|Photo Credit: Duke University|
|Credit: US Forest Service|
"Various entities have been designated keystone resources, but few tests have been attempted and we are unaware of any experimental manipulations of purported keystone resources. Mistletoes (Loranthaceae) provide structural and nutritional resources within canopies, and their pervasive influence on diversity led to their designation as keystone resources. We quantified the effect of Mistletoe on diversity with a woodland-scale experiment, comparing bird diversities before and after all Mistletoe plants were removed from 17 treatment sites, with those of 11 control sites and 12 sites in which Mistletoe was naturally absent. Three years after Mistletoe removal, treatment woodlands lost , on average, 20.9 percent of their total species richness, 26.5 percent of woodland-dependent bird species and 34.8 percent of their woodland-dependent residents, compared with moderate increases in controlled sites and no significant changes in Mistletoe-free sites. Treatment sites lost greater proportions of birds recorded nesting in Mistletoe, but changes in species recorded feeding on Mistletoe did not differ from control sites. Having confirmed the status of Mistletoe as a keystone resource, we suggest that nutrient enrichment via litter-fall is the main mechanism promoting species richness, driving small-scale heterogeneity in productivity and food availability for woodland animals. This explanation applies to other parasitic plants with high turnover of enriched leaves, and the community-scale influence of these plants is most apparent in low productivity systems."
What impact does the Dam
of a Keystone Species like a
Beaver play in an ecosystem ?
I truly enjoyed reading from the study here, about some of the benefits that Mistletoe actually provides in the plant communities. I've always known about the benefits to birds as far as food and nesting, but the intriguing benefits of Mistletoe leaves to the forest floor was very interesting. Again, who knew ? Who would have thought Mistletoe leaf litter contained further richness for which to effect other life on the forest floor ? So the Mistletoe actually provides more richness in nutrient drop debris, than simply it's own leaf litter. And as far as that label "Parasite", I hate it !!! Why ? Because the reason is, it's inaccurate of what I would consider a true parasite, you know, one that sucks almost all the life from it's host and gives nothing back ? But Mistletoe is different. scroll back up and look at the colour of that Mistletoe at the top of the page. Notice all the green ? That is Chlorophyll and for what purpose is Chlorophyll used for ? The manufacturing of food. So it's doesn't exactly draw from the tree's carbon stores what it needs, it manufactures it's own. What it does do is create roots within the tree's branches and trunk and draw water and nutrients. Mycorrhizae however does draw from the plant carbon sugar stores and yet we don't consider it a parasite. Why ? Because it actually increases nutrient and water uptake by the plant by 200% and you can actually see improvement. It actually makes the plant work harder, but more efficiently. So one has to wonder what other things Mistletoe may be giving back to the tree in the way of beneficial Chemical exchanges. We do know that through the mycorrhizal network that plants can make chemical exchange between all sorts of trees and shrubs. So mycorrhizae gets a much nicer word of association through Symbiosis.
Dwarf mistletoe on black spruce in
northern Minnesota, USA
Large clearcut in mistletoe infected jack pine stand in Manitoba. Cut boundaries located well beyond extent of infection. Site chained afterward to eliminate infected understory trees.
When I hear of certain specific reasons (excuses) made for why trees needed to be harvested to eradicate something or even plans for a prescribed or control burn to eradicate something, I know that as a general rule, some other motive is behind it. While there may be real circumstances where there could be a real need, how or why did such an overwhelming outbreak occur in the first place ? Take a clue from the photo above of the clearcut forest. They said on the forestry link that it had to be done because of the invasive Mistletoe. Really ? See anything odd or unnatural about that photo ? Yes, of course, it's a dead give away. It's not a normal occurrence for Jack Pine or any other species of tree to grow in a monoculture setting which looks more like row crops of a corn field somewhere in Iowa. Clearly, the unnatural circumstance of the Industrial Forestry created in the first place by humans is to blame, but that is not what gets the blame. Mistletoe is the evil villain. The above circumstance also justified taking out non-infected areas also. Open this link below here from the Warnell School of Forestry in Georgia and scroll on down to page 20 view the survey chart which shows the results of three Surveys taken in the U.S. states of Kentucky/Tennessee hardwood forests. The percentages shown for the majority of Mistletoe colonization are mostly tiny to none per species and yet the four highest percentage species listed certainly are not life threatening to the woodlands either. This is because the forest is extremely biodiverse and not monocropped like the Industrial Tree Farm of Jack Pine in the above photo.
Juglans nigra 35%Ulmus americana 21%Ulmus rubra 16%Robinia pseudoacacia 11%Prunus serotina 9%Fraxinus americana 7%Acer saccharinum 4%Celtis laevigata 4%Gleditsia triacanthos 4%Ulmus serotina 3%Ulmus thomasi 3%Acer rubrum 2%Carya ovata 2%Celtis occidentalis 2%Maclura pomifera 2%Fraxinus pennsylvanica 1%Liriodendron tulipifera 1%Nyssa sylvatica 1%Quercus alba 1%Castanea dentata 0.6%Platanus occidentalis 0.6%Acer saccharum 0.3%Fagus grandifolia 0.3%Liquidambar styraciflua 0.3%Ostrya virginiana 0.3%Quercus prinus 0.3%Sassafrass albidum 0.3%Ulmus alata 0.3%Quercus muhlenbergii 0.1%
There are numerous Mistletoe species and many of them host specific, which means they prefer one or two kinds of tree. The more biodiverse, the far less problem of an entire wipe out of an ecosystem. BTW, read that entire link. There are some fascinating educational information on Mistletoe life cycle and construct on that paper. Below is a photo of the use of prescribed burns for control.
Cut, felled and 'prescribe burn' of supposedly Mistletoe
infested Lodgepole pine in the United States.
Common scene of Japanese Fishermen fighting to keep Jellyfish from their nets. These creatures are also consuming the fish they may catch. But will the Fishermen blame government and big business for the off balanced abnormal conditions created by industrial pollution and demand something be done about it ? Or will yet apply another negative label to be attached to a creature who simply responds to genetic instructional instincts as triggered by it's environment for which humans are responsible ?
These two links here are of some of the negative uninformed mentality which rules. Further below are some more interesting links. You can actually Google more info and obtain 100s of other informative links with the same bad science viewpoint towards Mistletoe. In the mean time, when you next go walking on a nature hike, give consideration to those darker green lush patches high up in the tree's branches and give some thought to all the other biodiverse richness of life they provide to the entire system
Further Reading References on the importance of Mistletoe
"Beyond pills: Cardiologists examine alternatives to halt high blood pressure" (Mistletoe Extract Used in Chinese Medicine)