Doing Battle with Cedars (to benefit oaks) , NE

[edfrank]

Doing Battle with Cedars (to benefit oaks) , NE

http://beneficiallandscapes.blogspot.co ... -oaks.html


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In the southeast corner of Nebraska, near the little town of Salem (a stone's throw from the Kansas border) grows a unique population of oaks known as dwarf chinkapin oak. Depending on the type of soil they grow in, this close cousin of the chinkapin oak (Quercus muehlenbergii), can grow as small, multi-stem trees or as sprawling shrubs, resembling American plum...

Unfortunately, in recent years this area has seen an explosion in the growth of eastern redcedar, which are starting to choke out many of these unique oaks. Something needed to be done and recently a few of us from the Nebraska Forest Service spent a day on the property cutting out cedars. Armed with many chainsaws (and other saws) we happily cut and destroyed as many cedars as we could. We think we killed about 1,500. Many more still need to come out and we look forward to returning next year to continue the assault.... continued

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[Joe]

I wonder why the cedar is coming in-- is it due to a lack of fire? Is it late successional? Drought? Or, is the oak now subject to new diseases/pests and thus less competative? That article would have been more informative if it discussed the cause of this "problem".
Joe

[Don]

Joe
You're already on to it, I think. The article's second paragraph reads in part "...in recent years this area has seen an explosion in the growth of eastern redcedar...", which makes me think in terms of the time period we could associate with "global warming" or more amenably, "global climate change", which ever, as the change agent that 'caused' the explosion in growth of eastern redcedar. Fire, successional status, drought, new susceptibility to diseases/pests all can be expressions of a species' resilience to change.
Clearly the locals value the species and this could be sufficient to warrant energy and dollars to maintain the species viability. But hopefully the NFS folks are also providing educational support and pointing out that they're ultimately fighting a lost cause.
I'm just saying...
-Don

[edfrank]

NTS,

From what I have read the primary reason for the invasion of red cedar is because of fire suppression in the area. The problem exists across not only Nebraska, but in Oklahoma, Texas, and Kansas. The red cedar displaces native cover in non-commercial timberland, i.e. the Cross Timbers area, and encroaches on pastureland. Some effects include displacing native species, can alter micro-climate and switch from warm season grasses to cool season grasses, loss of native prairie birds, and loss of native prairie. There is also some indication that red cedar may exhibit alleopathic effects that inhibit growth of various native prairie grass species. I am sure that conversion of native grasslands/non-commercial timberland to pastureland plays a major role in the spread of the species as well as fire suppression. Climate change also likely exacerbates the problem.

http://oklahomainvasivespecies.okstate. ... cedar.html
ftp://ftp-fc.sc.egov.usda.gov/NE/Outgoi ... nsEQIP.pdf
http://digitalcommons.unl.edu/cgi/viewc ... roceedings
http://www.hpj.com/archives/2008/sep08/ ... elpcon.cfm

Edward Frank

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[Joe]

by this point- it's hard to believe there's any "native cover" anywhere in those states- it sounds like it's more a nuisance to the ranchers than any real ecological problem- some bird species may not like the red cedar but others might
Joe

[Chris]

Yep, lack of fire is main culprit blamed for red cedar expansion. But the "green glacier" [shrubs/tree invading grasslands] is also impacting grasslands worldwide, and is also maybe related to seed sources, increased C02 helping C4 species, nutrient deposition from the air.

In the "famous" dolomite glades of the Ozarks of southern Missouri and northern Arkansas, fire frequency in the past was 3-5 years. They become, very, very thick, cedar thickets, with basically no ground cover. You have to cut the damn things out just to walk through them, because they are only 20 ft tall.

Cedar Hell

Below is from the White River Balds, near "famous" Branson, Missouri, one of the "best" glades. Includes numerous Xerothermic species far outside main range, that got "trapped" when climate got wetter 4,000 years ago. Ashe Juniper, American Smoketree, cacti, rattlesnakes, etc...

[edfrank]

by this point- it's hard to believe there's any "native cover" anywhere in those states- it sounds like it's more a nuisance to the ranchers than any real ecological problem- some bird species may not like the red cedar but others might
Joe

Joe,

Perhaps you are right, but I want to offer a different perspective. If you look along the east coast we are still finding patches of old-growth forest that had never been logged, so I would expect that there are patches of prairie/non-commercial timberland that has likewise not been altered by farming and grazing. A second consideration is that old-growth forest can serve as a seed bank for younger forests surrounding it, so as t allow it to take on old-growth characteristics itself eventually. Since the grass and native trees in the area are smaller, perhaps it would take a smaller area of unaffected land to provide a viable seed bank. A third consideration is that much of this area is also within the cross-timbers area. many post oak trees in this area have been shown by David Stahle and others at UArk, to be several hundred years old. So much of the land has at least not been cleared for farming, although some livestock grazing may have taken place. Overall I think there are many patches of ground that were not subject to farming and grazing.

Another line of reasoning is that large areas in the region were part of the dust bowl in the 1930's from poor farming practices and drought. Many of the areas abandoned at that time have not been subject again to intense agriculture. So they have been left to their own devices, aside from aggressive fire suppression. So in the last 80 years the annual grasses have had 80 generations to reestablish a balance with the perennial grasses, shrubs, and trees. As a system I am not sure how long a generation might be, but certainly for the grasses as a whole there have been many generations in which to approach the same balance present prior to human utilization even in these heavily impacted areas. How long does it take one of these systems to become an "old-growth" grassland/non-commercial timber land after having been impacted? If you can't see any of the effects of direct human impact, does that make it a natural system?

The best counterargument is that people affect everywhere, which is true. But this can be said for areas whether they were initially impacted by grazing and farming or not.

Edward Frank

[th3rd3y3]

Part of the ERC problem in this area in particular is the fact that Dwarf Chinkapin Oak is not very aggressive at casting shade. This population is on an elevated limestone bluff which means sharp drainage, poor fertility, etc. Perfect ground for ERC to take over. I cannot speak to why it wasn't a problem in the past. DCO only received it's own species designation because of its rhizomatous growth habit which probably makes it more capable of populating the slopes and hill crests better than Q. muelenbergii and others that rely on seed dispersal. The squirrels can help, but acorns don't roll uphill! These steep slopes are worthless for cattle/crops so the farmers don't monitor these areas very often. With a national champion Q prinoides discovered there and our efforts to help them keep ERC at bay have opened the land owners eyes to what they have there. Beautiful territory!