{"id":1872,"date":"2017-12-05T13:05:30","date_gmt":"2017-12-05T20:05:30","guid":{"rendered":"http:\/\/blogs.oregonstate.edu\/treetopics\/?p=1872"},"modified":"2017-12-06T09:47:54","modified_gmt":"2017-12-06T16:47:54","slug":"measuring-a-woodland-plot","status":"publish","type":"post","link":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/2017\/12\/05\/measuring-a-woodland-plot\/","title":{"rendered":"Measuring plots in the woods"},"content":{"rendered":"

Brad Withrow-Robinson, OSU Forestry & Natural Resources Extension agent for Benton, Linn and Polk Counties<\/em><\/p>\n

\"\"<\/a>In this series about young stand thinning <\/a>, I\u2019ve worked on the assumption that people know the density of trees in their woods. I realize that in many cases, people don\u2019t really know that, so cannot easily apply that information to deciding if they have enough room for healthy growth or if trees need to be thinned.<\/p>\n

If you know what distance the trees were said to have been planted, you may have a fair idea of the density (a 10\u2019 x 10\u2019 spacing is about 440 trees per acre, a 12\u2019 x 12\u2019 is about 300 tpa). This is a good start, but not necessarily very accurate.\u00a0\u00a0 Actual planting spacing can vary quite a bit according to the conditions in the field and experience of the planters.\u00a0 And of course some seedlings die during establishment, or some other trees may seed in from outside.\u00a0 So it is probably a good idea to go out and get a better idea of what you\u2019ve got.\u00a0 The basic way to do this is to measure some plots.<\/p>\n

We commonly use circular plots for this since they are easy to install and measure accurately. We choose a radius for the size of the\"\"<\/a> plot we want, (typically 1\/100, 1\/50, 1\/20 or 1\/10 of an acre). We use larger plots for larger trees, smaller plots (and typically more of them) for smaller trees. See the table at right.\u00a0 It is never too early to get an idea of this.\u00a0 Checking the work of a planting crew often involves checking planting density with a lot of small plots.<\/p>\n

So how is this done? Let\u2019s walk through the process together.<\/p>\n

\"\"<\/a>First, if you have not measured a plot before, make it easy for yourself. Choose some easy ground with trees that have been pruned up and are not overrun with blackberries. \u00a0\u00a0Something like this, to the left.<\/p>\n

I realize this may not describe the young stand you are actually interested in measuring, but since this is a training practice, that is fine. If you don\u2019t have anything that fits this description, maybe ask a neighbor, or someone in your OSWA chapter to practice in theirs.<\/p>\n

For this exercise you\u2019ll want a few stakes, some flagging, paper and pencil, and a tape measure (a loggers tape is best). Oh, and maybe bring a friend along to help.<\/p>\n

Go into the woods and toss several stakes out around the stand (each with a piece of flagging). \"\"<\/a>Those will be the centers of your practice plots.\u00a0 Working together, figure out which trees fall within the radius of your plot (for example, 16\u2019 7\u201d feet for a 1\/50 acre plot).\u00a0 Some will be easy to tell, others will have to be measured from the plot center.\u00a0 If on the line, count it as \u201cin\u201d only if the center of the tree is within the radius at breast height (which is why it is good to have a helper).\u00a0 Let\u2019s say you count 6 trees within your 1\/50 acre plot.\u00a0 What\u2019s that mean? That represents a plot density of 300 tpa.\u00a0 To find that, you multiply your plot count by the denominator of your plot size to get density (or 6 trees x 50 =300tpa).\u00a0 Repeat on the other practice plots, or until you get the hang of it.<\/p>\n

 <\/p>\n

For bonus points, go back and measure the diameter of each of the \u201cin\u201d trees in the plot and record their diameter at breast height (dbh). If you figure the average and compare that to the illustration and description <\/a>from the earlier post\u00a0 you can learn how much competition those trees are contending with now, and how much room they have to grow in the future.<\/p>\n

So that is the idea. Not that difficult, really.\u00a0 Getting an accurate measure of a whole stand requires some rigor we will not go into here, but you\u2019ll have to read more about that elsewhere.\u00a0 But even a few plots can give you some important insight, so I\u2019d encourage you to put in some plots, and start getting an eye for what you have.\u00a0 It is easy to do when trees are small, before crown closure.\u00a0 Yes, it can be hard work if your stand is brushy and full of blackberries.\u00a0 You may want to do a little pruning and clearing in your plots to make it easier. But winter is a great time to do that sort of work.\u00a0 Good luck.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Brad Withrow-Robinson, OSU Forestry & Natural Resources Extension agent for Benton, Linn and Polk Counties In this series about young stand thinning , I\u2019ve worked on the assumption that people know the density of trees in their woods. I realize that in many cases, people don\u2019t really know that, so cannot easily apply that information… Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1151,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[3116,753417,603733],"class_list":["post-1872","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-forest-management","tag-thinning","tag-young-stand-management"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/posts\/1872","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/users\/1151"}],"replies":[{"embeddable":true,"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/comments?post=1872"}],"version-history":[{"count":6,"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/posts\/1872\/revisions"}],"predecessor-version":[{"id":1882,"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/posts\/1872\/revisions\/1882"}],"wp:attachment":[{"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/media?parent=1872"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/categories?post=1872"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dev.blogs.oregonstate.edu\/treetopics\/wp-json\/wp\/v2\/tags?post=1872"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}