tag:blogger.com,1999:blog-2834972773043127807.post5790771753153740407..comments2024-02-17T14:40:18.105+00:00Comments on Life On An Oxfordshire Lawn: The Rules of EngagementHenry Walloonhttp://www.blogger.com/profile/16370052352586546748noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-2834972773043127807.post-17593131602210159012007-06-23T13:20:00.000+01:002007-06-23T13:20:00.000+01:00""There are more organisms in one gram of soil tha...""There are more organisms in one gram of soil than there are human beings on this Earth!""<BR/><BR/>That is a bit much, but expand that to a cubic yard of soil and I would accept that. However, there are far fewer species in a gram of soil than that would suggest. Almost certainly fewer than 1000 species. And if you ignore bacteria and viruses, you have a much more manageable number. I suspect that your yard, if carefully explored, probably contains 250 - 750 species, and that would still be mostly small things like nematodes and mites. Stick to visible animals and plants? You would do well to find 75 species, so that is something you can handle!High Power Rocketryhttps://www.blogger.com/profile/11537203640644706903noreply@blogger.comtag:blogger.com,1999:blog-2834972773043127807.post-32248180744752242922007-01-27T12:12:00.000+00:002007-01-27T12:12:00.000+00:00Henry! This is a fantastic challenge you have set ...Henry! This is a fantastic challenge you have set yourself. I will follow with great interest and wonder. Thanks for your visit.Laurahttps://www.blogger.com/profile/04628996423706575881noreply@blogger.comtag:blogger.com,1999:blog-2834972773043127807.post-86170238468734413902007-01-15T18:30:00.000+00:002007-01-15T18:30:00.000+00:00Many thanks for the comment Roger. Not least as yo...Many thanks for the comment Roger. Not least as you have the high honour of being my very first blog commentator. <br /><br />The Wikipedia article is enlightening...to a point. As you rightly point out, the main article quotes "40 million" and gives a reference ("[2]").<br /><br />Following the reference however leads to a paper that states (in connection with table 2):<br /><br />"For forest soils, the number of prokaryotes in the top 1 m was 4 × 10^7 cells per gram of soil, and <br />in 1-8 m, it was 10^6 cells per gram of soil (16). For other soils, the number of prokaryotes in the top 1 m was 2 × 10^9 cells per gram of soil, and in 1-8 m, it was 108 cells per gram of soil (18)."<br /><br />"2 x 10^9" is 2 billion (I think) - on a par with the human population. If there's other "living stuff" in there as well, maybe the original suggestion is correct?<br /><br />How these figures relate to the Wikipedia "40 million..." statement isn't immediately clear to me?Henry Walloonhttps://www.blogger.com/profile/16370052352586546748noreply@blogger.comtag:blogger.com,1999:blog-2834972773043127807.post-45762801837277282862007-01-14T22:26:00.000+00:002007-01-14T22:26:00.000+00:00>"There are more organisms in one gram of soil tha...><i>"There are more organisms in one gram of soil than there are human beings on this Earth!"</i><br /><br />I think that's probably an exaggeration, even when you include bacteria.<br /><br />According to <a href="http://en.wikipedia.org/wiki/Bacteria">Wikipedia</a> <i>"there are typically 40 million bacterial cells in a gram of soil"</i>.<br /><br />That's a lot of organisms, but still fewer than the total human population (6.6 billion).Anonymousnoreply@blogger.com