minutes after the nitric acid and ammonia steps certainly increased the yield of small grains but by no means solved the problem. I would advise, therefore, that if you expect to find small pollen grains you do not use the Schultz method. To solve the problem of too much organic debris obscuring pollen I suggest you thin your slides out so that everything is clear. It may mean having to count more slides but at least you will know that the small taxa will be represented! hope this is of some assistance cheers Kate Kate Harle Centre for Palynology & Palaeoecology Dep. Geography & Environmental Science Monash University, Clayton Victoria 3168 Australia From: PO2::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 26-FEB-1996 09:03:15.86 To: Multiple recipients of list QUATERNARY CC: Subj: Re: Pollen preparation techniques Jon Lulu recently wrote (in response to Zuching Lu's previous query about getting pollen from organics with low concentrations) that he had "nice, peaty stuff" from northern Australia that seemed to be devoid of pollen no matter what the processing (including his use of Schulz solution). He didn't mention local bedrock geology, but one experience I had with a student several years ago might prove helpful. She, too, had brought back beautiful, rich organics from a marsh in Bermuda that, despite our best efforts, seemed to be all but devoid of pollen. On a hunch, I checked the pH of the sediments - and came up with an 8.0. Despite the richness of the organics, the alkaline conditions produced by the local limestone was probably responsible for near-complete pollen degradation. Samples collected more recently, from sites farther removed from the bog margins, showed good pollen concentrations and are producing valuable data. - Bob Nelson *********************************************** Alter Ego: The Mad Viking! Robert E. Nelson, Chair Phone: [207] 872-3247 Department of Geology FAX: [207] 872-3555 Colby College e-mail: renelson@colby.edu 5804 Mayflower Hill Drive Waterville, Maine 04901-8858 "Good science consists mostly of play disguised as work." - E. O. Wilson *********************************************** From: PO2::"QUATERNARY@MORGAN.UCS.MUN.CA" "Research in Quaternary Science" 26-FEB-1996 23:05:58.15 To: Multiple recipients of list QUATERNARY CC: Subj: Re: Pollen preparation techniques Bob Nelson recently wrote that he has had preservation problems with organic sediments with a pH of 8.0. I often process sediments that have pH values higher than 8.0 and get good pollen records. Often the sediments are not particularly organic. In my experience, the pH needs to be much higher to result in the obliteration of pollen from the sample. I had not responded to the discussion on removing organics because I have never used such harsh measures. I avoid nitric acid (and of course, Schulze solution), bleach, and most oxidizers. I do use a 9:1 mixture of acetolysis. I have varied the times for acetolysis. When I was working at INSTAAR, we used to acetolate pollen for 60 minutes (tubes in a boiling water bath at an elevation of over 5240 feet). The samples (most were peat or organic sediments) were beautiful. Pollen remaining (most of it???) was in a good to very good state of perservation. We did no tests to record differential destruction. I understand that INSTAAR does not use this technique any more (change with change in personnel). When I had the authority to be in charge of my own samples, I went back to 3-5 minute acetolation for most samples. I still occasionally split a sample and acetolate half of it for 15 minutes (or GASP 30 minutes), then count both halves. I always get better counts (more pollen of all sizes) from the half acetolated for a longer period of time when the original sample matrix was very organic. I have not yet noticed a destruction of samples of any single group (Juniperus or Poaceae, for instance). I attribute the "better" counts to my ability to see more pollen because more of the organic background was destroyed. I'm more comfortable with varying the time for acetolation than with varying the formula, which I DO NOT do. Linda Scott Cummings