Comments on: Seeds for thought http://slothcentral.com/archives/48 A 12,000 year-old mystery in SW Iowa Tue, 20 Apr 2010 02:51:50 -0700 http://wordpress.org/?v=2.8.4 hourly 1 By: Holmes Semken http://slothcentral.com/archives/48/comment-page-1#comment-1052 Holmes Semken Fri, 06 Feb 2009 21:37:47 +0000 http://slothcentral.com/?p=48#comment-1052 Dave, I just read a brief article describing how the ingestion of fruit by present-day, large animals disburses fruit trees. Borrell (2008) in the October issue of Smithsonian notes that cassowaries, 125-150 pound ostrich-like birds, are the largest land animals in Northern Australia. They have a home range of several hundred acres. The male, who is responsible for raising the young, guides his chicks to all fruit trees within his domain. When grown, the chicks disburse carrying their last meal or two. Scientists (p.20) have “identified the seeds of 300 plant species” in the scat of these birds and regard them as a key players in “spreading rain-forest plants over great distances.” Australian naturalists worry that the declining numbers of these birds will disrupt forest regeneration. Extinction is possible. Moreover, some cassowaries have learned that there are fruit trees in town and their numbers are further thinned by cars. Holmes Borrell, Brendan, 2008, Invasion of the Cassowaries, Smithsonian 39: 18-20. Dave, I just read a brief article describing how the ingestion of fruit by present-day, large animals disburses fruit trees. Borrell (2008) in the October issue of Smithsonian notes that cassowaries, 125-150 pound ostrich-like birds, are the largest land animals in Northern Australia. They have a home range of several hundred acres. The male, who is responsible for raising the young, guides his chicks to all fruit trees within his domain. When grown, the chicks disburse carrying their last meal or two. Scientists (p.20) have “identified the seeds of 300 plant species” in the scat of these birds and regard them as a key players in “spreading rain-forest plants over great distances.” Australian naturalists worry that the declining numbers of these birds will disrupt forest regeneration. Extinction is possible. Moreover, some cassowaries have learned that there are fruit trees in town and their numbers are further thinned by cars. Holmes
Borrell, Brendan, 2008, Invasion of the Cassowaries, Smithsonian 39: 18-20.

]]> By: David http://slothcentral.com/archives/48/comment-page-1#comment-524 David Sun, 14 Dec 2008 21:23:27 +0000 http://slothcentral.com/?p=48#comment-524 Hi Pete, Think about using camels instead next time, and can you borrow a black rhino from anyone? I heard a similar report about the success of fire at the Indian Creek Nature Center in Cedar Rapids this fall. A prairie fire there jumped a firebreak several years ago and swept up a hill into the woods. The difference between the burned and unburned areas is striking. They’ve kept up the burning. But, I’m intrigued by the charcoal and pollen studies that suggest Native Americans burned oak forests more frequently than lightning (Abrams, 1992) and in different seasons. Such fires couldn’t have gone far without a cooperative climate (in which case lightning would have done the job any way) but with a lot of Natives starting a lot of fires, you can affect an awful lot of the landscape. Platt et al. (2002) report significantly higher mortality of savanna pines after a hurricane which they attribute to the prescribed burns landscape managers have been doing in the dry season instead of the wet season, when historically lightning would have started them. They suggest the pines grow faster after dry-season burns, leaving tree trunks weaker and more apt to be snapped later in high winds. The trees that survive the hurricane suffer high mortality years later due to disease and insects that invade through the storm-damaged tree limbs. There are reports of oaks being similarly weakened after burns and more susceptible to subsequent major disturbances (Jenkins and Pollardy, 1995). We get enough straight-line winds and ice storms here in Iowa so that we should take notice. I’m interested in the sloth connection, of course, and know that the Natives replaced the mega-browsers imperfectly with their burning/woodland-opening. They changed the texture of the landscape and encouraged some species over others. I’m intrigued by reports coming out of Europe about the success of integrating large herbivores into the management plans of nature preserves (Wallis De Vries, 1995). Instead of using fire, I think you should talk your boss into letting you fence off a big section of that new nature area you are developing and introducing some large browsers to keep down the underbrush. Besides contributing some valuable research, they would be a big hit with the public! References Abrams, M.D. 1992. Fire and the development of oak forests. BioScience 42: 346-353. Jenkins, M.A./ and Pollardy, S.G. 1995. The influence of drought on red oak groups species growth and mortality in the Missouri Ozarks. Canadian Journal of Forest Research 25: 119-1127. Platt, W.J., Beckage, B., Doren, R.F., and Slater, F.H. 2002. Interactions of large-scale disturbances: prior fire regimes and hurricane mortalioty of savanna pines. Ecology 83: 1566-1572. Wallis De Vries, M.F. 1995. Large herbivores and the design of large-scale nature reserves in Western Europe. Conservation Biology 9: 25-33. Hi Pete, Think about using camels instead next time, and can you borrow a black rhino from anyone? I heard a similar report about the success of fire at the Indian Creek Nature Center in Cedar Rapids this fall. A prairie fire there jumped a firebreak several years ago and swept up a hill into the woods. The difference between the burned and unburned areas is striking. They’ve kept up the burning. But, I’m intrigued by the charcoal and pollen studies that suggest Native Americans burned oak forests more frequently than lightning (Abrams, 1992) and in different seasons. Such fires couldn’t have gone far without a cooperative climate (in which case lightning would have done the job any way) but with a lot of Natives starting a lot of fires, you can affect an awful lot of the landscape. Platt et al. (2002) report significantly higher mortality of savanna pines after a hurricane which they attribute to the prescribed burns landscape managers have been doing in the dry season instead of the wet season, when historically lightning would have started them. They suggest the pines grow faster after dry-season burns, leaving tree trunks weaker and more apt to be snapped later in high winds. The trees that survive the hurricane suffer high mortality years later due to disease and insects that invade through the storm-damaged tree limbs. There are reports of oaks being similarly weakened after burns and more susceptible to subsequent major disturbances (Jenkins and Pollardy, 1995). We get enough straight-line winds and ice storms here in Iowa so that we should take notice. I’m interested in the sloth connection, of course, and know that the Natives replaced the mega-browsers imperfectly with their burning/woodland-opening. They changed the texture of the landscape and encouraged some species over others. I’m intrigued by reports coming out of Europe about the success of integrating large herbivores into the management plans of nature preserves (Wallis De Vries, 1995). Instead of using fire, I think you should talk your boss into letting you fence off a big section of that new nature area you are developing and introducing some large browsers to keep down the underbrush. Besides contributing some valuable research, they would be a big hit with the public!

References

Abrams, M.D. 1992. Fire and the development of oak forests. BioScience 42: 346-353.

Jenkins, M.A./ and Pollardy, S.G. 1995. The influence of drought on red oak groups species growth and mortality in the Missouri Ozarks. Canadian Journal of Forest Research 25: 119-1127.

Platt, W.J., Beckage, B., Doren, R.F., and Slater, F.H. 2002. Interactions of large-scale disturbances: prior fire regimes and hurricane mortalioty of savanna pines. Ecology 83: 1566-1572.

Wallis De Vries, M.F. 1995. Large herbivores and the design of large-scale nature reserves in Western Europe. Conservation Biology 9: 25-33.

]]> By: Pete Eyheralde http://slothcentral.com/archives/48/comment-page-1#comment-451 Pete Eyheralde Mon, 01 Dec 2008 20:18:10 +0000 http://slothcentral.com/?p=48#comment-451 Here in southern Iowa, we've been conducting woodland burns in late fall for the last ten years or so. The fires kill back the undergrowth like raspberries and multiflora rose, as well as thin barked trees like dogwood and ironwood. As a result our oak regeneration has dramatically increased. After some burns, there has literally been a carpet of oak seedling sprouting up the following spring. Iowa forests can be hard to burn, but if you wait until the leaves drop in November there's usually enough fuel to carry a fire. It's slow and smoky with low flame heights but it gets the job done. Here in southern Iowa, we’ve been conducting woodland burns in late fall for the last ten years or so. The fires kill back the undergrowth like raspberries and multiflora rose, as well as thin barked trees like dogwood and ironwood. As a result our oak regeneration has dramatically increased. After some burns, there has literally been a carpet of oak seedling sprouting up the following spring. Iowa forests can be hard to burn, but if you wait until the leaves drop in November there’s usually enough fuel to carry a fire. It’s slow and smoky with low flame heights but it gets the job done.

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