[APWG] Percentage cover of each species to find constants

[Wayne Tyson]

Ty,

I don't disagree, but what "ecology dynamics" are relevant to cover (or 
vice-versa)?

WT


----- Original Message ----- 
From: <tyju at xmission.com>
To: <apwg at lists.plantconservation.org>
Sent: Thursday, October 11, 2012 3:31 PM
Subject: Re: [APWG] Percentage cover of each species to find constants


>I think that the Petri dish analogy is quite apt.  The complex 
>interactions between species which determine dominance as the macro  scale 
>are almost as obscure as those at the microscale, if not more  so.  I agree 
>that detailed canopy cover data are critical for  documenting and assessing 
>plant ecology dynamics in the face of  disturbance, invasion and 
>restoration.  Ty Harrison
>
> Quoting Craig Dremann - Redwood City Seed Company <Craig at astreet.com>:
>
>> Dear Wayne and All,
>>
>> I apologize if you thought I was not answering your questions-- I will 
>> try
>> and elaborate further in this email.
>>
>> WAYNE: I do think of the whole earth as a huge Petri dish, but I cannot
>> understand
>> what you are talking about. I asked "What ecological condition(s) are
>> revealed by cover?"
>>
>> CRAIG:  The whole world is a giant petri dish, because all teresstrial
>> life is closely confined in an extremely thin layer on the planet.  If we
>> shrank the planet to the size of a petri dish, all life would be a layer
>> about 30 millionths of an inch thick.
>>
>> In terms of plant interactions, if you think of the local ecosystem you
>> are working within, as one big giant petri dish, then the plant
>> interactions become more readily evident.   The ecological conditions
>> revealed by cover--cover is what shows you the interactions between the
>> two species of native plants, or between the native plants and the weeds.
>>
>> What is seen on a regular petri dish is the battle between a pathogen and
>> an antibiotic, and this battle is played out on a macroscopic scale in 
>> the
>> ecosystem cover interactions.  Every terrestrial non-riparian plant as it
>> grows, gives off natural herbicides in greater or lesser amounts and
>> potencies, that act like antibiotics.
>>
>> You can do experiments by adding native seeds as an antibiotic to a weed
>> patch, such as California poppy seeds.  Or add fertilizers to benefit 
>> your
>> preferred antibiotic/herbicide/allelopathy-producing plants, to change 
>> the
>> species composition of the weed cover.  You can then use cover to measure
>> the changes you made by adding the natives or the fertilizers, and you 
>> can
>> see some of those results  at http://www.ecoseeds.com/arastradero.html
>>
>> I am translating from the microscopic scale--what I have been working on
>> for almost 20 years--to the macroscopic scale.  In my petri dishes that 
>> my
>> lab cultures pathogens and then uses to discover new plant antibiotics
>> against pathogens like MRSA, we measure the zone diameters of the
>> antibiotics killing the pathogens, that you can see at
>> http://www.ecoseeds.com/mrsa.html.
>>
>> The same thing happens on the macroscopic scale, where one plant inhibits
>> another--we just have not gone out yet to measure the battle that is 
>> going
>> on out there each year, just like the pathogens and the antibiotics in 
>> the
>> petri dish.
>>
>> WAYNE: Do you think that ecological conditions that give rise to
>> ecological phenomena are not important to the subject at hand?
>>
>> CRAIG: Cover measurements, especially when done on a very fine scale, is
>> your very best tool to measure plant interactions.  When I do a transect,
>> I measure every single species, even if it is only a single plant within 
>> a
>> 100 foot long transect.
>>
>> WAYNE:  Please preserve the string of relevant emails in the future; I'll
>> greatly appreciate not having to hunt up previous emails to recall the
>> context and issues under discussion. Thank you.
>>
>> CRAIG: Sure.
>>
>> Sincerely,  Craig Dremann (650) 325-7333
>>
>>
>>
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>
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