Grey, Warren, and Forum:
NOTE: All-capitals are used to indicate ITALICS, as the listserve software
does not support ITALICS, if I understand correctly. No shouting is
intended.
Yes, Warren's effort is most interesting, as are Bálint's observations. I
will be interested in reading further from Warren, Grey, and Bálint, should
they make more of their work available here.
With respect to cattle grazing on California grasslands, I have observed
what appear to me to be points of reservation, and I wonder how the research
has found results to the contrary or in confirmation. I have noticed that
trampling seems to have more negative effects on SOME grasslands (e.g.,
Leymus triticoides*), to wit, the suppression of some indigenous species,
often to the benefit of alien species, leading one to suspect that the
suspect assumptions about cattle grazing might not . Ted St. John's
doctoral dissertation noted that even species like Nasella pulchra were
absent from grazed areas and were found "huddling" in cactus patches in
Southern California stands.
I have often wondered whether or not the fact that the western coastal
prairies and even some of the interior grasslands/forblands/shrublands did
not co-evolve with bison, even, much less cattle, and thus did not develop
complimentary adaptations as occurred in the Great Central Plains, perhaps,
and African savannas, for example. What were the specific effects of
climate, migratory patters, geology and soils, soil water budgets and
specific grazer/browser habits and species mixes? Certainly there is much
variation within this broad habitat class, and the tolerance and
responsiveness of grazing and trampling also will have varied.
Current-day habitats in most areas of the region, especially with respect to
species diversity and dominance are radically altered, and I have no doubt
that cattle grazing, properly managed (and I'm not sure how one would define
"properly") has some theoretical foundation and prima facie "evidence." I
placed "evidence" in quotes, not because I doubt that marginal improvements
in grassland "quality" can be observed within a few geological milliseconds
of the introduction of cattle as surrogates (however inferior) for
pronghorns, deer, and elk, but I do wonder about the effects of cattle
grazing's different effects upon other components of the
grassland/forbland/shrubland ecosystems in the short and long term. Cattle
are selective grazers, and while they might turn in impressive performances
in diminishing alien species, for example, I wonder how many indigenous
clovers, "wildflowers," and other preferentially-grazed species, scarce
enough among the weeds, might be relegated to extinction or degradation.
Finally (puff, puff), there is the specter of restoration. In any given
project area (disturbed site), there is a good chance that some species have
been either extirpated or their populations so reduced that their original
(not merely "as found") species may need to be determined by "extraordinary"
means, such as extensive herbarium study (how many are indexed to geographic
area, much less site location, requiring some inference about historic and
prehistoric species composition, density, and distribution. Perhaps cores
and pollen and other microfossil analysis might be needed?
There is no substitute for careful and adequate sampling, based on a
generous expansion beyond the minimum sampling effort determined by
conventional methods for determining sample size, as rare species cannot
always be expected to turn up in conventional surveys (micro-habitats within
the study area may need special treatment, and other techniques may be
necessary). I presume that the studies upon which the grazing management
programs have been based have been exceedingly thorough, from the earliest
records to the current composition, to comparable sites, refugia , and other
microsites, down at least to the soil surface cryptogams if not to fungi and
other subsurface evidence. That is, I hope that recent studies have gone
far beyond the "field trial" level of ancient times and have progressed into
cutting edge ecosystems analysis, restoration, and management.
_____________
*I have noticed that this species is very rare everywhere in the central and
southern coastal regions of California; many botanists often do not even
notice it (oddly enough), as I also have failed to do-upon casual
examination. When botanists, ecologists, and other biologists do find
long-rhizomatous Leymus stands they are almost always clones of sterile L.
triticoides x condensatus or x glaucus hybrids. I, at least, have made this
error. But this is not the only species overlooked or casually-I hesitate
to say carelessly-keyed, much less studied in careful comparison with local
and regional collections. I love to lump, except when damaged ecosystems
are involved. Herbaria, vital in any pre-management or restoration (not to
say "creation") study, bad enough at giving the student a splitting
headache, often need even more splitting, as there are errors there
aplenty-enough to permit the student to hang the scalps of some pretty
impressive antecedents on hisher belt. I shall refrain from going down the
path of ecotypes and their importance to resilience again . . .
Apologies for the long post . . .
WT
----- Original Message -----
From: "Grey Hayes" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, June 14, 2008 7:56 AM
Subject: [ECOLOG-L] Ecosystems, faux ecosystems, and habitat valuation
Hi Warren,
Your work valuing ecosystems is very interesting, and I'm looking forward
to seeing more.? I want to suggest one caveat for your work to see if you
might be able to integrate it.
On California's coast, according to my and others' research, it appears
that privately owned, cattle grazed grasslands might be valued in your
schema more highly than publicly owned, ungrazed grasslands.?
I understand some of the same ecological processes might be at work in
your state where unmanaged (eg., 'wilderness') areas often have some of
the major disturbance regimes suppressed, negatively impacting
disturbance-dependent native plant species.
In California's vernal pool systems of the Sacramento Valley, research
suggests a similar story, but also more clearly affecting native wildlife
populations.
And so, your valuation system might need to address (especially) grassland
ecosystems where privately managed land might be able to maintain some
elements of biodiversity more than on underfunded public lands.
Grey Hayes, PhD
Coastal Training Program Coordinator
Elkhorn Slough National Estuarine Research Reserve
Moss Landing, California, USA
-----Original Message-----
From: Warren W. Aney <[EMAIL PROTECTED]>
To: [email protected]
Sent: Fri, 13 Jun 2008 10:31 pm
Subject: Re: [ECOLOG-L] Ecosystems and faux ecosystems Re: [ECOLOG-L]
Wetland creation
Wayne, Bill, Andy, Amartya, et al., I'm in the process of relating all
this
discussion to a project I am currently working on and I have found our
exchanges helpful.
The basic question I've been working on is: how do we determine the actual
per land unit value of habitat (= ecosystem) that is modified or
destroyed?
To put it most simply, if, in a given area, broadly defined wildlife
related
activities each year create $2 billion in economic activity and we have 50
million land units of habitat, then each land unit is worth $40 in terms
of
annual economic activity. However, different categories of land have
different habitat values: A natural (or restored) wetland will have more
value than a created wetland, and this will have more value than a drained
wetland. A late successional forest will have more habitat value than a
tree farm, which will have more habitat value than a golf course, which
will
have more habitat value than a housing development.
So, for this project I arbitrarily assigned relative habitat values by
land
category:
RHV 1.0: Protected natural areas (ecosystems in Late Successional Forest
Reserves, Wilderness Areas, National Wildlife Refuges, National Parks and
Monuments, state wildlife areas, etc.). A protected natural wetland or
late
successional forest would fall into this category.
RHV 0.90: Managed resource lands (rangeland, public and private
forestland,
etc.). A restored wetland might fall into this category.
RHV 0.70: Pasture/rangeland (mostly privately owned). A tree farm might
fall into either this or the previous category, depending on how it is
managed. A created wetland might also fall into this category.
RHV 0.50: Farm cropland (harvested and pastured farm land). A golf course
might also fall into this category.
RHV 0.05: Urban built-up area (residential, industrial, commercial,
institutional land, etc.).
RHV 0.00: Roads and railroads.
Using these relative habitat values, the total economic activity generated
in the state of Oregon by wildlife (and fish) related activities in a
recent
year, and the state acreage in each of the above land categories, I came
up
with the following per acre per year values:
$40.56 for each acre of protected natural areas
$36.50 for each acre of managed resource lands
$28.39 for each acre of pasture/rangeland
$20.28 for each acre of farm cropland
$2.03 for each acre of built-up areas
$0 for each acre of roads and railroads
(These figures, multiplied by total land area in each category, sum up to
the total economic activity of $2,074 million.)
How can these figures be put to use? Let's say that one acre is changed
from managed resource lands to a built-up area. The reduction in wildlife
habitat value is $34.47 (the difference between $36.50 and $2.03). In
order
to provide $34.47 per year in repayment value, at an annual interest rate
of
6% this developer could contribute or mitigate a total one-time dollar
value
of $574.50 per acre.
These figures and categories are for the purpose of initiating discussion
and will probably be changed and refined if the process takes hold. But I
think the basic concept has merit and can be useful when assessing the
economic effect of land use changes when wildlife habitat is either
degraded
or improved. There is one caveat I've tried to remember: if this system
is
to be used and understood by a wide variety of decision makers,
administrators and land managers, it has to be kept reasonably simple.
If anyone wants more details, I'll be glad to share a more detailed
write-up
and the actual spreadsheet with formulas. Meanwhile, I'd be pleased to
receive your reactions, suggestions and criticisms (I know you're all good
at the latter). Does this seem to have merit? Is anyone aware of similar
attempts along this line by others?
Warren W. Aney
Senior Wildlife Ecologist
Tigard, OR 97223
(503) 246-8613 phone
(504) 539-1009 mobile
(503) 246-2605 fax
[EMAIL PROTECTED]
