[APWG] Ecosystem Restoration and the challenge of understanding ecological processes Re: What caused surprise results in PoppyProject?--Test soil for soil nutrient thresholds
Wayne Tyson
landrest at cox.net
Tue Sep 24 10:50:25 CDT 2013
APWG:
I'm soooo glad to hear from an actual plant physiologist--especially a plant
physiological ecologist--here; I wish I had had Harrison around 50+ years
ago when I was struggling with this. But I'm happy just to know that he
exists--and understands this issue in more detail than I.
I made a little crack in the "code" about 45 years ago, just enough to add
an avalanche of questions, including the kind of nutrition issues that
Harrison states, but I can tell everybody that it was a slooow process to
first start to understand the importance of mycorrhizal associations (a
"Wittman Sampler" of "knowledge" is not enough; one must acquire a deep
understanding of complex interrelationships), the role of free-living
N-fixers, micronutrients, soil organisms, soil atmosphere, and the infinite
interactions and combinations thereof that keeps real students of the
subject busy for lifetimes--with still a lot left to understand after that.
I have "worked" on arid and semi-arid ecosystem restoration issues
since--well, it's hard to put a date on it, but as far back as 1956--my
first botany/biology/ecology class (I had dug up my first Larrea a couple of
years before), and I'm still trying to learn more. Unfortunately, it was
hard to find ecology courses then, much less plant physiological ecology
back then--even if I'd had sense enough to take it up. If I had, I could
probably have compressed decades into a few years and accelerated my
understanding many-fold. I'm still working on it, and it's guys like
Harrison that help open up more clogs in my brain; at least what's left of
it.
WT
----- Original Message -----
From: <tyju at xmission.com>
To: <apwg at lists.plantconservation.org>
Sent: Monday, September 23, 2013 10:17 PM
Subject: Re: [APWG] What caused surprise results in PoppyProject?--Test soil
for soil nutrient thresholds
> APWG: I would like to add my support to Tyson and Beyfus' comments
> regarding nutrient levels in native grassland restorations. As a plant
> physiological ecologist I have bucked the horticulture/agronomy crowd's
> approach for many years. Native grasses are intensely mycorrhizal, and
> weeds are not (by and large). This has large implications for
> competition in a phosphorus limiting environment, not well understood by
> agronomists. Fertilization of any kind shifts the competitive balance
> between the drought tolerant, slow growing native grasses and the rapidly
> growing weeds. Nitogen sources are also involved in this competitive
> balance act. Rapidly growing weeds thrive on nitrate from bacterial
> nitrification whereas the slow growing native grasses utilize slowly
> released ammonium from organic sources via ammonification. Just the
> reverse of agronomic practices. We need to better understand these
> complex ecological soil process better to design more successful
> restoration techniques in arid ecosystems. Ty Harrison
>
> Quoting Wayne Tyson <landrest at cox.net>:
>
>> APWG:
>>
>>
>>
>> EXACTLY! Beyfuss is right again! My education was my biggest problem in
>> developing a viable program for ecosystem restoration here in CA; it
>> took me fifteen years to un-learn my agronomy and horticulture.
>> Ecosystems are the opposite of culture.
>>
>>
>>
>> Undisturbed ecosytems tend to sequester (tie-up) the available
>> nutrients as soon as they are made available by a root-death or a bit
>> of leaf or animal dropping. Agronomic soil tests will ALWAYS show a
>> "deficiency" in dynamically stable ecosystems. Even the amounts of P
>> and K, not to mention trace elements, that show up in such tests are
>> mostly in unavailable form. Ironically, lacing a site with
>> superphosphate tends to kill the very symbionts (mycorrhizae) that
>> convert the unavailable P into an available form and supply it to the
>> photosynthesizers in exchange for carbon (sugars).
>>
>>
>>
>> In the sudden flush of NPK following fire or other disturbance, "weedy"
>> plants flourish, and if nothing is done to replace the complex
>> ecosytem, especially its mycorrhizal nets, weeds will persist until the
>> very (relatively) slow process of re-colonization by indigenous
>> species, both above and below the surface, the process will be even
>> slower, especially if the biologically-active true soil is removed or
>> otherwise damaged. All "restoration" practitioners can do is accelerate
>> the process by setting up conditions favorable to that process.
>>
>>
>>
>> Much N is lost to the atmosphere following disturbance (especially
>> fire), but free-living and nodule-forming N-fixing bacteria are
>> apparently able to compensate for said loss, available to all-comers,
>> weeds and secondary successional colonists, native or alien. However,
>> since (this is highly simplified, but I hope adequate) most weeds
>> evolved in riparian zones and went rampant in cultivated fields where
>> they hybridized into many of the "monsters" we know, and indigenous
>> components of the complex ecosystem evolved together over the
>> millennia, the indigenous species (or aliens adapted to similar
>> environments) will tend, eventually to (more quickly, one hopes with
>> THE RIGHT KIND of "help") regain dominance over the weeds and aliens,
>> subject, of course, to the absence of further disturbance and other
>> environmental changes.
>>
>>
>>
>> Adding N and other fertilizers just makes weediness worse--a kind
>> "eutrophication," as it were . . .
>>
>>
>>
>> Many "weeds," particularly indigenous ones, are simply part of the
>> "succession" process-organisms doing what they can, where they can,
>> when they can. Spraying herbicides only makes the chem companies richer
>> and it does far more damage than good, however viscerally righteous it
>> might make its practitioners and amateur weed-haters feel.
>>
>>
>>
>> Even alien weeds can perform functions that are beneficial to ecosystem
>> restoration processes in many cases--especially where their presence is
>> primarily due to continued site disturbances such as by alien animals.
>>
>>
>>
>> If any soil testing is relevant at all, it would have to be performed
>> many times over a period of time to illustrate the trend of nutrients.
>> Sampling of nutrients in the tissue of living organisms might be more
>> useful in terms of exposing deficiencies, but the take-home lesson is
>> that the lower the available nutrients are (sequestered by plants and
>> other organisms), the lower the weed populations and stature.
>>
>>
>>
>> WT
>>
>>
>>
>>
>> ----- Original Message -----
>> From: Robert Layton Beyfuss
>> To: craig at astreet.com ; apwg at lists.plantconservation.org ;
>> craig at ecoseeds.com
>> Sent: Friday, September 20, 2013 7:21 AM
>> Subject: Re: [APWG] What caused surprise results in Poppy
>> Project?--Test soil for soil nutrient thresholds
>>
>>
>> Hi All
>>
>> Most home soil test kits are useless based on my experience comparing
>> their results with legitimate (University) lab results. Nitrogen or
>> even N0 3 levels are impossible to accurately gauge due to the fact
>> that this nutrient is constantly changing in soils in form and
>> availability over even short periods of time. Even home pH testers are
>> woefully inaccurate. I would never suggest a fertilizer program without
>> bona fide data to back it up. I am not aware of any laboratories that
>> provide nutrient guidelines for native plants in the Northeast, but
>> this may not be the case in the west. Most of our university soil labs
>> (sadly) can recommend nutrient levels for agronomic crops or ornamental
>> crops only!!
>>
>> Apparently this what you did on BLM land. Glad that at least some
>> labs are doing this!
>>
>> I like the concept of "default weeds". All weeds are default weeds in
>> the sense that they grow when conditions grant them the opportunity
>> (opportunistic weeds?) Some thrive in nutrient poor soils while others
>> thrive in soils that have far too many nutrients as is the case here in
>> the northeast. Farmers plant lagoons of reeds and cattails to suck up
>> extra nutrients and most waterways that are lined with exotic weeds are
>> overloaded with nutrients also. The biomass that plants such as
>> knotweed (formerly Polygonum cuspidatum) produce each year is
>> astonishing to see along many waterways here and this is due to high
>> nutrient levels. Wish that someone would harvest this stuff and burn it
>> for energy instead of planting willows and adding 75 pounds of N per
>> acre to get them to grow well.
>>
>> Of course there are other factors such as soil organic matter levels,
>> soil compaction (surely an issue in overgrazed land?) and possibly
>> allelopathic effects of exotics.
>>
>> I do like the quick and dirty idea of actually observing what is
>> going on and then trying to address the specific problems, instead of
>> simply spraying herbicides on the exotics and hoping that the natives
>> will return on their own. Unfortunately, that approach has seemed to
>> dominate invasion biology thinking for far too long but when funding
>> for "restoration" has come from weed killing entities, it is to be
>> expected.
>>
>>
>>
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>> From: APWG [apwg-bounces at lists.plantconservation.org] on behalf of
>> craig at astreet.com [craig at astreet.com]
>> Sent: Wednesday, September 18, 2013 4:34 PM
>> To: apwg at lists.plantconservation.org; craig at ecoseeds.com
>> Subject: Re: [APWG] What caused surprise results in Poppy
>> Project?--Test soil for soil nutrient thresholds
>>
>>
>> Dear Robert and All,
>>
>> Thanks for your question.
>>
>>
>>
>> About testing for the soil nutrient threshold, you can do it at least
>> three ways:
>>
>> 1.) HOME TEST KIT. Use a simple garden store soil test kit on at
>> least three locations for a native species--(a) Where you see native
>> seedlings surviving, (b) Where you see established native plants and no
>> seedlings, and (c) No native plants nearby existing native plants. It
>> costs about $10 to these three tests.
>>
>> 2.) SOIL TESTING LAB. Do these same three tests but send them to a lab
>> and have the N-P-K-pH run and get the threshold for each species in PPM
>> for the nutrients. That is what we did on the BLM land for the 600
>> acres of pipeline north of Reno.
>>
>> 3.) WATCH THE PLANTS. Sow native seeds or seedlings either on site or
>> in ex situ test pots, and add measured amounts of fertilizers to see the
>> responses. Use a native that easily shows nutrient problems, so you
>> can correct any problems rapidly so the seedlings do not die on you
>> before you can correct the problem. I use the California poppy and the
>> broad-leaved California brome, because they have a rapid response to
>> nutrient problems. A species not to use, is the Stipas or the
>> needlegrasses, because their responses are slow and they have very
>> narrow leaves that are hard to read. Broad leaved grasses or fast
>> growing forbs are best.
>>
>> Once you find your native seedling soil nutrient thresholds, you can
>> then take a look at local weed infestations, and see if the root cause
>> of their spread, instead of being invasive plants, is that they are
>> only Default Weeds, able to grow where the soil levels are too poor for
>> local native seedling survival, like cheatgrass, thistles, medusahead,
>> etc.
>>
>> I also use this technique of checking for soil nutrient problems by
>> watching the leaves, for my Haiti farming project, with corn to check
>> N-P-K and pepper leaves to check calcium, that you can see information
>> at http://www.ecoseeds.com/clear.html and http://www.haitiag.org.
>>
>> Sincerely, Craig Dremann (650) 325-7333
>>
>> ====================
>>
>> > So, did you test the soils for nutrient levels? Have you learned the
>> > optimal nutrient levels for the natives that you are trying to
>> reestablish
>> > and compared them to the soils you are now working with?
>> >
>> > ________________________________
>>
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>>
>>
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