You are NOT going to simulate grazing by large herbivore like that, you are going to simulate cutting-removal of whatever. That type of experiments have been totally obliterated in practice since they are quite misleading. There is evidence that animal's saliva can be affecting the leaves, the animal "chooses" what to eat quite differently than what we can tell, the animal is also urinating and leaving feaces, etc.
So, to say it bluntly if the objetive is to see what is going on with large herbivores you have to use them, if you want to see what is the effect of removal of leaves, etc. then you can use a mower. They are different and w should aknowledge that from the begining. Abraham de Alba Avila Terrestrial Plant Ecology INIFAP-Ags Ap. postal 20, Pabellón Arteaga, 20660 Aguascalientes, MEXICO SKYPE: adealba55 Tel: (465) 95-801-67 , & 801-86 ext. 126, FAX ext 102 alternate: dealba.abra...@inifap.gob.mx cel: 449-157-7070 ________________________________ From: "Reinhart, Kurt" <kurt.reinh...@ars.usda.gov> To: ECOLOG-L@LISTSERV.UMD.EDU Sent: Friday, May 8, 2009 8:50:26 AM Subject: [ECOLOG-L] simulate grazing with mowing treatments I am looking for ideas on modifying a lawn mower (or something functionally equivalent) to create mowing treatments that will approximate different levels of non-selective herbivory by livestock in semi-arid grasslands. Unfortunately, the chemical treatments to the vegetation that I'm planning prevents utilizing e.g. sheep to naturally graze plots. A mowing solution might require modifying it to attach to an alternate frame to create the ability for setting a wide range of cutting heights to produce different utilization levels (e.g. 45 and 75%) and compensate for variable production among years. Ideally it will also collect/suck up cut material to avoid creating profuse leaf litter so it might need a separate vacuum for sucking up material when cutting at e.g. 25cm off the ground. I suspect safety flaps will also need to be installed to protect the operator from flying debri. We have some really handy shop staff that can build just about anything. So I'm mostly looking for ideas, likely pitfalls to avoid, etc. Any body built something similar or know someone that has? Kurt <mailto:ECOLOG-L@LISTSERV.UMD.EDU> Kurt Reinhart, Research Ecologist USDA-ARS Fort Keogh Livestock & Range Research Laboratory 243 Fort Keogh Road Miles City, MT 59301 USA email: kurt.reinh...@ars.usda.gov Office: (406) 874-8211 Fax: (406) 874-8289 educational website: http://iecology.net <http://iecology.net/>