Keith's response to Tom:
Thanks Tom for your valuable input.
I totally agree with you on the benefits of doing more grazing at the SRP, at least in certain areas. Perhaps this is the reason why I feel we had better wildflower bloom back in the old days when the effects of grazing was still evident in controlling the non-natives.
I feel you, and others, are absolutely right in your approach, on first tackling the more recent invaders. In my short experience I was successful in eliminating Russian thistle in a small area of infestation. And I had pretty good control, although not 100% by any means of Mustard at some locations.
As you mentioned, concentrate on the healthy areas first by eliminating all of the non-natives weeds in those area first then work outward.
I am sure Zach and Ted agrees and practices this philosophy.
At Johnson Ranch I concentrated on making healthy plots of chaparral larger by treating, mowing, and reseeding their perimeters. I wasn’t there long enough to evaluate the results. I though maybe since beneficial mycorrhizae were already present and near by, they would help accelerate the expansion of the pristine areas.
Like I said before, I am no expert in this field and rely on all of you for your expert opinions.
I just feel burning grassland is not a good thing any time.
On Sat, Nov 19, 2011 at 8:46 AM, Tom Chester <tom@tchester.org> wrote:
> hi, keith!
> I feel you, and others, are absolutely right in your approach, on first
>> tackling the more recent invaders. In my short experience I was successful
>> in eliminating Russian thistle in a small area of infestation. And I had
>> pretty good control, although not 100% by any means of Mustard at some
>> locations.
> i'm very heartened to hear this. i love to hear success stories in controlling non-natives!
>> At Johnson Ranch I concentrated on making healthy plots of chaparral larger
>> by treating, mowing, and reseeding their perimeters.I wasn’t there long
>> enough to evaluate the results.I though maybe since beneficial mycorrhizae
>> were already present and near by, they would help accelerate the expansion
>> of the pristine areas.
> that was a wonderful approach!
>> I just feel burning grassland is not a good thing any time.
> i'm not sure that "burning is not a good thing" is true for a native-only grassland, but i'm pretty sure that is the case in the actual situation we have, of a mostly non-native grassland.
> tom chester
Keith Haworth to Tom, Zachary, ted, Michael
Tom,
It is true that sometimes you just want to burn everything off and start over again. There may not be a better, low cost way for restoring areas consisting of 100 percent non-natives. I just don't like the idea of instantly increasing the available nutrients for the non-natives, causing them to flourish and making it more difficult for the natives to take hold. However, even if you graze you still have the same problem caused from the addition of manure from the grazers.
We have had excellent results with spraying with a grass selective herbicide, Fusilade, but it is very expensive and wouldn't be good if there are any native grasses you want to preserve. Unless you just reseeded the native grasses, which we have also done in the past. Fusilade has been found partially effective against Erodium too, even though it is not a grass.
Ted and Zach would probably agree with me that a very good way to handle areas that are all non-natives is to nuke everything with glyphosate and collect and reseed with local native seed. The biggest objection being the cost, but in the long run I think it is well worth it.
Again though, Ted and Zach are the experts on this subject.
On Sat, Nov 19, 2011 at 5:09 PM, Tom Chester <tom@tchester.org> wrote:
hi, keith!
>>On 11/19/2011 12:03 PM, Keith Haworth wrote:
>>Tom,
>>It is true that sometimes you just want to burn everything off and start
>>over again. There may not be a better, low cost way for restoring areas
>>consisting of 100 percent non-natives."
>if you are referring to my possibly somewhat confusing comment (due to the double negative):
>i'm not sure that "burning is not a good thing" is true for a native-only grassland
>let me clarify.
>entirely native grasslands are almost surely fire-adapted. we know quite certainly that lightning-caused fires occur frequently in >grassland, since they still occur, and hence it is almost certain that native grasslands evolved under that regime.
>our native grasslands also evolved with the "Pleistocene megafauna", which primarily grazed it. those megafauna survived 24 glacial >cycles in the pleistocene, each roughly 100,000 years long, but were almost certainly extirpated by humans on the 25th cycle. it surely >isn't a coincidence that they all went extinct in the first glacial cycle in which humans, the supreme hunters and killers of mega- and >minor-fauna everywhere they go, appeared. there was nothing otherwise special about the 25th glacial cycle.
>those grazers of course resulted in shorter plants which were less likely to spread fires, so the lightning-caused fires spread entirely differently than they do in the non-native, unbrowsed grasslands we have now.
tom chester
Keith Haworth to Tom, Zachary, ted, Michael
show details 6:58 PM (1 hour ago)
Tom,
Your clarification makes sense. When I stated "I just feel burning grassland is not a good thing any time." I wasn't referring to native grasslands. Burning native grassland is natural and a healthy thing, as you pointed out.
Keith
To Zach from Keith
Zach,
I find your comment about the effect of Oct rains interesting. Several acres at Johnson Ranch were heavily infested with Black Mustard for a couple of years, no treatment was done in the area. All of a sudden, one year, not a Mustard plant in site, just non-native grasses. I don't recall if we had Oct rain that year but goes to show you how things can change so drastically without doing anything. This makes sense to me because Avena and other grasses that germinate in the fall are really cool-season grasses and thrive that time of the year. Whereas many of the wildflowers need a little more heat to get going. Thus, if we have a dry fall and a wet spring, we should have a better showing of wildflowers. Correct?
Response from Zach Principe
Hi Keith, Yup, that is the theory anyway, that with a drier fall and early winter and wet late winter and spring we should get better wildflowers. I have heard a lot about this at meeting and conferences, but never have actually seen hard data to confirm it. Seems that most of the grassland experts here in California agree with the concept, so I think they must be seeing this occur as I think I have over the course of their careers as well.
Unfortunately, looks like we are in for another grass year this year if my yard is any indication,
- Zach
Keith Haworth to Zach, ted, Tom, Michael
Zach, After the burning of Poppy Hill in 1997, did the poppy and Lupine count increase at all the following year?
Keith
On Fri, Nov 18, 2011 at 12:54 PM, Zachary Principe <zprincipe@tnc.org> wrote:
> Not sure, as although I was around I was so focused on oaks for my research I had blinders on to everything else in those days.
> Maybe on your site you could ask people to upload photos with dates to help get better documentation. My major photo work in grasslands did not start until 2001.
> Zach
If any one has any old photos of wildflower blooms of Poppy Hill or any other areas of the SRP, I would appreciate your sending them to me to post. keith@california-natives.com
On Wed, Nov 23, 2011 at 4:34 AM, Ted St John <doctor_ted@earthlink.net> wrote:
Have any of you read the book on this topic by Richard Minnich? It is called California's fading wildflowers: lost legacy and biological invasions. I am only part way through but hope to finish it on my Thanksgiving trip to Arizona.
Whatever you may think of RM's research methods and ego, I have to say I am impressed with the straightforward way he dug into information that might otherwise be lost to science. For one thing, he read the wildflower forecasts in old newspapers. In general he supports Keith's suspicion that the flowers are fading, although the book is about the whole state and several centuries of records.
Ted
On Wed, Nov 23, 2011 at 11:17 AM, Zachary Principe <zprincipe@tnc.org> wrote:
> Yes, I have been wanting to read it, as have heard good things about it despite his reputation. Right now selling for $50 on amazon, a little pricey for me. It will be interesting to hear about his conclusions on the why.
> I will start out with saying that there is no single right answer for grassland management in California. As you are all aware we have vast area that are mostly non-native annual grasslands with virtually no natives. We have areas that can be better classified as forblands or wildflower fields that are now usually dominated by non-native annual grasses, but retain high native forb diversity. We also have coastal prairies which generally support more native perennials, both grasses and forbs. Santa Rosa Plateau is best classified at this high level as coastal prairie. Although we have small populations of non-natives that can take over after fire (yellow star thistle, fennel and artichoke thistle) we treat them to prevent their spread. So, from a management stand point we are looking at high native perennial forb and grass cover and very low occurrences of highly problematic fire-following weeds. With the fact that we see a reduction in non-native grass cover and increase in native forb cover after fire, we are pretty happy with the results for something that can be done at the 100 to 1000-acre scale. Both Nassella and non-native grass cover return to their pre-burn levels with 4-5 years. So, although I do not know if we are killing off the Nassella, it easily recovers spatial extent after fire as we are using it.
> For the few areas that are virtually native-free, we have never focused on restoration as those area are generally small and may well be type converted from sage scrub or chaparral. Some research was done in those areas a few years back and unfortunately the plots only treated with Fusilade came up almost 100% Vulpia myuros cover, so actually much worse than untreated controls. We were unhappy because we were really hoping it work and these plots were actually seeded with natives as well. Roundup worked much better, as killed everything and allowed the seeded species to dominate those plots. So, completely agree that for areas with no native, clean them up somehow and then seed with natives.
> Unlike Roundup or in some cases Fusilade, fire actually does not actually burn everything off and let you start new. Fire only shifts species composition for 4-5 years, which means it is not fundamentally changing the site. I have actually read a few papers that document that fire can result in a net loss of nitrogen from a site, as although you get a short-term pulse of more nitrogen that is available to plants some is lost to the atmosphere. As a result nitrogen fixers, like deerweed and some species of Ceanothus are the dominant species that recruit from seed following fires in our area in chap and css.
> Back to grassland restoration of completely degraded sites. The ranger out at Lake Skinner has been doing some grassland restoration on the side out there. He has some good potential areas to restore. Best I have heard for getting Nassella established after getting the site clean is a drill seeder, anyone know if there is one available for rent locally?
> Zach
On Wed, Nov 23, 2011 at 5:31 PM, <doctor_ted@earthlink.net> wrote:
> Zach- a drill seeder is a great way to plant exotic bromes. BLM has dozens of the damned things and are stuck on them because they sunk a lot of money and credibility into them. I have some pictures somewhere of fields where they tried to plant their wheatgrasses with a rangeland drill and you can see the disturbance effect at work- tidy little rows of cheatgrass. Who knows what happened to the wheatgrass but the cheatgrass loved the disturbance.
> The right way to do it is imprinting and well-timed mowing. There are imprinters for hire, let me know and I can hook you up. Another option is to use your livestock as imprinters. Spread the seeds then run them over the seeds a few times. More detail if you like.
> Both fire and decomposition result in lower total N and higher labile N. Disturbance hastens mineralization and nitrification at the same time it stops or reduces plant uptake, leading to accumulation. Ruderals love labile N, especially nitrate. I can get you citations for all this if you want.
> Well, good luck. Let me know if you want more details about any of this or want photos and eco-stories of cases where it has worked.
> Ted
On Sun, Nov 27, 2011 at 5:41 PM, Tom Chester <tom@tchester.org> wrote:
hi, keith!
alas, this year, 2011 to 2012, is already clearly another "grass year" at the srp, as zach defined it:
-----------------
Also, in multiple years recently we have had the unfortunate fortune of getting early rains (early and mid October) which greatly favor non-native annual grasses leading to what is referred to as a grass year. From what I have heard and observed 2011 was a grass year in the grasslands throughout California.
-----------------
i was at the srp yesterday, 11/26/11, and observed that the grasses are already taller than many of the native wildflowers (like ground pinks) will ever be. the only plant i saw that was competing with the non-native grasses in growth were numerous viola pedunculata, but they, too, will be overshadowed soon by the non-native grasses.
of course, there will still be plants like calochortus, blue dicks, etc. that will be almost as tall as the non-native grasses. but it was interesting that i saw not a single calochortus leaf yesterday, even though i checked the base of numerous dead calochortus infl from last year. they will have to play catch-up, without getting as much sunlight on their early leaves as they would in the absence of non-native grasses.
here is a pix of a typical scene in the grasslands:
http://tchester.org/temp/111126/non_native_grasses_tall_llready_3_35.jpg
all you see in the above pix are non-native grasses, and the remnants of non-native grasses from last year.
i should have put a scale in the pix, or measured how high they were. my memory is that they were already about 6 inches high, ~15 cm.
here is a pix of poppy hill i took just for you, showing the dominance by non-native grasses this early in the season:
http://tchester.org/temp/111126/pano_poppy_hill_1_crop.jpg
to a very high approximation, all the green you see in this pix on poppy hill on the south side, which is the aspect favored by california poppies, is from non-native grasses. germinating poppies don't have a chance against those non-natives, especially if they didn't germinate simultaneously. so once again, poppy hill will have very few poppies.
it will be very interesting to see what the density of non-native grasses is right now in the grazed area on the mesa de colorado, after one year of grazing. if they are much less, the wildflowers might look much better there this year.
of course, it might take multiple years of grazing to knock down the non-native grasses, depending on how long the seeds are viable.
--
tom chester
On Sun, Nov 27, 2011 at 7:39 PM, Keith Haworth <kdhaworth@gmail.com> wrote:
Tom, Did you see any poppy seedlings at all? I noticed in my front yard I am getting a lot of poppy seedlings coming up, but don't have the grass to contend with. Which makes me wonder, do you or anyone else know if poppy seeds need a photo response to germinate? For example, you don't cover some varieties of lettuce seed because they need light to stimulate germination. That would explain a lot on why the poppies don't even sprout when the grass is shading them out. I imagine the photoperiod of long days may have something to do with it too. It may be both, a combination of the proper day length and the intensity of light.
So when we don't have Fall rain, do both the grasses and poppies come up simultaneously when the later rains come around? I am beginning to think that we need the later rains, and enough of it to germinate the poppies, but then we need no rain to stress out the grasses. I bet the poppies will go longer and do better without water than the grasses. Thus, a good show of poppies.
I am guessing that the poppies will develop a deeper tap root than the grasses. I don't know if that is true, does anyone know? They are perennials. I am just blowing smoke here.???
Keith
On Sun, Nov 27, 2011 at 8:30 PM, Tom Chester <tom@tchester.org> wrote:
hi, keith!
On 11/27/2011 8:39 PM, Keith Haworth wrote:
>>Tom, Did you see any poppy seedlings at all?
>no, but we only stopped at poppy hill itself briefly, to look at the opuntia vaseyi there, and incidentally then saw the nice masses of >this year's growth of phacelia ramosissima (a perennial) as large green patches.
>the only place i've noticed poppies on poppy hill in the past is farther up the hill and/or along the trans preserve trail there.
>also, i'm pretty sure that all, or at least most, of the poppies i've seen at the srp are perennials (but my memory struggles to recall >things i saw last week, let alone things from 2005 like this). many perennials only rarely come up from seedlings (although this >recollection might be heavily biased by my work at high elevations and in the desert). i don't remember whether i've ever seen >seedling poppies at the srp.
>>I noticed in my front yard I
>>am getting a lot of poppy seedlings coming up, but don't have the grass to
>>contend with.
>did they come up with the first rain in october? or with one of the later rains?
>our rain history in fallbrook is here:
>http://tchester.org/bd/blooms/2012.html#rain
>the 10/5/11 rainfall only germinated a very small percentage of the non-native weeds in my yard. apparently, that rain was too >little, and/or when it was too hot, even for them.
>the 11/4 and 11/6 rain germinated everything in my yard.
>> Which makes me wonder, do you or anyone else know if poppy
>>seeds need a photo response to germinate?
>apparently not. the book "parks success with seeds" does not say "do not cover", which they do say for lettuce and similar >species.
>>So when we don't have Fall rain, do both the grasses and poppies come up
>>simultaneously when the later rains come around?
>yes. that's the best case situation for our native annuals.
>although an even better case situation is to germinate only the non-natives with an early rain, followed by intense heat and >dryness that kills the non-natives. (:-)
>however, in my experience, the non-natives are extremely hardy, and most hang in there, near death, and come roaring back to >life when the rain finally comes.
>death almost happened this year to them, with the small percentage of the 10/5/11 germinated weeds looking very bad in my yard >prior to the 11/4 rain. but those plants are now very much taller and more robust than all the other plants in my yard; they won >once again. (:-(
>the grasses at the srp are equally big, so i'm pretty sure they germinated in the 10/5/11 event. that rain produced much better >non-native germination at the srp than in my yard since the srp is higher, probably got more rainfall, and is cooler at this time of >year.
>this difference in germination requirements apparently results from the different fall rain pattern in the mediterranean area and >socal. apparently conditions after a light first rainfall in the mediterranean area are such than anything that germinates is most >likely to survive, which is not the case in socal. hence our annuals either wait until it is cooler to germinate, or for heavier rains, >which then guarantee plant survival.
> > I am beginning to think that we need the later rains, and enough of it to germinate the poppies,
>>but then we need no rain to stress out the grasses.
>the grasses will never lose in such a situation to our natives. see above for the only case where they can lose.
>>I am guessing that the poppies will develop a deeper tap root than the
>>grasses. I don't know if that is true, does anyone know? They are
>>perennials. I am just blowing smoke here.???
>poppies are weird. they are both annuals and perennials, and apparently consist of a zillion different ecotypes.
>besides, a deeper tap root is of no use in a light rain which wets only the uppermost part of the soil.
>see more info here (highlighted section are my asterisks):
------------------
>How do I grow California poppies?
>Some important considerations:
California poppies should be planted by direct seeding when possible
They transplant best when very young
They need good drainage
They do not perform well in small containers
They grow best in cool, sunny conditions
*******************
> They respond poorly to heat
*******************
>http://www.csupomona.edu/~jcclark/poppy/faq.html#growing
---------------------
>Eschscholzia californica Cham.
>The species is highly variable, including long-lived prostrate perennials along the coast, erect perennials of inland valleys, and >annuals in the interior.
>Although E. californica has escaped from cultivation in many parts of its native range, it is often possible to identify native >populations by their seed dormancy, which is generally absent in plants of cultivated heritage.
>PLANT perennial herb or annual, 0.5-6 dm tall, erect or spreading, glaucous or glabrous. TAPROOT heavy in perennial forms.
>http://www.csupomona.edu/~jcclark/poppy/cal.html
------------------------
--
tom chester
On Mon, Nov 28, 2011 at 12:55 PM, Tom Chester <tom@tchester.org> wrote:
hi, keith!
>>So when we don't have Fall rain, do both the grasses and poppies come up
>>simultaneously when the later rains come around?
>yes. that's the best case situation for our native annuals.
>although an even better case situation is to germinate only the non-natives
>with an early rain, followed by intense heat and dryness that kills the
>non-natives. (:-)
>however, in my experience, the non-natives are extremely hardy, and most
>hang in there, near death, and come roaring back to life when the rain
>finally comes.
>there has been at least one year, and maybe two, in the last decade that have killed off 99% or more of two non-native grasses, that >illustrates one difference between these mediterranean natives and our california natives.
>in the severe drought year of 2001-2002, essentially no native annuals germinated, which was very smart on their part, since anything >that germinated probably would have died without producing seed.
>i don't remember now whether annual rye grass, lolium multiflorum, and nit grass, gastridium ventricosum, germinated or not, but it >doesn't matter. 99+% of their seeds only live for one year, and hence the reserve was essentially totally free of these weeds for the next >several years.
>in particular, the lolium forms dense masses around the vernal pools, and former vernal pools, and it was essentially all gone in the next >year of 2002-2003.
>replacing it in the old vernal pool by the "perc pit" on the vernal pool trail, was instead a huge field of the native warty spurge, Euphorbia >spathulata, which obviously was very pleased at what had happened. (;-) it had seen droughts like this before, and had evolved to >withstand them.
>the lolium and gastridium clearly are from a place where if you can germinate with the first rain, you're going to make it, either with >enough subsequent rains, or with enough supplied by the first rain to produce at least some seeds, or maybe just via the following >mechanism.
>unfortunately, either a very small percentage of their seeds were able to survive two years, or they survived in areas with more moisture >at the srp, since both weeds gradually went back to their former abundance in subsequent years.
>this may have happened again with the severe drought year of 2006-2007, but i wasn't botanizing the SRP then, so i don't know what >happened.
re:
> it is not normal for any area in coastal socal to have good poppy
> displays year after year, with the possible exception of the del dios
> area near lake hodges in coastal san diego county. (i think james
> dillane has told me that this area consistently has good displays of
> wildflowers, including poppies.)
>james dillane reminded me that i had confused two separate things:
------------
>To clarify: Del Dios Gorge had an incredible display of poppies and other followers in 2008 following the fire. I have traveled the Del Dios >Hwy for over 30 years and have never seen anything there even close before or since.
>I believe you are remembering my comments on the Piedras Pintadas Trail on the south side of Lake Hodges. The top of the ridge >consistently has a great display of wildflowers dominated by Lasthenia, Senecio californica, Phacelia distans, Lupines, etc. This ridge is >unique in this area for its consistent displays, even in dry years.
------------
>so my bet still is that the SRP "Poppy Hill" was named for an unusual excellent display, and it never had a consistent display of a large >poppy bloom.
>but that is only my bet. it sure would be nice to see some past data on good poppy blooms there.
--
tom chester
Response from Keith:
Tom, I remember several good years of not only poppy blooms but also Bush Lupines, prior to the 1997 prescribed burning.
It would be interesting to know when the hill got its name of Poppy Hill.
Hello Keith:
Hello from the center of the continent! I just read the fascinating discussion on prescribed burning at your SRP site. We have similar discussions going on regarding management of grasslands and oak woodlands in the Midwest. Here, there is a lot of concern among entomologists regarding the destruction of grassland and savanna specialist insects, etc., particularly any whose habitat preferences place them where they are cooked by fire during prescribed burns. I know your focus is the plants, but do you know of work on butterflies, stem inhabiting beetles or what-have-you in your part of the country?
Regards,
James C. Trager
Naturalist at Shaw Nature Reserve near St. Louis MO
Hello Keith
http://www.santarosaplateau.com/0/%20: Interesting discussion about “to burn or not to burn” at SRP. I visited there once several years ago – Very cool place (deserving of a far a more eloquent expression)!
Anyway, discussions of prescribed burning are not limited to the effects on plant life.
To wit: http://www.aprairiehaven.com/?page_id=5693
I work at a site where we do a lot of burning, but I have serious qualms, and have been increasingly expressive of them to our director.
Best regards, James
PS You may have met or heard of my brother, John, who works at the Huntington BG, and took me to SRP when I was visiting the area.
James C. Trager, Ph. D.
Biologist - Naturalist
Shaw Nature Reserve
P.O. Box 38
Gray Summit MO 63039
636-451-3512 ext. 6002
Subject:
RE: Comment from SRP
From:
"James Trager" <James.Trager@mobot.org> (Add as Preferred Sender)
Date: Tue, Jan 17, 2012 12:19 pm
To: <keith@california-natives.com>
Broadly speaking, Keith, I think flora may be more resilient than small fauna, especially in small preserves. Fortunately SRP is fairly large.
I’m an ant taxonomist by training, and I think it quite nice that there is actually an ant list for SRP, a rare thing! Even among ants, by the way, species that live above ground in stems, twigs or galls, or in forest litter, can be quite diminished by fire, while soil-dwelling species tend to “like” it, unless it makes the grasses grow too dense and robustly, thus overly shading their nesting habitat. Nature is so wonderfully complex, that it is difficult to conceive of any management plan for our preserves that can favor all the native species in them. It would seem that while no management is not good, we probably could do less, and more varied, management to good end, biodiversity-wise.
Keep up the good work, including challenging the managers. I’m one of them in my day job, and always like it when thoughtful queries are made about my work here.
James.
James C. Trager, Ph. D.
Biologist - Naturalist
Shaw Nature Reserve
P.O. Box 38
Gray Summit MO 63039
636-451-3512 ext. 6002
Hello Keith :
This published experimental evidence seems to have a lot of relevance to some of the statements I read at your blog about burning at SRP
James
James C. Trager, Ph. D.
Biologist - Naturalist
Shaw Nature Reserve
P.O. Box 38
Gray Summit MO 63039
636-451-3512 ext. 6002
---------------------------------------------------------------
Title:
The interaction of prescribed burning and site characteristics on the diversity and composition of a grassland community on Santa Cruz Island, California
Document Type:
Journal
Author(s):
Klinger, R.C. ; Messer, I.
Publication Year:
2001
Description:
During the last 2 centuries, grasslands in California have undergone dramatic changes as community composition has been severely altered, leading to a conversion from communities dominated by native perennial bunchgrasses and forbs to communities comprising predominantly normative annual grasses and forbs. A series of 3 prescribed burns was done in grasslands on Santa Cruz Island, California, between 1993 and 1995. The 2 main goals of the burns were to (1) begin an evaluation of the effect of fire as an ecological process in the islands vegetation communities, and (2) determine if fire can be used as a restoration tool to enhance native plant species distribution and abundance in grasslands on the Channel Islands. Prior to burning, species composition was correlated most strongly with gradients of aspect, elevation, and the proportion of bare ground at a site. Topography was an important influence on species composition post-burn, but fire effects had a greater influence on species composition than site characteristics did during the first 2 years after the burn. Alpha diversity did not differ between burned and unburned plots, but species turnover was greater in burned plots. The response to burning varied among different vegetation guilds and within the different burn areas. Burned and unburned plots were dominated by normative grasses in all years, while annual forbs tended to show the greatest positive response to the burns. The richness and abundance of native species tended to either increase or remain unchanged as a result of the burns, but these effects were relatively transient. Rainfall was an important factor influencing vegetation response to the burn. Cover and species richness of annual grasses increased in wet years and probably inhibited germination and growth of most other herbaceous species. By the third year post-burn, site characteristics had a greater effect on species composition than fire effects did, and the burned plots were beginning to return to a composition similar to pre-burn conditions. If fire is to continue to be used as a restoration tool in Mediterranean-type grasslands, a better understanding of the interaction between components of fire regimes and site characteristics is needed.
Citation:
Klinger, R. C., and I. Messer. 2001. The interaction of prescribed burning and site characteristics on the diversity and composition of a grassland community on Santa Cruz Island, California. Proceedings of the Invasive Species Workshop: Tall Timbers Research Station Miscellaneous Publication, v. No. 11, p. 66-80.